/* This Source Code Form is subject to the terms of the Mozilla Public * License, v. 2.0. If a copy of the MPL was not distributed with this * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ //! # Scene building //! //! Scene building is the phase during which display lists, a representation built for //! serialization, are turned into a scene, webrender's internal representation that is //! suited for rendering frames. //! //! This phase is happening asynchronously on the scene builder thread. //! //! # General algorithm //! //! The important aspects of scene building are: //! - Building up primitive lists (much of the cost of scene building goes here). //! - Creating pictures for content that needs to be rendered into a surface, be it so that //! filters can be applied or for caching purposes. //! - Maintaining a temporary stack of stacking contexts to keep track of some of the //! drawing states. //! - Stitching multiple display lists which reference each other (without cycles) into //! a single scene (see build_reference_frame). //! - Interning, which detects when some of the retained state stays the same between display //! lists. //! //! The scene builder linearly traverses the serialized display list which is naturally //! ordered back-to-front, accumulating primitives in the top-most stacking context's //! primitive list. //! At the end of each stacking context (see pop_stacking_context), its primitive list is //! either handed over to a picture if one is created, or it is concatenated into the parent //! stacking context's primitive list. //! //! The flow of the algorithm is mostly linear except when handling: //! - shadow stacks (see push_shadow and pop_all_shadows), //! - backdrop filters (see add_backdrop_filter) //! use api::{AlphaType, BorderDetails, BorderDisplayItem, BuiltDisplayListIter, BuiltDisplayList, PrimitiveFlags}; use api::{ClipId, ColorF, CommonItemProperties, ComplexClipRegion, ComponentTransferFuncType, RasterSpace}; use api::{DisplayItem, DisplayItemRef, ExtendMode, ExternalScrollId, FilterData}; use api::{FilterOp, FilterPrimitive, FontInstanceKey, FontSize, GlyphInstance, GlyphOptions, GradientStop}; use api::{IframeDisplayItem, ImageKey, ImageRendering, ItemRange, ColorDepth, QualitySettings}; use api::{LineOrientation, LineStyle, NinePatchBorderSource, PipelineId, MixBlendMode, StackingContextFlags}; use api::{PropertyBinding, ReferenceFrameKind, ScrollFrameDescriptor, ReferenceFrameMapper}; use api::{APZScrollGeneration, HasScrollLinkedEffect, Shadow, SpatialId, StickyFrameDescriptor, ImageMask, ItemTag}; use api::{ClipMode, PrimitiveKeyKind, TransformStyle, YuvColorSpace, ColorRange, YuvData, TempFilterData}; use api::{ReferenceTransformBinding, Rotation, FillRule, SpatialTreeItem, ReferenceFrameDescriptor}; use api::units::*; use crate::image_tiling::simplify_repeated_primitive; use crate::clip::{ClipItemKey, ClipStore, ClipItemKeyKind}; use crate::clip::{ClipInternData, ClipNodeId, ClipLeafId}; use crate::clip::{PolygonDataHandle, ClipTreeBuilder}; use crate::segment::EdgeAaSegmentMask; use crate::spatial_tree::{SceneSpatialTree, SpatialNodeContainer, SpatialNodeIndex, get_external_scroll_offset}; use crate::frame_builder::{FrameBuilderConfig}; use glyph_rasterizer::{FontInstance, SharedFontResources}; use crate::hit_test::HitTestingScene; use crate::intern::Interner; use crate::internal_types::{FastHashMap, LayoutPrimitiveInfo, Filter, PlaneSplitterIndex, PipelineInstanceId}; use crate::picture::{Picture3DContext, PictureCompositeMode, PicturePrimitive}; use crate::picture::{BlitReason, OrderedPictureChild, PrimitiveList, SurfaceInfo, PictureFlags}; use crate::picture_graph::PictureGraph; use crate::prim_store::{PrimitiveInstance}; use crate::prim_store::{PrimitiveInstanceKind, NinePatchDescriptor, PrimitiveStore}; use crate::prim_store::{InternablePrimitive, SegmentInstanceIndex, PictureIndex}; use crate::prim_store::{PolygonKey}; use crate::prim_store::backdrop::{BackdropCapture, BackdropRender}; use crate::prim_store::borders::{ImageBorder, NormalBorderPrim}; use crate::prim_store::gradient::{ GradientStopKey, LinearGradient, RadialGradient, RadialGradientParams, ConicGradient, ConicGradientParams, optimize_radial_gradient, apply_gradient_local_clip, optimize_linear_gradient, self, }; use crate::prim_store::image::{Image, YuvImage}; use crate::prim_store::line_dec::{LineDecoration, LineDecorationCacheKey, get_line_decoration_size}; use crate::prim_store::picture::{Picture, PictureCompositeKey, PictureKey}; use crate::prim_store::text_run::TextRun; use crate::render_backend::SceneView; use crate::resource_cache::ImageRequest; use crate::scene::{Scene, ScenePipeline, BuiltScene, SceneStats, StackingContextHelpers}; use crate::scene_builder_thread::Interners; use crate::space::SpaceSnapper; use crate::spatial_node::{ ReferenceFrameInfo, StickyFrameInfo, ScrollFrameKind, SpatialNodeUid, SpatialNodeType }; use crate::tile_cache::TileCacheBuilder; use euclid::approxeq::ApproxEq; use std::{f32, mem, usize}; use std::collections::vec_deque::VecDeque; use std::sync::Arc; use crate::util::{VecHelper, MaxRect}; use crate::filterdata::{SFilterDataComponent, SFilterData, SFilterDataKey}; /// Offsets primitives (and clips) by the external scroll offset /// supplied to scroll nodes. pub struct ScrollOffsetMapper { pub current_spatial_node: SpatialNodeIndex, pub current_offset: LayoutVector2D, } impl ScrollOffsetMapper { fn new() -> Self { ScrollOffsetMapper { current_spatial_node: SpatialNodeIndex::INVALID, current_offset: LayoutVector2D::zero(), } } /// Return the accumulated external scroll offset for a spatial /// node. This caches the last result, which is the common case, /// or defers to the spatial tree to build the value. fn external_scroll_offset( &mut self, spatial_node_index: SpatialNodeIndex, spatial_tree: &SceneSpatialTree, ) -> LayoutVector2D { if spatial_node_index != self.current_spatial_node { self.current_spatial_node = spatial_node_index; self.current_offset = get_external_scroll_offset(spatial_tree, spatial_node_index); } self.current_offset } } /// A data structure that keeps track of mapping between API Ids for spatials and the indices /// used internally in the SpatialTree to avoid having to do HashMap lookups for primitives /// and clips during frame building. #[derive(Default)] pub struct NodeIdToIndexMapper { spatial_node_map: FastHashMap, } impl NodeIdToIndexMapper { fn add_spatial_node(&mut self, id: SpatialId, index: SpatialNodeIndex) { let _old_value = self.spatial_node_map.insert(id, index); assert!(_old_value.is_none()); } fn get_spatial_node_index(&self, id: SpatialId) -> SpatialNodeIndex { self.spatial_node_map[&id] } } #[derive(Debug, Clone, Default)] pub struct CompositeOps { // Requires only a single texture as input (e.g. most filters) pub filters: Vec, pub filter_datas: Vec, pub filter_primitives: Vec, // Requires two source textures (e.g. mix-blend-mode) pub mix_blend_mode: Option, } impl CompositeOps { pub fn new( filters: Vec, filter_datas: Vec, filter_primitives: Vec, mix_blend_mode: Option ) -> Self { CompositeOps { filters, filter_datas, filter_primitives, mix_blend_mode, } } pub fn is_empty(&self) -> bool { self.filters.is_empty() && self.filter_primitives.is_empty() && self.mix_blend_mode.is_none() } /// Returns true if this CompositeOps contains any filters that affect /// the content (false if no filters, or filters are all no-ops). fn has_valid_filters(&self) -> bool { // For each filter, create a new image with that composite mode. let mut current_filter_data_index = 0; for filter in &self.filters { match filter { Filter::ComponentTransfer => { let filter_data = &self.filter_datas[current_filter_data_index]; let filter_data = filter_data.sanitize(); current_filter_data_index = current_filter_data_index + 1; if filter_data.is_identity() { continue } else { return true; } } _ => { if filter.is_noop() { continue; } else { return true; } } } } if !self.filter_primitives.is_empty() { return true; } false } } /// Represents the current input for a picture chain builder (either a /// prim list from the stacking context, or a wrapped picture instance). enum PictureSource { PrimitiveList { prim_list: PrimitiveList, }, WrappedPicture { instance: PrimitiveInstance, }, } /// Helper struct to build picture chains during scene building from /// a flattened stacking context struct. struct PictureChainBuilder { /// The current input source for the next picture current: PictureSource, /// Positioning node for this picture chain spatial_node_index: SpatialNodeIndex, /// Prim flags for any pictures in this chain flags: PrimitiveFlags, /// Requested raster space for enclosing stacking context raster_space: RasterSpace, /// If true, set first picture as a resolve target set_resolve_target: bool, /// If true, mark the last picture as a sub-graph establishes_sub_graph: bool, } impl PictureChainBuilder { /// Create a new picture chain builder, from a primitive list fn from_prim_list( prim_list: PrimitiveList, flags: PrimitiveFlags, spatial_node_index: SpatialNodeIndex, raster_space: RasterSpace, is_sub_graph: bool, ) -> Self { PictureChainBuilder { current: PictureSource::PrimitiveList { prim_list, }, spatial_node_index, flags, raster_space, establishes_sub_graph: is_sub_graph, set_resolve_target: is_sub_graph, } } /// Create a new picture chain builder, from a picture wrapper instance fn from_instance( instance: PrimitiveInstance, flags: PrimitiveFlags, spatial_node_index: SpatialNodeIndex, raster_space: RasterSpace, ) -> Self { PictureChainBuilder { current: PictureSource::WrappedPicture { instance, }, flags, spatial_node_index, raster_space, establishes_sub_graph: false, set_resolve_target: false, } } /// Wrap the existing content with a new picture with the given parameters #[must_use] fn add_picture( self, composite_mode: PictureCompositeMode, clip_node_id: ClipNodeId, context_3d: Picture3DContext, interners: &mut Interners, prim_store: &mut PrimitiveStore, prim_instances: &mut Vec, clip_tree_builder: &mut ClipTreeBuilder, ) -> PictureChainBuilder { let prim_list = match self.current { PictureSource::PrimitiveList { prim_list } => { prim_list } PictureSource::WrappedPicture { instance } => { let mut prim_list = PrimitiveList::empty(); prim_list.add_prim( instance, LayoutRect::zero(), self.spatial_node_index, self.flags, prim_instances, clip_tree_builder, ); prim_list } }; let flags = if self.set_resolve_target { PictureFlags::IS_RESOLVE_TARGET } else { PictureFlags::empty() }; let pic_index = PictureIndex(prim_store.pictures .alloc() .init(PicturePrimitive::new_image( Some(composite_mode.clone()), context_3d, self.flags, prim_list, self.spatial_node_index, self.raster_space, flags, )) ); let instance = create_prim_instance( pic_index, Some(composite_mode).into(), self.raster_space, clip_node_id, interners, clip_tree_builder, ); PictureChainBuilder { current: PictureSource::WrappedPicture { instance, }, spatial_node_index: self.spatial_node_index, flags: self.flags, raster_space: self.raster_space, // We are now on a subsequent picture, so set_resolve_target has been handled set_resolve_target: false, establishes_sub_graph: self.establishes_sub_graph, } } /// Finish building this picture chain. Set the clip chain on the outermost picture fn finalize( self, clip_node_id: ClipNodeId, interners: &mut Interners, prim_store: &mut PrimitiveStore, clip_tree_builder: &mut ClipTreeBuilder, ) -> PrimitiveInstance { let mut flags = PictureFlags::empty(); if self.establishes_sub_graph { flags |= PictureFlags::IS_SUB_GRAPH; } match self.current { PictureSource::WrappedPicture { instance } => { let pic_index = instance.kind.as_pic(); prim_store.pictures[pic_index.0].flags |= flags; instance } PictureSource::PrimitiveList { prim_list } => { if self.set_resolve_target { flags |= PictureFlags::IS_RESOLVE_TARGET; } // If no picture was created for this stacking context, create a // pass-through wrapper now. This is only needed in 1-2 edge cases // now, and will be removed as a follow up. let pic_index = PictureIndex(prim_store.pictures .alloc() .init(PicturePrimitive::new_image( None, Picture3DContext::Out, self.flags, prim_list, self.spatial_node_index, self.raster_space, flags, )) ); create_prim_instance( pic_index, None.into(), self.raster_space, clip_node_id, interners, clip_tree_builder, ) } } } /// Returns true if this builder wraps a picture #[allow(dead_code)] fn has_picture(&self) -> bool { match self.current { PictureSource::WrappedPicture { .. } => true, PictureSource::PrimitiveList { .. } => false, } } } bitflags! { /// Slice flags pub struct SliceFlags : u8 { /// Slice created by a prim that has PrimitiveFlags::IS_SCROLLBAR_CONTAINER const IS_SCROLLBAR = 1; /// Represents an atomic container (can't split out compositor surfaces in this slice) const IS_ATOMIC = 2; } } /// A structure that converts a serialized display list into a form that WebRender /// can use to later build a frame. This structure produces a BuiltScene. Public /// members are typically those that are destructured into the BuiltScene. pub