Fixed few HLSL->GLSL conversion issues on MacOS

5 files changed, 130 insertions, 48 deletions

diff --git a/Graphics/GraphicsEngineOpenGL/src/GLContextMacOS.mm b/Graphics/GraphicsEngineOpenGL/src/GLContextMacOS.mm
index b578dd92..65942afb 100644
--- a/Graphics/GraphicsEngineOpenGL/src/GLContextMacOS.mm
+++ b/Graphics/GraphicsEngineOpenGL/src/GLContextMacOS.mm
@@ -30,6 +30,22 @@
 #include "GLTypeConversions.h"
 #include "EngineGLAttribs.h"
 
+static void glDrawArraysInstancedBaseInstance_stub(GLenum mode, GLint first, GLsizei count, GLsizei primcount, GLuint baseinstance)
+{
+    LOG_ERROR_MESSAGE_ONCE("glDrawArraysInstancedBaseInstance is not supported on MacOS");
+}
+
+static void glDrawElementsInstancedBaseInstance_stub(GLenum mode, GLsizei count, GLenum type, const void *indices, GLsizei primcount, GLuint baseinstance)
+{
+    LOG_ERROR_MESSAGE_ONCE("glDrawElementsInstancedBaseInstance is not supported on MacOS");
+}
+
+static void  glDrawElementsInstancedBaseVertexBaseInstance_stub(GLenum mode, GLsizei count, GLenum type, const void *indices, GLsizei primcount, GLint basevertex, GLuint baseinstance)
+{
+    LOG_ERROR_MESSAGE_ONCE("glDrawElementsInstancedBaseVertexBaseInstance is not supported on MacOS");
+}
+
+
 namespace Diligent
 {
     GLContext::GLContext( const EngineGLAttribs &InitAttribs, DeviceCaps &DeviceCaps )
@@ -44,7 +60,13 @@ namespace Diligent
         GLenum err = glewInit();
         if( GLEW_OK != err )
             LOG_ERROR_AND_THROW( "Failed to initialize GLEW" );
-
+        if(glDrawArraysInstancedBaseInstance == nullptr)
+            glDrawArraysInstancedBaseInstance = glDrawArraysInstancedBaseInstance_stub;
+        if(glDrawElementsInstancedBaseInstance == nullptr)
+            glDrawElementsInstancedBaseInstance = glDrawElementsInstancedBaseInstance_stub;
+        if(glDrawElementsInstancedBaseVertexBaseInstance == nullptr)
+            glDrawElementsInstancedBaseVertexBaseInstance = glDrawElementsInstancedBaseVertexBaseInstance_stub;
+  
         //Checking GL version
         const GLubyte *GLVersionString = glGetString( GL_VERSION );
         const GLubyte *GLRenderer = glGetString(GL_RENDERER);
diff --git a/Graphics/HLSL2GLSLConverterLib/include/GLSLDefinitions.h b/Graphics/HLSL2GLSLConverterLib/include/GLSLDefinitions.h
index cdf517d1..cac5e9d7 100644
--- a/Graphics/HLSL2GLSLConverterLib/include/GLSLDefinitions.h
+++ b/Graphics/HLSL2GLSLConverterLib/include/GLSLDefinitions.h
@@ -202,13 +202,8 @@ uvec4 f32tof16( vec4 f4 )
 }
 #endif
 
-#ifndef GL_ES // double is not supported on GLES
-double asdouble(uint lowbits, uint highbits)
-{
-    return packDouble2x32( uvec2( lowbits, highbits ) );
-}
-#endif
-
+// Use #define as double is not supported on GLES
+#define asdouble(lowbits, highbits) packDouble2x32( uvec2( lowbits, highbits ) )
 
 // Floating point functions
 
@@ -532,15 +527,50 @@ void _TypeConvertStore( out int   Dst, in int   Src ){ Dst = int( Src ); }
 void _TypeConvertStore( out int   Dst, in uint  Src ){ Dst = int( Src ); }
 void _TypeConvertStore( out int   Dst, in float Src ){ Dst = int( Src ); }
 
