Add code to allow for depth buffer query (Fixes #18)

openVulkanoCpp/Base/Render/IRenderer.hpp

@@ -35,5 +35,8 @@ namespace OpenVulkano
 		virtual Scene::UI::Ui* GetActiveUi() = 0;
 
 		virtual IResourceManager* GetIResourceManager() = 0;
+
+		virtual float GetLastQueriedDepthValue() = 0;
+		virtual void SetQueryDepthValue(const Math::Vector2f& depthCoordinates) = 0;
 	};
 }

openVulkanoCpp/Vulkan/DepthBufferQuery.cpp

@@ -0,0 +1,96 @@
+/*
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/.
+ */
+
+#include "DepthBufferQuery.hpp"
+#include "Renderer.hpp"
+#include <vulkan/vulkan.hpp>
+
+//TODO resize
+
+namespace OpenVulkano::Vulkan
+{
+	void DepthBufferQuery::Init()
+	{
+		auto device = renderer.GetContext().device->device;
+
+		vk::BufferCreateInfo bufferInfo = { {}, 25 * sizeof(float), vk::BufferUsageFlagBits::eTransferDst };
+		bufferDepth = device.createBuffer(bufferInfo);
+		const vk::MemoryRequirements memRequirements = device.getBufferMemoryRequirements(bufferDepth);
+		size_t size = memRequirements.size;
+		const vk::MemoryAllocateInfo memAllocInfo = { size, renderer.GetContext().device->GetMemoryType(memRequirements.memoryTypeBits, vk::MemoryPropertyFlagBits::eHostCoherent | vk::MemoryPropertyFlagBits::eHostVisible) };
+
+		memory = device.allocateMemory(memAllocInfo);
+		cpuDepthBuffer = static_cast<float*>(device.mapMemory(memory, 0, VK_WHOLE_SIZE, {}));
+
+		device.bindBufferMemory(bufferDepth, memory, 0);
+	}
+
+	void DepthBufferQuery::Close()
+	{
+		auto device = renderer.GetContext().device->device;
+		device.destroy(bufferDepth);
+		device.unmapMemory(memory);
+		device.free(memory);
+		cpuDepthBuffer = nullptr;
+	}
+	
+	void DepthBufferQuery::Resize(uint32_t width, uint32_t height)
+	{
+		//TODO
+	}
+	
+	float DepthBufferQuery::GetQueriedValue() const
+	{
+		if (cpuDepthBuffer[0] == -2) return -2;
+		if (cpuDepthBuffer[12] > 0 && cpuDepthBuffer[12] < 1) return cpuDepthBuffer[12];
+		double val = 0;
+		int validCount = 0;
+		for (int i = 0; i < 25; i++)
+		{
+			float f = cpuDepthBuffer[i];
+			if (f > 0 && f < 1)
+			{
+				val += f;
+				validCount++;
+			}
+		}
+		if (validCount == 0) return 1; // Prevent divide by 0
+		return val / validCount;
+	}
+	
+	vk::Offset3D DepthBufferQuery::GetCopyOffset() const
+	{
+		vk::Extent3D depthExtent = renderer.GetContext().swapChain.GetCurrentDepthBuffer().extent;
+		
+		int32_t x = static_cast<int32_t>(depthQueryCoordinates.x * depthExtent.width);
+		x = std::min<int32_t>(depthExtent.width - 5, std::max(0, x));
+		
+		int32_t y = static_cast<int32_t>(depthQueryCoordinates.y * depthExtent.height);
+		y = std::min<int32_t>(depthExtent.height - 5, std::max(0, y));
+		
+		return { x, y, 0 };
+	}
+
+	void DepthBufferQuery::Encode(vk::CommandBuffer& commandBuffer)
+	{
+		if (!copyDepthBuffer) return;
+		copyDepthBuffer = false;
+		std::fill(cpuDepthBuffer, cpuDepthBuffer + 25, -2.0f); // Invalidate data in buffer to allow detecting if copy is done
+		const vk::ImageAspectFlags aspectMask = vk::ImageAspectFlagBits::eDepth | vk::ImageAspectFlagBits::eStencil;
+		const Image& depthBufferImage = renderer.GetContext().swapChain.GetCurrentDepthBuffer();
+
+		constexpr vk::Extent3D copySize = { 5, 5, 1 };
+		const vk::ImageSubresourceLayers layout = { vk::ImageAspectFlagBits::eDepth, 0, 0, 1 };
+		vk::BufferImageCopy imgCopy = { 0, 5, 5, layout, GetCopyOffset(), copySize };
+
+		const vk::ImageMemoryBarrier imgMemBarrier({}, vk::AccessFlagBits::eTransferRead, vk::ImageLayout::eDepthStencilAttachmentOptimal, vk::ImageLayout::eTransferSrcOptimal, 0, 0, depthBufferImage.image, vk::ImageSubresourceRange(aspectMask, 0, 1, 0, 1));
+		commandBuffer.pipelineBarrier(vk::PipelineStageFlagBits::eTopOfPipe, vk::PipelineStageFlagBits::eTransfer, {}, nullptr, nullptr, imgMemBarrier);
+
+		commandBuffer.copyImageToBuffer(depthBufferImage.image, vk::ImageLayout::eTransferSrcOptimal, bufferDepth, 1, &imgCopy);
+
+		depthBufferImage.SetLayout(commandBuffer, aspectMask, vk::ImageLayout::eDepthStencilAttachmentOptimal, vk::ImageLayout::eTransferSrcOptimal);
+	}
+}