struct SceneBuilder<'a> { /// The scene that we are currently building. scene: &'a Scene, /// The map of all font instances. fonts: SharedFontResources, /// The data structure that converts between ClipId/SpatialId and the various /// index types that the SpatialTree uses. id_to_index_mapper_stack: Vec, /// A stack of stacking context properties. sc_stack: Vec, /// Stack of spatial node indices forming containing block for 3d contexts containing_block_stack: Vec, /// Stack of requested raster spaces for stacking contexts raster_space_stack: Vec, /// Maintains state for any currently active shadows pending_shadow_items: VecDeque, /// The SpatialTree that we are currently building during building. pub spatial_tree: &'a mut SceneSpatialTree, /// The store of primitives. pub prim_store: PrimitiveStore, /// Information about all primitives involved in hit testing. pub hit_testing_scene: HitTestingScene, /// The store which holds all complex clipping information. pub clip_store: ClipStore, /// The configuration to use for the FrameBuilder. We consult this in /// order to determine the default font. pub config: FrameBuilderConfig, /// Reference to the set of data that is interned across display lists. interners: &'a mut Interners, /// Helper struct to map stacking context coords <-> reference frame coords. rf_mapper: ReferenceFrameMapper, /// Helper struct to map spatial nodes to external scroll offsets. external_scroll_mapper: ScrollOffsetMapper, /// The current recursion depth of iframes encountered. Used to restrict picture /// caching slices to only the top-level content frame. iframe_size: Vec, /// Clip-chain for root iframes applied to any tile caches created within this iframe root_iframe_clip: Option, /// The current quality / performance settings for this scene. quality_settings: QualitySettings, /// Maintains state about the list of tile caches being built for this scene. tile_cache_builder: TileCacheBuilder, /// A helper struct to snap local rects in device space. During frame /// building we may establish new raster roots, however typically that is in /// cases where we won't be applying snapping (e.g. has perspective), or in /// edge cases (e.g. SVG filter) where we can accept slightly incorrect /// behaviour in favour of getting the common case right. snap_to_device: SpaceSnapper, /// A DAG that represents dependencies between picture primitives. This builds /// a set of passes to run various picture processing passes in during frame /// building, in a way that pictures are processed before (or after) their /// dependencies, without relying on recursion for those passes. picture_graph: PictureGraph, /// Keep track of allocated plane splitters for this scene. A plane /// splitter is allocated whenever we encounter a new 3d rendering context. /// They are stored outside the picture since it makes it easier for them /// to be referenced by both the owning 3d rendering context and the child /// pictures that contribute to the splitter. /// During scene building "allocating" a splitter is just incrementing an index. /// Splitter objects themselves are allocated and recycled in the frame builder. next_plane_splitter_index: usize, /// A list of all primitive instances in the scene. We store them as a single /// array so that multiple different systems (e.g. tile-cache, visibility, property /// animation bindings) can store index buffers to prim instances. prim_instances: Vec, /// A map of pipeline ids encountered during scene build - used to create unique /// pipeline instance ids as they are encountered. pipeline_instance_ids: FastHashMap, /// A list of surfaces (backing textures) that are relevant for this scene. /// Every picture is assigned to a surface (either a new surface if the picture /// has a composite mode, or the parent surface if it's a pass-through). surfaces: Vec, /// Used to build a ClipTree from the clip-chains, clips and state during scene building. clip_tree_builder: ClipTreeBuilder, } impl<'a> SceneBuilder<'a> { pub fn build( scene: &Scene, fonts: SharedFontResources, view: &SceneView, frame_builder_config: &FrameBuilderConfig, interners: &mut Interners, spatial_tree: &mut SceneSpatialTree, stats: &SceneStats, ) -> BuiltScene { profile_scope!("build_scene"); // We checked that the root pipeline is available on the render backend. let root_pipeline_id = scene.root_pipeline_id.unwrap(); let root_pipeline = scene.pipelines.get(&root_pipeline_id).unwrap(); let root_reference_frame_index = spatial_tree.root_reference_frame_index(); // During scene building, we assume a 1:1 picture -> raster pixel scale let snap_to_device = SpaceSnapper::new( root_reference_frame_index, RasterPixelScale::new(1.0), ); let mut builder = SceneBuilder { scene, spatial_tree, fonts, config: *frame_builder_config, id_to_index_mapper_stack: Vec::new(), hit_testing_scene: HitTestingScene::new(&stats.hit_test_stats), pending_shadow_items: VecDeque::new(), sc_stack: Vec::new(), containing_block_stack: Vec::new(), raster_space_stack: vec![RasterSpace::Screen], prim_store: PrimitiveStore::new(&stats.prim_store_stats), clip_store: ClipStore::new(), interners, rf_mapper: ReferenceFrameMapper::new(), external_scroll_mapper: ScrollOffsetMapper::new(), iframe_size: Vec::new(), root_iframe_clip: None, quality_settings: view.quality_settings, tile_cache_builder: TileCacheBuilder::new( root_reference_frame_index, frame_builder_config.background_color, ), snap_to_device, picture_graph: PictureGraph::new(), next_plane_splitter_index: 0, prim_instances: Vec::new(), pipeline_instance_ids: FastHashMap::default(), surfaces: Vec::new(), clip_tree_builder: ClipTreeBuilder::new(), }; builder.build_all( root_pipeline_id, &root_pipeline, ); // Construct the picture cache primitive instance(s) from the tile cache builder let (tile_cache_config, tile_cache_pictures) = builder.tile_cache_builder.build( &builder.config, &mut builder.prim_store, &builder.spatial_tree, &builder.prim_instances, &mut builder.clip_tree_builder, ); // Add all the tile cache pictures as roots of the picture graph for pic_index in &tile_cache_pictures { builder.picture_graph.add_root(*pic_index); SceneBuilder::finalize_picture( *pic_index, &mut builder.prim_store.pictures, None, ); } let clip_tree = builder.clip_tree_builder.finalize(); BuiltScene { has_root_pipeline: scene.has_root_pipeline(), pipeline_epochs: scene.pipeline_epochs.clone(), output_rect: view.device_rect.size().into(), hit_testing_scene: Arc::new(builder.hit_testing_scene), prim_store: builder.prim_store, clip_store: builder.clip_store, config: builder.config, tile_cache_config, tile_cache_pictures, picture_graph: builder.picture_graph, num_plane_splitters: builder.next_plane_splitter_index, prim_instances: builder.prim_instances, surfaces: builder.surfaces, clip_tree, } } /// Traverse the picture prim list and update any late-set spatial nodes // TODO(gw): This is somewhat hacky - it's unfortunate we need to do this, but it's // because we can't determine the scroll root until we have checked all the // primitives in the slice. Perhaps we could simplify this by doing some // work earlier in the DL builder, so we know what scroll root will be picked? fn finalize_picture( pic_index: PictureIndex, pictures: &mut [PicturePrimitive], parent_spatial_node_index: Option, ) { // Extract the prim_list (borrow check) and select the spatial node to // assign to unknown clusters let (mut prim_list, spatial_node_index) = { let pic = &mut pictures[pic_index.0]; assert_ne!(pic.spatial_node_index, SpatialNodeIndex::UNKNOWN); if pic.flags.contains(PictureFlags::IS_RESOLVE_TARGET) { pic.flags |= PictureFlags::DISABLE_SNAPPING; } // If we're a surface, use that spatial node, otherwise the parent let spatial_node_index = match pic.composite_mode { Some(_) => pic.spatial_node_index, None => parent_spatial_node_index.expect("bug: no parent"), }; ( mem::replace(&mut pic.prim_list, PrimitiveList::empty()), spatial_node_index, ) }; // Update the spatial node of any unknown clusters for cluster in &mut prim_list.clusters { if cluster.spatial_node_index == SpatialNodeIndex::UNKNOWN { cluster.spatial_node_index = spatial_node_index; } } // Update the spatial node of any child pictures for child_pic_index in &prim_list.child_pictures { let child_pic = &mut pictures[child_pic_index.0]; if child_pic.spatial_node_index == SpatialNodeIndex::UNKNOWN { child_pic.spatial_node_index = spatial_node_index; } // Recurse into child pictures which may also have unknown spatial nodes SceneBuilder::finalize_picture( *child_pic_index, pictures, Some(spatial_node_index), ); if pictures[child_pic_index.0].flags.contains(PictureFlags::DISABLE_SNAPPING) { pictures[pic_index.0].flags |= PictureFlags::DISABLE_SNAPPING; } } // Restore the prim_list pictures[pic_index.0].prim_list = prim_list; } /// Retrieve the current offset to allow converting a stacking context /// relative coordinate to be relative to the owing reference frame, /// also considering any external scroll offset on the provided /// spatial node. fn current_offset( &mut self, spatial_node_index: SpatialNodeIndex, ) -> LayoutVector2D { // Get the current offset from stacking context <-> reference frame space. let rf_offset = self.rf_mapper.current_offset(); // Get the external scroll offset, if applicable. let scroll_offset = self .external_scroll_mapper .external_scroll_offset( spatial_node_index, self.spatial_tree, ); rf_offset + scroll_offset } fn build_spatial_tree_for_display_list( &mut self, dl: &BuiltDisplayList, pipeline_id: PipelineId, instance_id: PipelineInstanceId, ) { dl.iter_spatial_tree(|item| { match item { SpatialTreeItem::ScrollFrame(descriptor) => { let parent_space = self.get_space(descriptor.parent_space); self.build_scroll_frame( descriptor, parent_space, pipeline_id, instance_id, ); } SpatialTreeItem::ReferenceFrame(descriptor) => { let parent_space = self.get_space(descriptor.parent_spatial_id); self.build_reference_frame( descriptor, parent_space, pipeline_id, instance_id, ); } SpatialTreeItem::StickyFrame(descriptor) => { let parent_space = self.get_space(descriptor.parent_spatial_id); self.build_sticky_frame( descriptor, parent_space, instance_id, ); } SpatialTreeItem::Invalid => { unreachable!(); } } }); } fn build_all( &mut self, root_pipeline_id: PipelineId, root_pipeline: &ScenePipeline, ) { enum ContextKind<'a> { Root, StackingContext { sc_info: StackingContextInfo, }, ReferenceFrame, Iframe { parent_traversal: BuiltDisplayListIter<'a>, } } struct BuildContext<'a> { pipeline_id: PipelineId, kind: ContextKind<'a>, } self.id_to_index_mapper_stack.push(NodeIdToIndexMapper::default()); let instance_id = self.get_next_instance_id_for_pipeline(root_pipeline_id); self.push_root( root_pipeline_id, instance_id, ); self.build_spatial_tree_for_display_list( &root_pipeline.display_list.display_list, root_pipeline_id, instance_id, ); let mut stack = vec![BuildContext { pipeline_id: root_pipeline_id, kind: ContextKind::Root, }]; let mut traversal = root_pipeline.display_list.iter(); 'outer: while let Some(bc) = stack.pop() { loop { let item = match traversal.next() { Some(item) => item, None => break, }; match item.item() { DisplayItem::PushStackingContext(ref info) => { profile_scope!("build_stacking_context"); let spatial_node_index = self.get_space(info.spatial_id); let mut subtraversal = item.sub_iter(); // Avoid doing unnecessary work for empty stacking contexts. if subtraversal.current_stacking_context_empty() { subtraversal.skip_current_stacking_context(); traversal = subtraversal; continue; } let composition_operations = CompositeOps::new( filter_ops_for_compositing(item.filters()), filter_datas_for_compositing(item.filter_datas()), filter_primitives_for_compositing(item.filter_primitives()), info.stacking_context.mix_blend_mode_for_compositing(), ); let sc_info = self.push_stacking_context( composition_operations, info.stacking_context.transform_style, info.prim_flags, spatial_node_index, info.stacking_context.clip_chain_id, info.stacking_context.raster_space, info.stacking_context.flags, ); self.rf_mapper.push_offset(info.origin.to_vector()); let new_context = BuildContext { pipeline_id: bc.pipeline_id, kind: ContextKind::StackingContext { sc_info, }, }; stack.push(bc); stack.push(new_context); subtraversal.merge_debug_stats_from(&mut traversal); traversal = subtraversal; continue 'outer; } DisplayItem::PushReferenceFrame(..) => { profile_scope!("build_reference_frame"); let mut subtraversal = item.sub_iter(); self.rf_mapper.push_scope(); let new_context = BuildContext { pipeline_id: bc.pipeline_id, kind: ContextKind::ReferenceFrame, }; stack.push(bc); stack.push(new_context); subtraversal.merge_debug_stats_from(&mut traversal); traversal = subtraversal; continue 'outer; } DisplayItem::PopReferenceFrame | DisplayItem::PopStackingContext => break, DisplayItem::Iframe(ref info) => { profile_scope!