Fix spirv generation for using output stream in a function. (#3806)

* Fix spirv generation for using output stream in a function.

* polish.

1 files changed, 44 insertions, 0 deletions

diff --git a/tests/spirv/geometry-shader-sub-func.slang b/tests/spirv/geometry-shader-sub-func.slang
new file mode 100644
index 000000000..6c6944f31
--- /dev/null
+++ b/tests/spirv/geometry-shader-sub-func.slang
@@ -0,0 +1,44 @@
+// geometry-shader-sub-func.slang
+
+//TEST:SIMPLE(filecheck=SPIRV): -target spirv -emit-spirv-directly -O0
+
+struct CoarseVertex
+{
+    float4 position     : POSITION;
+    float3 color        : COLOR;
+    uint   id           : ID;
+}
+
+struct RasterVertex
+{
+    float4 position : POSITION;
+    float3 color    : COLOR;
+    uint   id       : SV_RenderTargetArrayIndex;
+}
+
+// SPIRV: OpEntryPoint
+// SPIRV: OpStore %outputStream_position
+// SPIRV: OpEmitVertex
+void appendVertex(TriangleStream<RasterVertex> outputStream, RasterVertex vert)
+{
+    outputStream.Append(vert);
+}
+
+[shader("geometry")]
+[maxvertexcount(3)]
+void main(
+    triangle CoarseVertex coarseVertices[3],
+    inout TriangleStream<RasterVertex> outputStream,
+    uint primitiveID : SV_PrimitiveID)
+{
+    [ForceUnroll]
+    for(int ii = 0; ii < 3; ++ii)
+    {
+        CoarseVertex coarseVertex = coarseVertices[ii];
+        RasterVertex rasterVertex;
+        rasterVertex.position   = coarseVertex.position;
+        rasterVertex.color      = coarseVertex.color;
+        rasterVertex.id         = coarseVertex.id + primitiveID;
+        appendVertex(outputStream, rasterVertex);
+    }
+}