-int _ToInt( int x )  { return int(x);       }
-int _ToInt( uint x ) { return int(x);       }
-int _ToInt( float x ){ return int(x);       }
-int _ToInt( bool x ) { return x ? 1 : 0;    }
+
+int _ToInt( int x )    { return int(x);     }
+int _ToInt( ivec2 v )  { return int(v.x);   }
+int _ToInt( ivec3 v )  { return int(v.x);   }
+int _ToInt( ivec4 v )  { return int(v.x);   }
+
+int _ToInt( uint x )   { return int(x);     }
+int _ToInt( uvec2 v )  { return int(v.x);   }
+int _ToInt( uvec3 v )  { return int(v.x);   }
+int _ToInt( uvec4 v )  { return int(v.x);   }
+
+int _ToInt( float x )  { return int(x);     }
+int _ToInt( vec2 v )   { return int(v.x);   }
+int _ToInt( vec3 v )   { return int(v.x);   }
+int _ToInt( vec4 v )   { return int(v.x);   }
+
+int _ToInt( bool x )   { return x   ? 1 : 0;}
+int _ToInt( bvec2 v )  { return v.x ? 1 : 0;}
+int _ToInt( bvec3 v )  { return v.x ? 1 : 0;}
+int _ToInt( bvec4 v )  { return v.x ? 1 : 0;}
+
+
 
 float _ToFloat( int x )  { return float(x);     }
+float _ToFloat( ivec2 v ){ return float(v.x);   }
+float _ToFloat( ivec3 v ){ return float(v.x);   }
+float _ToFloat( ivec4 v ){ return float(v.x);   }
+
 float _ToFloat( uint x ) { return float(x);     }
+float _ToFloat( uvec2 v ){ return float(v.x);   }
+float _ToFloat( uvec3 v ){ return float(v.x);   }
+float _ToFloat( uvec4 v ){ return float(v.x);   }
+
 float _ToFloat( float x ){ return float(x);     }
-float _ToFloat( bool x ) { return x ? 1.0 : 0.0;}
+float _ToFloat( vec2 v ) { return float(v.x);   }
+float _ToFloat( vec3 v ) { return float(v.x);   }
+float _ToFloat( vec4 v ) { return float(v.x);   }
+
+float _ToFloat( bool x ) { return x   ? 1.0 : 0.0;}
+float _ToFloat( bvec2 v ){ return v.x ? 1.0 : 0.0;}
+float _ToFloat( bvec3 v ){ return v.x ? 1.0 : 0.0;}
+float _ToFloat( bvec4 v ){ return v.x ? 1.0 : 0.0;}
+
+
 
 uint _ToUint( int x )  { return uint(x);     }
 uint _ToUint( uint x ) { return uint(x);     }
@@ -796,7 +826,7 @@ uvec4  _ToUvec( vec4  f4 ){ return _ToUvec4( f4.x, f4.y, f4.z, f4.w ); }
 // in the second to last component of Coords. (The second component of Coords is unused for 1D shadow lookups.)
 // For cube array textures, Dsub is specified as a separate parameter
 //                                                                                                                                     mip
-#define SampleCmpLevel0Tex1D_3(Tex, Sampler, Coords, CompareValue)      textureLod(Tex, _ToVec3((Coords).x,        0.0, CompareValue), 0.0)
+#define SampleCmpLevel0Tex1D_3(Tex, Sampler, Coords, CompareValue)      textureLod(Tex, _ToVec3( Coords,           0.0, CompareValue), 0.0)
 #define SampleCmpLevel0Tex1DArr_3(Tex, Sampler, Coords, CompareValue)   textureLod(Tex, _ToVec3((Coords).x, (Coords).y, CompareValue), 0.0)
 #define SampleCmpLevel0Tex2D_3(Tex, Sampler, Coords, CompareValue)      textureLod(Tex, _ToVec3((Coords).x, (Coords).y, CompareValue), 0.0)
 #define SampleCmpLevel0Tex2DArr_3(Tex, Sampler, Coords, CompareValue)   0.0 // No textureLod for sampler2DArrayShadow
@@ -804,7 +834,7 @@ uvec4  _ToUvec( vec4  f4 ){ return _ToUvec4( f4.x, f4.y, f4.z, f4.w ); }
 #define SampleCmpLevel0TexCubeArr_3(Tex, Sampler, Coords, CompareValue) 0.0 // No textureLod for samplerCubeArrayShadow
 