("iframe"); let space = self.get_space(info.space_and_clip.spatial_id); let subtraversal = match self.push_iframe(info, space) { Some(pair) => pair, None => continue, }; let new_context = BuildContext { pipeline_id: info.pipeline_id, kind: ContextKind::Iframe { parent_traversal: mem::replace(&mut traversal, subtraversal), }, }; stack.push(bc); stack.push(new_context); continue 'outer; } _ => { self.build_item(item); } }; } match bc.kind { ContextKind::Root => {} ContextKind::StackingContext { sc_info } => { self.rf_mapper.pop_offset(); self.pop_stacking_context(sc_info); } ContextKind::ReferenceFrame => { self.rf_mapper.pop_scope(); } ContextKind::Iframe { parent_traversal } => { self.iframe_size.pop(); self.rf_mapper.pop_scope(); self.clip_tree_builder.pop_clip(); self.clip_tree_builder.pop_clip(); if self.iframe_size.is_empty() { assert!(self.root_iframe_clip.is_some()); self.root_iframe_clip = None; self.add_tile_cache_barrier_if_needed(SliceFlags::empty()); } self.id_to_index_mapper_stack.pop().unwrap(); traversal = parent_traversal; } } // TODO: factor this out to be part of capture if cfg!(feature = "display_list_stats") { let stats = traversal.debug_stats(); let total_bytes: usize = stats.iter().map(|(_, stats)| stats.num_bytes).sum(); debug!("item, total count, total bytes, % of DL bytes, bytes per item"); for (label, stats) in stats { debug!("{}, {}, {}kb, {}%, {}", label, stats.total_count, stats.num_bytes / 1000, ((stats.num_bytes as f32 / total_bytes.max(1) as f32) * 100.0) as usize, stats.num_bytes / stats.total_count.max(1)); } debug!(""); } } debug_assert!(self.sc_stack.is_empty()); self.id_to_index_mapper_stack.pop().unwrap(); assert!(self.id_to_index_mapper_stack.is_empty()); } fn build_sticky_frame( &mut self, info: &StickyFrameDescriptor, parent_node_index: SpatialNodeIndex, instance_id: PipelineInstanceId, ) { let sticky_frame_info = StickyFrameInfo::new( info.bounds, info.margins, info.vertical_offset_bounds, info.horizontal_offset_bounds, info.previously_applied_offset, ); let index = self.spatial_tree.add_sticky_frame( parent_node_index, sticky_frame_info, info.id.pipeline_id(), info.key, instance_id, ); self.id_to_index_mapper_stack.last_mut().unwrap().add_spatial_node(info.id, index); } fn build_reference_frame( &mut self, info: &ReferenceFrameDescriptor, parent_space: SpatialNodeIndex, pipeline_id: PipelineId, instance_id: PipelineInstanceId, ) { let transform = match info.reference_frame.transform { ReferenceTransformBinding::Static { binding } => binding, ReferenceTransformBinding::Computed { scale_from, vertical_flip, rotation } => { let content_size = &self.iframe_size.last().unwrap(); let mut transform = if let Some(scale_from) = scale_from { // If we have a 90/270 degree rotation, then scale_from // and content_size are in different coordinate spaces and // we need to swap width/height for them to be correct. match rotation { Rotation::Degree0 | Rotation::Degree180 => { LayoutTransform::scale( content_size.width / scale_from.width, content_size.height / scale_from.height, 1.0 ) }, Rotation::Degree90 | Rotation::Degree270 => { LayoutTransform::scale( content_size.height / scale_from.width, content_size.width / scale_from.height, 1.0 ) } } } else { LayoutTransform::identity() }; if vertical_flip { let content_size = &self.iframe_size.last().unwrap(); let content_height = match rotation { Rotation::Degree0 | Rotation::Degree180 => content_size.height, Rotation::Degree90 | Rotation::Degree270 => content_size.width, }; transform = transform .then_translate(LayoutVector3D::new(0.0, content_height, 0.0)) .pre_scale(1.0, -1.0, 1.0); } let rotate = rotation.to_matrix(**content_size); let transform = transform.then(&rotate); PropertyBinding::Value(transform) }, }; self.push_reference_frame( info.reference_frame.id, parent_space, pipeline_id, info.reference_frame.transform_style, transform, info.reference_frame.kind, info.origin.to_vector(), SpatialNodeUid::external(info.reference_frame.key, pipeline_id, instance_id), ); } fn build_scroll_frame( &mut self, info: &ScrollFrameDescriptor, parent_node_index: SpatialNodeIndex, pipeline_id: PipelineId, instance_id: PipelineInstanceId, ) { // This is useful when calculating scroll extents for the // SpatialNode::scroll(..) API as well as for properly setting sticky // positioning offsets. let content_size = info.content_rect.size(); self.add_scroll_frame( info.scroll_frame_id, parent_node_index, info.external_id, pipeline_id, &info.frame_rect, &content_size, ScrollFrameKind::Explicit, info.external_scroll_offset, info.scroll_offset_generation, info.has_scroll_linked_effect, SpatialNodeUid::external(info.key, pipeline_id, instance_id), ); } /// Advance and return the next instance id for a given pipeline id fn get_next_instance_id_for_pipeline( &mut self, pipeline_id: PipelineId, ) -> PipelineInstanceId { let next_instance = self.pipeline_instance_ids .entry(pipeline_id) .or_insert(0); let instance_id = PipelineInstanceId::new(*next_instance); *next_instance += 1; instance_id } fn push_iframe( &mut self, info: &IframeDisplayItem, spatial_node_index: SpatialNodeIndex, ) -> Option> { let iframe_pipeline_id = info.pipeline_id; let pipeline = match self.scene.pipelines.get(&iframe_pipeline_id) { Some(pipeline) => pipeline, None => { debug_assert!(info.ignore_missing_pipeline); return None }, }; self.clip_tree_builder.push_clip_chain(Some(info.space_and_clip.clip_chain_id), false); // TODO(gw): This is the only remaining call site that relies on ClipId parenting, remove me! self.add_rect_clip_node( ClipId::root(iframe_pipeline_id), info.space_and_clip.spatial_id, &info.clip_rect, ); self.clip_tree_builder.push_clip_id(ClipId::root(iframe_pipeline_id)); let instance_id = self.get_next_instance_id_for_pipeline(iframe_pipeline_id); self.id_to_index_mapper_stack.push(NodeIdToIndexMapper::default()); let bounds = self.snap_rect( &info.bounds, spatial_node_index, ); let spatial_node_index = self.push_reference_frame( SpatialId::root_reference_frame(iframe_pipeline_id), spatial_node_index, iframe_pipeline_id, TransformStyle::Flat, PropertyBinding::Value(LayoutTransform::identity()), ReferenceFrameKind::Transform { is_2d_scale_translation: true, should_snap: true, paired_with_perspective: false, }, bounds.min.to_vector(), SpatialNodeUid::root_reference_frame(iframe_pipeline_id, instance_id), ); let iframe_rect = LayoutRect::from_size(bounds.size()); let is_root_pipeline = self.iframe_size.is_empty(); self.add_scroll_frame( SpatialId::root_scroll_node(iframe_pipeline_id), spatial_node_index, ExternalScrollId(0, iframe_pipeline_id), iframe_pipeline_id, &iframe_rect, &bounds.size(), ScrollFrameKind::PipelineRoot { is_root_pipeline, }, LayoutVector2D::zero(), APZScrollGeneration::default(), HasScrollLinkedEffect::No, SpatialNodeUid::root_scroll_frame(iframe_pipeline_id, instance_id), ); // If this is a root iframe, force a new tile cache both before and after // adding primitives for this iframe. if self.iframe_size.is_empty() { assert!(self.root_iframe_clip.is_none()); self.root_iframe_clip = Some(ClipId::root(iframe_pipeline_id)); self.add_tile_cache_barrier_if_needed(SliceFlags::empty()); } self.iframe_size.push(info.bounds.size()); self.rf_mapper.push_scope(); self.build_spatial_tree_for_display_list( &pipeline.display_list.display_list, iframe_pipeline_id, instance_id, ); Some(pipeline.display_list.iter()) } fn get_space( &self, spatial_id: SpatialId, ) -> SpatialNodeIndex { self.id_to_index_mapper_stack.last().unwrap().get_spatial_node_index(spatial_id) } fn get_clip_node( &mut self, clip_chain_id: api::ClipChainId, ) -> ClipNodeId { self.clip_tree_builder.build_clip_set( clip_chain_id, ) } fn process_common_properties( &mut self, common: &CommonItemProperties, bounds: Option<&LayoutRect>, ) -> (LayoutPrimitiveInfo, LayoutRect, SpatialNodeIndex, ClipNodeId) { let spatial_node_index = self.get_space(common.spatial_id); let current_offset = self.current_offset(spatial_node_index); let unsnapped_clip_rect = common.clip_rect.translate(current_offset); let unsnapped_rect = bounds.map(|bounds| { bounds.translate(current_offset) }); // If no bounds rect is given, default to clip rect. let (rect, clip_rect) = if common.flags.contains(PrimitiveFlags::ANTIALISED) { (unsnapped_rect.unwrap_or(unsnapped_clip_rect), unsnapped_clip_rect) } else { let clip_rect = self.snap_rect( &unsnapped_clip_rect, spatial_node_index, ); let rect = unsnapped_rect.map_or(clip_rect, |bounds| { self.snap_rect( &bounds, spatial_node_index, ) }); (rect, clip_rect) }; let clip_node_id = self.get_clip_node( common.clip_chain_id, ); let layout = LayoutPrimitiveInfo { rect, clip_rect, flags: common.flags, }; (layout, unsnapped_rect.unwrap_or(unsnapped_clip_rect), spatial_node_index, clip_node_id) } fn process_common_properties_with_bounds( &mut self, common: &CommonItemProperties, bounds: &LayoutRect, ) -> (LayoutPrimitiveInfo, LayoutRect, SpatialNodeIndex, ClipNodeId) { self.process_common_properties( common, Some(bounds), ) } pub fn snap_rect( &mut self, rect: &LayoutRect, target_spatial_node: SpatialNodeIndex, ) -> LayoutRect { self.snap_to_device.set_target_spatial_node( target_spatial_node, self.spatial_tree, ); self.snap_to_device.snap_rect(&rect) } fn build_item<'b>( &'b mut self, item: DisplayItemRef, ) { match *item.item() { DisplayItem::Image(ref info) => { profile_scope!("image"); let (layout, _, spatial_node_index, clip_node_id) = self.process_common_properties_with_bounds( &info.common, &info.bounds, ); self.add_image( spatial_node_index, clip_node_id, &layout, layout.rect.size(), LayoutSize::zero(), info.image_key, info.image_rendering, info.alpha_type, info.color, ); } DisplayItem::RepeatingImage(ref info) => { profile_scope!("repeating_image"); let (layout, unsnapped_rect, spatial_node_index, clip_node_id) = self.process_common_properties_with_bounds( &info.common, &info.bounds, ); let stretch_size = process_repeat_size( &layout.rect, &unsnapped_rect, info.stretch_size, ); self.add_image( spatial_node_index, clip_node_id, &layout, stretch_size, info.tile_spacing, info.image_key, info.image_rendering, info.alpha_type, info.color, ); } DisplayItem::YuvImage(ref info) => { profile_scope!("yuv_image"); let (layout, _, spatial_node_index, clip_node_id) = self.process_common_properties_with_bounds( &info.common, &info.bounds, ); self.add_yuv_image( spatial_node_index, clip_node_id, &layout, info.yuv_data, info.color_depth, info.color_space, info.color_range, info.image_rendering, ); } DisplayItem::Text(ref info) => { profile_scope!("text"); // TODO(aosmond): Snapping text primitives does not make much sense, given the // primitive bounds and clip are supposed to be conservative, not definitive. // E.g. they should be able to grow and not impact the output. However there // are subtle interactions between the primitive origin and the glyph offset // which appear to be significant (presumably due to some sort of accumulated // error throughout the layers). We should fix this at some point. let (layout, _, spatial_node_index, clip_node_id) = self.process_common_properties_with_bounds( &info.common, &info.bounds, ); self.add_text( spatial_node_index, clip_node_id, &layout, &info.font_key, &info.color, item.glyphs(), info.glyph_options, ); } DisplayItem::Rectangle(ref info) => { profile_scope!("rect"); let (layout, _, spatial_node_index, clip_node_id) = self.process_common_properties_with_bounds( &info.common, &info.bounds, ); self.add_primitive( spatial_node_index, clip_node_id, &layout, Vec::new(), PrimitiveKeyKind::Rectangle { color: info.color.into(), }, ); if info.common.flags.contains(PrimitiveFlags::CHECKERBOARD_BACKGROUND) { self.add_tile_cache_barrier_if_needed(SliceFlags::empty()); } } DisplayItem::HitTest(ref info) => { profile_scope!("hit_test"); let spatial_node_index = self.get_space(info.spatial_id); let current_offset = self.current_offset(spatial_node_index); let unsnapped_rect = info.rect.translate(current_offset); let rect = self.snap_rect( &unsnapped_rect, spatial_node_index, ); let layout = LayoutPrimitiveInfo { rect, clip_rect: rect, flags: info.flags, }; let spatial_node = self.spatial_tree.get_node_info(spatial_node_index); let anim_id: u64 = match spatial_node.node_type { SpatialNodeType::ReferenceFrame(ReferenceFrameInfo { source_transform: PropertyBinding::Binding(key, _), .. }) => key.clone().into(), _ => 0, }; let clip_node_id = self.get_clip_node(info.clip_chain_id); self.add_primitive_to_hit_testing_list( &layout, spatial_node_index, clip_node_id, info.tag, anim_id, ); } DisplayItem::ClearRectangle(ref info) => { profile_scope!("clear"); let (layout, _, spatial_node_index, clip_node_id) = self.process_common_properties_with_bounds( &info.common, &info.bounds, ); self.add_clear_rectangle( spatial_node_index, clip_node_id, &layout, ); } DisplayItem::Line(ref info) => { profile_scope!("line"); let (layout, _, spatial_node_index, clip_node_id) = self.process_common_properties_with_bounds( &info.common, &info.area, ); self.add_line( spatial_node_index, clip_node_id, &layout, info.wavy_line_thickness, info.orientation, info.color, info.style, ); } DisplayItem::Gradient(ref info) => { profile_scope!