Fix atomic operations on RWBuffer (#593)

* Fix atomic operations on RWBuffer

An earlier change added support for passing true pointers to `__ref` parameters to fix the global `Interlocked*()` functions when applied to `groupshared` variables or `RWStructureBuffer<T>` elements.
That change didn't apply to `RWBuffer<T>` or `RWTexture2D<T>`, etc. because those types had so far only declared `get` and `set` accessors, but not any `ref` accessors (which return a pointer).

The main fixes here are:

* Add `ref` accessors to the subscript oeprations on the `RW*` resource types

* Adjust the logic for emitting calls to subscript accessors so that we don't get quite as eager about invoking a `ref` accessor, and instead try to invoke just a `get` or `set` accessor when these will suffice. This is important for Vulkan cross-compilation, where we don't yet support the semantics of our `ref` accessors.

* Add a test case for atomics on a `RWBuffer`

* Fix up `render-test` so that we can specify a format for a buffer resource, which allows us to use things other than `*StructuredBuffer` and `*ByteAddressBuffer`. The work there is probably not complete; I just did what I could to get the test working.

* A bunch of files got whitespace edits thanks to the fact that I'm using editorconfig and others on the project seemingly arent...

* fixup: remove ifdefed-out code

1 files changed, 7 insertions, 2 deletions

diff --git a/source/slang/core.meta.slang b/source/slang/core.meta.slang
index 00afde2ac..507ae014e 100644
--- a/source/slang/core.meta.slang
+++ b/source/slang/core.meta.slang
@@ -326,7 +326,7 @@ for( int C = 2; C <= 4; ++C )
 sb << "__magic_type(SamplerState," << int(SamplerStateFlavor::SamplerState) << ")\n";
 sb << "__intrinsic_type(" << kIROp_SamplerStateType << ")\n";
 sb << "struct SamplerState {};";
-        
+
 sb << "__magic_type(SamplerState," << int(SamplerStateFlavor::SamplerComparisonState) << ")\n";
 sb << "__intrinsic_type(" << kIROp_SamplerComparisonStateType << ")\n";
 sb << "struct SamplerComparisonState {};";
@@ -688,6 +688,11 @@ for (int tt = 0; tt < kBaseTextureTypeCount; ++tt)
 
                 default:
                     sb << "__target_intrinsic(glsl, \"imageStore($0, " << ivecN << "($1), $2)\") set;\n";
+
+                    // TODO: really need a way to map access through `ref` accessor (e.g., when
+                    // used with an atomic operation) over to GLSL equivalent.
+                    //
+                    sb << "ref;\n";
                     break;
                 }
 
@@ -911,7 +916,7 @@ for (int tt = 0; tt < kBaseTextureTypeCount; ++tt)
                     auto componentName = kk.componentName;
 
                     EMIT_LINE_DIRECTIVE();
-                            
+
                     sb << "__target_intrinsic(glsl, \"textureGather($p, $2, " << componentIndex << ")\")\n";
                     sb << "vector<T, 4> Gather" << componentName << "(SamplerState s, ";
                     sb << "float" << kBaseTextureTypes[tt].coordCount << " location);\n";