vulkan: reduce memory usage when many shaders are being used with many draw calls.

Descriptor pools are now shared among shaders that have the same descriptor counts, instead of being unique per shader.

src/modules/graphics/vulkan/Graphics.cpp

@@ -612,6 +612,7 @@ void Graphics::present(void *screenshotCallbackdata)
 	updateTemporaryResources();
 
 	currentFrame = (currentFrame + 1) % MAX_FRAMES_IN_FLIGHT;
+	realFrameIndex++;
 
 	beginFrame();
 }
@@ -1413,7 +1414,7 @@ void Graphics::beginFrame()
 	Vulkan::resetShaderSwitches();
 
 	for (const auto &shader : usedShadersInFrame)
-		shader->newFrame();
+		shader->newFrame(realFrameIndex);
 	usedShadersInFrame.clear();
 
 	localUniformBuffer->nextFrame();
@@ -2852,6 +2853,52 @@ VkSampler Graphics::getCachedSampler(const SamplerState &samplerState)
 	}
 }
 
+static uint64 getDescriptorPoolsKey(int dynamicUniformBuffers, int sampledTextures, int storageTextures, int texelBuffers, int storageBuffers)
+{
+	return (((int64)dynamicUniformBuffers & 0xFF) << 0)
+		| (((int64)sampledTextures & 0xFF) << 8)
+		| (((int64)storageTextures & 0xFF) << 16)
+		| (((int64)texelBuffers    & 0xFF) << 24)
+		| (((int64)storageBuffers  & 0xFF) << 32);
+}
+
+SharedDescriptorPools *Graphics::acquireDescriptorPools(int dynamicUniformBuffers, int sampledTextures, int storageTextures, int texelBuffers, int storageBuffers)
+{
+	uint64 key = getDescriptorPoolsKey(dynamicUniformBuffers, sampledTextures, storageTextures, texelBuffers, storageBuffers);
+
+	auto it = sharedDescriptorPools.find(key);
+	if (it != sharedDescriptorPools.end())
+	{
+		it->second.referenceCount++;
+		return it->second.pools;
+	}
+
+	auto pools = new SharedDescriptorPools(device, dynamicUniformBuffers, sampledTextures, storageTextures, texelBuffers, storageBuffers);
+
+	SharedDescriptorPoolsRef ref{};
+	ref.pools = pools;
+	ref.referenceCount = 1;
+	sharedDescriptorPools[key] = ref;
+
+	return pools;
+}
+
+void Graphics::releaseDescriptorPools(SharedDescriptorPools *p)
+{
+	uint64 key = getDescriptorPoolsKey(p->dynamicUniformBuffers, p->sampledTextures, p->storageTextures, p->texelBuffers, p->storageBuffers);
+
+	auto it = sharedDescriptorPools.find(key);
+	if (it != sharedDescriptorPools.end())
+	{
+		it->second.referenceCount--;
+		if (it->second.referenceCount <= 0)
+		{
+			delete it->second.pools;
+			sharedDescriptorPools.erase(key);
+		}
+	}
+}
+
 VkPipeline Graphics::createGraphicsPipeline(Shader *shader, const GraphicsPipelineConfigurationCore &configuration, const GraphicsPipelineConfigurationNoDynamicState *noDynamicStateConfiguration)
 {
 	VkGraphicsPipelineCreateInfo pipelineInfo{};