("gradient"); if !info.gradient.is_valid() { return; } let (mut layout, unsnapped_rect, spatial_node_index, clip_node_id) = self.process_common_properties_with_bounds( &info.common, &info.bounds, ); let mut tile_size = process_repeat_size( &layout.rect, &unsnapped_rect, info.tile_size, ); let mut stops = read_gradient_stops(item.gradient_stops()); let mut start = info.gradient.start_point; let mut end = info.gradient.end_point; let flags = layout.flags; let optimized = optimize_linear_gradient( &mut layout.rect, &mut tile_size, info.tile_spacing, &layout.clip_rect, &mut start, &mut end, info.gradient.extend_mode, &mut stops, &mut |rect, start, end, stops, edge_aa_mask| { let layout = LayoutPrimitiveInfo { rect: *rect, clip_rect: *rect, flags }; if let Some(prim_key_kind) = self.create_linear_gradient_prim( &layout, start, end, stops.to_vec(), ExtendMode::Clamp, rect.size(), LayoutSize::zero(), None, edge_aa_mask, ) { self.add_nonshadowable_primitive( spatial_node_index, clip_node_id, &layout, Vec::new(), prim_key_kind, ); } } ); if !optimized && !tile_size.ceil().is_empty() { if let Some(prim_key_kind) = self.create_linear_gradient_prim( &layout, start, end, stops, info.gradient.extend_mode, tile_size, info.tile_spacing, None, EdgeAaSegmentMask::all(), ) { self.add_nonshadowable_primitive( spatial_node_index, clip_node_id, &layout, Vec::new(), prim_key_kind, ); } } } DisplayItem::RadialGradient(ref info) => { profile_scope!("radial"); if !info.gradient.is_valid() { return; } let (mut layout, unsnapped_rect, spatial_node_index, clip_node_id) = self.process_common_properties_with_bounds( &info.common, &info.bounds, ); let mut center = info.gradient.center; let stops = read_gradient_stops(item.gradient_stops()); let mut tile_size = process_repeat_size( &layout.rect, &unsnapped_rect, info.tile_size, ); let mut prim_rect = layout.rect; let mut tile_spacing = info.tile_spacing; optimize_radial_gradient( &mut prim_rect, &mut tile_size, &mut center, &mut tile_spacing, &layout.clip_rect, info.gradient.radius, info.gradient.end_offset, info.gradient.extend_mode, &stops, &mut |solid_rect, color| { self.add_nonshadowable_primitive( spatial_node_index, clip_node_id, &LayoutPrimitiveInfo { rect: *solid_rect, .. layout }, Vec::new(), PrimitiveKeyKind::Rectangle { color: PropertyBinding::Value(color) }, ); } ); // TODO: create_radial_gradient_prim already calls // this, but it leaves the info variable that is // passed to add_nonshadowable_primitive unmodified // which can cause issues. simplify_repeated_primitive(&tile_size, &mut tile_spacing, &mut prim_rect); if !tile_size.ceil().is_empty() { layout.rect = prim_rect; let prim_key_kind = self.create_radial_gradient_prim( &layout, center, info.gradient.start_offset * info.gradient.radius.width, info.gradient.end_offset * info.gradient.radius.width, info.gradient.radius.width / info.gradient.radius.height, stops, info.gradient.extend_mode, tile_size, tile_spacing, None, ); self.add_nonshadowable_primitive( spatial_node_index, clip_node_id, &layout, Vec::new(), prim_key_kind, ); } } DisplayItem::ConicGradient(ref info) => { profile_scope!("conic"); if !info.gradient.is_valid() { return; } let (mut layout, unsnapped_rect, spatial_node_index, clip_node_id) = self.process_common_properties_with_bounds( &info.common, &info.bounds, ); let tile_size = process_repeat_size( &layout.rect, &unsnapped_rect, info.tile_size, ); let offset = apply_gradient_local_clip( &mut layout.rect, &tile_size, &info.tile_spacing, &layout.clip_rect, ); let center = info.gradient.center + offset; if !tile_size.ceil().is_empty() { let prim_key_kind = self.create_conic_gradient_prim( &layout, center, info.gradient.angle, info.gradient.start_offset, info.gradient.end_offset, item.gradient_stops(), info.gradient.extend_mode, tile_size, info.tile_spacing, None, ); self.add_nonshadowable_primitive( spatial_node_index, clip_node_id, &layout, Vec::new(), prim_key_kind, ); } } DisplayItem::BoxShadow(ref info) => { profile_scope!("box_shadow"); let (layout, _, spatial_node_index, clip_node_id) = self.process_common_properties_with_bounds( &info.common, &info.box_bounds, ); self.add_box_shadow( spatial_node_index, clip_node_id, &layout, &info.offset, info.color, info.blur_radius, info.spread_radius, info.border_radius, info.clip_mode, ); } DisplayItem::Border(ref info) => { profile_scope!("border"); let (layout, _, spatial_node_index, clip_node_id) = self.process_common_properties_with_bounds( &info.common, &info.bounds, ); self.add_border( spatial_node_index, clip_node_id, &layout, info, item.gradient_stops(), ); } DisplayItem::ImageMaskClip(ref info) => { profile_scope!("image_clip"); self.add_image_mask_clip_node( info.id, info.spatial_id, &info.image_mask, info.fill_rule, item.points(), ); } DisplayItem::RoundedRectClip(ref info) => { profile_scope!("rounded_clip"); self.add_rounded_rect_clip_node( info.id, info.spatial_id, &info.clip, ); } DisplayItem::RectClip(ref info) => { profile_scope!("rect_clip"); self.add_rect_clip_node( info.id, info.spatial_id, &info.clip_rect, ); } DisplayItem::ClipChain(ref info) => { profile_scope!("clip_chain"); self.clip_tree_builder.define_clip_chain( info.id, info.parent, item.clip_chain_items().into_iter(), ); }, DisplayItem::BackdropFilter(ref info) => { profile_scope!("backdrop"); let (layout, _, spatial_node_index, clip_node_id) = self.process_common_properties( &info.common, None, ); let filters = filter_ops_for_compositing(item.filters()); let filter_datas = filter_datas_for_compositing(item.filter_datas()); let filter_primitives = filter_primitives_for_compositing(item.filter_primitives()); self.add_backdrop_filter( spatial_node_index, clip_node_id, &layout, filters, filter_datas, filter_primitives, ); } // Do nothing; these are dummy items for the display list parser DisplayItem::SetGradientStops | DisplayItem::SetFilterOps | DisplayItem::SetFilterData | DisplayItem::SetFilterPrimitives | DisplayItem::SetPoints => {} // Special items that are handled in the parent method DisplayItem::PushStackingContext(..) | DisplayItem::PushReferenceFrame(..) | DisplayItem::PopReferenceFrame | DisplayItem::PopStackingContext | DisplayItem::Iframe(_) => { unreachable!("Handled in `build_all`") } DisplayItem::ReuseItems(key) | DisplayItem::RetainedItems(key) => { unreachable!("Iterator logic error: {:?}", key); } DisplayItem::PushShadow(info) => { profile_scope!("push_shadow"); let spatial_node_index = self.get_space(info.space_and_clip.spatial_id); self.push_shadow( info.shadow, spatial_node_index, info.space_and_clip.clip_chain_id, info.should_inflate, ); } DisplayItem::PopAllShadows => { profile_scope!("pop_all_shadows"); self.pop_all_shadows(); } } } /// Create a primitive and add it to the prim store. This method doesn't /// add the primitive to the draw list, so can be used for creating /// sub-primitives. /// /// TODO(djg): Can this inline into `add_interned_prim_to_draw_list` fn create_primitive

( &mut self, info: &LayoutPrimitiveInfo, spatial_node_index: SpatialNodeIndex, clip_leaf_id: ClipLeafId, prim: P, ) -> PrimitiveInstance where P: InternablePrimitive, Interners: AsMut>, { // Build a primitive key. let prim_key = prim.into_key(info); let current_offset = self.current_offset(spatial_node_index); let interner = self.interners.as_mut(); let prim_data_handle = interner .intern(&prim_key, || ()); let instance_kind = P::make_instance_kind( prim_key, prim_data_handle, &mut self.prim_store, current_offset, ); PrimitiveInstance::new( instance_kind, clip_leaf_id, ) } fn add_primitive_to_hit_testing_list( &mut self, info: &LayoutPrimitiveInfo, spatial_node_index: SpatialNodeIndex, clip_node_id: ClipNodeId, tag: ItemTag, anim_id: u64, ) { self.hit_testing_scene.add_item( tag, anim_id, info, spatial_node_index, clip_node_id, &self.clip_tree_builder, self.interners, ); } /// Add an already created primitive to the draw lists. pub fn add_primitive_to_draw_list( &mut self, prim_instance: PrimitiveInstance, prim_rect: LayoutRect, spatial_node_index: SpatialNodeIndex, flags: PrimitiveFlags, ) { // Add primitive to the top-most stacking context on the stack. // If we have a valid stacking context, the primitive gets added to that. // Otherwise, it gets added to a top-level picture cache slice. match self.sc_stack.last_mut() { Some(stacking_context) => { stacking_context.prim_list.add_prim( prim_instance, prim_rect, spatial_node_index, flags, &mut self.prim_instances, &self.clip_tree_builder, ); } None => { self.tile_cache_builder.add_prim( prim_instance, prim_rect, spatial_node_index, flags, self.spatial_tree, self.interners, &self.quality_settings, &mut self.prim_instances, &self.clip_tree_builder, ); } } } /// Convenience interface that creates a primitive entry and adds it /// to the draw list. fn add_nonshadowable_primitive

( &mut self, spatial_node_index: SpatialNodeIndex, clip_node_id: ClipNodeId, info: &LayoutPrimitiveInfo, clip_items: Vec, prim: P, ) where P: InternablePrimitive + IsVisible, Interners: AsMut>, { if prim.is_visible() { let clip_leaf_id = self.clip_tree_builder.build_for_prim( clip_node_id, info, &clip_items, &mut self.interners, ); self.add_prim_to_draw_list( info, spatial_node_index, clip_leaf_id, prim, ); } } pub fn add_primitive

( &mut self, spatial_node_index: SpatialNodeIndex, clip_node_id: ClipNodeId, info: &LayoutPrimitiveInfo, clip_items: Vec, prim: P, ) where P: InternablePrimitive + IsVisible, Interners: AsMut>, ShadowItem: From> { // If a shadow context is not active, then add the primitive // directly to the parent picture. if self.pending_shadow_items.is_empty() { self.add_nonshadowable_primitive( spatial_node_index, clip_node_id, info, clip_items, prim, ); } else { debug_assert!(clip_items.is_empty(), "No per-prim clips expected for shadowed primitives"); // There is an active shadow context. Store as a pending primitive // for processing during pop_all_shadows. self.pending_shadow_items.push_back(PendingPrimitive { spatial_node_index, clip_node_id, info: *info, prim, }.into()); } } fn add_prim_to_draw_list

( &mut self, info: &LayoutPrimitiveInfo, spatial_node_index: SpatialNodeIndex, clip_leaf_id: ClipLeafId, prim: P, ) where P: InternablePrimitive, Interners: AsMut>, { let prim_instance = self.create_primitive( info, spatial_node_index, clip_leaf_id, prim, ); self.add_primitive_to_draw_list( prim_instance, info.rect, spatial_node_index, info.flags, ); } fn make_current_slice_atomic_if_required(&mut self) { let has_non_wrapping_sc = self.sc_stack .iter() .position(|sc| { !sc.flags.contains(StackingContextFlags::WRAPS_BACKDROP_FILTER) }) .is_some(); if has_non_wrapping_sc { return; } // Shadows can only exist within a stacking context assert!(self.pending_shadow_items.is_empty()); self.tile_cache_builder.make_current_slice_atomic(); } /// If no stacking contexts are present (i.e. we are adding prims to a tile /// cache), set a barrier to force creation of a slice before the next prim fn add_tile_cache_barrier_if_needed( &mut self, slice_flags: SliceFlags, ) { if self.sc_stack.is_empty() { // Shadows can only exist within a stacking context assert!(self.pending_shadow_items.is_empty()); self.tile_cache_builder.add_tile_cache_barrier( slice_flags, self.root_iframe_clip, ); } } /// Push a new stacking context. Returns context that must be passed to pop_stacking_context(). fn push_stacking_context( &mut self, composite_ops: CompositeOps, transform_style: TransformStyle, prim_flags: PrimitiveFlags, spatial_node_index: SpatialNodeIndex, clip_chain_id: Option, requested_raster_space: RasterSpace, flags: StackingContextFlags, ) -> StackingContextInfo { profile_scope!("push_stacking_context"); let clip_node_id = match clip_chain_id { Some(id) => { self.clip_tree_builder.build_clip_set(id) } None => { self.clip_tree_builder.build_clip_set(api::ClipChainId::INVALID) } }; self.clip_tree_builder.push_clip_chain( clip_chain_id, !composite_ops.is_empty(), ); let new_space = match (self.raster_space_stack.last(), requested_raster_space) { // If no parent space, just use the requested space (None, _) => requested_raster_space, // If screen, use the parent (Some(parent_space), RasterSpace::Screen) => *parent_space, // If currently screen, select the requested (Some(RasterSpace::Screen), space) => space, // If both local, take the maximum scale (Some(RasterSpace::Local(parent_scale)), RasterSpace::Local(scale)) => RasterSpace::Local(parent_scale.max(scale)), }; self.raster_space_stack.push(new_space); // Get the transform-style of the parent stacking context, // which determines if we *might* need to draw this on // an intermediate surface for plane splitting purposes. let (parent_is_3d, extra_3d_instance, plane_splitter_index) = match self.sc_stack.last_mut() { Some(ref mut sc) if sc.is_3d() => { let (flat_items_context_3d, plane_splitter_index) = match sc.context_3d { Picture3DContext::In { ancestor_index, plane_splitter_index, .. } => { ( Picture3DContext::In { root_data: None, ancestor_index, plane_splitter_index, }, plane_splitter_index, ) } Picture3DContext::Out => panic!