naga: Add support for GLSL signed/unsigned samplers (#6513)

CHANGELOG.md

@@ -99,6 +99,7 @@ By @ErichDonGubler in [#6456](https://github.com/gfx-rs/wgpu/pull/6456), [#6148]
 - Fix an issue where `naga` CLI would incorrectly skip the first positional argument when `--stdin-file-path` was specified. By @ErichDonGubler in [#6480](https://github.com/gfx-rs/wgpu/pull/6480).
 - Fix textureNumLevels in the GLSL backend. By @magcius in [#6483](https://github.com/gfx-rs/wgpu/pull/6483).
 - Implement `quantizeToF16()` for WGSL frontend, and WGSL, SPIR-V, HLSL, MSL, and GLSL backends. By @jamienicol in [#6519](https://github.com/gfx-rs/wgpu/pull/6519).
+- Add support for GLSL `usampler*` and `isampler*`. By @DavidPeicho in [#6513](https://github.com/gfx-rs/wgpu/pull/6513).
 
 #### General
 

naga/src/front/glsl/builtins.rs

@@ -462,37 +462,54 @@ fn inject_standard_builtins(
     module: &mut Module,
     name: &str,
 ) {
-    match name {
+    // Some samplers (sampler1D, etc...) can be float, int, or uint
+    let anykind_sampler = if name.starts_with("sampler") {
+        Some((name, Sk::Float))
+    } else if name.starts_with("usampler") {
+        Some((&name[1..], Sk::Uint))
+    } else if name.starts_with("isampler") {
+        Some((&name[1..], Sk::Sint))
+    } else {
+        None
+    };
+    if let Some((sampler, kind)) = anykind_sampler {
+        match sampler {
             "sampler1D" | "sampler1DArray" | "sampler2D" | "sampler2DArray" | "sampler2DMS"
             | "sampler2DMSArray" | "sampler3D" | "samplerCube" | "samplerCubeArray" => {
                 declaration.overloads.push(module.add_builtin(
                     vec![
                         TypeInner::Image {
-                        dim: match name {
+                            dim: match sampler {
                                 "sampler1D" | "sampler1DArray" => Dim::D1,
-                            "sampler2D" | "sampler2DArray" | "sampler2DMS" | "sampler2DMSArray" => {
+                                "sampler2D" | "sampler2DArray" | "sampler2DMS"
-                                Dim::D2
+                                | "sampler2DMSArray" => Dim::D2,
-                            }
                                 "sampler3D" => Dim::D3,
                                 _ => Dim::Cube,
                             },
                             arrayed: matches!(
-                            name,
+                                sampler,
                                 "sampler1DArray"
                                     | "sampler2DArray"
                                     | "sampler2DMSArray"
                                     | "samplerCubeArray"
                             ),
                             class: ImageClass::Sampled {
-                            kind: Sk::Float,
+                                kind,
-                            multi: matches!(name, "sampler2DMS" | "sampler2DMSArray"),
+                                multi: matches!(sampler, "sampler2DMS" | "sampler2DMSArray"),
                             },
                         },
                         TypeInner::Sampler { comparison: false },
                     ],
                     MacroCall::Sampler,
-            ))
+                ));
+                return;
             }
+            _ => (),
+        }
+    }
+
+    match name {
+        // Shadow sampler can only be of kind `Sk::Float`
         "sampler1DShadow"
         | "sampler1DArrayShadow"
         | "sampler2DShadow"

naga/tests/in/glsl/samplers.frag

@@ -8,7 +8,11 @@ layout(set = 1, binding = 3) uniform texture2DArray tex2DArray;
 layout(set = 1, binding = 4) uniform textureCube texCube;
 layout(set = 1, binding = 5) uniform textureCubeArray texCubeArray;
 layout(set = 1, binding = 6) uniform texture3D tex3D;
-layout(set = 1, binding = 7) uniform sampler samp;
+
+layout(set = 1, binding = 7) uniform utexture2D utex2D;
+layout(set = 1, binding = 8) uniform itexture2D itex2D;
+
+layout(set = 2, binding = 0) uniform sampler samp;
 
 // WGSL doesn't have 1D depth samplers.
 #define HAS_1D_DEPTH_TEXTURES 0
@@ -129,16 +133,26 @@ void testTex2D(in vec2 coord) {
     vec4 c;
     c = texture(sampler2D(tex2D, samp), coord);
     c = texture(sampler2D(tex2D, samp), coord, 2.0);
+    /* Signed/Unsigned samplers not supported in the WGSL specification with `textureSample()` */
+
     c = textureGrad(sampler2D(tex2D, samp), coord, vec2(4.0), vec2(4.0));
+    /* Signed/Unsigned samplers not supported in the WGSL specification with `textureSampleGrad()` */
+
     c = textureGradOffset(sampler2D(tex2D, samp), coord, vec2(4.0), vec2(4.0), ivec2(5));
+    /* Signed/Unsigned samplers not supported in the WGSL specification with `textureSampleGrad()` */
+
     c = textureLod(sampler2D(tex2D, samp), coord, 3.0);
+    /* Signed/Unsigned samplers not supported in the WGSL specification with `textureSampleLevel()` */
+
     c = textureLodOffset(sampler2D(tex2D, samp), coord, 3.0, ivec2(5));
     c = textureOffset(sampler2D(tex2D, samp), coord, ivec2(5));
     c = textureOffset(sampler2D(tex2D, samp), coord, ivec2(5), 2.0);
+
     c = textureProj(sampler2D(tex2D, samp), vec3(coord, 6.0));
     c = textureProj(sampler2D(tex2D, samp), vec4(coord, 0.0, 6.0));
     c = textureProj(sampler2D(tex2D, samp), vec3(coord, 6.0), 2.0);
     c = textureProj(sampler2D(tex2D, samp), vec4(coord, 0.0, 6.0), 2.0);
+
     c = textureProjGrad(sampler2D(tex2D, samp), vec3(coord, 6.0), vec2(4.0), vec2(4.0));
     c = textureProjGrad(sampler2D(tex2D, samp), vec4(coord, 0.0, 6.0), vec2(4.0), vec2(4.0));
     c = textureProjGradOffset(sampler2D(tex2D, samp), vec3(coord, 6.0), vec2(4.0), vec2(4.0), ivec2(5));
@@ -151,8 +165,14 @@ void testTex2D(in vec2 coord) {
     c = textureProjOffset(sampler2D(tex2D, samp), vec4(coord, 0.0, 6.0), ivec2(5));
     c = textureProjOffset(sampler2D(tex2D, samp), vec3(coord, 6.0), ivec2(5), 2.0);
     c = textureProjOffset(sampler2D(tex2D, samp), vec4(coord, 0.0, 6.0), ivec2(5), 2.0);
+
     c = texelFetch(sampler2D(tex2D, samp), ivec2(coord), 3);
+    c = vec4(texelFetch(usampler2D(utex2D, samp), ivec2(coord), 3));
+    c = vec4(texelFetch(isampler2D(itex2D, samp), ivec2(coord), 3));
+
     c = texelFetchOffset(sampler2D(tex2D, samp), ivec2(coord), 3, ivec2(5));
+    c = vec4(texelFetchOffset(usampler2D(utex2D, samp), ivec2(coord), 3, ivec2(5)));
+    c = vec4(texelFetchOffset(isampler2D(itex2D, samp), ivec2(coord), 3, ivec2(5)));
 }
 
 void testTex2DShadow(vec2 coord) {