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Diffstat (limited to 'gfx/wr/webrender/src/prim_store/gradient/linear.rs')
-rw-r--r-- | gfx/wr/webrender/src/prim_store/gradient/linear.rs | 750 |
1 files changed, 750 insertions, 0 deletions
diff --git a/gfx/wr/webrender/src/prim_store/gradient/linear.rs b/gfx/wr/webrender/src/prim_store/gradient/linear.rs new file mode 100644 index 0000000000..85da4b670a --- /dev/null +++ b/gfx/wr/webrender/src/prim_store/gradient/linear.rs @@ -0,0 +1,750 @@ +/* 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/. */ + +//! Linear gradients +//! +//! Specification: https://drafts.csswg.org/css-images-4/#linear-gradients +//! +//! Linear gradients are rendered via cached render tasks and composited with the image brush. + +use euclid::approxeq::ApproxEq; +use euclid::{point2, vec2, size2}; +use api::{ExtendMode, GradientStop, LineOrientation, PremultipliedColorF, ColorF, ColorU}; +use api::units::*; +use crate::scene_building::IsVisible; +use crate::frame_builder::FrameBuildingState; +use crate::intern::{Internable, InternDebug, Handle as InternHandle}; +use crate::internal_types::LayoutPrimitiveInfo; +use crate::image_tiling::simplify_repeated_primitive; +use crate::prim_store::{BrushSegment, GradientTileRange}; +use crate::prim_store::{PrimitiveInstanceKind, PrimitiveOpacity}; +use crate::prim_store::{PrimKeyCommonData, PrimTemplateCommonData, PrimitiveStore}; +use crate::prim_store::{NinePatchDescriptor, PointKey, SizeKey, InternablePrimitive}; +use crate::render_task::{RenderTask, RenderTaskKind}; +use crate::render_task_graph::RenderTaskId; +use crate::render_task_cache::{RenderTaskCacheKeyKind, RenderTaskCacheKey, RenderTaskParent}; +use crate::renderer::GpuBufferAddress; +use crate::segment::EdgeAaSegmentMask; +use crate::picture::{SurfaceIndex}; +use crate::util::pack_as_float; +use super::{stops_and_min_alpha, GradientStopKey, GradientGpuBlockBuilder, apply_gradient_local_clip}; +use std::ops::{Deref, DerefMut}; +use std::mem::swap; + +pub const MAX_CACHED_SIZE: f32 = 1024.0; + +/// Identifying key for a linear gradient. +#[cfg_attr(feature = "capture", derive(Serialize))] +#[cfg_attr(feature = "replay", derive(Deserialize))] +#[derive(Debug, Clone, Eq, PartialEq, Hash, MallocSizeOf)] +pub struct LinearGradientKey { + pub common: PrimKeyCommonData, + pub extend_mode: ExtendMode, + pub start_point: PointKey, + pub end_point: PointKey, + pub stretch_size: SizeKey, + pub tile_spacing: SizeKey, + pub stops: Vec<GradientStopKey>, + pub reverse_stops: bool, + pub cached: bool, + pub nine_patch: Option<Box<NinePatchDescriptor>>, + pub edge_aa_mask: EdgeAaSegmentMask, +} + +impl LinearGradientKey { + pub fn new( + info: &LayoutPrimitiveInfo, + linear_grad: LinearGradient, + ) -> Self { + LinearGradientKey { + common: info.into(), + extend_mode: linear_grad.extend_mode, + start_point: linear_grad.start_point, + end_point: linear_grad.end_point, + stretch_size: linear_grad.stretch_size, + tile_spacing: linear_grad.tile_spacing, + stops: linear_grad.stops, + reverse_stops: linear_grad.reverse_stops, + cached: linear_grad.cached, + nine_patch: linear_grad.nine_patch, + edge_aa_mask: linear_grad.edge_aa_mask, + } + } +} + +impl InternDebug for LinearGradientKey {} + +#[cfg_attr(feature = "capture", derive(Serialize))] +#[cfg_attr(feature = "replay", derive(Deserialize))] +#[derive(Debug, MallocSizeOf)] +pub struct LinearGradientTemplate { + pub common: PrimTemplateCommonData, + pub extend_mode: ExtendMode, + pub start_point: DevicePoint, + pub end_point: DevicePoint, + pub task_size: DeviceIntSize, + pub scale: DeviceVector2D, + pub stretch_size: LayoutSize, + pub tile_spacing: LayoutSize, + pub stops_opacity: