vulkan: remap bindings to prevent clash

Vulkan does not differentiate between between bindings for textures
and buffers, as opposed to opengl. This can lead to situations, where
different uniforms get assigned the same binding leading to a crash,
when trying to update a descriptor set with the wrong type.
This patch solves this problem, by remapping the bindings when needed.

src/modules/graphics/vulkan/Graphics.cpp

@@ -579,9 +579,9 @@ void Graphics::initCapabilities()
 	capabilities.limits[LIMIT_CUBE_TEXTURE_SIZE] = properties.limits.maxImageDimensionCube;
 	capabilities.limits[LIMIT_TEXEL_BUFFER_SIZE] = properties.limits.maxTexelBufferElements;
 	capabilities.limits[LIMIT_SHADER_STORAGE_BUFFER_SIZE] = properties.limits.maxStorageBufferRange;
-	capabilities.limits[LIMIT_THREADGROUPS_X] = properties.limits.maxComputeWorkGroupSize[0];
-	capabilities.limits[LIMIT_THREADGROUPS_Y] = properties.limits.maxComputeWorkGroupSize[1];
-	capabilities.limits[LIMIT_THREADGROUPS_Z] = properties.limits.maxComputeWorkGroupSize[2];
+	capabilities.limits[LIMIT_THREADGROUPS_X] = properties.limits.maxComputeWorkGroupCount[0];
+	capabilities.limits[LIMIT_THREADGROUPS_Y] = properties.limits.maxComputeWorkGroupCount[1];
+	capabilities.limits[LIMIT_THREADGROUPS_Z] = properties.limits.maxComputeWorkGroupCount[2];
 	capabilities.limits[LIMIT_RENDER_TARGETS] = properties.limits.maxColorAttachments;
 	capabilities.limits[LIMIT_TEXTURE_MSAA] = static_cast<double>(getMsaaCount(64));
 	capabilities.limits[LIMIT_ANISOTROPY] = properties.limits.maxSamplerAnisotropy;

src/modules/graphics/vulkan/Shader.cpp

@@ -144,6 +144,72 @@ static const TBuiltInResource defaultTBuiltInResource = {
 static const uint32_t STREAMBUFFER_DEFAULT_SIZE = 16;
 static const uint32_t DESCRIPTOR_POOL_SIZE = 1;
 
+class BindingMapper
+{
+public:
+	uint32_t operator()(spirv_cross::CompilerGLSL &comp, std::vector<uint32_t> &spirv, const std::string &name, const spirv_cross::ID &id)
+	{
+		auto it = bindingMappings.find(name);
+		if (it == bindingMappings.end())
+		{
+			auto binding = comp.get_decoration(id, spv::DecorationBinding);
+
+			if (isFreeBinding(binding))
+			{
+				bindingMappings[name] = binding;
+				return binding;
+			}
+			else
+			{
+				uint32_t freeBinding = getFreeBinding();
+
+				uint32_t binaryBindingOffset;
+				if (!comp.get_binary_offset_for_decoration(id, spv::DecorationBinding, binaryBindingOffset))
+					throw love::Exception("could not get binary offset for binding");
+
+				spirv[binaryBindingOffset] = freeBinding;
+
+				bindingMappings[name] = freeBinding;
+
+				return freeBinding;
+			}
+		}
+		else
+			return it->second;
+	};
+
+
+private:
+	uint32_t getFreeBinding() {
+		for (uint32_t i = 0;; i++)
+		{
+			bool free = true;
+			for (const auto &entry : bindingMappings)
+			{
+				if (entry.second == i)
+				{
+					free = false;
+					break;
+				}
+			}
+			if (free)
+				return i;
+		}
+	}
+
+	bool isFreeBinding(uint32_t binding) {
+		for (const auto &entry : bindingMappings)
+		{
+			if (entry.second == binding)
+				return false;
+		}
+		return true;
+	}
+
+	std::map<std::string, uint32_t> bindingMappings;
+
+};
+
 static VkShaderStageFlagBits getStageBit(ShaderStageType type)
 {
 	switch (type)
@@ -735,14 +801,16 @@ void Shader::compileShaders()
 
 	uniformInfos.clear();
 
+	BindingMapper bindingMapper;
+
 	for (int i = 0; i < SHADERSTAGE_MAX_ENUM; i++)
 	{
 		auto shaderStage = (ShaderStageType)i;
 		auto glslangStage = getGlslShaderType(shaderStage);
 		auto intermediate = program->getIntermediate(glslangStage);
-		if (intermediate == nullptr) {
+
+		if (intermediate == nullptr)
 			continue;
-		}
 
 		spv::SpvBuildLogger logger;
 		glslang::SpvOptions opt;
@@ -751,31 +819,6 @@ void Shader::compileShaders()
 		std::vector<uint32_t> spirv;
 		GlslangToSpv(*intermediate, spirv, &logger, &opt);
 
