1 files changed, 93 insertions, 0 deletions
diff --git a/gfx/wr/webrender/src/image_source.rs b/gfx/wr/webrender/src/image_source.rs
new file mode 100644
index 0000000000..c2223ab6f1
--- /dev/null
+++ b/gfx/wr/webrender/src/image_source.rs
@@ -0,0 +1,93 @@
+/* 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/. */
+
+//! This module contains the logic to obtain a primitive's source texture and uv rect.
+//!
+//! Currently this is a somewhat involved process because the code grew into having ad-hoc
+//! ways to store this information depending on how the image data is produced. The goal
+//! is for any textured primitive to be able to read from any source (texture cache, render
+//! tasks, etc.) without primitive-specific code.
+
+use crate::api::ExternalImageType;
+use crate::api::units::*;
+use crate::gpu_cache::GpuCache;
+use crate::prim_store::DeferredResolve;
+use crate::renderer::BLOCKS_PER_UV_RECT;
+use crate::render_task_cache::RenderTaskCacheEntryHandle;
+use crate::resource_cache::{ResourceCache, ImageRequest, CacheItem};
+use crate::internal_types::{TextureSource, DeferredResolveIndex};
+
+/// Resolve a resource cache's imagre request into a texture cache item.
+pub fn resolve_image(
+    request: ImageRequest,
+    resource_cache: &ResourceCache,
+    gpu_cache: &mut GpuCache,
+    deferred_resolves: &mut Vec<DeferredResolve>,
+) -> CacheItem {
+    match resource_cache.get_image_properties(request.key) {
+        Some(image_properties) => {
+            // Check if an external image that needs to be resolved
+            // by the render thread.
+            match image_properties.external_image {
+                Some(external_image) => {
+                    // This is an external texture - we will add it to
+                    // the deferred resolves list to be patched by
+                    // the render thread...
+                    let cache_handle = gpu_cache.push_deferred_per_frame_blocks(BLOCKS_PER_UV_RECT);
+
+                    let deferred_resolve_index = DeferredResolveIndex(deferred_resolves.len() as u32);
+
+                    let image_buffer_kind = match external_image.image_type {
+                        ExternalImageType::TextureHandle(target) => {
+                            target
+                        }
+                        ExternalImageType::Buffer => {
+                            // The ExternalImageType::Buffer should be handled by resource_cache.
+                            // It should go through the non-external case.
+                            panic!("Unexpected non-texture handle type");
+                        }
+                    };
+
+                    let cache_item = CacheItem {
+                        texture_id: TextureSource::External(deferred_resolve_index, image_buffer_kind),
+                        uv_rect_handle: cache_handle,
+                        uv_rect: DeviceIntRect::from_size(
+                            image_properties.descriptor.size,
+                        ),
+                        user_data: [0.0; 4],
+                    };
+
+                    deferred_resolves.push(DeferredResolve {
+                        image_properties,
+                        address: gpu_cache.get_address(&cache_handle),
+                        rendering: request.rendering,
+                    });
+
+                    cache_item
+                }
+                None => {
+                    if let Ok(cache_item) = resource_cache.get_cached_image(request) {
+                        cache_item
+                    } else {
+                        // There is no usable texture entry for the image key. Just return an invalid texture here.
+                        CacheItem::invalid()
+                    }
+                }
+            }
+        }
+        None => {
+            CacheItem::invalid()
+        }
+    }
+}
+
+pub fn resolve_cached_render_task(
+    handle: &RenderTaskCacheEntryHandle,
+    resource_cache: &ResourceCache,
+) -> CacheItem {
+    let rt_cache_entry = resource_cache
+        .get_cached_render_task(&handle);
+
+    resource_cache.get_texture_cache_item(&rt_cache_entry.handle)
+}