Add SPIRV intrinsics for texture footprint query. (#3345)

* Add SPIRV intrinsics for texture footprint query.

* Cleanup.

---------

Co-authored-by: Yong He <yhe@nvidia.com>

1 files changed, 12 insertions, 0 deletions

diff --git a/source/slang/slang-emit-glsl.cpp b/source/slang/slang-emit-glsl.cpp
index bbfefc75c..0fc54ca1f 100644
--- a/source/slang/slang-emit-glsl.cpp
+++ b/source/slang/slang-emit-glsl.cpp
@@ -2347,6 +2347,18 @@ void GLSLSourceEmitter::emitSimpleTypeImpl(IRType* type)
             m_writer->emit("hitObjectNV");
             return;
         }
+        case kIROp_TextureFootprintType:
+        {
+            m_glslExtensionTracker->requireExtension(UnownedStringSlice("GL_NV_shader_texture_footprint"));
+            m_glslExtensionTracker->requireVersion(ProfileVersion::GLSL_450);
+
+            m_writer->emit("gl_TextureFootprint");
+            auto intLit = as<IRIntLit>(type->getOperand(0));
+            if (intLit)
+                m_writer->emit(intLit->getValue());
+            m_writer->emit("DNV");
+            return;
+        }
         default: break;
     }