Add SV_DrawIndex. (#5787)

Co-authored-by: Ellie Hermaszewska <ellieh@nvidia.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/source/slang/slang-emit-spirv.cpp b/source/slang/slang-emit-spirv.cpp
index 58f5e4f66..f4aa900db 100644
--- a/source/slang/slang-emit-spirv.cpp
+++ b/source/slang/slang-emit-spirv.cpp
@@ -5137,6 +5137,11 @@ struct SPIRVEmitContext : public SourceEmitterBase, public SPIRVEmitSharedContex
                     // float in hlsl & glsl
                     return getBuiltinGlobalVar(inst->getFullType(), SpvBuiltInPointSize, inst);
                 }
+                else if (semanticName == "sv_drawindex")
+                {
+                    requireSPIRVCapability(SpvCapabilityDrawParameters);
+                    return getBuiltinGlobalVar(inst->getFullType(), SpvBuiltInDrawIndex, inst);
+                }
                 else if (semanticName == "sv_primitiveid")
                 {
                     auto entryPoints = m_referencingEntryPoints.tryGetValue(inst);