 //                                                                                                                                                 mip
-#define SampleCmpLevel0Tex1D_4(Tex, Sampler, Coords, CompareValue, Offset)    textureLodOffset(Tex, _ToVec3((Coords).x,        0.0, CompareValue), 0.0, int(Offset))
+#define SampleCmpLevel0Tex1D_4(Tex, Sampler, Coords, CompareValue, Offset)    textureLodOffset(Tex, _ToVec3( Coords,           0.0, CompareValue), 0.0, int(Offset))
 #define SampleCmpLevel0Tex1DArr_4(Tex, Sampler, Coords, CompareValue, Offset) textureLodOffset(Tex, _ToVec3((Coords).x, (Coords).y, CompareValue), 0.0, int(Offset))
 #define SampleCmpLevel0Tex2D_4(Tex, Sampler, Coords, CompareValue, Offset)    textureLodOffset(Tex, _ToVec3((Coords).x, (Coords).y, CompareValue), 0.0, ivec2((Offset).xy))
 #define SampleCmpLevel0Tex2DArr_4(Tex, Sampler, Coords, CompareValue, Offset) 0.0 // No textureLodOffset for sampler2DArrayShadow
@@ -818,14 +848,14 @@ uvec4  _ToUvec( vec4  f4 ){ return _ToUvec4( f4.x, f4.y, f4.z, f4.w ); }
 #   define SampleBias_3(Tex, Sampler, Coords, Bias)         texture      (Tex, _ToVec(Coords), _ToFloat(Bias))
 #   define SampleBias_4(Tex, Sampler, Coords, Bias, Offset) textureOffset(Tex, _ToVec(Coords), Offset, _ToFloat(Bias))
 
-#   define SampleCmpTex1D_3(Tex, Sampler, Coords, CompareValue)      texture(Tex, _ToVec3((Coords).x,        0.0, CompareValue))
+#   define SampleCmpTex1D_3(Tex, Sampler, Coords, CompareValue)      texture(Tex, _ToVec3( Coords,           0.0, CompareValue))
 #   define SampleCmpTex1DArr_3(Tex, Sampler, Coords, CompareValue)   texture(Tex, _ToVec3((Coords).x, (Coords).y, CompareValue))
 #   define SampleCmpTex2D_3(Tex, Sampler, Coords, CompareValue)      texture(Tex, _ToVec3((Coords).x, (Coords).y, CompareValue))
 #   define SampleCmpTex2DArr_3(Tex, Sampler, Coords, CompareValue)   texture(Tex, _ToVec4((Coords).x, (Coords).y, (Coords).z, CompareValue))
 #   define SampleCmpTexCube_3(Tex, Sampler, Coords, CompareValue)    texture(Tex, _ToVec4((Coords).x, (Coords).y, (Coords).z, CompareValue))
 #   define SampleCmpTexCubeArr_3(Tex, Sampler, Coords, CompareValue) texture(Tex, _ToVec4((Coords).x, (Coords).y, (Coords).z, (Coords).w), _ToFloat(CompareValue))
 
-#   define SampleCmpTex1D_4(Tex, Sampler, Coords, CompareValue, Offset)    textureOffset(Tex, _ToVec3((Coords).x,        0.0, CompareValue), int(Offset))
+#   define SampleCmpTex1D_4(Tex, Sampler, Coords, CompareValue, Offset)    textureOffset(Tex, _ToVec3( Coords,           0.0, CompareValue), int(Offset))
 #   define SampleCmpTex1DArr_4(Tex, Sampler, Coords, CompareValue, Offset) textureOffset(Tex, _ToVec3((Coords).x, (Coords).y, CompareValue), int(Offset))
 #   define SampleCmpTex2D_4(Tex, Sampler, Coords, CompareValue, Offset)    textureOffset(Tex, _ToVec3((Coords).x, (Coords).y, CompareValue), ivec2((Offset).xy))
 #   define SampleCmpTex2DArr_4(Tex, Sampler, Coords, CompareValue, Offset) textureOffset(Tex, _ToVec4((Coords).x, (Coords).y, (Coords).z, CompareValue), ivec2((Offset).xy))
@@ -886,7 +916,7 @@ uvec4  _ToUvec( vec4  f4 ){ return _ToUvec4( f4.x, f4.y, f4.z, f4.w ); }
 #define LoadTex2DMSArr_3(Tex, Location, Sample, Offset)texelFetch(Tex, _ToIvec3( (Location).x + (Offset).x, (Location).y + (Offset).y, (Location).z), int(Sample)) // No texelFetchOffset for texture2DMSArray
 