("Unexpected out of 3D context"), }; // Cut the sequence of flat children before starting a child stacking context, // so that the relative order between them and our current SC is preserved. let extra_instance = sc.cut_item_sequence( &mut self.prim_store, &mut self.interners, Some(PictureCompositeMode::Blit(BlitReason::PRESERVE3D)), flat_items_context_3d, &mut self.clip_tree_builder, ); let extra_instance = extra_instance.map(|(_, instance)| { ExtendedPrimitiveInstance { instance, spatial_node_index: sc.spatial_node_index, flags: sc.prim_flags, } }); (true, extra_instance, Some(plane_splitter_index)) }, _ => (false, None, None), }; if let Some(instance) = extra_3d_instance { self.add_primitive_instance_to_3d_root(instance); } // If this is preserve-3d *or* the parent is, then this stacking // context is participating in the 3d rendering context. In that // case, hoist the picture up to the 3d rendering context // container, so that it's rendered as a sibling with other // elements in this context. let participating_in_3d_context = composite_ops.is_empty() && (parent_is_3d || transform_style == TransformStyle::Preserve3D); let context_3d = if participating_in_3d_context { // Get the spatial node index of the containing block, which // defines the context of backface-visibility. let ancestor_index = self.containing_block_stack .last() .cloned() .unwrap_or(self.spatial_tree.root_reference_frame_index()); let plane_splitter_index = plane_splitter_index.unwrap_or_else(|| { let index = self.next_plane_splitter_index; self.next_plane_splitter_index += 1; PlaneSplitterIndex(index) }); Picture3DContext::In { root_data: if parent_is_3d { None } else { Some(Vec::new()) }, plane_splitter_index, ancestor_index, } } else { Picture3DContext::Out }; // Force an intermediate surface if the stacking context has a // complex clip node. In the future, we may decide during // prepare step to skip the intermediate surface if the // clip node doesn't affect the stacking context rect. let mut blit_reason = BlitReason::empty(); // If this stacking context has any complex clips, we need to draw it // to an off-screen surface. if let Some(clip_chain_id) = clip_chain_id { if self.clip_tree_builder.clip_chain_has_complex_clips(clip_chain_id, &self.interners) { blit_reason |= BlitReason::CLIP; } } // Check if we know this stacking context is redundant (doesn't need a surface) // The check for blend-container redundancy is more involved so it's handled below. let mut is_redundant = FlattenedStackingContext::is_redundant( &context_3d, &composite_ops, blit_reason, self.sc_stack.last(), prim_flags, ); // If the stacking context is a blend container, and if we're at the top level // of the stacking context tree, we may be able to make this blend container into a tile // cache. This means that we get caching and correct scrolling invalidation for // root level blend containers. For these cases, the readbacks of the backdrop // are handled by doing partial reads of the picture cache tiles during rendering. if flags.contains(StackingContextFlags::IS_BLEND_CONTAINER) { // Check if we're inside a stacking context hierarchy with an existing surface match self.sc_stack.last() { Some(_) => { // If we are already inside a stacking context hierarchy with a surface, then we // need to do the normal isolate of this blend container as a regular surface blit_reason |= BlitReason::ISOLATE; is_redundant = false; } None => { // If the current slice is empty, then we can just mark the slice as // atomic (so that compositor surfaces don't get promoted within it) // and use that slice as the backing surface for the blend container if self.tile_cache_builder.is_current_slice_empty() && self.spatial_tree.is_root_coord_system(spatial_node_index) && !self.clip_tree_builder.clip_node_has_complex_clips(clip_node_id, &self.interners) { self.add_tile_cache_barrier_if_needed(SliceFlags::IS_ATOMIC); self.tile_cache_builder.make_current_slice_atomic(); } else { // If the slice wasn't empty, we need to isolate a separate surface // to ensure that the content already in the slice is not used as // an input to the mix-blend composite blit_reason |= BlitReason::ISOLATE; is_redundant = false; } } } } // If stacking context is a scrollbar, force a new slice for the primitives // within. The stacking context will be redundant and removed by above check. let set_tile_cache_barrier = prim_flags.contains(PrimitiveFlags::IS_SCROLLBAR_CONTAINER); if set_tile_cache_barrier { self.add_tile_cache_barrier_if_needed(SliceFlags::IS_SCROLLBAR); } let mut sc_info = StackingContextInfo { pop_stacking_context: false, pop_containing_block: false, set_tile_cache_barrier, }; // If this is not 3d, then it establishes an ancestor root for child 3d contexts. if !participating_in_3d_context { sc_info.pop_containing_block = true; self.containing_block_stack.push(spatial_node_index); } // If not redundant, create a stacking context to hold primitive clusters if !is_redundant { sc_info.pop_stacking_context = true; // Push the SC onto the stack, so we know how to handle things in // pop_stacking_context. self.sc_stack.push(FlattenedStackingContext { prim_list: PrimitiveList::empty(), prim_flags, spatial_node_index, clip_node_id, composite_ops, blit_reason, transform_style, context_3d, flags, raster_space: new_space, }); } sc_info } fn pop_stacking_context( &mut self, info: StackingContextInfo, ) { profile_scope!("pop_stacking_context"); self.clip_tree_builder.pop_clip(); // Pop off current raster space (pushed unconditionally in push_stacking_context) self.raster_space_stack.pop().unwrap(); // If the stacking context formed a containing block, pop off the stack if info.pop_containing_block { self.containing_block_stack.pop().unwrap(); } if info.set_tile_cache_barrier { self.add_tile_cache_barrier_if_needed(SliceFlags::empty()); } // If the stacking context was otherwise redundant, early exit if !info.pop_stacking_context { return; } let stacking_context = self.sc_stack.pop().unwrap(); let mut source = match stacking_context.context_3d { // TODO(gw): For now, as soon as this picture is in // a 3D context, we draw it to an intermediate // surface and apply plane splitting. However, // there is a large optimization opportunity here. // During culling, we can check if there is actually // perspective present, and skip the plane splitting // completely when that is not the case. Picture3DContext::In { ancestor_index, plane_splitter_index, .. } => { let composite_mode = Some( PictureCompositeMode::Blit(BlitReason::PRESERVE3D | stacking_context.blit_reason) ); // Add picture for this actual stacking context contents to render into. let pic_index = PictureIndex(self.prim_store.pictures .alloc() .init(PicturePrimitive::new_image( composite_mode.clone(), Picture3DContext::In { root_data: None, ancestor_index, plane_splitter_index }, stacking_context.prim_flags, stacking_context.prim_list, stacking_context.spatial_node_index, stacking_context.raster_space, PictureFlags::empty(), )) ); let instance = create_prim_instance( pic_index, composite_mode.into(), stacking_context.raster_space, stacking_context.clip_node_id, &mut self.interners, &mut self.clip_tree_builder, ); PictureChainBuilder::from_instance( instance, stacking_context.prim_flags, stacking_context.spatial_node_index, stacking_context.raster_space, ) } Picture3DContext::Out => { if stacking_context.blit_reason.is_empty() { PictureChainBuilder::from_prim_list( stacking_context.prim_list, stacking_context.prim_flags, stacking_context.spatial_node_index, stacking_context.raster_space, false, ) } else { let composite_mode = Some( PictureCompositeMode::Blit(stacking_context.blit_reason) ); // Add picture for this actual stacking context contents to render into. let pic_index = PictureIndex(self.prim_store.pictures .alloc() .init(PicturePrimitive::new_image( composite_mode.clone(), Picture3DContext::Out, stacking_context.prim_flags, stacking_context.prim_list, stacking_context.spatial_node_index, stacking_context.raster_space, PictureFlags::empty(), )) ); let instance = create_prim_instance( pic_index, composite_mode.into(), stacking_context.raster_space, stacking_context.clip_node_id, &mut self.interners, &mut self.clip_tree_builder, ); PictureChainBuilder::from_instance( instance, stacking_context.prim_flags, stacking_context.spatial_node_index, stacking_context.raster_space, ) } } }; // If establishing a 3d context, the `cur_instance` represents // a picture with all the *trailing* immediate children elements. // We append this to the preserve-3D picture set and make a container picture of them. if let Picture3DContext::In { root_data: Some(mut prims), ancestor_index, plane_splitter_index } = stacking_context.context_3d { let instance = source.finalize( ClipNodeId::NONE, &mut self.interners, &mut self.prim_store, &mut self.clip_tree_builder, ); prims.push(ExtendedPrimitiveInstance { instance, spatial_node_index: stacking_context.spatial_node_index, flags: stacking_context.prim_flags, }); let mut prim_list = PrimitiveList::empty(); // Web content often specifies `preserve-3d` on pages that don't actually need // a 3d rendering context (as a hint / hack to convince other browsers to // layerize these elements to an off-screen surface). Detect cases where the // preserve-3d has no effect on correctness and convert them to pass-through // pictures instead. This has two benefits for WR: // // (1) We get correct subpixel-snapping behavior between preserve-3d elements // that don't have complex transforms without additional complexity of // handling subpixel-snapping across different surfaces. // (2) We can draw this content directly in to the parent surface / tile cache, // which is a performance win by avoiding allocating, drawing, // plane-splitting and blitting an off-screen surface. let mut needs_3d_context = false; for ext_prim in prims.drain(..) { // If all the preserve-3d elements are in the root coordinate system, we // know that there is no need for a true 3d rendering context / plane-split. // TODO(gw): We can expand this in future to handle this in more cases // (e.g. a non-root coord system that is 2d within the 3d context). if !self.spatial_tree.is_root_coord_system(ext_prim.spatial_node_index) { needs_3d_context = true; } prim_list.add_prim( ext_prim.instance, LayoutRect::zero(), ext_prim.spatial_node_index, ext_prim.flags, &mut self.prim_instances, &self.clip_tree_builder, ); } let context_3d = if needs_3d_context { Picture3DContext::In { root_data: Some(Vec::new()), ancestor_index, plane_splitter_index, } } else { // If we didn't need a 3d rendering context, walk the child pictures // that make up this context and disable the off-screen surface and // 3d render context. for child_pic_index in &prim_list.child_pictures { let child_pic = &mut self.prim_store.pictures[child_pic_index.0]; child_pic.composite_mode = None; child_pic.context_3d = Picture3DContext::Out; } Picture3DContext::Out }; // This is the acttual picture representing our 3D hierarchy root. let pic_index = PictureIndex(self.prim_store.pictures .alloc() .init(PicturePrimitive::new_image( None, context_3d, stacking_context.prim_flags, prim_list, stacking_context.spatial_node_index, stacking_context.raster_space, PictureFlags::empty(), )) ); let instance = create_prim_instance( pic_index, PictureCompositeKey::Identity, stacking_context.raster_space, stacking_context.clip_node_id, &mut self.interners, &mut self.clip_tree_builder, ); source = PictureChainBuilder::from_instance( instance, stacking_context.prim_flags, stacking_context.spatial_node_index, stacking_context.raster_space, ); } let has_filters = stacking_context.composite_ops.has_valid_filters(); source = self.wrap_prim_with_filters( source, stacking_context.clip_node_id, stacking_context.composite_ops.filters, stacking_context.composite_ops.filter_primitives, stacking_context.composite_ops.filter_datas, None, ); // Same for mix-blend-mode, except we can skip if this primitive is the first in the parent // stacking context. // From https://drafts.fxtf.org/compositing-1/#generalformula, the formula for blending is: // Cs = (1 - ab) x Cs + ab x Blend(Cb, Cs) // where // Cs = Source color // ab = Backdrop alpha // Cb = Backdrop color // // If we're the first primitive within a stacking context, then we can guarantee that the // backdrop alpha will be 0, and then the blend equation collapses to just // Cs = Cs, and the blend mode isn't taken into account at all. if let Some(mix_blend_mode) = stacking_context.composite_ops.mix_blend_mode { let composite_mode = PictureCompositeMode::MixBlend(mix_blend_mode); source = source.add_picture( composite_mode, stacking_context.clip_node_id, Picture3DContext::Out, &mut self.interners, &mut self.prim_store, &mut self.prim_instances, &mut self.clip_tree_builder, ); } // Set the stacking context clip on the outermost picture in the chain, // unless we already set it on the leaf picture. let cur_instance = source.finalize( stacking_context.clip_node_id, &mut self.interners, &mut self.prim_store, &mut self.clip_tree_builder, ); // The primitive instance for the remainder of flat children of this SC // if it's a part of 3D hierarchy but not the root of it. let trailing_children_instance = match self.sc_stack.last_mut() { // Preserve3D path (only relevant if there are no filters/mix-blend modes) Some(ref parent_sc) if !has_filters && parent_sc.is_3d() => { Some(cur_instance) } // Regular parenting path Some(ref mut parent_sc) => { parent_sc.prim_list.add_prim( cur_instance, LayoutRect::zero(), stacking_context.spatial_node_index, stacking_context.prim_flags, &mut self.prim_instances, &self.clip_tree_builder, ); None } // This must be the root stacking context None => { self.add_primitive_to_draw_list( cur_instance, LayoutRect::zero(), stacking_context.spatial_node_index, stacking_context.prim_flags, ); None } }; // finally, if there any outstanding 3D primitive instances, // find the 3D hierarchy root and add them there. if let Some(instance) = trailing_children_instance { self.add_primitive_instance_to_3d_root(ExtendedPrimitiveInstance { instance, spatial_node_index: stacking_context.spatial_node_index, flags: stacking_context.prim_flags, }); } assert!