Crate webrender

A GPU based renderer for the web.

It serves as an experimental render backend for Servo, but it can also be used as such in a standalone application.

External dependencies

WebRender currently depends on FreeType

Api Structure

The main entry point to WebRender is the crate::Renderer.

By calling Renderer::new(...) you get a Renderer, as well as a RenderApiSender. Your Renderer is responsible to render the previously processed frames onto the screen.

By calling yourRenderApiSender.create_api(), you’ll get a RenderApi instance, which is responsible for managing resources and documents. A worker thread is used internally to untie the workload from the application thread and therefore be able to make better use of multicore systems.

Frame

What is referred to as a frame, is the current geometry on the screen. A new Frame is created by calling set_display_list() on the RenderApi. When the geometry is processed, the application will be informed via a RenderNotifier, a callback which you pass to [Renderer::new]. More information about stacking contexts.

set_display_list() also needs to be supplied with BuiltDisplayLists. These are obtained by finalizing a DisplayListBuilder. These are used to draw your geometry. But it doesn’t only contain trivial geometry, it can also store another StackingContext, as they’re nestable.

Re-exports

• pub extern crate api;
• pub extern crate euclid;
• pub use crate::intern::ItemUid;
• pub use api as webrender_api;
• pub use glyph_rasterizer;
• pub use crate::render_api::*;

Modules

• api_resources 🔒
• batch 🔒
• border 🔒
• box_shadow 🔒
• capture 🔒
• clip 🔒
  Internal representation of clips in WebRender.
• command_buffer 🔒
• composite 🔒
• compositor 🔒
• debug_colors 🔒
• debug_font_data 🔒
• debug_item 🔒
• device 🔒
• ellipse 🔒
• filterdata 🔒
• frame_builder 🔒
• freelist 🔒
  A generic backing store for caches.
• glyph_cache 🔒
• gpu_cache 🔒
  Overview of the GPU cache.
• gpu_types 🔒
• hit_test 🔒
• image_source 🔒
  This module contains the logic to obtain a primitive’s source texture and uv rect.
• image_tiling 🔒
• intern
  The interning module provides a generic data structure interning container. It is similar in concept to a traditional string interning container, but it is specialized to the WR thread model.
• internal_types 🔒
• lru_cache 🔒
• pattern 🔒
• picture 🔒
  A picture represents a dynamically rendered image.
• picture_graph 🔒
• picture_textures 🔒
• prepare 🔒
  Prepare pass
• prim_store 🔒
• print_tree 🔒
• profiler 🔒
  Overlay profiler
• quad 🔒
• rectangle_occlusion 🔒
  A simple occlusion culling algorithm for axis-aligned rectangles.
• render_api
• render_backend 🔒
  The high-level module responsible for managing the pipeline and preparing commands to be issued by the Renderer.
• render_target 🔒
• render_task 🔒
• render_task_cache 🔒
• render_task_graph 🔒
  This module contains the render task graph.
• renderer 🔒
  The high-level module responsible for interfacing with the GPU.
• resource_cache 🔒
• scene 🔒
• scene_builder_thread 🔒
• scene_building 🔒
  Scene building
• screen_capture 🔒
  Screen capture infrastructure for the Gecko Profiler and Composition Recorder.
• segment 🔒
  Primitive segmentation
• shader_source
• space 🔒
  Utilities to deal with coordinate spaces.
• spatial_node 🔒
• spatial_tree 🔒
• surface 🔒
• telemetry 🔒
• texture_cache 🔒
• texture_pack 🔒
• tile_cache 🔒
• util 🔒
• visibility 🔒
  Visibility pass

Macros

• c_str
• enumerate_interners
  Meta-macro to enumerate the various interner identifiers and types.
• matches 🔒