PrimitiveOpacity, + pub stops: Vec<GradientStop>, + pub brush_segments: Vec<BrushSegment>, + pub reverse_stops: bool, + pub is_fast_path: bool, + pub cached: bool, + pub src_color: Option<RenderTaskId>, +} + +impl Deref for LinearGradientTemplate { + type Target = PrimTemplateCommonData; + fn deref(&self) -> &Self::Target { + &self.common + } +} + +impl DerefMut for LinearGradientTemplate { + fn deref_mut(&mut self) -> &mut Self::Target { + &mut self.common + } +} + +/// Perform a few optimizations to the gradient that are relevant to scene building. +/// +/// Returns true if the gradient was decomposed into fast-path primitives, indicating +/// that we shouldn't emit a regular gradient primitive after this returns. +pub fn optimize_linear_gradient( + prim_rect: &mut LayoutRect, + tile_size: &mut LayoutSize, + mut tile_spacing: LayoutSize, + clip_rect: &LayoutRect, + start: &mut LayoutPoint, + end: &mut LayoutPoint, + extend_mode: ExtendMode, + stops: &mut [GradientStopKey], + // Callback called for each fast-path segment (rect, start end, stops). + callback: &mut dyn FnMut(&LayoutRect, LayoutPoint, LayoutPoint, &[GradientStopKey], EdgeAaSegmentMask) +) -> bool { + // First sanitize the gradient parameters. See if we can remove repetitions, + // tighten the primitive bounds, etc. + + simplify_repeated_primitive(&tile_size, &mut tile_spacing, prim_rect); + + let vertical = start.x.approx_eq(&end.x); + let horizontal = start.y.approx_eq(&end.y); + + let mut horizontally_tiled = prim_rect.width() > tile_size.width; + let mut vertically_tiled = prim_rect.height() > tile_size.height; + + // Check whether the tiling is equivalent to stretching on either axis. + // Stretching the gradient is more efficient than repeating it. + if vertically_tiled && horizontal && tile_spacing.height == 0.0 { + tile_size.height = prim_rect.height(); + vertically_tiled = false; + } + + if horizontally_tiled && vertical && tile_spacing.width == 0.0 { + tile_size.width = prim_rect.width(); + horizontally_tiled = false; + } + + let offset = apply_gradient_local_clip( + prim_rect, + &tile_size, + &tile_spacing, + &clip_rect + ); + + // The size of gradient render tasks depends on the tile_size. No need to generate + // large stretch sizes that will be clipped to the bounds of the primitive. + tile_size.width = tile_size.width.min(prim_rect.width()); + tile_size.height = tile_size.height.min(prim_rect.height()); + + *start += offset; + *end += offset; + + // Next, in the case of axis-aligned gradients, see if it is worth + // decomposing the gradient into multiple gradients with only two + // gradient stops per segment to get a faster shader. + + if extend_mode != ExtendMode::Clamp || stops.is_empty() { + return false; + } + + if !vertical && !horizontal { + return false; + } + + if vertical && horizontal { + return false; + } + + if !tile_spacing.is_empty() || vertically_tiled || horizontally_tiled { + return false; + } + + // If the gradient is small, no need to bother with decomposing it. + if (horizontal && tile_size.width < 256.0) + || (vertical && tile_size.height < 256.0) { + + return false; + } + + // Flip x and y if need be so that we only deal with the horizontal case. + + // From now on don't return false. We are going modifying the caller's + // variables and not bother to restore them. If the control flow changes, + // Make sure to to restore &mut parameters to sensible values before + // returning false. + + let adjust_rect = &mut |rect: &mut LayoutRect| { + if vertical { + swap(&mut rect.min.x, &mut rect.min.y); + swap(&mut rect.max.x, &mut rect.max.y); + } + }; + + let adjust_size = &mut |size: &mut LayoutSize| { + if vertical { swap(&mut size.width, &mut