( self.pending_shadow_items.is_empty(), "Found unpopped shadows when popping stacking context!" ); } pub fn push_reference_frame( &mut self, reference_frame_id: SpatialId, parent_index: SpatialNodeIndex, pipeline_id: PipelineId, transform_style: TransformStyle, source_transform: PropertyBinding, kind: ReferenceFrameKind, origin_in_parent_reference_frame: LayoutVector2D, uid: SpatialNodeUid, ) -> SpatialNodeIndex { let index = self.spatial_tree.add_reference_frame( parent_index, transform_style, source_transform, kind, origin_in_parent_reference_frame, pipeline_id, uid, ); self.id_to_index_mapper_stack.last_mut().unwrap().add_spatial_node(reference_frame_id, index); index } fn push_root( &mut self, pipeline_id: PipelineId, instance: PipelineInstanceId, ) { let spatial_node_index = self.push_reference_frame( SpatialId::root_reference_frame(pipeline_id), self.spatial_tree.root_reference_frame_index(), pipeline_id, TransformStyle::Flat, PropertyBinding::Value(LayoutTransform::identity()), ReferenceFrameKind::Transform { is_2d_scale_translation: true, should_snap: true, paired_with_perspective: false, }, LayoutVector2D::zero(), SpatialNodeUid::root_reference_frame(pipeline_id, instance), ); let viewport_rect = LayoutRect::max_rect(); self.add_scroll_frame( SpatialId::root_scroll_node(pipeline_id), spatial_node_index, ExternalScrollId(0, pipeline_id), pipeline_id, &viewport_rect, &viewport_rect.size(), ScrollFrameKind::PipelineRoot { is_root_pipeline: true, }, LayoutVector2D::zero(), APZScrollGeneration::default(), HasScrollLinkedEffect::No, SpatialNodeUid::root_scroll_frame(pipeline_id, instance), ); } fn add_image_mask_clip_node( &mut self, new_node_id: ClipId, spatial_id: SpatialId, image_mask: &ImageMask, fill_rule: FillRule, points_range: ItemRange, ) { let spatial_node_index = self.get_space(spatial_id); let snapped_mask_rect = self.snap_rect( &image_mask.rect, spatial_node_index, ); let points: Vec = points_range.iter().collect(); // If any points are provided, then intern a polygon with the points and fill rule. let mut polygon_handle: Option = None; if points.len() > 0 { let item = PolygonKey::new(&points, fill_rule); let handle = self .interners .polygon .intern(&item, || item); polygon_handle = Some(handle); } let item = ClipItemKey { kind: ClipItemKeyKind::image_mask(image_mask, snapped_mask_rect, polygon_handle), spatial_node_index, }; let handle = self .interners .clip .intern(&item, || { ClipInternData { key: item, } }); self.clip_tree_builder.define_image_mask_clip( new_node_id, handle, ); } /// Add a new rectangle clip, positioned by the spatial node in the `space_and_clip`. fn add_rect_clip_node( &mut self, new_node_id: ClipId, spatial_id: SpatialId, clip_rect: &LayoutRect, ) { let spatial_node_index = self.get_space(spatial_id); let snapped_clip_rect = self.snap_rect( clip_rect, spatial_node_index, ); let item = ClipItemKey { kind: ClipItemKeyKind::rectangle(snapped_clip_rect, ClipMode::Clip), spatial_node_index, }; let handle = self .interners .clip .intern(&item, || { ClipInternData { key: item, } }); self.clip_tree_builder.define_rect_clip( new_node_id, handle, ); } fn add_rounded_rect_clip_node( &mut self, new_node_id: ClipId, spatial_id: SpatialId, clip: &ComplexClipRegion, ) { let spatial_node_index = self.get_space(spatial_id); let snapped_region_rect = self.snap_rect( &clip.rect, spatial_node_index, ); let item = ClipItemKey { kind: ClipItemKeyKind::rounded_rect( snapped_region_rect, clip.radii, clip.mode, ), spatial_node_index, }; let handle = self .interners .clip .intern(&item, || { ClipInternData { key: item, } }); self.clip_tree_builder.define_rounded_rect_clip( new_node_id, handle, ); } pub fn add_scroll_frame( &mut self, new_node_id: SpatialId, parent_node_index: SpatialNodeIndex, external_id: ExternalScrollId, pipeline_id: PipelineId, frame_rect: &LayoutRect, content_size: &LayoutSize, frame_kind: ScrollFrameKind, external_scroll_offset: LayoutVector2D, scroll_offset_generation: APZScrollGeneration, has_scroll_linked_effect: HasScrollLinkedEffect, uid: SpatialNodeUid, ) -> SpatialNodeIndex { let node_index = self.spatial_tree.add_scroll_frame( parent_node_index, external_id, pipeline_id, frame_rect, content_size, frame_kind, external_scroll_offset, scroll_offset_generation, has_scroll_linked_effect, uid, ); self.id_to_index_mapper_stack.last_mut().unwrap().add_spatial_node(new_node_id, node_index); node_index } pub fn push_shadow( &mut self, shadow: Shadow, spatial_node_index: SpatialNodeIndex, clip_chain_id: api::ClipChainId, should_inflate: bool, ) { self.clip_tree_builder.push_clip_chain(Some(clip_chain_id), false); // Store this shadow in the pending list, for processing // during pop_all_shadows. self.pending_shadow_items.push_back(ShadowItem::Shadow(PendingShadow { shadow, spatial_node_index, should_inflate, })); } pub fn pop_all_shadows( &mut self, ) { assert!(!self.pending_shadow_items.is_empty(), "popped shadows, but none were present"); let mut items = mem::replace(&mut self.pending_shadow_items, VecDeque::new()); // // The pending_shadow_items queue contains a list of shadows and primitives // that were pushed during the active shadow context. To process these, we: // // Iterate the list, popping an item from the front each iteration. // // If the item is a shadow: // - Create a shadow picture primitive. // - Add *any* primitives that remain in the item list to this shadow. // If the item is a primitive: // - Add that primitive as a normal item (if alpha > 0) // while let Some(item) = items.pop_front() { match item { ShadowItem::Shadow(pending_shadow) => { // Quote from https://drafts.csswg.org/css-backgrounds-3/#shadow-blur // "the image that would be generated by applying to the shadow a // Gaussian blur with a standard deviation equal to half the blur radius." let std_deviation = pending_shadow.shadow.blur_radius * 0.5; // Add any primitives that come after this shadow in the item // list to this shadow. let mut prim_list = PrimitiveList::empty(); let blur_filter = Filter::Blur { width: std_deviation, height: std_deviation, should_inflate: pending_shadow.should_inflate, }; let blur_is_noop = blur_filter.is_noop(); for item in &items { let (instance, info, spatial_node_index) = match item { ShadowItem::Image(ref pending_image) => { self.create_shadow_prim( &pending_shadow, pending_image, blur_is_noop, ) } ShadowItem::LineDecoration(ref pending_line_dec) => { self.create_shadow_prim( &pending_shadow, pending_line_dec, blur_is_noop, ) } ShadowItem::NormalBorder(ref pending_border) => { self.create_shadow_prim( &pending_shadow, pending_border, blur_is_noop, ) } ShadowItem::Primitive(ref pending_primitive) => { self.create_shadow_prim( &pending_shadow, pending_primitive, blur_is_noop, ) } ShadowItem::TextRun(ref pending_text_run) => { self.create_shadow_prim( &pending_shadow, pending_text_run, blur_is_noop, ) } _ => { continue; } }; if blur_is_noop { self.add_primitive_to_draw_list( instance, info.rect, spatial_node_index, info.flags, ); } else { prim_list.add_prim( instance, info.rect, spatial_node_index, info.flags, &mut self.prim_instances, &self.clip_tree_builder, ); } } // No point in adding a shadow here if there were no primitives // added to the shadow. if !prim_list.is_empty() { // Create a picture that the shadow primitives will be added to. If the // blur radius is 0, the code in Picture::prepare_for_render will // detect this and mark the picture to be drawn directly into the // parent picture, which avoids an intermediate surface and blur. assert!(!blur_filter.is_noop()); let composite_mode = Some(PictureCompositeMode::Filter(blur_filter)); let composite_mode_key = composite_mode.clone().into(); let raster_space = RasterSpace::Screen; // Create the primitive to draw the shadow picture into the scene. let shadow_pic_index = PictureIndex(self.prim_store.pictures .alloc() .init(PicturePrimitive::new_image( composite_mode, Picture3DContext::Out, PrimitiveFlags::IS_BACKFACE_VISIBLE, prim_list, pending_shadow.spatial_node_index, raster_space, PictureFlags::empty(), )) ); let shadow_pic_key = PictureKey::new( Picture { composite_mode_key, raster_space }, ); let shadow_prim_data_handle = self.interners .picture .intern(&shadow_pic_key, || ()); let clip_node_id = self.clip_tree_builder.build_clip_set(api::ClipChainId::INVALID); let shadow_prim_instance = PrimitiveInstance::new( PrimitiveInstanceKind::Picture { data_handle: shadow_prim_data_handle, pic_index: shadow_pic_index, segment_instance_index: SegmentInstanceIndex::INVALID, }, self.clip_tree_builder.build_for_picture(clip_node_id), ); // Add the shadow primitive. This must be done before pushing this // picture on to the shadow stack, to avoid infinite recursion! self.add_primitive_to_draw_list( shadow_prim_instance, LayoutRect::zero(), pending_shadow.spatial_node_index, PrimitiveFlags::IS_BACKFACE_VISIBLE, ); } self.clip_tree_builder.pop_clip(); } ShadowItem::Image(pending_image) => { self.add_shadow_prim_to_draw_list( pending_image, ) }, ShadowItem::LineDecoration(pending_line_dec) => { self.add_shadow_prim_to_draw_list( pending_line_dec, ) }, ShadowItem::NormalBorder(pending_border) => { self.add_shadow_prim_to_draw_list( pending_border, ) }, ShadowItem::Primitive(pending_primitive) => { self.add_shadow_prim_to_draw_list( pending_primitive, ) }, ShadowItem::TextRun(pending_text_run) => { self.add_shadow_prim_to_draw_list( pending_text_run, ) }, } } debug_assert!(items.is_empty()); self.pending_shadow_items = items; } fn create_shadow_prim

( &mut self, pending_shadow: &PendingShadow, pending_primitive: &PendingPrimitive

, blur_is_noop: bool, ) -> (PrimitiveInstance, LayoutPrimitiveInfo, SpatialNodeIndex) where P: InternablePrimitive + CreateShadow, Interners: AsMut>, { // Offset the local rect and clip rect by the shadow offset. The pending // primitive has already been snapped, but we will need to snap the // shadow after translation. We don't need to worry about the size // changing because the shadow has the same raster space as the // primitive, and thus we know the size is already rounded. let mut info = pending_primitive.info.clone(); info.rect = info.rect.translate(pending_shadow.shadow.offset); info.clip_rect = info.clip_rect.translate(pending_shadow.shadow.offset); let clip_set = self.clip_tree_builder.build_for_prim( pending_primitive.clip_node_id, &info, &[], &mut self.interners, ); // Construct and add a primitive for the given shadow. let shadow_prim_instance = self.create_primitive( &info, pending_primitive.spatial_node_index, clip_set, pending_primitive.prim.create_shadow( &pending_shadow.shadow, blur_is_noop, self.raster_space_stack.last().cloned().unwrap(), ), ); (shadow_prim_instance, info, pending_primitive.spatial_node_index) } fn add_shadow_prim_to_draw_list

( &mut self, pending_primitive: PendingPrimitive

