Shader: Add support for FragCoord builtin

include/Nazara/Shader/Ast/Enums.hpp

@@ -43,7 +43,8 @@ namespace Nz::ShaderAst
 
 	enum class BuiltinEntry
 	{
-		VertexPosition, // gl_Position
+		FragCoord      = 1, // gl_FragCoord
+		VertexPosition = 0, // gl_Position
 	};
 
 	enum class ExpressionCategory

src/Nazara/Shader/GlslWriter.cpp

@@ -85,6 +85,7 @@ namespace Nz
 		};
 
 		std::unordered_map<ShaderAst::BuiltinEntry, Builtin> s_builtinMapping = {
+			{ ShaderAst::BuiltinEntry::FragCoord,      { "gl_FragCoord", ShaderStageType::Fragment } },
 			{ ShaderAst::BuiltinEntry::VertexPosition, { "gl_Position", ShaderStageType::Vertex } }
 		};
 	}
@@ -191,6 +192,10 @@ namespace Nz
 	{
 		switch (builtin)
 		{
+			case ShaderAst::BuiltinEntry::FragCoord:
+				Append("gl_FragCoord");
+				break;
+
 			case ShaderAst::BuiltinEntry::VertexPosition:
 				Append("gl_Position");
 				break;

src/Nazara/Shader/LangWriter.cpp

@@ -231,6 +231,10 @@ namespace Nz
 
 		switch (*builtin.builtin)
 		{
+			case ShaderAst::BuiltinEntry::FragCoord:
+				Append("builtin(fragcoord)");
+				break;
+
 			case ShaderAst::BuiltinEntry::VertexPosition:
 				Append("builtin(position)");
 				break;

src/Nazara/Shader/ShaderLangParser.cpp

@@ -34,6 +34,7 @@ namespace Nz::ShaderLang
 		};
 
 		std::unordered_map<std::string, ShaderAst::BuiltinEntry> s_builtinMapping = {
+			{ "fragcoord", ShaderAst::BuiltinEntry::FragCoord },
 			{ "position", ShaderAst::BuiltinEntry::VertexPosition }
 		};
 

src/Nazara/Shader/SpirvWriter.cpp

@@ -36,7 +36,8 @@ namespace Nz
 		};
 
 		std::unordered_map<ShaderAst::BuiltinEntry, Builtin> s_builtinMapping = {
-			{ ShaderAst::BuiltinEntry::VertexPosition, { "VertexPosition", ShaderStageType::Vertex, SpirvBuiltIn::Position } }
+			{ ShaderAst::BuiltinEntry::FragCoord,      { "FragmentCoordinates", ShaderStageType::Fragment, SpirvBuiltIn::FragCoord } },
+			{ ShaderAst::BuiltinEntry::VertexPosition, { "VertexPosition", ShaderStageType::Vertex,   SpirvBuiltIn::Position } }
 		};
 
 		class PreVisitor : public ShaderAst::AstRecursiveVisitor