size.height); } + }; + + let adjust_point = &mut |p: &mut LayoutPoint| { + if vertical { swap(&mut p.x, &mut p.y); } + }; + + let clip_rect = match clip_rect.intersection(prim_rect) { + Some(clip) => clip, + None => { + return false; + } + }; + + adjust_rect(prim_rect); + adjust_point(start); + adjust_point(end); + adjust_size(tile_size); + + let length = (end.x - start.x).abs(); + + // Decompose the gradient into simple segments. This lets us: + // - separate opaque from semi-transparent segments, + // - compress long segments into small render tasks, + // - make sure hard stops stay so even if the primitive is large. + + let reverse_stops = start.x > end.x; + + // Handle reverse stops so we can assume stops are arranged in increasing x. + if reverse_stops { + stops.reverse(); + swap(start, end); + } + + // Use fake gradient stop to emulate the potential constant color sections + // before and after the gradient endpoints. + let mut prev = *stops.first().unwrap(); + let mut last = *stops.last().unwrap(); + + // Set the offsets of the fake stops to position them at the edges of the primitive. + prev.offset = -start.x / length; + last.offset = (tile_size.width - start.x) / length; + if reverse_stops { + prev.offset = 1.0 - prev.offset; + last.offset = 1.0 - last.offset; + } + + let (side_edges, first_edge, last_edge) = if vertical { + ( + EdgeAaSegmentMask::LEFT | EdgeAaSegmentMask::RIGHT, + EdgeAaSegmentMask::TOP, + EdgeAaSegmentMask::BOTTOM + ) + } else { + ( + EdgeAaSegmentMask::TOP | EdgeAaSegmentMask::BOTTOM, + EdgeAaSegmentMask::LEFT, + EdgeAaSegmentMask::RIGHT + ) + }; + + let mut is_first = true; + let last_offset = last.offset; + for stop in stops.iter().chain((&[last]).iter()) { + let prev_stop = prev; + prev = *stop; + + if prev_stop.color.a == 0 && stop.color.a == 0 { + continue; + } + + + let prev_offset = if reverse_stops { 1.0 - prev_stop.offset } else { prev_stop.offset }; + let offset = if reverse_stops { 1.0 - stop.offset } else { stop.offset }; + + // In layout space, relative to the primitive. + let segment_start = start.x + prev_offset * length; + let segment_end = start.x + offset * length; + let segment_length = segment_end - segment_start; + + if segment_length <= 0.0 { + continue; + } + + let mut segment_rect = *prim_rect; + segment_rect.min.x += segment_start; + segment_rect.max.x = segment_rect.min.x + segment_length; + + let mut start = point2(0.0, 0.0); + let mut end = point2(segment_length, 0.0); + + adjust_point(&mut start); + adjust_point(&mut end); + adjust_rect(&mut segment_rect); + + let origin_before_clip = segment_rect.min; + segment_rect = match segment_rect.intersection(&clip_rect) { + Some(rect) => rect, + None => { + continue; + } + }; + let offset = segment_rect.min - origin_before_clip; + + // Account for the clipping since start and end are relative to the origin. + start -= offset; + end -= offset; + + let mut edge_flags = side_edges; + if is_first { + edge_flags |= first_edge; + is_first = false; + } + if stop.offset == last_offset { + edge_flags |= last_edge; + } + + callback( + &segment_rect, + start, + end, + &[ + GradientStopKey { offset: 0.0, .. prev_stop }, + GradientStopKey { offset: 1.0, .. *stop }, + ], + edge_flags, + ); + } + + true +} + +impl From<LinearGradientKey> for LinearGradientTemplate { + fn from(item: LinearGradientKey) -> Self { + + let mut common = PrimTemplateCommonData::with_key_common(item.common); + common.edge_aa_mask = item.edge_aa_mask; + + let (mut stops, min_alpha) = stops_and_min_alpha(&item.stops); + + let mut brush_segments = Vec::new(); + + if let Some(ref nine_patch) = item.nine_patch { + brush_segments = nine_patch.create_segments(common.prim_rect.size()); + } + + // Save