Handle `Buffer` types more like textures

Fixes #94

We'd been handling HLSL `Buffer` and `RWBuffer` in a one-off fashion, and that led to a lot of code duplication, and also to the issue that we weren't handling `RasterizerOrderedBuffer` at all.

This change basically folds `Buffer` in so that it is conceptually a texture type (just with a unique shape). Hopefully all the other logic still works.

7 files changed, 69 insertions, 81 deletions

diff --git a/source/slang/emit.cpp b/source/slang/emit.cpp
index c6efa88dc..ef922c418 100644
--- a/source/slang/emit.cpp
+++ b/source/slang/emit.cpp
@@ -771,6 +771,7 @@ struct EmitVisitor
         case TextureType::Shape2D:		Emit("Texture2D");		break;
         case TextureType::Shape3D:		Emit("Texture3D");		break;
         case TextureType::ShapeCube:	Emit("TextureCube");	break;
+        case TextureType::ShapeBuffer:  Emit("Buffer");         break;
         default:
             assert(!"unreachable");
             break;
diff --git a/source/slang/reflection.cpp b/source/slang/reflection.cpp
index aaeae5595..18fa3362d 100644
--- a/source/slang/reflection.cpp
+++ b/source/slang/reflection.cpp
@@ -123,10 +123,6 @@ SLANG_API SlangTypeKind spReflectionType_GetKind(SlangReflectionType* inType)
         return SLANG_TYPE_KIND_RESOURCE;    \
     } while(0)
 
-    CASE(HLSLBufferType);
-    CASE(HLSLRWBufferType);
-    CASE(HLSLBufferType);
-    CASE(HLSLRWBufferType);
     CASE(HLSLStructuredBufferType);
     CASE(HLSLRWStructuredBufferType);
     CASE(HLSLAppendStructuredBufferType);
@@ -342,10 +338,6 @@ SLANG_API SlangResourceShape spReflectionType_GetResourceShape(SlangReflectionTy
         return SHAPE;               \
     } while(0)
 
-    CASE(HLSLBufferType,                    SLANG_TEXTURE_BUFFER, SLANG_RESOURCE_ACCESS_READ);
-    CASE(HLSLRWBufferType,                  SLANG_TEXTURE_BUFFER, SLANG_RESOURCE_ACCESS_READ_WRITE);
-    CASE(HLSLBufferType,                    SLANG_TEXTURE_BUFFER, SLANG_RESOURCE_ACCESS_READ);
-    CASE(HLSLRWBufferType,                  SLANG_TEXTURE_BUFFER, SLANG_RESOURCE_ACCESS_READ_WRITE);
     CASE(HLSLStructuredBufferType,          SLANG_STRUCTURED_BUFFER, SLANG_RESOURCE_ACCESS_READ);
     CASE(HLSLRWStructuredBufferType,        SLANG_STRUCTURED_BUFFER, SLANG_RESOURCE_ACCESS_READ_WRITE);
     CASE(HLSLAppendStructuredBufferType,    SLANG_STRUCTURED_BUFFER, SLANG_RESOURCE_ACCESS_APPEND);
@@ -379,10 +371,6 @@ SLANG_API SlangResourceAccess spReflectionType_GetResourceAccess(SlangReflection
         return ACCESS;              \
     } while(0)
 
-    CASE(HLSLBufferType,                    SLANG_TEXTURE_BUFFER, SLANG_RESOURCE_ACCESS_READ);
-    CASE(HLSLRWBufferType,                  SLANG_TEXTURE_BUFFER, SLANG_RESOURCE_ACCESS_READ_WRITE);
-    CASE(HLSLBufferType,                    SLANG_TEXTURE_BUFFER, SLANG_RESOURCE_ACCESS_READ);
-    CASE(HLSLRWBufferType,                  SLANG_TEXTURE_BUFFER, SLANG_RESOURCE_ACCESS_READ_WRITE);
     CASE(HLSLStructuredBufferType,          SLANG_STRUCTURED_BUFFER, SLANG_RESOURCE_ACCESS_READ);
     CASE(HLSLRWStructuredBufferType,        SLANG_STRUCTURED_BUFFER, SLANG_RESOURCE_ACCESS_READ_WRITE);
     CASE(HLSLAppendStructuredBufferType,    SLANG_STRUCTURED_BUFFER, SLANG_RESOURCE_ACCESS_APPEND);
@@ -419,11 +407,6 @@ SLANG_API SlangReflectionType* spReflectionType_GetResourceResultType(SlangRefle
         return convert(type->As<TYPE>()->elementType.Ptr());                            \
     } while(0)
 
