More cross-compilation fixes

- Add GLSL mappings for more `Texture*` methods
  - The annoying one here is `Texture*.Load()` because it doesn't take a sampler, but the GLSL equivalent needs one (while the SPIR-V does *not*). I've hacked this pretty seriously for now.

- Try to ensure that we add `uniform` to global declarations that need it in GLSL

- When outputting an `in` or `out` variable that might have been created from an `inout` shader parameter, filter the layout qualifiers that we output to only cover the appropriate resource kind.

1 files changed, 29 insertions, 0 deletions

diff --git a/source/slang/slang-stdlib.cpp b/source/slang/slang-stdlib.cpp
index e2d5829b4..23d66201a 100644
--- a/source/slang/slang-stdlib.cpp
+++ b/source/slang/slang-stdlib.cpp
@@ -1431,6 +1431,22 @@ namespace Slang
                     {
                         int loadCoordCount = kBaseTextureTypes[tt].coordCount + isArray + (isMultisample?0:1);
 
+                        // When translating to GLSL, we need to break apart the `location` argument.
+                        //
+                        // TODO: this should realy be handled by having this member actually get lowered!
+                        int glslLoadCoordCount = kBaseTextureTypes[tt].coordCount + isArray;
+                        static const char* kGLSLLoadCoordsSwizzle[] = { "", "", "x", "xy", "xyz", "xyzw" };
+                        static const char* kGLSLLoadLODSwizzle[]    = { "", "", "y", "z", "w", "error" };
+
+                        if (isMultisample)
+                        {
+                            sb << "__intrinsic(glsl, \"texelFetch($P, $0, $1)\")\n";
+                        }
+                        else
+                        {
+                            sb << "__intrinsic(glsl, \"texelFetch($P, ($0)." << kGLSLLoadCoordsSwizzle[loadCoordCount] << ", ($0)." << kGLSLLoadLODSwizzle[loadCoordCount] << ")\")\n";
+                        }
+                        sb << "__intrinsic\n";
                         sb << "T Load(";
                         sb << "int" << loadCoordCount << " location";
                         if(isMultisample)
@@ -1439,6 +1455,15 @@ namespace Slang
                         }
                         sb << ");\n";
 
+                        if (isMultisample)
+                        {
+                            sb << "__intrinsic(glsl, \"texelFetchOffset($P, $0, $1, $2)\")\n";
+                        }
+                        else
+                        {
+                            sb << "__intrinsic(glsl, \"texelFetch($P, ($0)." << kGLSLLoadCoordsSwizzle[loadCoordCount] << ", ($0)." << kGLSLLoadLODSwizzle[loadCoordCount] << ", $1)\")\n";
+                        }
+                        sb << "__intrinsic\n";
                         sb << "T Load(";
                         sb << "int" << loadCoordCount << " location";
                         if(isMultisample)
@@ -1470,11 +1495,15 @@ namespace Slang
                     {
                         // `Sample()`
 
+                        sb << "__intrinsic(glsl, \"texture($p, $1)\")\n";
+                        sb << "__intrinsic\n";
                         sb << "T Sample(SamplerState s, ";
                         sb << "float" << kBaseTextureTypes[tt].coordCount + isArray << " location);\n";
 
                         if( baseShape != TextureType::ShapeCube )
                         {
+                            sb << "__intrinsic(glsl, \"textureOffset($p, $1)\")\n";
+                            sb << "__intrinsic\n";
                             sb << "T Sample(SamplerState s, ";
                             sb << "float" << kBaseTextureTypes[tt].coordCount + isArray << " location, ";
                             sb << "int" << kBaseTextureTypes[tt].coordCount << " offset);\n";