 //https://www.opengl.org/sdk/docs/man/html/imageLoad.xhtml
-#define LoadRWTex1D_1(Tex, Location)    imageLoad(Tex, _ToIvec((Location).x)   )
+#define LoadRWTex1D_1(Tex, Location)    imageLoad(Tex, _ToInt(Location)        )
 #define LoadRWTex1DArr_1(Tex, Location) imageLoad(Tex, _ToIvec((Location).xy)  )
 #define LoadRWTex2D_1(Tex, Location)    imageLoad(Tex, _ToIvec((Location).xy)  )
 #define LoadRWTex2DArr_1(Tex, Location) imageLoad(Tex, _ToIvec((Location).xyz) )
diff --git a/Graphics/HLSL2GLSLConverterLib/include/GLSLDefinitions_inc.h b/Graphics/HLSL2GLSLConverterLib/include/GLSLDefinitions_inc.h
index cda30cef..34175df4 100644
--- a/Graphics/HLSL2GLSLConverterLib/include/GLSLDefinitions_inc.h
+++ b/Graphics/HLSL2GLSLConverterLib/include/GLSLDefinitions_inc.h
@@ -202,13 +202,8 @@
 "}\n"
 "#endif\n"
 "\n"
-"#ifndef GL_ES // double is not supported on GLES\n"
-"double asdouble(uint lowbits, uint highbits)\n"
-"{\n"
-"    return packDouble2x32( uvec2( lowbits, highbits ) );\n"
-"}\n"
-"#endif\n"
-"\n"
+"// Use #define as double is not supported on GLES\n"
+"#define asdouble(lowbits, highbits) packDouble2x32( uvec2( lowbits, highbits ) )\n"
 "\n"
 "// Floating point functions\n"
 "\n"
@@ -532,15 +527,50 @@
 "void _TypeConvertStore( out int   Dst, in uint  Src ){ Dst = int( Src ); }\n"
 "void _TypeConvertStore( out int   Dst, in float Src ){ Dst = int( Src ); }\n"
 "\n"
-"int _ToInt( int x )  { return int(x);       }\n"
-"int _ToInt( uint x ) { return int(x);       }\n"
-"int _ToInt( float x ){ return int(x);       }\n"
-"int _ToInt( bool x ) { return x ? 1 : 0;    }\n"
+"\n"
+"int _ToInt( int x )    { return int(x);     }\n"
+"int _ToInt( ivec2 v )  { return int(v.x);   }\n"
+"int _ToInt( ivec3 v )  { return int(v.x);   }\n"
+"int _ToInt( ivec4 v )  { return int(v.x);   }\n"
+"\n"
+"int _ToInt( uint x )   { return int(x);     }\n"
+"int _ToInt( uvec2 v )  { return int(v.x);   }\n"
+"int _ToInt( uvec3 v )  { return int(v.x);   }\n"
+"int _ToInt( uvec4 v )  { return int(v.x);   }\n"
+"\n"
+"int _ToInt( float x )  { return int(x);     }\n"
+"int _ToInt( vec2 v )   { return int(v.x);   }\n"
+"int _ToInt( vec3 v )   { return int(v.x);   }\n"
+"int _ToInt( vec4 v )   { return int(v.x);   }\n"
+"\n"
+"int _ToInt( bool x )   { return x   ? 1 : 0;}\n"
+"int _ToInt( bvec2 v )  { return v.x ? 1 : 0;}\n"
+"int _ToInt( bvec3 v )  { return v.x ? 1 : 0;}\n"
+"int _ToInt( bvec4 v )  { return v.x ? 1 : 0;}\n"
+"\n"
+"\n"
 "\n"
 "float _ToFloat( int x )  { return float(x);     }\n"
+"float _ToFloat( ivec2 v ){ return float(v.x);   }\n"
+"float _ToFloat( ivec3 v ){ return float(v.x);   }\n"
+"float _ToFloat( ivec4 v ){ return float(v.x);   }\n"
+"\n"
 "float _ToFloat( uint x ) { return float(x);     }\n"
+"float _ToFloat( uvec2 v ){ return float(v.x);   }\n"
+"float _ToFloat( uvec3 v ){ return float(v.x);   }\n"
+"float _ToFloat( uvec4 v ){ return float(v.x);   }\n"
+"\n"
 "float _ToFloat( float x ){ return float(x);     }\n"
-"float _ToFloat( bool x ) { return x ? 1.0 : 0.0;}\n"
+"float _ToFloat( vec2 v ) { return float(v.x);   }\n"
+"float _ToFloat( vec3 v ) { return float(v.x);   }\n"
+"float _ToFloat( vec4 v ) { return float(v.x);   }\n"
+"\n"
