Shader: Fix function calls with OpenGL

tests/Engine/Shader/FunctionsTests.cpp

@@ -0,0 +1,91 @@
+#include <Engine/Shader/ShaderUtils.hpp>
+#include <Nazara/Core/File.hpp>
+#include <Nazara/Core/StringExt.hpp>
+#include <Nazara/Shader/ShaderBuilder.hpp>
+#include <Nazara/Shader/ShaderLangParser.hpp>
+#include <catch2/catch.hpp>
+#include <cctype>
+
+TEST_CASE("functions", "[Shader]")
+{
+	SECTION("Simple function call")
+	{
+		std::string_view nzslSource = R"(
+[nzsl_version("1.0")]
+module;
+
+struct FragOut
+{
+	[location(0)] value: f32
+}
+
+fn GetValue() -> f32
+{
+	return 42.0;
+}
+
+[entry(frag)]
+fn main() -> FragOut
+{
+	let output: FragOut;
+	output.value = GetValue();
+
+	return output;
+}
+)";
+
+		Nz::ShaderAst::ModulePtr shaderModule = Nz::ShaderLang::Parse(nzslSource);
+		shaderModule = SanitizeModule(*shaderModule);
+
+		ExpectGLSL(*shaderModule, R"(
+float GetValue()
+{
+	return 42.000000;
+}
+
+/*************** Outputs ***************/
+layout(location = 0) out float _NzOut_value;
+
+void main()
+{
+	FragOut output_;
+	output_.value = GetValue();
+	
+	_NzOut_value = output_.value;
+	return;
+}
+)");
+
+		ExpectNZSL(*shaderModule, R"(
+fn GetValue() -> f32
+{
+	return 42.000000;
+}
+
+[entry(frag)]
+fn main() -> FragOut
+{
+	let output: FragOut;
+	output.value = GetValue();
+	return output;
+}
+)");
+
+		ExpectSPIRV(*shaderModule, R"(
+OpFunction
+OpLabel
+OpReturnValue
+OpFunctionEnd
+OpFunction
+OpLabel
+OpVariable
+OpFunctionCall
+OpAccessChain
+OpStore
+OpLoad
+OpCompositeExtract
+OpStore
+OpReturn
+OpFunctionEnd)");
+	}
+}