-    CASE(HLSLBufferType,                    SLANG_TEXTURE_BUFFER, SLANG_RESOURCE_ACCESS_READ);
-    CASE(HLSLRWBufferType,                  SLANG_TEXTURE_BUFFER, SLANG_RESOURCE_ACCESS_READ_WRITE);
-    CASE(HLSLBufferType,                    SLANG_TEXTURE_BUFFER, SLANG_RESOURCE_ACCESS_READ);
-    CASE(HLSLRWBufferType,                  SLANG_TEXTURE_BUFFER, SLANG_RESOURCE_ACCESS_READ_WRITE);
-
     // TODO: structured buffer needs to expose type layout!
 
     CASE(HLSLStructuredBufferType,          SLANG_STRUCTURED_BUFFER, SLANG_RESOURCE_ACCESS_READ);
diff --git a/source/slang/slang-stdlib.cpp b/source/slang/slang-stdlib.cpp
index 3de33f554..5800a5deb 100644
--- a/source/slang/slang-stdlib.cpp
+++ b/source/slang/slang-stdlib.cpp
@@ -50,17 +50,6 @@ __generic<T> __magic_type(HLSLAppendStructuredBufferType) struct AppendStructure
         out uint stride);
 };
 
-__generic<T> __magic_type(HLSLBufferType) struct Buffer
-{
-    __intrinsic void GetDimensions(
-        out uint dim);
-
-    __intrinsic T Load(int location);
-    __intrinsic T Load(int location, out uint status);
-
-    __intrinsic __subscript(uint index) -> T;
-};
-
 __magic_type(HLSLByteAddressBufferType) struct ByteAddressBuffer
 {
     __intrinsic void GetDimensions(
@@ -110,19 +99,6 @@ __generic<T, let N : int> __magic_type(HLSLOutputPatchType) struct OutputPatch
     __intrinsic __subscript(uint index) -> T { set; }
 };
 
-__generic<T> __magic_type(HLSLRWBufferType) struct RWBuffer
-{
-    // Note(tfoley): duplication with declaration of `Buffer`
-
-    __intrinsic void GetDimensions(
-        out uint dim);
-
-    __intrinsic T Load(int location);
-    __intrinsic T Load(int location, out uint status);
-
-    __intrinsic __subscript(uint index) -> T { get; set; }
-};
-
 __magic_type(HLSLRWByteAddressBufferType) struct RWByteAddressBuffer
 {
     // Note(tfoley): supports alll operations from `ByteAddressBuffer`
@@ -1985,10 +1961,6 @@ namespace Slang
         StringBuilder sb;
 
 
-//        sb << "__generic<T> __magic_type(PackedBuffer) struct PackedBuffer {};\n";
-//        sb << "__generic<T> __magic_type(Uniform) struct Uniform {};\n";
-//        sb << "__generic<T> __magic_type(Patch) struct Patch {};\n";
-
         // Component-wise multiplication ops
         for(auto op : binaryOps)
         {
@@ -2019,6 +1991,48 @@ namespace Slang
             }
         }
 