+"float _ToFloat( bool x ) { return x   ? 1.0 : 0.0;}\n"
+"float _ToFloat( bvec2 v ){ return v.x ? 1.0 : 0.0;}\n"
+"float _ToFloat( bvec3 v ){ return v.x ? 1.0 : 0.0;}\n"
+"float _ToFloat( bvec4 v ){ return v.x ? 1.0 : 0.0;}\n"
+"\n"
+"\n"
 "\n"
 "uint _ToUint( int x )  { return uint(x);     }\n"
 "uint _ToUint( uint x ) { return uint(x);     }\n"
@@ -796,7 +826,7 @@
 "// in the second to last component of Coords. (The second component of Coords is unused for 1D shadow lookups.)\n"
 "// For cube array textures, Dsub is specified as a separate parameter\n"
 "//                                                                                                                                     mip\n"
-"#define SampleCmpLevel0Tex1D_3(Tex, Sampler, Coords, CompareValue)      textureLod(Tex, _ToVec3((Coords).x,        0.0, CompareValue), 0.0)\n"
+"#define SampleCmpLevel0Tex1D_3(Tex, Sampler, Coords, CompareValue)      textureLod(Tex, _ToVec3( Coords,           0.0, CompareValue), 0.0)\n"
 "#define SampleCmpLevel0Tex1DArr_3(Tex, Sampler, Coords, CompareValue)   textureLod(Tex, _ToVec3((Coords).x, (Coords).y, CompareValue), 0.0)\n"
 "#define SampleCmpLevel0Tex2D_3(Tex, Sampler, Coords, CompareValue)      textureLod(Tex, _ToVec3((Coords).x, (Coords).y, CompareValue), 0.0)\n"
 "#define SampleCmpLevel0Tex2DArr_3(Tex, Sampler, Coords, CompareValue)   0.0 // No textureLod for sampler2DArrayShadow\n"
@@ -804,7 +834,7 @@
 "#define SampleCmpLevel0TexCubeArr_3(Tex, Sampler, Coords, CompareValue) 0.0 // No textureLod for samplerCubeArrayShadow\n"
 "\n"
 "//                                                                                                                                                 mip\n"
-"#define SampleCmpLevel0Tex1D_4(Tex, Sampler, Coords, CompareValue, Offset)    textureLodOffset(Tex, _ToVec3((Coords).x,        0.0, CompareValue), 0.0, int(Offset))\n"
+"#define SampleCmpLevel0Tex1D_4(Tex, Sampler, Coords, CompareValue, Offset)    textureLodOffset(Tex, _ToVec3( Coords,           0.0, CompareValue), 0.0, int(Offset))\n"
 "#define SampleCmpLevel0Tex1DArr_4(Tex, Sampler, Coords, CompareValue, Offset) textureLodOffset(Tex, _ToVec3((Coords).x, (Coords).y, CompareValue), 0.0, int(Offset))\n"
 "#define SampleCmpLevel0Tex2D_4(Tex, Sampler, Coords, CompareValue, Offset)    textureLodOffset(Tex, _ToVec3((Coords).x, (Coords).y, CompareValue), 0.0, ivec2((Offset).xy))\n"
 "#define SampleCmpLevel0Tex2DArr_4(Tex, Sampler, Coords, CompareValue, Offset) 0.0 // No textureLodOffset for sampler2DArrayShadow\n"
@@ -818,14 +848,14 @@
 "#   define SampleBias_3(Tex, Sampler, Coords, Bias)         texture      (Tex, _ToVec(Coords), _ToFloat(Bias))\n"
 "#   define SampleBias_4(Tex, Sampler, Coords, Bias, Offset) textureOffset(Tex, _ToVec(Coords), Offset, _ToFloat(Bias))\n"
 "\n"
-"#   define SampleCmpTex1D_3(Tex, Sampler, Coords, CompareValue)      texture(Tex, _ToVec3((Coords).x,        0.0, CompareValue))\n"
+"#   define SampleCmpTex1D_3(Tex, Sampler, Coords, CompareValue)      texture(Tex, _ToVec3( Coords,           0.0, CompareValue))\n"
 "#   define SampleCmpTex1DArr_3(Tex, Sampler, Coords, CompareValue)   texture(Tex, _ToVec3((Coords).x, (Coords).y, CompareValue))\n"
