Add reflection API access to global params type layout (#1577)

This change adds a single new entry point to our reflection API that allows an application to query the `TypeLayout` that represents the global-scope shader parameters. This can be used by the application in order to detect when the global parameters have required allocation of a default constant buffer, or simply to unify the handling of the global scope with handling of other kinds of parameters.

2 files changed, 18 insertions, 0 deletions

diff --git a/slang.h b/slang.h
index acbee3982..31daf2caa 100644
--- a/slang.h
+++ b/slang.h
@@ -2191,6 +2191,9 @@ extern "C"
         /// Count should *NOT* include terminating zero.
     SLANG_API int spComputeStringHash(const char* chars, size_t count);
 
+    SLANG_API SlangReflectionTypeLayout* spReflection_getGlobalParamsTypeLayout(
+        SlangReflection* reflection);
+
 #ifdef __cplusplus
 }
 
@@ -2856,6 +2859,12 @@ namespace slang
         {
             return spReflection_getHashedString((SlangReflection*)this, index, outCount);
         }
+
+        TypeLayoutReflection* getGlobalParamsTypeLayout()
+        {
+            return (TypeLayoutReflection*) spReflection_getGlobalParamsTypeLayout((SlangReflection*) this);
+        }
+
     };
 
     typedef ISlangBlob IBlob;
diff --git a/source/slang/slang-reflection.cpp b/source/slang/slang-reflection.cpp
index 1daec501d..1b0a590cc 100644
--- a/source/slang/slang-reflection.cpp
+++ b/source/slang/slang-reflection.cpp
@@ -1560,3 +1560,12 @@ SLANG_API int spComputeStringHash(const char* chars, size_t count)
 {
     return (int)getStableHashCode32(chars, count);
 }
+
+SLANG_API SlangReflectionTypeLayout* spReflection_getGlobalParamsTypeLayout(
+    SlangReflection* reflection)
+{
+    auto programLayout = convert(reflection);
+    if(!programLayout) return nullptr;
+
+    return convert(programLayout->parametersLayout->typeLayout);
+}