opacity of the stops for use in + // selecting which pass this gradient + // should be drawn in. + let stops_opacity = PrimitiveOpacity::from_alpha(min_alpha); + + let start_point = DevicePoint::new(item.start_point.x, item.start_point.y); + let end_point = DevicePoint::new(item.end_point.x, item.end_point.y); + let tile_spacing: LayoutSize = item.tile_spacing.into(); + let stretch_size: LayoutSize = item.stretch_size.into(); + let mut task_size: DeviceSize = stretch_size.cast_unit(); + + let horizontal = start_point.y.approx_eq(&end_point.y); + let vertical = start_point.x.approx_eq(&end_point.x); + + if horizontal { + // Completely horizontal, we can stretch the gradient vertically. + task_size.height = 1.0; + } + + if vertical { + // Completely vertical, we can stretch the gradient horizontally. + task_size.width = 1.0; + } + + // See if we can render the gradient using a special fast-path shader. + // The fast path path only works with two gradient stops. + let mut is_fast_path = false; + if item.cached && stops.len() == 2 && brush_segments.is_empty() { + if horizontal + && stretch_size.width >= common.prim_rect.width() + && start_point.x.approx_eq(&0.0) + && end_point.x.approx_eq(&stretch_size.width) { + is_fast_path = true; + task_size.width = task_size.width.min(256.0); + } + if vertical + && stretch_size.height >= common.prim_rect.height() + && start_point.y.approx_eq(&0.0) + && end_point.y.approx_eq(&stretch_size.height) { + is_fast_path = true; + task_size.height = task_size.height.min(256.0); + } + + if stops[0].color == stops[1].color { + is_fast_path = true; + task_size = size2(1.0, 1.0); + } + + if is_fast_path && item.reverse_stops { + // The fast path doesn't use the gradient gpu blocks builder so handle + // reversed stops here. + stops.swap(0, 1); + } + } + + // Avoid rendering enormous gradients. Linear gradients are mostly made of soft transitions, + // so it is unlikely that rendering at a higher resolution than 1024 would produce noticeable + // differences, especially with 8 bits per channel. + + let mut scale = vec2(1.0, 1.0); + + if task_size.width > MAX_CACHED_SIZE { + scale.x = task_size.width / MAX_CACHED_SIZE; + task_size.width = MAX_CACHED_SIZE; + } + + if task_size.height > MAX_CACHED_SIZE { + scale.y = task_size.height / MAX_CACHED_SIZE; + task_size.height = MAX_CACHED_SIZE; + } + + LinearGradientTemplate { + common, + extend_mode: item.extend_mode, + start_point, + end_point, + task_size: task_size.ceil().to_i32(), + scale, + stretch_size, + tile_spacing, + stops_opacity, + stops, + brush_segments, + reverse_stops: item.reverse_stops, + is_fast_path, + cached: item.cached, + src_color: None, + } + } +} + +impl LinearGradientTemplate { + /// Update the GPU cache for a given primitive template. This may be called multiple + /// times per frame, by each primitive reference that refers to this interned + /// template. The initial request call to the GPU cache ensures that work is only + /// done if the cache entry is invalid (due to first use or eviction). + pub fn update( + &mut self, + frame_state: &mut FrameBuildingState, + parent_surface: SurfaceIndex, + ) { + if let Some(mut request) = frame_state.gpu_cache.request( + &mut self.common.gpu_cache_handle + ) { + + // Write_prim_gpu_blocks + if self.cached { + // We are using the image brush. + request.push(PremultipliedColorF::WHITE); + request.push(PremultipliedColorF::WHITE); + request.push([ + self.stretch_size.width, + self.stretch_size.height, + 0.0, + 0.0, + ]); + } else { + // We are using the gradient brush. + request.push([ + self.start_point.x, + self.start_point.y, + self.end_point.x, + self.end_point.y, + ]); + request.push([ + pack_as_float(self.extend_mode as u32), + self.stretch_size.width, + self.stretch_size.height, + 0.0, + ]); + } + + // write_segment_gpu_blocks + for segment in &self.brush_segments { + // has to match VECS_PER_SEGMENT + request.write_segment( + segment.local_rect, + segment.extra_data, + ); + } + } + + // Tile spacing is always handled by decomposing into separate draw calls so the + // primitive opacity is equivalent to stops opacity. This might change to being + // set to non-opaque in the presence of tile spacing if/when tile spacing is handled + // in the same way as with the image primitive. + self.opacity = self.stops_opacity; + + if !self.cached { + return; + } + + let task_id = if self.is_fast_path { + let orientation = if self.task_size.width > self.task_size.height { + LineOrientation::Horizontal + } else { + LineOrientation::Vertical + }; + + let gradient = FastLinearGradientTask { + color0: self.stops[0].color.into(), + color1: self.stops[1].color.into(), + orientation, + }; + + frame_state.resource_cache.request_render_task( + RenderTaskCacheKey { + size: self.task_size, + kind: RenderTaskCacheKeyKind::FastLinearGradient(gradient), + }, + frame_state.gpu_cache, + frame_state.frame_gpu_data, + frame_state.rg_builder, + None, + false, + RenderTaskParent::Surface(parent_surface), + &mut frame_state.surface_builder, + |rg_builder, _| { + rg_builder.add().init(RenderTask::new_dynamic( + self.task_size, + RenderTaskKind::FastLinearGradient(gradient), + )) + } + ) + } else { + let cache_key = LinearGradientCacheKey { + size: self.task_size, + start: PointKey { x: self.start_point.x, y: self.start_point.y }, + end: PointKey { x: self.end_point.x, y: self.end_point.y }, + scale: PointKey { x: self.scale.x, y: self.scale.y }, + extend_mode: self.extend_mode, + stops: self.stops.iter().map(|stop| (*stop).into()).collect(), + reversed_stops: self.reverse_stops, + }; + + frame_state.resource_cache.request_render_task( + RenderTaskCacheKey { + size: self.task_size, + kind: RenderTaskCacheKeyKind::LinearGradient(cache_key), + }, + frame_state.gpu_cache, + frame_state.frame_gpu_data, + frame_state.rg_builder, + None, + false, + RenderTaskParent::Surface(parent_surface), + &mut frame_state.surface_builder, + |rg_builder, gpu_buffer_builder| { + let stops = Some(GradientGpuBlockBuilder::build( + self.reverse_stops, + gpu_buffer_builder, + &self.stops, + )); + + rg_builder.add().init(RenderTask::new_dynamic( + self.task_size, + RenderTaskKind::LinearGradient(LinearGradientTask { + start: self.start_point, + end: self.end_point, + scale: self.scale, + extend_mode: self.extend_mode, + stops: stops.unwrap(), + }), + )) + } + ) + }; + + self.src_color = Some(task_id); + } +} + +pub type LinearGradientDataHandle = InternHandle<LinearGradient>; + +#[derive(Debug, MallocSizeOf)] +#[cfg_attr(feature = "capture", derive(Serialize))] +#[cfg_attr(feature = "replay", derive(Deserialize))] +pub struct LinearGradient { + pub extend_mode: ExtendMode, + pub start_point: PointKey, + pub end_point: PointKey, + pub stretch_size: SizeKey, + pub tile_spacing: SizeKey, + pub stops: Vec<GradientStopKey>, + pub reverse_stops: bool, + pub nine_patch: Option<Box<NinePatchDescriptor>>, + pub cached: bool, + pub edge_aa_mask: EdgeAaSegmentMask, +} + +impl Internable for LinearGradient { + type Key = LinearGradientKey; + type StoreData = LinearGradientTemplate; + type InternData = (); + const PROFILE_COUNTER: usize = crate::profiler::INTERNED_LINEAR_GRADIENTS; +} + +impl InternablePrimitive for LinearGradient { + fn into_key( + self, + info: &LayoutPrimitiveInfo, + ) -> LinearGradientKey { + LinearGradientKey::new(info, self) + } + + fn make_instance_kind( + key: LinearGradientKey, + data_handle: LinearGradientDataHandle, + _prim_store: &mut PrimitiveStore, + _reference_frame_relative_offset: LayoutVector2D, + ) -> PrimitiveInstanceKind { + if key.cached { + PrimitiveInstanceKind::CachedLinearGradient { + data_handle, + visible_tiles_range: GradientTileRange::empty(), + } + } else { + PrimitiveInstanceKind::LinearGradient { + data_handle, + visible_tiles_range: GradientTileRange::empty(), + } + } + } +} + +impl IsVisible for LinearGradient { + fn is_visible(&self) -> bool { + true + } +} + +#[derive(Debug)] +#[cfg_attr(feature = "capture", derive(Serialize))] +pub struct LinearGradientPrimitive { + pub cache_segments: Vec<CachedGradientSegment>, + pub visible_tiles_range: GradientTileRange, +} + +#[derive(Debug)] +#[cfg_attr(feature = "capture", derive(Serialize))] +pub struct CachedGradientSegment { + pub render_task: RenderTaskId, + pub local_rect: LayoutRect, +} + + +#[derive(Copy, Clone, Debug, Hash, MallocSizeOf, PartialEq, Eq)] +#[cfg_attr(feature = "capture", derive(Serialize))] +#[cfg_attr(feature = "replay", derive(Deserialize))] +pub struct FastLinearGradientTask { + pub color0: ColorU, + pub color1: ColorU, + pub orientation: LineOrientation, +} + +impl FastLinearGradientTask { + pub fn to_instance(&self, target_rect: &DeviceIntRect) -> FastLinearGradientInstance { + FastLinearGradientInstance { + task_rect: target_rect.to_f32(), + color0: ColorF::from(self.color0).premultiplied(), + color1: ColorF::from(self.color1).premultiplied(), + axis_select: match self.orientation { + LineOrientation::Horizontal => 0.0, + LineOrientation::Vertical => 1.0, + }, + } + } +} + +pub type FastLinearGradientCacheKey = FastLinearGradientTask; + +/// The per-instance shader input of a fast-path linear gradient render task. +/// +/// Must match the FAST_LINEAR_GRADIENT instance description in renderer/vertex.rs. +#[cfg_attr(feature = "capture", derive(Serialize))] +#[cfg_attr(feature = "replay", derive(Deserialize))] +#[repr(C)] +#[derive(Clone, Debug)] +pub struct FastLinearGradientInstance { + pub task_rect: DeviceRect, + pub color0: PremultipliedColorF, + pub color1: PremultipliedColorF, + pub axis_select: f32, +} + +#[derive(Debug)] +#[cfg_attr(feature = "capture", derive(Serialize))] +#[cfg_attr(feature = "replay", derive(Deserialize))] +pub struct LinearGradientTask { + pub start: DevicePoint, + pub end: DevicePoint, + pub scale: DeviceVector2D, + pub extend_mode: ExtendMode, + pub stops: GpuBufferAddress, +} + +impl LinearGradientTask { + pub fn to_instance(&self, target_rect: &DeviceIntRect) -> LinearGradientInstance { + LinearGradientInstance { + task_rect: target_rect.to_f32(), + start: self.start, + end: self.end, + scale: self.scale, + extend_mode: self.extend_mode as i32, + gradient_stops_address: self.stops.as_int(), + } + } +} + +/// The per-instance shader input of a linear gradient render task. +/// +/// Must match the LINEAR_GRADIENT instance description in renderer/vertex.rs. +#[cfg_attr(feature = "capture", derive(Serialize))] +#[cfg_attr(feature = "replay", derive(Deserialize))] +#[repr(C)] +#[derive(Clone, Debug)] +pub struct LinearGradientInstance { + pub task_rect: DeviceRect, + pub start: DevicePoint, + pub end: DevicePoint, + pub scale: DeviceVector2D, + pub extend_mode: i32, + pub gradient_stops_address: i32, +} + +#[derive(Clone, Debug, Hash, PartialEq, Eq)] +#[cfg_attr(feature = "capture", derive(Serialize))] +#[cfg_attr(feature = "replay", derive(Deserialize))] +pub struct LinearGradientCacheKey { + pub size: DeviceIntSize, + pub start: PointKey, + pub end: PointKey, + pub scale: PointKey, + pub extend_mode: ExtendMode, + pub stops: Vec<GradientStopKey>, + pub reversed_stops: bool, +} |