 "#   define SampleCmpTex2D_3(Tex, Sampler, Coords, CompareValue)      texture(Tex, _ToVec3((Coords).x, (Coords).y, CompareValue))\n"
 "#   define SampleCmpTex2DArr_3(Tex, Sampler, Coords, CompareValue)   texture(Tex, _ToVec4((Coords).x, (Coords).y, (Coords).z, CompareValue))\n"
 "#   define SampleCmpTexCube_3(Tex, Sampler, Coords, CompareValue)    texture(Tex, _ToVec4((Coords).x, (Coords).y, (Coords).z, CompareValue))\n"
 "#   define SampleCmpTexCubeArr_3(Tex, Sampler, Coords, CompareValue) texture(Tex, _ToVec4((Coords).x, (Coords).y, (Coords).z, (Coords).w), _ToFloat(CompareValue))\n"
 "\n"
-"#   define SampleCmpTex1D_4(Tex, Sampler, Coords, CompareValue, Offset)    textureOffset(Tex, _ToVec3((Coords).x,        0.0, CompareValue), int(Offset))\n"
+"#   define SampleCmpTex1D_4(Tex, Sampler, Coords, CompareValue, Offset)    textureOffset(Tex, _ToVec3( Coords,           0.0, CompareValue), int(Offset))\n"
 "#   define SampleCmpTex1DArr_4(Tex, Sampler, Coords, CompareValue, Offset) textureOffset(Tex, _ToVec3((Coords).x, (Coords).y, CompareValue), int(Offset))\n"
 "#   define SampleCmpTex2D_4(Tex, Sampler, Coords, CompareValue, Offset)    textureOffset(Tex, _ToVec3((Coords).x, (Coords).y, CompareValue), ivec2((Offset).xy))\n"
 "#   define SampleCmpTex2DArr_4(Tex, Sampler, Coords, CompareValue, Offset) textureOffset(Tex, _ToVec4((Coords).x, (Coords).y, (Coords).z, CompareValue), ivec2((Offset).xy))\n"
@@ -886,7 +916,7 @@
 "#define LoadTex2DMSArr_3(Tex, Location, Sample, Offset)texelFetch(Tex, _ToIvec3( (Location).x + (Offset).x, (Location).y + (Offset).y, (Location).z), int(Sample)) // No texelFetchOffset for texture2DMSArray\n"
 "\n"
 "//https://www.opengl.org/sdk/docs/man/html/imageLoad.xhtml\n"
-"#define LoadRWTex1D_1(Tex, Location)    imageLoad(Tex, _ToIvec((Location).x)   )\n"
+"#define LoadRWTex1D_1(Tex, Location)    imageLoad(Tex, _ToInt(Location)        )\n"
 "#define LoadRWTex1DArr_1(Tex, Location) imageLoad(Tex, _ToIvec((Location).xy)  )\n"
 "#define LoadRWTex2D_1(Tex, Location)    imageLoad(Tex, _ToIvec((Location).xy)  )\n"
 "#define LoadRWTex2DArr_1(Tex, Location) imageLoad(Tex, _ToIvec((Location).xyz) )\n"
diff --git a/Graphics/HLSL2GLSLConverterLib/include/HLSL2GLSLConverterImpl.h b/Graphics/HLSL2GLSLConverterLib/include/HLSL2GLSLConverterImpl.h
index ba1a6a58..7ec35bd8 100644
--- a/Graphics/HLSL2GLSLConverterLib/include/HLSL2GLSLConverterImpl.h
+++ b/Graphics/HLSL2GLSLConverterLib/include/HLSL2GLSLConverterImpl.h
@@ -328,7 +328,7 @@ namespace Diligent
             };
             void ParseShaderParameter(TokenListType::iterator &Token, ShaderParameterInfo &ParamInfo);
             void ProcessFunctionParameters( TokenListType::iterator &Token, std::vector<ShaderParameterInfo>& Params, bool &bIsVoid );
-            String AddFlatQualifier(const String& Type);
+            bool RequiresFlatQualifier(const String& Type);
             void ProcessFragmentShaderArguments( std::vector<ShaderParameterInfo>& Params,
                                                  String &GlobalVariables,
                                                  std::stringstream &ReturnHandlerSS,
@@ -538,4 +538,4 @@ namespace Diligent
 