, ) where P: InternablePrimitive + IsVisible, Interners: AsMut>, { // For a normal primitive, if it has alpha > 0, then we add this // as a normal primitive to the parent picture. if pending_primitive.prim.is_visible() { let clip_set = self.clip_tree_builder.build_for_prim( pending_primitive.clip_node_id, &pending_primitive.info, &[], &mut self.interners, ); self.add_prim_to_draw_list( &pending_primitive.info, pending_primitive.spatial_node_index, clip_set, pending_primitive.prim, ); } } pub fn add_clear_rectangle( &mut self, spatial_node_index: SpatialNodeIndex, clip_node_id: ClipNodeId, info: &LayoutPrimitiveInfo, ) { // Clear prims must be in their own picture cache slice to // be composited correctly. self.add_tile_cache_barrier_if_needed(SliceFlags::empty()); self.add_primitive( spatial_node_index, clip_node_id, info, Vec::new(), PrimitiveKeyKind::Clear, ); self.add_tile_cache_barrier_if_needed(SliceFlags::empty()); } pub fn add_line( &mut self, spatial_node_index: SpatialNodeIndex, clip_node_id: ClipNodeId, info: &LayoutPrimitiveInfo, wavy_line_thickness: f32, orientation: LineOrientation, color: ColorF, style: LineStyle, ) { // For line decorations, we can construct the render task cache key // here during scene building, since it doesn't depend on device // pixel ratio or transform. let size = get_line_decoration_size( &info.rect.size(), orientation, style, wavy_line_thickness, ); let cache_key = size.map(|size| { LineDecorationCacheKey { style, orientation, wavy_line_thickness: Au::from_f32_px(wavy_line_thickness), size: size.to_au(), } }); self.add_primitive( spatial_node_index, clip_node_id, &info, Vec::new(), LineDecoration { cache_key, color: color.into(), }, ); } pub fn add_border( &mut self, spatial_node_index: SpatialNodeIndex, clip_node_id: ClipNodeId, info: &LayoutPrimitiveInfo, border_item: &BorderDisplayItem, gradient_stops: ItemRange, ) { match border_item.details { BorderDetails::NinePatch(ref border) => { let nine_patch = NinePatchDescriptor { width: border.width, height: border.height, slice: border.slice, fill: border.fill, repeat_horizontal: border.repeat_horizontal, repeat_vertical: border.repeat_vertical, widths: border_item.widths.into(), }; match border.source { NinePatchBorderSource::Image(key, rendering) => { let prim = ImageBorder { request: ImageRequest { key, rendering, tile: None, }, nine_patch, }; self.add_nonshadowable_primitive( spatial_node_index, clip_node_id, info, Vec::new(), prim, ); } NinePatchBorderSource::Gradient(gradient) => { let prim = match self.create_linear_gradient_prim( &info, gradient.start_point, gradient.end_point, read_gradient_stops(gradient_stops), gradient.extend_mode, LayoutSize::new(border.height as f32, border.width as f32), LayoutSize::zero(), Some(Box::new(nine_patch)), EdgeAaSegmentMask::all(), ) { Some(prim) => prim, None => return, }; self.add_nonshadowable_primitive( spatial_node_index, clip_node_id, info, Vec::new(), prim, ); } NinePatchBorderSource::RadialGradient(gradient) => { let prim = self.create_radial_gradient_prim( &info, gradient.center, gradient.start_offset * gradient.radius.width, gradient.end_offset * gradient.radius.width, gradient.radius.width / gradient.radius.height, read_gradient_stops(gradient_stops), gradient.extend_mode, LayoutSize::new(border.height as f32, border.width as f32), LayoutSize::zero(), Some(Box::new(nine_patch)), ); self.add_nonshadowable_primitive( spatial_node_index, clip_node_id, info, Vec::new(), prim, ); } NinePatchBorderSource::ConicGradient(gradient) => { let prim = self.create_conic_gradient_prim( &info, gradient.center, gradient.angle, gradient.start_offset, gradient.end_offset, gradient_stops, gradient.extend_mode, LayoutSize::new(border.height as f32, border.width as f32), LayoutSize::zero(), Some(Box::new(nine_patch)), ); self.add_nonshadowable_primitive( spatial_node_index, clip_node_id, info, Vec::new(), prim, ); } }; } BorderDetails::Normal(ref border) => { self.add_normal_border( info, border, border_item.widths, spatial_node_index, clip_node_id, ); } } } pub fn create_linear_gradient_prim( &mut self, info: &LayoutPrimitiveInfo, start_point: LayoutPoint, end_point: LayoutPoint, stops: Vec, extend_mode: ExtendMode, stretch_size: LayoutSize, mut tile_spacing: LayoutSize, nine_patch: Option>, edge_aa_mask: EdgeAaSegmentMask, ) -> Option { let mut prim_rect = info.rect; simplify_repeated_primitive(&stretch_size, &mut tile_spacing, &mut prim_rect); let mut has_hard_stops = false; let mut is_entirely_transparent = true; let mut prev_stop = None; for stop in &stops { if Some(stop.offset) == prev_stop { has_hard_stops = true; } prev_stop = Some(stop.offset); if stop.color.a > 0 { is_entirely_transparent = false; } } // If all the stops have no alpha, then this // gradient can't contribute to the scene. if is_entirely_transparent { return None; } // Try to ensure that if the gradient is specified in reverse, then so long as the stops // are also supplied in reverse that the rendered result will be equivalent. To do this, // a reference orientation for the gradient line must be chosen, somewhat arbitrarily, so // just designate the reference orientation as start < end. Aligned gradient rendering // manages to produce the same result regardless of orientation, so don't worry about // reversing in that case. let reverse_stops = start_point.x > end_point.x || (start_point.x == end_point.x && start_point.y > end_point.y); // To get reftests exactly matching with reverse start/end // points, it's necessary to reverse the gradient // line in some cases. let (sp, ep) = if reverse_stops { (end_point, start_point) } else { (start_point, end_point) }; // We set a limit to the resolution at which cached gradients are rendered. // For most gradients this is fine but when there are hard stops this causes // noticeable artifacts. If so, fall back to non-cached gradients. let max = gradient::LINEAR_MAX_CACHED_SIZE; let caching_causes_artifacts = has_hard_stops && (stretch_size.width > max || stretch_size.height > max); let is_tiled = prim_rect.width() > stretch_size.width || prim_rect.height() > stretch_size.height; // SWGL has a fast-path that can render gradients faster than it can sample from the // texture cache so we disable caching in this configuration. Cached gradients are // faster on hardware. let cached = (!self.config.is_software || is_tiled) && !caching_causes_artifacts; Some(LinearGradient { extend_mode, start_point: sp.into(), end_point: ep.into(), stretch_size: stretch_size.into(), tile_spacing: tile_spacing.into(), stops, reverse_stops, nine_patch, cached, edge_aa_mask, }) } pub fn create_radial_gradient_prim( &mut self, info: &LayoutPrimitiveInfo, center: LayoutPoint, start_radius: f32, end_radius: f32, ratio_xy: f32, stops: Vec, extend_mode: ExtendMode, stretch_size: LayoutSize, mut tile_spacing: LayoutSize, nine_patch: Option>, ) -> RadialGradient { let mut prim_rect = info.rect; simplify_repeated_primitive(&stretch_size, &mut tile_spacing, &mut prim_rect); let params = RadialGradientParams { start_radius, end_radius, ratio_xy, }; RadialGradient { extend_mode, center: center.into(), params, stretch_size: stretch_size.into(), tile_spacing: tile_spacing.into(), nine_patch, stops, } } pub fn create_conic_gradient_prim( &mut self, info: &LayoutPrimitiveInfo, center: LayoutPoint, angle: f32, start_offset: f32, end_offset: f32, stops: ItemRange, extend_mode: ExtendMode, stretch_size: LayoutSize, mut tile_spacing: LayoutSize, nine_patch: Option>, ) -> ConicGradient { let mut prim_rect = info.rect; simplify_repeated_primitive(&stretch_size, &mut tile_spacing, &mut prim_rect); let stops = stops.iter().map(|stop| { GradientStopKey { offset: stop.offset, color: stop.color.into(), } }).collect(); ConicGradient { extend_mode, center: center.into(), params: ConicGradientParams { angle, start_offset, end_offset }, stretch_size: stretch_size.into(), tile_spacing: tile_spacing.into(), nine_patch, stops, } } pub fn add_text( &mut self, spatial_node_index: SpatialNodeIndex, clip_node_id: ClipNodeId, prim_info: &LayoutPrimitiveInfo, font_instance_key: &FontInstanceKey, text_color: &ColorF, glyph_range: ItemRange, glyph_options: Option, ) { let offset = self.current_offset(spatial_node_index); let text_run = { let shared_key = self.fonts.instance_keys.map_key(font_instance_key); let font_instance = match self.fonts.instances.get_font_instance(shared_key) { Some(instance) => instance, None => { warn!("Unknown font instance key"); debug!("key={:?} shared={:?}", font_instance_key, shared_key); return; } }; // Trivial early out checks if font_instance.size <= FontSize::zero() { return; } // TODO(gw): Use a proper algorithm to select // whether this item should be rendered with // subpixel AA! let mut render_mode = self.config .default_font_render_mode .limit_by(font_instance.render_mode); let mut flags = font_instance.flags; if let Some(options) = glyph_options { render_mode = render_mode.limit_by(options.render_mode); flags |= options.flags; } let font = FontInstance::new( font_instance, (*text_color).into(), render_mode, flags, ); // TODO(gw): It'd be nice not to have to allocate here for creating // the primitive key, when the common case is that the // hash will match and we won't end up creating a new // primitive template. let prim_offset = prim_info.rect.min.to_vector() - offset; let glyphs = glyph_range .iter() .map(|glyph| { GlyphInstance { index: glyph.index, point: glyph.point - prim_offset, } }) .collect(); // Query the current requested raster space (stack handled by push/pop // stacking context). let requested_raster_space = self.raster_space_stack .last() .cloned() .unwrap(); TextRun { glyphs: Arc::new(glyphs), font, shadow: false, requested_raster_space, } }; self.add_primitive( spatial_node_index, clip_node_id, prim_info, Vec::new(), text_run, ); } pub fn add_image( &mut self, spatial_node_index: SpatialNodeIndex, clip_node_id: ClipNodeId, info: &LayoutPrimitiveInfo, stretch_size: LayoutSize, mut tile_spacing: LayoutSize, image_key: ImageKey, image_rendering: ImageRendering, alpha_type: AlphaType, color: ColorF, ) { let mut prim_rect = info.rect; simplify_repeated_primitive(&stretch_size, &mut tile_spacing, &mut prim_rect); let info = LayoutPrimitiveInfo { rect: prim_rect, .. *info }; self.add_primitive( spatial_node_index, clip_node_id, &info, Vec::new(), Image { key: image_key, tile_spacing: tile_spacing.into(), stretch_size: stretch_size.into(), color: color.into(), image_rendering, alpha_type, }, ); } pub fn add_yuv_image( &mut self, spatial_node_index: SpatialNodeIndex, clip_node_id: ClipNodeId, info: &LayoutPrimitiveInfo, yuv_data: YuvData, color_depth: ColorDepth, color_space: YuvColorSpace, color_range: ColorRange, image_rendering: ImageRendering, ) { let format = yuv_data.get_format(); let yuv_key = match yuv_data { YuvData::NV12(plane_0, plane_1) => [plane_0, plane_1, ImageKey::DUMMY], YuvData::P010(plane_0, plane_1) => [plane_0, plane_1, ImageKey::DUMMY], YuvData::PlanarYCbCr(plane_0, plane_1, plane_2) => [plane_0, plane_1, plane_2], YuvData::InterleavedYCbCr(plane_0) => [plane_0, ImageKey::DUMMY, ImageKey::DUMMY], }; self.add_nonshadowable_primitive( spatial_node_index, clip_node_id, info, Vec::new(), YuvImage { color_depth, yuv_key, format, color_space, color_range, image_rendering, }, ); } fn add_primitive_instance_to_3d_root( &mut self, prim: ExtendedPrimitiveInstance, ) { // find the 3D root and append to the children list for sc in self.sc_stack.iter_mut().rev() { match sc.context_3d { Picture3DContext::In { root_data: Some(ref mut prims), .. } => { prims.push(prim); break; } Picture3DContext::In { .. } => {} Picture3DContext::Out => panic!("Unable to find 3D root"), } } } #[allow(dead_code)] pub fn add_backdrop_filter( &mut self, spatial_node_index: SpatialNodeIndex, clip_node_id: ClipNodeId, info: &LayoutPrimitiveInfo, filters: Vec, filter_datas: Vec, filter_primitives: Vec, ) { // We don't know the spatial node for a backdrop filter, as it's whatever is the // backdrop root, but we can't know this if the root is a picture cache slice // (which is the common case). It will get resolved later during `finalize_picture`. let filter_spatial_node_index = SpatialNodeIndex::UNKNOWN; self.make_current_slice_atomic_if_required(); // Ensure we create a clip-chain for the capture primitive that matches // the render primitive, otherwise one might get culled while the other // is considered visible. let clip_leaf_id = self.clip_tree_builder.build_for_prim( clip_node_id, info, &[], &mut self.interners, ); // Create the backdrop prim - this is a placeholder which sets the size of resolve // picture that reads from the backdrop root let backdrop_capture_instance = self.create_primitive( info, spatial_node_index, clip_leaf_id, BackdropCapture { }, ); // Create a prim_list for this backdrop prim and add to a picture chain builder, which // is needed for the call to `wrap_prim_with_filters` below let mut prim_list = PrimitiveList::empty(); prim_list.add_prim( backdrop_capture_instance, info.rect, spatial_node_index, info.flags, &mut self.prim_instances, &self.clip_tree_builder, ); let mut source = PictureChainBuilder::from_prim_list( prim_list, info.flags, filter_spatial_node_index, RasterSpace::Screen, true, ); // Wrap the backdrop primitive picture with the filters that were specified. This // produces a picture chain with 1+ pictures with the filter composite modes set. source = self.wrap_prim_with_filters( source, clip_node_id, filters, filter_primitives, filter_datas, Some(false), ); // If all the filters were no-ops (e.g. opacity(0)) then we don't get a picture here // and we can skip adding the backdrop-filter. if source.has_picture() { source = source.add_picture( PictureCompositeMode::IntermediateSurface, clip_node_id, Picture3DContext::Out, &mut self.interners, &mut self.prim_store, &mut self.prim_instances, &mut self.clip_tree_builder, ); let filtered_instance = source.finalize( clip_node_id, &mut self.interners, &mut self.prim_store, &mut self.clip_tree_builder, ); // Extract the pic index for the intermediate surface. We need to // supply this to the capture prim below. let output_pic_index = match filtered_instance.kind { PrimitiveInstanceKind::Picture { pic_index, .. } => pic_index, _ => panic!