-		std::string msgs = logger.getAllMessages();
-
-		VkShaderModuleCreateInfo createInfo{};
-		createInfo.sType = VK_STRUCTURE_TYPE_SHADER_MODULE_CREATE_INFO;
-		createInfo.codeSize = spirv.size() * sizeof(uint32_t);
-		createInfo.pCode = spirv.data();
-
-		auto device = vgfx->getDevice();
-
-		VkShaderModule shaderModule;
-
-		if (vkCreateShaderModule(device, &createInfo, nullptr, &shaderModule) != VK_SUCCESS) {
-			throw love::Exception("failed to create shader module");
-		}
-
-		shaderModules.push_back(shaderModule);
-
-		VkPipelineShaderStageCreateInfo shaderStageInfo{};
-		shaderStageInfo.sType = VK_STRUCTURE_TYPE_PIPELINE_SHADER_STAGE_CREATE_INFO;
-		shaderStageInfo.stage = getStageBit((ShaderStageType)i);
-		shaderStageInfo.module = shaderModule;
-		shaderStageInfo.pName = "main";
-
-		shaderStages.push_back(shaderStageInfo);
-
 		spirv_cross::CompilerGLSL comp(spirv);
 
 		// we only care about variables that are actually getting used.
@@ -792,7 +835,7 @@ void Shader::compileShaders()
 				auto defaultUniformBlockSize = comp.get_declared_struct_size(type);
 				localUniformStagingData.resize(defaultUniformBlockSize);
 				localUniformData.resize(defaultUniformBlockSize);
-				localUniformLocation = comp.get_decoration(resource.id, spv::DecorationBinding);
+				localUniformLocation = bindingMapper(comp, spirv, resource.name, resource.id);
 
 				memset(localUniformStagingData.data(), 0, defaultUniformBlockSize);
 				memset(localUniformData.data(), 0, defaultUniformBlockSize);
@@ -813,7 +856,7 @@ void Shader::compileShaders()
 			const SPIRType &imagetype = comp.get_type(basetype.image.type);
 
 			graphics::Shader::UniformInfo info;
-			info.location = comp.get_decoration(r.id, spv::DecorationBinding);
+			info.location = bindingMapper(comp, spirv, r.name, r.id);
 			info.baseType = UNIFORM_SAMPLER;
 			info.name = r.name;
 			info.count = type.array.empty() ? 1 : type.array[0];
@@ -894,7 +937,7 @@ void Shader::compileShaders()
 			if (!fillUniformReflectionData(u))
 				continue;
 
-			u.location = comp.get_decoration(r.id, spv::DecorationBinding);
+			u.location = bindingMapper(comp, spirv, r.name, r.id);
 			u.buffers = new love::graphics::Buffer *[u.count];
 
 			for (int i = 0; i < u.count; i++)
@@ -917,13 +960,11 @@ void Shader::compileShaders()
 				continue;
 
 			u.textures = new love::graphics::Texture *[u.count];
-			u.location = comp.get_decoration(r.id, spv::DecorationBinding);
+			u.location = bindingMapper(comp, spirv, r.name, r.id);
 
 			for (int i = 0; i < u.count; i++)
 				u.textures[i] = nullptr;
 
-			// some stuff missing ?
-
 			uniformInfos[u.name] = u;
 		}
 
@@ -936,6 +977,28 @@ void Shader::compileShaders()
 				attributes[name] = attributeLocation;
 			}
 		}
+
+		VkShaderModuleCreateInfo createInfo{};
+		createInfo.sType = VK_STRUCTURE_TYPE_SHADER_MODULE_CREATE_INFO;
+		createInfo.codeSize = spirv.size() * sizeof(uint32_t);
+		createInfo.pCode = spirv.data();
+
+		auto device = vgfx->getDevice();
+
+		VkShaderModule shaderModule;
+
+		if (vkCreateShaderModule(device, &createInfo, nullptr, &shaderModule) != VK_SUCCESS)
+			throw love::Exception("failed to create shader module");
+
+		shaderModules.push_back(shaderModule);
+
+		VkPipelineShaderStageCreateInfo shaderStageInfo{};
+		shaderStageInfo.sType = VK_STRUCTURE_TYPE_PIPELINE_SHADER_STAGE_CREATE_INFO;
+		shaderStageInfo.stage = getStageBit((ShaderStageType)i);
+		shaderStageInfo.module = shaderModule;
+		shaderStageInfo.pName = "main";
+
+		shaderStages.push_back(shaderStageInfo);
 	}
 
 	delete program;