+        //
+
+        // Buffer types
+
+        static const struct {
+            char const*         name;
+            SlangResourceAccess access;
+        } kBaseBufferAccessLevels[] = {
+            { "",                   SLANG_RESOURCE_ACCESS_READ },
+            { "RW",                 SLANG_RESOURCE_ACCESS_READ_WRITE },
+            { "RasterizerOrdered",  SLANG_RESOURCE_ACCESS_RASTER_ORDERED },
+        };
+        static const int kBaseBufferAccessLevelCount = sizeof(kBaseBufferAccessLevels) / sizeof(kBaseBufferAccessLevels[0]);
+
+        for (int aa = 0; aa < kBaseBufferAccessLevelCount; ++aa)
+        {
+
+            sb << "__generic<T> __magic_type(Texture, ";
+            sb << ResourceType::makeFlavor(ResourceType::Shape::ShapeBuffer, kBaseBufferAccessLevels[aa].access);
+            sb << ") struct ";
+            sb << kBaseBufferAccessLevels[aa].name;
+            sb << "Buffer {\n";
+
+            sb << "__intrinsic void GetDimensions(out uint dim);\n";
+
+            sb << "__intrinsic T Load(int location);\n";
+            sb << "__intrinsic T Load(int location, out uint status);\n";
+
+            sb << "__intrinsic __subscript(uint index) -> T";
+
+            if (kBaseBufferAccessLevels[aa].access != SLANG_RESOURCE_ACCESS_READ)
+            {
+                sb << " { get; set; }\n";
+            }
+            else
+            {
+                sb << ";\n";
+            }
+
+            sb << "};\n";
+        }
+
         // Output a suitable `#line` directive to point at our raw stdlib code above
         sb << "\n#line " << kHLSLLibIncludeStringLine << " \"" << getStdlibPath() << "\"\n";
 
diff --git a/source/slang/syntax.cpp b/source/slang/syntax.cpp
index 0d7a5ad74..503fbbb0e 100644
--- a/source/slang/syntax.cpp
+++ b/source/slang/syntax.cpp
@@ -421,13 +421,7 @@ void ExpressionType::accept(IValVisitor* visitor, void* extra)
             CASE(GLSLOutputParameterBlockType, GLSLOutputParameterBlockType)
             CASE(GLSLShaderStorageBufferType, GLSLShaderStorageBufferType)
 
-            CASE(PackedBuffer, PackedBufferType)
-            CASE(Uniform, UniformBufferType)
-            CASE(Patch, PatchType)
-
-            CASE(HLSLBufferType, HLSLBufferType)
             CASE(HLSLStructuredBufferType, HLSLStructuredBufferType)
-            CASE(HLSLRWBufferType, HLSLRWBufferType)
             CASE(HLSLRWStructuredBufferType, HLSLRWStructuredBufferType)
             CASE(HLSLAppendStructuredBufferType, HLSLAppendStructuredBufferType)
             CASE(HLSLConsumeStructuredBufferType, HLSLConsumeStructuredBufferType)
diff --git a/source/slang/type-defs.h b/source/slang/type-defs.h
index 461a27b18..138b0a849 100644
--- a/source/slang/type-defs.h
+++ b/source/slang/type-defs.h
@@ -91,16 +91,8 @@ protected:
 )
 END_SYNTAX_CLASS()
 
-
-SYNTAX_CLASS(TextureTypeBase, DeclRefType)
-    // The type that results from fetching an element from this texture
-    SYNTAX_FIELD(RefPtr<ExpressionType>, elementType)
-
-    // Bits representing the kind of texture type we are looking at
-    // (e.g., `Texture2DMS` vs. `TextureCubeArray`)
-    RAW(typedef uint16_t Flavor;)
-    FIELD(Flavor, flavor)
-
+// Base type for things we think of as "resources"
+ABSTRACT_SYNTAX_CLASS(ResourceTypeBase, DeclRefType)
 RAW(
     enum
     {
@@ -132,7 +124,6 @@ RAW(
         // No Shape3DArray
         ShapeCubeArray	= ShapeCube | ArrayFlag,
     };
-            
 
     Shape GetBaseShape() const { return Shape(flavor & ShapeMask); }
     bool isArray() const { return (flavor & ArrayFlag) != 0; }
@@ -142,14 +133,35 @@ RAW(
     SlangResourceShape getShape() const { return flavor & 0xFF; }
     SlangResourceAccess getAccess() const { return (flavor >> 8) & 0xFF; }
 
