Handling SV_ClipDistance system semantic on GLSL/VK (#2942)

* Small fixes and improvements around reflection tool.

* Make PrettyWriter printing a class.

* WIP support for gl_ClipDistance

* Working but doesn't have layout.

* Check out param works with gl_ClipDistance.

* Test clip distance works with out parameters.

* Enable file check.

* Add a test that splits clip distance writing.

---------

Co-authored-by: Yong He <yonghe@outlook.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 a86971bf5..64afb7ff1 100644
--- a/source/slang/slang-emit-glsl.cpp
+++ b/source/slang/slang-emit-glsl.cpp
@@ -826,6 +826,18 @@ void GLSLSourceEmitter::_maybeEmitGLSLBuiltin(IRGlobalParam* var, UnownedStringS
         emitType(varType, getName(var));
         m_writer->emit(";\n\n");
     }
+    else if (name == "gl_ClipDistance")
+    {
+        auto varType = var->getDataType();
+        if (auto outType = as<IROutType>(varType))
+        {
+            varType = outType->getValueType();
+        }
+
+        m_writer->emit("out ");
+        emitType(varType, getName(var));
+        m_writer->emit(";\n\n");
+    }
 }
 
 void GLSLSourceEmitter::_requireBaseType(BaseType baseType)