From 8fb7bb78a5eb4bdbc766931084c2f0a819c9a2fd Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=A9r=C3=B4me=20Leclercq?= <lynix680@gmail.com>
Date: Thu, 27 Aug 2020 19:26:59 +0200
Subject: [PATCH] Add a shader generation unit test

---
 build/scripts/tools/ndk_server.lua   |   1 +
 tests/Engine/Shader/AccessMember.cpp | 145 +++++++++++++++++++++++++++
 2 files changed, 146 insertions(+)
 create mode 100644 tests/Engine/Shader/AccessMember.cpp

diff --git a/build/scripts/tools/ndk_server.lua b/build/scripts/tools/ndk_server.lua
index 96ef7a0ab..e50d8c802 100644
--- a/build/scripts/tools/ndk_server.lua
+++ b/build/scripts/tools/ndk_server.lua
@@ -46,5 +46,6 @@ TOOL.Libraries = {
 	"NazaraNetwork",
 	"NazaraPhysics2D",
 	"NazaraPhysics3D",
+	"NazaraShader",
 	"NazaraUtility"
 }
diff --git a/tests/Engine/Shader/AccessMember.cpp b/tests/Engine/Shader/AccessMember.cpp
new file mode 100644
index 000000000..7ed92bd9c
--- /dev/null
+++ b/tests/Engine/Shader/AccessMember.cpp
@@ -0,0 +1,145 @@
+#include <Nazara/Core/File.hpp>
+#include <Nazara/Shader/GlslWriter.hpp>
+#include <Nazara/Shader/ShaderAst.hpp>
+#include <Nazara/Shader/ShaderBuilder.hpp>
+#include <Nazara/Shader/SpirvPrinter.hpp>
+#include <Nazara/Shader/SpirvWriter.hpp>
+#include <Catch/catch.hpp>
+#include <cctype>
+
+std::string_view Trim(std::string_view str)
+{
+	while (!str.empty() && std::isspace(str.front()))
+		str.remove_prefix(1);
+
+	while (!str.empty() && std::isspace(str.back()))
+		str.remove_suffix(1);
+
+	return str;
+}
+
+void ExpectingGLSL(const Nz::ShaderAst& shader, std::string_view expectedOutput)
+{
+	Nz::GlslWriter writer;
+
+	std::string output = writer.Generate(shader);
+	std::size_t funcOffset = output.find("void main()");
+	std::string_view subset = Trim(output).substr(funcOffset);
+	expectedOutput = Trim(expectedOutput);
+
+	REQUIRE(subset == expectedOutput);
+}
+
+void ExpectingSpirV(const Nz::ShaderAst& shader, std::string_view expectedOutput)
+{
+	Nz::SpirvWriter writer;
+	auto spirv = writer.Generate(shader);
+
+	Nz::SpirvPrinter printer;
+
+	Nz::SpirvPrinter::Settings settings;
+	settings.printHeader = false;
+	settings.printParameters = false;
+
+	std::string output = printer.Print(spirv.data(), spirv.size(), settings);
+	std::size_t funcOffset = output.find("OpFunction");
+	std::string_view subset = Trim(output).substr(funcOffset);
+	expectedOutput = Trim(expectedOutput);
+
+	REQUIRE(subset == expectedOutput);
+}
+
+SCENARIO("Shader generation", "[Shader]")
+{
+	SECTION("Nested member loading")
+	{
+		Nz::ShaderAst baseShader(Nz::ShaderStageType::Vertex);
+		baseShader.AddStruct("innerStruct", {
+			{
+				"field",
+				Nz::ShaderNodes::BasicType::Float3
+			}
+		});
+		
+		baseShader.AddStruct("outerStruct", {
+			{
+				"s",
+				"innerStruct"
+			}
+		});
+
+		baseShader.AddUniform("ubo", "outerStruct");
+		baseShader.AddOutput("result", Nz::ShaderNodes::BasicType::Float1);
+
+		SECTION("Nested AccessMember")
+		{
+			Nz::ShaderAst shader = baseShader;
+
+			auto uniform = Nz::ShaderBuilder::Uniform("ubo", "outerStruct");
+			auto output = Nz::ShaderBuilder::Output("result", Nz::ShaderNodes::BasicType::Float1);
+
+			auto access = Nz::ShaderBuilder::Swizzle(Nz::ShaderBuilder::AccessMember(Nz::ShaderBuilder::AccessMember(Nz::ShaderBuilder::Identifier(uniform), 0, "innerStruct"), 0, Nz::ShaderNodes::BasicType::Float3), Nz::ShaderNodes::SwizzleComponent::Third);
+			auto assign = Nz::ShaderBuilder::Assign(Nz::ShaderBuilder::Identifier(output), access);
+
+			shader.AddFunction("main", Nz::ShaderBuilder::ExprStatement(assign));
+
+			SECTION("Generating GLSL")
+			{
+				ExpectingGLSL(shader, R"(
+void main()
+{
+	result = ubo.s.field.z;
+}
+)");
+			}
+			SECTION("Generating Spir-V")
+			{
+				ExpectingSpirV(shader, R"(
+OpFunction
+OpLabel
+OpAccessChain
+OpAccessChain
+OpLoad
+OpCompositeExtract
+OpStore
+OpReturn
+OpFunctionEnd)");
+			}
+		}
+
+		SECTION("AccessMember with multiples fields")
+		{
+			Nz::ShaderAst shader = baseShader;
+
+			auto uniform = Nz::ShaderBuilder::Uniform("ubo", "outerStruct");
+			auto output = Nz::ShaderBuilder::Output("result", Nz::ShaderNodes::BasicType::Float1);
+
+			auto access = Nz::ShaderBuilder::Swizzle(Nz::ShaderBuilder::AccessMember(Nz::ShaderBuilder::Identifier(uniform), std::vector<std::size_t>{ 0, 0 }, Nz::ShaderNodes::BasicType::Float3), Nz::ShaderNodes::SwizzleComponent::Third);
+			auto assign = Nz::ShaderBuilder::Assign(Nz::ShaderBuilder::Identifier(output), access);
+
+			shader.AddFunction("main", Nz::ShaderBuilder::ExprStatement(assign));
+
+			SECTION("Generating GLSL")
+			{
+				ExpectingGLSL(shader, R"(
+void main()
+{
+	result = ubo.s.field.z;
+}
+)");
+			}
+			SECTION("Generating Spir-V")
+			{
+				ExpectingSpirV(shader, R"(
+OpFunction
+OpLabel
+OpAccessChain
+OpLoad
+OpCompositeExtract
+OpStore
+OpReturn
+OpFunctionEnd)");
+			}
+		}
+	}
+}