FilterColorMatrix.h File Reference

The SVG color-matrix filter primitive, expressed in the donner::gpu::shader IR. More...

#include "donner/gpu/shader/IrModule.h"

Include dependency graph for FilterColorMatrix.h:

Namespaces
namespace	donner
	Top-level Donner namespace, which is split into different sub-namespaces such as donner::svg and donner::css.

Enumerations
enum class	donner::gpu::shader::programs::FilterColorMatrixBinding : uint32_t {   InputTexture = 0 ,   OutputTexture = 1 ,   Params = 2 }
	Bind group indices of the color-matrix filter program, shared by the IR builder and every host that creates its bind group layout. More...

Functions
ShaderResult< IrModule >	donner::gpu::shader::programs::BuildFilterColorMatrixModule ()
	Builds the SVG color-matrix filter program: one @compute @workgroup_size(8, 8, 1) entry point named cs_main that applies a four-by-five color matrix to every texel.

Variables
constexpr uint32_t	donner::gpu::shader::programs::kFilterColorMatrixWorkgroupSize = 8
	Workgroup size the color-matrix filter entry point declares. Hosts divide the destination extent by this to compute dispatch counts.

Detailed Description

The SVG color-matrix filter primitive, expressed in the donner::gpu::shader IR.

Enumeration Type Documentation

FilterColorMatrixBinding

enum class donner::gpu::shader::programs::FilterColorMatrixBinding : uint32_t

strong

Bind group indices of the color-matrix filter program, shared by the IR builder and every host that creates its bind group layout.

Enumerator
InputTexture	Sampled texture_2d<f32> source.
OutputTexture	texture_storage_2d<rgba8unorm, write> destination.
Params	Uniform buffer holding the five matrix columns.

Function Documentation

BuildFilterColorMatrixModule()

ShaderResult< IrModule > donner::gpu::shader::programs::BuildFilterColorMatrixModule

(

)

Builds the SVG color-matrix filter program: one @compute @workgroup_size(8, 8, 1) entry point named cs_main that applies a four-by-five color matrix to every texel.

The matrix arrives as five columns: four of per-input-channel multipliers and a constant column added after them. Every matrix form the specification defines - the explicit one, saturation, hue rotation, and luminance-to-alpha - is baked into those five columns by the caller, so this program has one path rather than a branch per form.

The specification defines the operation on straight-alpha values while the filter chain carries premultiplied ones, so the program un-premultiplies, applies the matrix, clamps each channel to the representable range, and premultiplies again. A fully transparent source texel has no straight-alpha value to recover, so it is handled directly: the constant column is the whole result there, and it produces transparent black unless that column raises alpha.

Invocations outside the destination extent return without writing, so a dispatch rounded up to whole workgroups is safe.