("bug: not a picture"), }; // Find which stacking context (or root tile cache) to add the // backdrop-filter chain to let sc_index = self.sc_stack.iter().rposition(|sc| { !sc.flags.contains(StackingContextFlags::WRAPS_BACKDROP_FILTER) }); match sc_index { Some(sc_index) => { self.sc_stack[sc_index].prim_list.add_prim( filtered_instance, info.rect, filter_spatial_node_index, info.flags, &mut self.prim_instances, &self.clip_tree_builder, ); } None => { self.tile_cache_builder.add_prim( filtered_instance, info.rect, filter_spatial_node_index, info.flags, self.spatial_tree, self.interners, &self.quality_settings, &mut self.prim_instances, &self.clip_tree_builder, ); } } // Add the prim that renders the result of the backdrop filter chain let mut backdrop_render_instance = self.create_primitive( info, spatial_node_index, clip_leaf_id, BackdropRender { }, ); // Set up the picture index for the backdrop-filter output in the prim // that will draw it match backdrop_render_instance.kind { PrimitiveInstanceKind::BackdropRender { ref mut pic_index, .. } => { assert_eq!(*pic_index, PictureIndex::INVALID); *pic_index = output_pic_index; } _ => panic!("bug: unexpected prim kind"), } self.add_primitive_to_draw_list( backdrop_render_instance, info.rect, spatial_node_index, info.flags, ); } } #[must_use] fn wrap_prim_with_filters( &mut self, mut source: PictureChainBuilder, clip_node_id: ClipNodeId, mut filter_ops: Vec, mut filter_primitives: Vec, filter_datas: Vec, should_inflate_override: Option, ) -> PictureChainBuilder { // TODO(cbrewster): Currently CSS and SVG filters live side by side in WebRender, but unexpected results will // happen if they are used simulataneously. Gecko only provides either filter ops or filter primitives. // At some point, these two should be combined and CSS filters should be expressed in terms of SVG filters. assert!(filter_ops.is_empty() || filter_primitives.is_empty(), "Filter ops and filter primitives are not allowed on the same stacking context."); // For each filter, create a new image with that composite mode. let mut current_filter_data_index = 0; for filter in &mut filter_ops { let composite_mode = match filter { Filter::ComponentTransfer => { let filter_data = &filter_datas[current_filter_data_index]; let filter_data = filter_data.sanitize(); current_filter_data_index = current_filter_data_index + 1; if filter_data.is_identity() { continue } else { let filter_data_key = SFilterDataKey { data: SFilterData { r_func: SFilterDataComponent::from_functype_values( filter_data.func_r_type, &filter_data.r_values), g_func: SFilterDataComponent::from_functype_values( filter_data.func_g_type, &filter_data.g_values), b_func: SFilterDataComponent::from_functype_values( filter_data.func_b_type, &filter_data.b_values), a_func: SFilterDataComponent::from_functype_values( filter_data.func_a_type, &filter_data.a_values), }, }; let handle = self.interners .filter_data .intern(&filter_data_key, || ()); PictureCompositeMode::ComponentTransferFilter(handle) } } _ => { if filter.is_noop() { continue; } else { let mut filter = filter.clone(); // backdrop-filter spec says that blurs should assume edgeMode=Duplicate // We can do this by not inflating the bounds, which means the blur // shader will duplicate pixels outside the sample rect if let Some(should_inflate_override) = should_inflate_override { if let Filter::Blur { ref mut should_inflate, .. } = filter { *should_inflate = should_inflate_override; } } PictureCompositeMode::Filter(filter) } } }; source = source.add_picture( composite_mode, clip_node_id, Picture3DContext::Out, &mut self.interners, &mut self.prim_store, &mut self.prim_instances, &mut self.clip_tree_builder, ); } if !filter_primitives.is_empty() { let filter_datas = filter_datas.iter() .map(|filter_data| filter_data.sanitize()) .map(|filter_data| { SFilterData { r_func: SFilterDataComponent::from_functype_values( filter_data.func_r_type, &filter_data.r_values), g_func: SFilterDataComponent::from_functype_values( filter_data.func_g_type, &filter_data.g_values), b_func: SFilterDataComponent::from_functype_values( filter_data.func_b_type, &filter_data.b_values), a_func: SFilterDataComponent::from_functype_values( filter_data.func_a_type, &filter_data.a_values), } }) .collect(); // Sanitize filter inputs for primitive in &mut filter_primitives { primitive.sanitize(); } let composite_mode = PictureCompositeMode::SvgFilter( filter_primitives, filter_datas, ); source = source.add_picture( composite_mode, clip_node_id, Picture3DContext::Out, &mut self.interners, &mut self.prim_store, &mut self.prim_instances, &mut self.clip_tree_builder, ); } source } } pub trait CreateShadow { fn create_shadow( &self, shadow: &Shadow, blur_is_noop: bool, current_raster_space: RasterSpace, ) -> Self; } pub trait IsVisible { fn is_visible(&self) -> bool; } /// A primitive instance + some extra information about the primitive. This is /// stored when constructing 3d rendering contexts, which involve cutting /// primitive lists. struct ExtendedPrimitiveInstance { instance: PrimitiveInstance, spatial_node_index: SpatialNodeIndex, flags: PrimitiveFlags, } /// Internal tracking information about the currently pushed stacking context. /// Used to track what operations need to happen when a stacking context is popped. struct StackingContextInfo { /// If true, pop and entry from the containing block stack. pop_containing_block: bool, /// If true, pop an entry from the flattened stacking context stack. pop_stacking_context: bool, /// If true, set a tile cache barrier when popping the stacking context. set_tile_cache_barrier: bool, } /// Properties of a stacking context that are maintained /// during creation of the scene. These structures are /// not persisted after the initial scene build. struct FlattenedStackingContext { /// The list of primitive instances added to this stacking context. prim_list: PrimitiveList, /// Primitive instance flags for compositing this stacking context prim_flags: PrimitiveFlags, /// The positioning node for this stacking context spatial_node_index: SpatialNodeIndex, /// The clip chain for this stacking context clip_node_id: ClipNodeId, /// The list of filters / mix-blend-mode for this /// stacking context. composite_ops: CompositeOps, /// Bitfield of reasons this stacking context needs to /// be an offscreen surface. blit_reason: BlitReason, /// CSS transform-style property. transform_style: TransformStyle, /// Defines the relationship to a preserve-3D hiearachy. context_3d: Picture3DContext, /// Flags identifying the type of container (among other things) this stacking context is flags: StackingContextFlags, /// Requested raster space for this stacking context raster_space: RasterSpace, } impl FlattenedStackingContext { /// Return true if the stacking context has a valid preserve-3d property pub fn is_3d(&self) -> bool { self.transform_style == TransformStyle::Preserve3D && self.composite_ops.is_empty() } /// Return true if the stacking context isn't needed. pub fn is_redundant( context_3d: &Picture3DContext, composite_ops: &CompositeOps, blit_reason: BlitReason, parent: Option<&FlattenedStackingContext>, prim_flags: PrimitiveFlags, ) -> bool { // Any 3d context is required if let Picture3DContext::In { .. } = context_3d { return false; } // If any filters are present that affect the output if composite_ops.has_valid_filters() { return false; } // If a mix-blend is active, we'll need to apply it in most cases if composite_ops.mix_blend_mode.is_some() { match parent { Some(ref parent) => { // However, if the parent stacking context is empty, then the mix-blend // is a no-op, and we can skip it if !parent.prim_list.is_empty() { return false; } } None => { // TODO(gw): For now, we apply mix-blend ops that may be no-ops on a root // level picture cache slice. We could apply a similar optimization // to above with a few extra checks here, but it's probably quite rare. return false; } } } // If need to isolate in surface due to clipping / mix-blend-mode if !blit_reason.is_empty() { return false; } // If backface visibility is explicitly set. if !prim_flags.contains(PrimitiveFlags::IS_BACKFACE_VISIBLE) { return false; } // It is redundant! true } /// Cut the sequence of the immediate children recorded so far and generate a picture from them. pub fn cut_item_sequence( &mut self, prim_store: &mut PrimitiveStore, interners: &mut Interners, composite_mode: Option, flat_items_context_3d: Picture3DContext, clip_tree_builder: &mut ClipTreeBuilder, ) -> Option<(PictureIndex, PrimitiveInstance)> { if self.prim_list.is_empty() { return None } let pic_index = PictureIndex(prim_store.pictures .alloc() .init(PicturePrimitive::new_image( composite_mode.clone(), flat_items_context_3d, self.prim_flags, mem::replace(&mut self.prim_list, PrimitiveList::empty()), self.spatial_node_index, self.raster_space, PictureFlags::empty(), )) ); let prim_instance = create_prim_instance( pic_index, composite_mode.into(), self.raster_space, self.clip_node_id, interners, clip_tree_builder, ); Some((pic_index, prim_instance)) } } /// A primitive that is added while a shadow context is /// active is stored as a pending primitive and only /// added to pictures during pop_all_shadows. pub struct PendingPrimitive { spatial_node_index: SpatialNodeIndex, clip_node_id: ClipNodeId, info: LayoutPrimitiveInfo, prim: T, } /// As shadows are pushed, they are stored as pending /// shadows, and handled at once during pop_all_shadows. pub struct PendingShadow { shadow: Shadow, should_inflate: bool, spatial_node_index: SpatialNodeIndex, } pub enum ShadowItem { Shadow(PendingShadow), Image(PendingPrimitive), LineDecoration(PendingPrimitive), NormalBorder(PendingPrimitive), Primitive(PendingPrimitive), TextRun(PendingPrimitive), } impl From> for ShadowItem { fn from(image: PendingPrimitive) -> Self { ShadowItem::Image(image) } } impl From> for ShadowItem { fn from(line_dec: PendingPrimitive) -> Self { ShadowItem::LineDecoration(line_dec) } } impl From> for ShadowItem { fn from(border: PendingPrimitive) -> Self { ShadowItem::NormalBorder(border) } } impl From> for ShadowItem { fn from(container: PendingPrimitive) -> Self { ShadowItem::Primitive(container) } } impl From> for ShadowItem { fn from(text_run: PendingPrimitive) -> Self { ShadowItem::TextRun(text_run) } } fn create_prim_instance( pic_index: PictureIndex, composite_mode_key: PictureCompositeKey, raster_space: RasterSpace, clip_node_id: ClipNodeId, interners: &mut Interners, clip_tree_builder: &mut ClipTreeBuilder, ) -> PrimitiveInstance { let pic_key = PictureKey::new( Picture { composite_mode_key, raster_space, }, ); let data_handle = interners .picture .intern(&pic_key, || ()); PrimitiveInstance::new( PrimitiveInstanceKind::Picture { data_handle, pic_index, segment_instance_index: SegmentInstanceIndex::INVALID, }, clip_tree_builder.build_for_picture( clip_node_id, ), ) } fn filter_ops_for_compositing( input_filters: ItemRange, ) -> Vec { // TODO(gw): Now that we resolve these later on, // we could probably make it a bit // more efficient than cloning these here. input_filters.iter().map(|filter| filter.into()).collect() } fn filter_datas_for_compositing( input_filter_datas: &[TempFilterData], ) -> Vec { // TODO(gw): Now that we resolve these later on, // we could probably make it a bit // more efficient than cloning these here. let mut filter_datas = vec![]; for temp_filter_data in input_filter_datas { let func_types : Vec = temp_filter_data.func_types.iter().collect(); debug_assert!(func_types.len() == 4); filter_datas.push( FilterData { func_r_type: func_types[0], r_values: temp_filter_data.r_values.iter().collect(), func_g_type: func_types[1], g_values: temp_filter_data.g_values.iter().collect(), func_b_type: func_types[2], b_values: temp_filter_data.b_values.iter().collect(), func_a_type: func_types[3], a_values: temp_filter_data.a_values.iter().collect(), }); } filter_datas } fn filter_primitives_for_compositing( input_filter_primitives: ItemRange, ) -> Vec { // Resolve these in the flattener? // TODO(gw): Now that we resolve these later on, // we could probably make it a bit // more efficient than cloning these here. input_filter_primitives.iter().map(|primitive| primitive).collect() } fn process_repeat_size( snapped_rect: &LayoutRect, unsnapped_rect: &LayoutRect, repeat_size: LayoutSize, ) -> LayoutSize { // FIXME(aosmond): The tile size is calculated based on several parameters // during display list building. It may produce a slightly different result // than the bounds due to floating point error accumulation, even though in // theory they should be the same. We do a fuzzy check here to paper over // that. It may make more sense to push the original parameters into scene // building and let it do a saner calculation with more information (e.g. // the snapped values). const EPSILON: f32 = 0.001; LayoutSize::new( if repeat_size.width.approx_eq_eps(&unsnapped_rect.width(), &EPSILON) { snapped_rect.width() } else { repeat_size.width }, if repeat_size.height.approx_eq_eps(&unsnapped_rect.height(), &EPSILON) { snapped_rect.height() } else { repeat_size.height }, ) } fn read_gradient_stops(stops: ItemRange) -> Vec { stops.iter().map(|stop| { GradientStopKey { offset: stop.offset, color: stop.color.into(), } }).collect() }