UnitTests/Shader: Add sanitization and optimizations unit tests

tests/Engine/Shader/Optimizations.cpp

@@ -0,0 +1,145 @@
+#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 <Nazara/Shader/Ast/AstOptimizer.hpp>
+#include <Nazara/Shader/Ast/SanitizeVisitor.hpp>
+#include <catch2/catch.hpp>
+#include <cctype>
+
+void ExpectOptimization(std::string_view sourceCode, std::string_view expectedOptimizedResult)
+{
+	Nz::ShaderAst::StatementPtr shader;
+	REQUIRE_NOTHROW(shader = Nz::ShaderLang::Parse(sourceCode));
+	REQUIRE_NOTHROW(shader = Nz::ShaderAst::Sanitize(*shader));
+	REQUIRE_NOTHROW(shader = Nz::ShaderAst::Optimize(*shader));
+
+	ExpectNZSL(*shader, expectedOptimizedResult);
+}
+
+TEST_CASE("optimizations", "[Shader]")
+{
+	WHEN("propaging constants")
+	{
+		ExpectOptimization(R"(
+[entry(frag)]
+fn main()
+{
+	let output = 8.0 * (7.0 + 5.0) * 2.0 / 4.0 - 6.0;
+}
+)", R"(
+[entry(frag)]
+fn main()
+{
+	let output: f32 = 42.000000;
+)");
+	}
+
+	WHEN("propaging vector constants")
+	{
+		ExpectOptimization(R"(
+[entry(frag)]
+fn main()
+{
+	let output = vec4<f32>(8.0, 2.0, -7.0, 0.0) * (7.0 + 5.0) * 2.0 / 4.0;
+}
+)", R"(
+[entry(frag)]
+fn main()
+{
+	let output: vec4<f32> = vec4<f32>(48.000000, 12.000000, -42.000000, 0.000000);
+)");
+	}
+
+	WHEN("eliminating simple branch")
+	{
+		ExpectOptimization(R"(
+[entry(frag)]
+fn main()
+{
+	if (5 + 3 < 2)
+		discard;
+}
+)", R"(
+[entry(frag)]
+fn main()
+{
+	
+}
+)");
+	}
+
+	WHEN("eliminating multiple branches")
+	{
+		ExpectOptimization(R"(
+[entry(frag)]
+fn main()
+{
+	let output = 0.0;
+	if (5 <= 3)
+		output = 5.0;
+	else if (4 <= 3)
+		output = 4.0;
+	else if (3 <= 3)
+		output = 3.0;
+	else if (2 <= 3)
+		output = 2.0;
+	else if (1 <= 3)
+		output = 1.0;
+	else
+		output = 0.0;
+}
+)", R"(
+[entry(frag)]
+fn main()
+{
+	let output: f32 = 0.000000;
+	output = 3.000000;
+}
+)");
+	}
+
+
+	WHEN("eliminating multiple splitted branches")
+	{
+		ExpectOptimization(R"(
+[entry(frag)]
+fn main()
+{
+	let output = 0.0;
+	if (5 <= 3)
+		output = 5.0;
+	else
+	{
+		if (4 <= 3)
+			output = 4.0;
+		else
+		{
+			if (3 <= 3)
+				output = 3.0;
+			else
+			{
+				if (2 <= 3)
+					output = 2.0;
+				else
+				{
+					if (1 <= 3)
+						output = 1.0;
+					else
+						output = 0.0;
+				}
+			}
+		}
+	}
+}
+)", R"(
+[entry(frag)]
+fn main()
+{
+	let output: f32 = 0.000000;
+	output = 3.000000;
+}
+)");
+	}
+}