GLSL half texture access (#931)

* * Added $c macro - that will do casting to target type. Used here to cast texture reads back to half. Works in tandem with $z which will close parens.
* half-texture.slang test
* Make binding failing if TextureView fails

* Simplify logic around parens.

* Improve comment around $c macro.

* Test against hlsl output to avoid error on CI.

1 files changed, 41 insertions, 0 deletions

diff --git a/tests/compute/half-texture.slang b/tests/compute/half-texture.slang
new file mode 100644
index 000000000..635336c66
--- /dev/null
+++ b/tests/compute/half-texture.slang
@@ -0,0 +1,41 @@
+//TEST:SIMPLE: -target spirv -entry computeMain -profile cs_6_2
+//TEST:SIMPLE: -target hlsl -entry computeMain -profile cs_6_2 
+
+//TEST_INPUT:ubuffer(data=[0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0], stride=16):dxbinding(0),glbinding(0),out
+RWStructuredBuffer<int> outputBuffer;
+
+//TEST_INPUT: Texture2D(size=4):dxbinding(1),glbinding(1)
+RWTexture2D<half> halfTexture;
+//TEST_INPUT: Texture2D(size=4):dxbinding(2),glbinding(2)
+RWTexture2D<half2> halfTexture2;
+//TEST_INPUT: Texture2D(size=4):dxbinding(3),glbinding(3)
+RWTexture2D<half4> halfTexture4;
+
+//TEST_INPUT: Sampler : dxbinding(0),glbinding(0)
+SamplerState 	s;
+
+[numthreads(4, 4, 1)]
+void computeMain(uint3 dispatchThreadID : SV_DispatchThreadID)
+{
+    int2 pos = int2(dispatchThreadID.xy);
+    float2 uv = pos * (1.0f / 3.0f);
+    int2 pos2 = int2(3 - pos.y, 3 - pos.x);
+    
+#if 0 
+    half  h = halfTexture.Sample(s, uv);
+    half2 h2 = halfTexture2.Sample(s, uv);
+    half4 h4 = halfTexture4.Sample(s, uv);
+#else
+    half  h = halfTexture[pos2];
+    half2 h2 = halfTexture2[pos2];
+    half4 h4 = halfTexture4[pos2];
+#endif    
+    
+    // Store a results
+    halfTexture[pos] = h2.x + h2.y;
+    halfTexture2[pos] = h4.xy;
+    halfTexture4[pos] = half4(h2, h, h);
+    
+    int index = pos.x + pos.y * 4;
+    outputBuffer[index] = index;
+}
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