 
 // * Input variables to a shader stage must be listed in exact same order as outputs from
-//   the previous stage. Function return value counts as the first output argument.
\ No newline at end of file
+//   the previous stage. Function return value counts as the first output argument.
diff --git a/Graphics/HLSL2GLSLConverterLib/src/HLSL2GLSLConverterImpl.cpp b/Graphics/HLSL2GLSLConverterLib/src/HLSL2GLSLConverterImpl.cpp
index 78bc255b..0759ab4c 100644
--- a/Graphics/HLSL2GLSLConverterLib/src/HLSL2GLSLConverterImpl.cpp
+++ b/Graphics/HLSL2GLSLConverterLib/src/HLSL2GLSLConverterImpl.cpp
@@ -2917,7 +2917,7 @@ void HLSL2GLSLConverterImpl::ConversionStream::ProcessShaderArgument( const Shad
     }
 }
 
-String HLSL2GLSLConverterImpl::ConversionStream::AddFlatQualifier(const String& Type)
+bool HLSL2GLSLConverterImpl::ConversionStream::RequiresFlatQualifier(const String& Type)
 {
     auto keywordIt = m_Converter.m_HLSLKeywords.find(Type.c_str());
     bool RequiresFlat = false;
@@ -2931,7 +2931,7 @@ String HLSL2GLSLConverterImpl::ConversionStream::AddFlatQualifier(const String&
                        (kw >= TokenType::kw_min12int  && kw <= TokenType::kw_min12int4x4) ||
                        (kw >= TokenType::kw_min16uint && kw <= TokenType::kw_min16uint4x4);
     }
-    return RequiresFlat ? String("flat ") + Type : Type;
+    return RequiresFlat;
 }
 
