Add support for shader hotreloading

src/Nazara/Graphics/UberShader.cpp

@@ -3,6 +3,7 @@
 // For conditions of distribution and use, see copyright notice in Config.hpp
 
 #include <Nazara/Graphics/UberShader.hpp>
+#include <Nazara/Core/Error.hpp>
 #include <Nazara/Graphics/Graphics.hpp>
 #include <Nazara/Renderer/RenderDevice.hpp>
 #include <Nazara/Shader/Ast/AstReflect.hpp>
@@ -13,13 +14,81 @@
 
 namespace Nz
 {
+	UberShader::UberShader(ShaderStageTypeFlags shaderStages, std::string moduleName) :
+	UberShader(shaderStages, *Graphics::Instance()->GetShaderModuleResolver(), std::move(moduleName))
+	{
+	}
+
+	UberShader::UberShader(ShaderStageTypeFlags shaderStages, ShaderModuleResolver& moduleResolver, std::string moduleName) :
+	m_shaderStages(shaderStages)
+	{
+		m_shaderModule = moduleResolver.Resolve(moduleName);
+		NazaraAssert(m_shaderModule, "invalid shader module");
+
+		Validate(*m_shaderModule);
+
+		m_onShaderModuleUpdated.Connect(moduleResolver.OnModuleUpdated, [this, name = std::move(moduleName)](ShaderModuleResolver* resolver, const std::string& updatedModuleName)
+		{
+			if (updatedModuleName != name)
+				return;
+
+			ShaderAst::ModulePtr newShaderModule = resolver->Resolve(name);
+			if (!newShaderModule)
+			{
+				NazaraError("failed to retrieve updated shader module " + name);
+				return;
+			}
+
+			try
+			{
+				// FIXME: Validate is destructive, in case of failure it can invalidate the shader
+				Validate(*newShaderModule);
+			}
+			catch (const std::exception& e)
+			{
+				NazaraError("failed to retrieve updated shader module " + name + ": " + e.what());
+				return;
+			}
+
+			m_shaderModule = std::move(newShaderModule);
+
+			// Clear cache
+			m_combinations.clear();
+
+			OnShaderUpdated(this);
+		});
+	}
+
 	UberShader::UberShader(ShaderStageTypeFlags shaderStages, ShaderAst::ModulePtr shaderModule) :
 	m_shaderModule(std::move(shaderModule)),
 	m_shaderStages(shaderStages)
 	{
-		NazaraAssert(m_shaderStages != 0, "there must be at least one shader stage");
 		NazaraAssert(m_shaderModule, "invalid shader module");
 
+		Validate(*m_shaderModule);
+	}
+
+	const std::shared_ptr<ShaderModule>& UberShader::Get(const Config& config)
+	{
+		auto it = m_combinations.find(config);
+		if (it == m_combinations.end())
+		{
+			ShaderWriter::States states;
+			states.optionValues = config.optionValues;
+			states.shaderModuleResolver = Graphics::Instance()->GetShaderModuleResolver();
+
+			std::shared_ptr<ShaderModule> stage = Graphics::Instance()->GetRenderDevice()->InstantiateShaderModule(m_shaderStages, *m_shaderModule, std::move(states));
+
+			it = m_combinations.emplace(config, std::move(stage)).first;
+		}
+
+		return it->second;
+	}
+
+	void UberShader::Validate(ShaderAst::Module& module)
+	{
+		NazaraAssert(m_shaderStages != 0, "there must be at least one shader stage");
+
 		//TODO: Try to partially sanitize shader?
 
 		std::size_t optionCount = 0;
@@ -44,26 +113,9 @@ namespace Nz
 		};
 
 		ShaderAst::AstReflect reflect;
-		reflect.Reflect(*m_shaderModule->rootNode, callbacks);
+		reflect.Reflect(*module.rootNode, callbacks);
 
 		if ((m_shaderStages & supportedStageType) != m_shaderStages)
 			throw std::runtime_error("shader doesn't support all required shader stages");
 	}
-
-	const std::shared_ptr<ShaderModule>& UberShader::Get(const Config& config)
-	{
-		auto it = m_combinations.find(config);
-		if (it == m_combinations.end())
-		{
-			ShaderWriter::States states;
-			states.optionValues = config.optionValues;
-			states.shaderModuleResolver = Graphics::Instance()->GetShaderModuleResolver();
-
-			std::shared_ptr<ShaderModule> stage = Graphics::Instance()->GetRenderDevice()->InstantiateShaderModule(m_shaderStages, *m_shaderModule, std::move(states));
-
-			it = m_combinations.emplace(config, std::move(stage)).first;
-		}
-
-		return it->second;
-	}
 }