Add support for SV_ViewID (#2440)

closes https://github.com/shader-slang/slang/issues/2410

Co-authored-by: Yong He <yonghe@outlook.com>

2 files changed, 9 insertions, 0 deletions

diff --git a/source/slang/slang-ir-glsl-legalize.cpp b/source/slang/slang-ir-glsl-legalize.cpp
index 59f741050..76c73796f 100644
--- a/source/slang/slang-ir-glsl-legalize.cpp
+++ b/source/slang/slang-ir-glsl-legalize.cpp
@@ -662,6 +662,14 @@ GLSLSystemValueInfo* getGLSLSystemValueInfo(
         requiredType = builder->getBasicType(BaseType::Int);
         name = "gl_VertexIndex";
     }
+    else if (semanticName == "sv_viewid")
+    {
+        // uint in hlsl, int in glsl
+        // https://github.com/KhronosGroup/GLSL/blob/master/extensions/ext/GL_EXT_multiview.txt
+        requiredType = builder->getBasicType(BaseType::Int);
+        context->requireGLSLExtension(UnownedStringSlice::fromLiteral("GL_EXT_multiview"));
+        name = "gl_ViewIndex";
+    }
     else if (semanticName == "sv_viewportarrayindex")
     {
         // uint on hlsl, int on glsl
diff --git a/source/slang/slang-language-server-completion.cpp b/source/slang/slang-language-server-completion.cpp
index c1d6fc9b5..92a0b3860 100644
--- a/source/slang/slang-language-server-completion.cpp
+++ b/source/slang/slang-language-server-completion.cpp
@@ -65,6 +65,7 @@ static const char* hlslSemanticNames[] = {
     "SV_Target",
     "SV_TessFactor",
     "SV_VertexID",
+    "SV_ViewID",
     "SV_ViewportArrayIndex",
     "SV_ShadingRate",
 };