Structs

• AsyncScreenshotHandle
  A handle to a screenshot that is being asynchronously captured and scaled.
• CpuProfile
• DebugFlags
  Flags to enable/disable various builtin debugging tools.
• Device
• DirtyTileDebugInfo
  Debug information about a tile that was dirty and was rasterized
• FormatDesc
• GpuProfile
• GraphicsApiInfo
• MappedTileInfo
  Information about the underlying data buffer of a mapped tile.
• NativeSurfaceId
  An arbitrary identifier for a native (OS compositor) surface
• NativeSurfaceInfo
  Information about a bound surface that the native compositor returns to WR.
• NativeTileId
• PictureCacheDebugInfo
  Debug information about a set of picture cache slices, exposed via RenderResults
• PipelineInfo
• ProgramBinary
• ProgramCache
• ProgramSourceDigest
• RecordedFrameHandle
  A handle to a recorded frame that was captured.
• RenderResults
  Return type from render(), which contains some repr(C) statistics as well as some non-repr(C) data.
• Renderer
  The renderer is responsible for submitting to the GPU the work prepared by the RenderBackend.
• RendererStats
  Some basic statistics about the rendered scene, used in Gecko, as well as in wrench reftests to ensure that tests are batching and/or allocating on render targets as we expect them to.
• SWGLCompositeSurfaceInfo
  Descriptor for a locked surface that will be directly composited by SWGL.
• ShaderPrecacheFlags
  Flags that control how shaders are pre-cached, if at all.
• Shaders
• SharedHitTester
• SliceDebugInfo
  Debug information about a set of picture cache tiles, exposed via RenderResults
• TextureCacheConfig
  Startup parameters for the texture cache.
• TileDescriptor
  Uniquely describes the content of this tile, in a way that can be (reasonably) efficiently hashed and compared.
• TileId
  A stable ID for a given tile, to help debugging. These are also used as unique identifiers for tile surfaces when using a native compositor.
• TileNode
  A node in the dirty rect tracking quadtree.
• WebRenderOptions
• WindowVisibility

Enums

• CompareHelperResult
  Optional extra information returned by is_same when logging is enabled.
• GraphicsApi
• InvalidationReason
  Debugging information about why a tile was invalidated
• PrimitiveCompareResult
  The result of a primitive dependency comparison. Size is a u8 since this is a hot path in the code, and keeping the data small is a performance win.
• RendererError
• ShaderKind
• TileDebugInfo
  Debug information about the state of a tile
• TileNodeKind
  Details for a node in a quadtree that tracks dirty rects for a tile.
• UploadMethod
  Method of uploading texel data from CPU to GPU.
• VertexUsageHint

Constants

• MAX_VERTEX_TEXTURE_WIDTH
• ONE_TIME_USAGE_HINT
  Use this hint for all vertex data re-initialization. This allows the driver to better re-use RBOs internally.

Traits

• AsyncPropertySampler
  Allows callers to hook into the main render_backend loop and provide additional frame ops for generate_frame transactions. These functions are all called from the render backend thread.
• MappableCompositor
  A Compositor variant that supports mapping tiles into CPU memory.
• PartialPresentCompositor
  Defines an interface to a non-native (application-level) Compositor which handles partial present. This is required if webrender must query the backbuffer’s age. TODO: Use the Compositor trait for native and non-native compositors, and integrate this functionality there.
• ProfilerHooks
  Defines the interface for hooking up an external profiler to WR.
• ProgramCacheObserver
  The interfaces that an application can implement to handle ProgramCache update
• SceneBuilderHooks
  Allows callers to hook in at certain points of the async scene build. These functions are all called from the scene builder thread.

Functions

• create_webrender_instance
  Initializes WebRender and creates a Renderer and RenderApiSender.
• get_gl_target
• get_unoptimized_shader_source
• set_profiler_hooks
  Set the profiler callbacks, or None to disable the profiler. This function must only ever be called before any WR instances have been created, or the hooks will not be set.

Type Aliases

• FastHashMap
• SharedShaders
• TileOffset