 void HLSL2GLSLConverterImpl::ConversionStream::ProcessFragmentShaderArguments(std::vector<ShaderParameterInfo>& Params,
@@ -2954,7 +2954,7 @@ void HLSL2GLSLConverterImpl::ConversionStream::ProcessFragmentShaderArguments(st
                     else
                     {
                         auto InputVarName = BuildParameterName(MemberStack, '_', "_in_");
-                        DefineInterfaceVar(InLocation++, "in", AddFlatQualifier(Param.Type), InputVarName, InterfaceVarsSS );   
+                        DefineInterfaceVar(InLocation++, RequiresFlatQualifier(Param.Type) ? "flat in" : "in", Param.Type, InputVarName, InterfaceVarsSS );
                         InitVariable(FullParamName, InputVarName, PrologueSS );
                     }
                 }
@@ -3071,7 +3071,7 @@ void HLSL2GLSLConverterImpl::ConversionStream::ProcessVertexShaderArguments( std
                     else
                     {
                         auto OutputVarName =  BuildParameterName(MemberStack, '_', "_vsout_");
-                        DefineInterfaceVar( OutLocation++, "out", AddFlatQualifier(Param.Type), OutputVarName, InterfaceVarsSS );
+                        DefineInterfaceVar( OutLocation++, RequiresFlatQualifier(Param.Type) ? "flat out" : "out", Param.Type, OutputVarName, InterfaceVarsSS );
                         ReturnHandlerSS << OutputVarName << " = " << FullParamName << ";\\\n";
                     }
                 }
@@ -3143,8 +3143,8 @@ void HLSL2GLSLConverterImpl::ConversionStream::ProcessGeometryShaderArguments( T
                     {
                         auto VarName = BuildParameterName(MemberStack, '_', "_gsin_");
                         auto InputVarName = VarName+"[i]";
-                        DefineInterfaceVar( inLocation++, "in", AddFlatQualifier(Param.Type), VarName + "[]", InterfaceVarsInSS );   
-                        InitVariable( FullIndexedParamName, InputVarName, PrologueSS );                    
+                        DefineInterfaceVar( inLocation++, RequiresFlatQualifier(Param.Type) ? "flat in" : "in", Param.Type, VarName + "[]", InterfaceVarsInSS );
+                        InitVariable( FullIndexedParamName, InputVarName, PrologueSS );
                     }
                 }
             );
@@ -3181,7 +3181,7 @@ void HLSL2GLSLConverterImpl::ConversionStream::ProcessGeometryShaderArguments( T
                         // variable that fragment shader will read.
                         // Note that gl_Layer is available in fragment shader, but only starting with GL4.3+
                         auto OutputVarName =  BuildParameterName(MemberStack, '_', "_gsout_");
-                        DefineInterfaceVar( outLocation++, "out", AddFlatQualifier(Param.Type), OutputVarName, InterfaceVarsOutSS );
+                        DefineInterfaceVar( outLocation++, RequiresFlatQualifier(Param.Type) ? "flat out" : "out", Param.Type, OutputVarName, InterfaceVarsOutSS );
                         EmitVertexDefineSS << OutputVarName << " = " << MacroArgumentName << ";\\\n";
                     }
                 }
@@ -3662,7 +3662,7 @@ void HLSL2GLSLConverterImpl::ConversionStream::ProcessHullShaderArguments( Token
                         auto VarName = BuildParameterName(MemberStack, '_', "_hsin_");
                         auto InputVarName = VarName + (IsPatch ? "[i]" : "");
                         // User-defined inputs can be declared as unbounded arrays
-                        DefineInterfaceVar( inLocation++, "in", AddFlatQualifier(Param.Type), VarName + (IsPatch ? "[]" : ""), InterfaceVarsInSS );   
+                        DefineInterfaceVar( inLocation++, RequiresFlatQualifier(Param.Type) ? "flat in" : "in", Param.Type, VarName + (IsPatch ? "[]" : ""), InterfaceVarsInSS );
                         InitVariable( FullIndexedParamName, InputVarName, PrologueSS );
                     }
                 }
@@ -3692,7 +3692,7 @@ void HLSL2GLSLConverterImpl::ConversionStream::ProcessHullShaderArguments( Token
                         auto OutputVarName =  BuildParameterName(MemberStack, '_', "_hsout_");
                         // Per-vertex outputs are aggregated into arrays.
                         // https://www.khronos.org/opengl/wiki/Tessellation_Control_Shader#Outputs
-                        DefineInterfaceVar( outLocation++, "out", AddFlatQualifier(Param.Type), OutputVarName + "[]", InterfaceVarsOutSS );
+                        DefineInterfaceVar( outLocation++, RequiresFlatQualifier(Param.Type) ? "flat out" : "out", Param.Type, OutputVarName + "[]", InterfaceVarsOutSS );
                         // A TCS can only ever write to the per-vertex output variable that corresponds to their invocation,
                         // so writes to per-vertex outputs must be of the form vertexTexCoord[gl_InvocationID]
                         ReturnHandlerSS << OutputVarName << "[gl_InvocationID] = " << SrcParamName << ";\\\n";
@@ -3868,7 +3868,7 @@ void HLSL2GLSLConverterImpl::ConversionStream::ProcessDomainShaderArguments( Tok
                         auto VarName = BuildParameterName(MemberStack, '_', "_dsin_");
                         auto InputVarName = VarName + (IsPatch ? "[i]" : "");
                         // User-defined inputs can be declared as unbounded arrays
-                        DefineInterfaceVar( inLocation++, "in", AddFlatQualifier(Param.Type), VarName + (IsPatch ? "[]" : ""), InterfaceVarsInSS );   
+                        DefineInterfaceVar( inLocation++, RequiresFlatQualifier(Param.Type) ? "flat out" : "in", Param.Type, VarName + (IsPatch ? "[]" : ""), InterfaceVarsInSS );
                         InitVariable( FullIndexedParamName, InputVarName, PrologueSS );
                     }
                     else
@@ -3894,7 +3894,7 @@ void HLSL2GLSLConverterImpl::ConversionStream::ProcessDomainShaderArguments( Tok
                         auto OutputVarName =  BuildParameterName(MemberStack, '_', "_hsout_");
                         // Per-vertex outputs are aggregated into arrays.
                         // https://www.khronos.org/opengl/wiki/Tessellation_Control_Shader#Outputs
-                        DefineInterfaceVar( outLocation++, "out", AddFlatQualifier(Param.Type), OutputVarName, InterfaceVarsOutSS );
+                        DefineInterfaceVar( outLocation++, RequiresFlatQualifier(Param.Type) ? "flat out" : "out", Param.Type, OutputVarName, InterfaceVarsOutSS );
                         // A TCS can only ever write to the per-vertex output variable that corresponds to their invocation,
                         // so writes to per-vertex outputs must be of the form vertexTexCoord[gl_InvocationID]
                         ReturnHandlerSS << OutputVarName << " = " << SrcParamName << ";\\\n";