`textureGatherCompare`

Function

Compares the reference depth ref against the four texels a linear filter would blend at the coordinate on mip level 0, through the comparison sampler smp, and returns the four results (0 or 1 each) as a vec4 in the order (umin,vmax), (umax,vmax), (umax,vmin), (umin,vmin), in any stage.

The signature and the sentence under each name are the compiler's own text at commit 26de7be8.

Syntax

declare function textureGatherCompare(
  tex: texture_depth_2d,
  smp: sampler_comparison,
  uv: vec2,
  ref: number,
): vec4
declare function textureGatherCompare(
  tex: texture_depth_2d_array,
  smp: sampler_comparison,
  uv: vec2,
  layer: number,
  ref: number,
): vec4
declare function textureGatherCompare(
  tex: texture_depth_cube,
  smp: sampler_comparison,
  dir: vec3,
  ref: number,
): vec4
declare function textureGatherCompare(
  tex: texture_depth_cube_array,
  smp: sampler_comparison,
  dir: vec3,
  layer: number,
  ref: number,
): vec4

A number in a parameter or a return position is the scalar slot. The ambient file declares a GPU scalar as a branded number whose brand is optional, so a literal and any branded scalar both fill it.

type f32 = number & { readonly [f32Tag]?: true }

A declaration you write still needs a width, and a bare number on a field or a parameter is refused; the TypeScript constructs page carries that row with the compiler's own message.

Parameters

tex texture_depth_2dtexture_depth_2d_arraytexture_depth_cubetexture_depth_cube_array
smp sampler_comparison
uv optional vec2
dir optional vec3
ref number
layer optional number

Return value

vec4

Description

On a texture_depth_2d_array or a texture_depth_cube_array the layer comes before the reference. Compiles to textureGatherCompare on WGSL; GLSL ES 3.00 has no gather, so a module using it emits WGSL alone.

The CPU oracle has no texture memory and no neighbouring fragments. The call throws unless the module was compiled with { gpuStubs: true }, which returns a placeholder.

Targets

WGSL: textureGatherCompare(a, b, c, d)
GLSL ES 3.00: textureGatherCompare has no GLSL ES 3.00 spelling (textureGather is ES 3.10)

Examples

cube-array-gather.shade.ts