+    // Bits representing the kind of resource we are looking at
+    // (e.g., `Texture2DMS` vs. `TextureCubeArray`)
+    typedef uint16_t Flavor;
+
+    static Flavor makeFlavor(SlangResourceShape shape, SlangResourceAccess access)
+    {
+        return Flavor(shape | (access << 8));
+    }
+)
+    FIELD(Flavor, flavor)
+END_SYNTAX_CLASS()
+
+// Resources that contain "elements" that can be fetched
+ABSTRACT_SYNTAX_CLASS(ResourceType, ResourceTypeBase)
+    // The type that results from fetching an element from this resource
+    SYNTAX_FIELD(RefPtr<ExpressionType>, elementType)
+END_SYNTAX_CLASS()
+
+ABSTRACT_SYNTAX_CLASS(TextureTypeBase, ResourceType)
+RAW(
     TextureTypeBase()
     {}
     TextureTypeBase(
         Flavor flavor,
         RefPtr<ExpressionType> elementType)
-        : elementType(elementType)
-        , flavor(flavor)
-    {}
+    {
+        this->elementType = elementType;
+        this->flavor = flavor;
+    }
 )
 END_SYNTAX_CLASS()
 
@@ -213,17 +225,8 @@ END_SYNTAX_CLASS()
 // in the element type.
 SIMPLE_SYNTAX_CLASS(PointerLikeType, BuiltinGenericType)
 
-// Generic types used in existing Slang code
-// TODO(tfoley): check that these are actually working right...
-SIMPLE_SYNTAX_CLASS(PatchType, PointerLikeType)
-SIMPLE_SYNTAX_CLASS(StorageBufferType, BuiltinGenericType)
-SIMPLE_SYNTAX_CLASS(UniformBufferType, PointerLikeType)
-SIMPLE_SYNTAX_CLASS(PackedBufferType, BuiltinGenericType)
-
 // HLSL buffer-type resources
 
-SIMPLE_SYNTAX_CLASS(HLSLBufferType, BuiltinGenericType)
-SIMPLE_SYNTAX_CLASS(HLSLRWBufferType, BuiltinGenericType)
 SIMPLE_SYNTAX_CLASS(HLSLStructuredBufferType, BuiltinGenericType)
 SIMPLE_SYNTAX_CLASS(HLSLRWStructuredBufferType, BuiltinGenericType)
 
diff --git a/source/slang/type-layout.cpp b/source/slang/type-layout.cpp
index 6ca2d68fb..b4bf8949f 100644
--- a/source/slang/type-layout.cpp
+++ b/source/slang/type-layout.cpp
@@ -361,14 +361,12 @@ struct HLSLObjectLayoutRulesImpl : ObjectLayoutRulesImpl
 
         case ShaderParameterKind::TextureUniformBuffer:
         case ShaderParameterKind::StructuredBuffer:
-        case ShaderParameterKind::SampledBuffer:
         case ShaderParameterKind::RawBuffer:
         case ShaderParameterKind::Buffer:
         case ShaderParameterKind::Texture:
             return SimpleLayoutInfo(LayoutResourceKind::ShaderResource, 1);
 
         case ShaderParameterKind::MutableStructuredBuffer:
-        case ShaderParameterKind::MutableSampledBuffer:
         case ShaderParameterKind::MutableRawBuffer:
         case ShaderParameterKind::MutableBuffer:
         case ShaderParameterKind::MutableTexture:
@@ -1041,8 +1039,6 @@ SimpleLayoutInfo GetLayoutImpl(
             type, rules, outTypeLayout);                        \
     } while(0)
 
-    CASE(HLSLBufferType,                    SampledBuffer);
-    CASE(HLSLRWBufferType,                  MutableSampledBuffer);
     CASE(HLSLByteAddressBufferType,         RawBuffer);
     CASE(HLSLRWByteAddressBufferType,       MutableRawBuffer);
 
diff --git a/source/slang/type-layout.h b/source/slang/type-layout.h
index d5c96abf2..81ca1350c 100644
--- a/source/slang/type-layout.h
+++ b/source/slang/type-layout.h
@@ -403,9 +403,6 @@ enum class ShaderParameterKind
     StructuredBuffer,
     MutableStructuredBuffer,
 
-    SampledBuffer,
-    MutableSampledBuffer,
-
     RawBuffer,
     MutableRawBuffer,