openVulkanoCpp/Vulkan/DepthBufferQuery.hpp

@@ -0,0 +1,48 @@
+/*
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/.
+ */
+
+#pragma once
+
+#include "Math/Math.hpp"
+#include "Vulkan/Image.hpp"
+
+namespace OpenVulkano::Vulkan
+{
+	class Renderer;
+
+	class DepthBufferQuery final
+	{
+		Renderer& renderer;
+		vk::DeviceMemory memory;
+		vk::Buffer bufferDepth;
+		float* cpuDepthBuffer = nullptr;
+		Math::Vector2f depthQueryCoordinates = { 0.5f, 0.5f };
+		bool copyDepthBuffer = true;
+		
+		vk::Offset3D GetCopyOffset() const;
+
+	public:
+		DepthBufferQuery(Renderer& renderer): renderer(renderer) {}
+
+		~DepthBufferQuery() { if (cpuDepthBuffer != nullptr) Close(); }
+
+		void Init();
+
+		void Close();
+
+		void Encode(vk::CommandBuffer& commandBuffer);
+		
+		void Resize(uint32_t width, uint32_t height);
+
+		float GetQueriedValue() const;
+
+		void SetQueryCoordinates(const Math::Vector2f& coords)
+		{
+			copyDepthBuffer = true;
+			depthQueryCoordinates = coords;
+		}
+	};
+}

openVulkanoCpp/Vulkan/FrameBuffer.hpp

@@ -90,5 +90,7 @@ namespace OpenVulkano::Vulkan
 		[[nodiscard]] const vk::Viewport& GetFullscreenViewport() const { return fullscreenViewport; }
 
 		[[nodiscard]] const vk::Rect2D& GetFullscreenScissor() const { return fullscreenScissor; }
+
+		[[nodiscard]] const Image& GetCurrentDepthBuffer() { return depthBuffer; }
 	};
 }

openVulkanoCpp/Vulkan/RenderPass.cpp

@@ -57,7 +57,7 @@ namespace OpenVulkano::Vulkan
 		if (m_frameBuffer->UseDepthBuffer())
 		{ // Depth attachment
 			attachments.emplace_back(vk::AttachmentDescriptionFlags(), m_frameBuffer->GetDepthFormat(), vk::SampleCountFlagBits::e1,
-									 m_useClearDepth ? vk::AttachmentLoadOp::eClear : vk::AttachmentLoadOp::eLoad, vk::AttachmentStoreOp::eDontCare, m_useClearDepth ? vk::AttachmentLoadOp::eClear : vk::AttachmentLoadOp::eLoad,
+									 m_useClearDepth ? vk::AttachmentLoadOp::eClear : vk::AttachmentLoadOp::eLoad, vk::AttachmentStoreOp::eStore, m_useClearDepth ? vk::AttachmentLoadOp::eClear : vk::AttachmentLoadOp::eLoad,
 									 vk::AttachmentStoreOp::eDontCare, vk::ImageLayout::eDepthStencilAttachmentOptimal, vk::ImageLayout::eDepthStencilAttachmentOptimal);
 			depthReference = new vk::AttachmentReference(1, vk::ImageLayout::eDepthStencilAttachmentOptimal);
 		}

openVulkanoCpp/Vulkan/Renderer.cpp

@@ -18,6 +18,11 @@
 
 namespace OpenVulkano::Vulkan
 {
+	Renderer::Renderer()
+		: depthBufferQuery(*this)
+	{
+	}
+
 	void Renderer::Init(IGraphicsAppManager* graphicsAppManager, IWindow* window)
 	{
 		logger = Logger::RENDER;
@@ -62,6 +67,8 @@ namespace OpenVulkano::Vulkan
 			}
 		}
 
+		depthBufferQuery.Init();
+
 		logger->info("Vulkan renderer initialized");
 	}
 
@@ -87,6 +94,7 @@ namespace OpenVulkano::Vulkan
 			closeables.pop_back();
 			closeable->Close();
 		}
+		depthBufferQuery.Close();
 		uiRenderer.Close();
 		resourceManager.Close();
 		commands.clear();
@@ -138,6 +146,7 @@ namespace OpenVulkano::Vulkan
 		CommandHelper* cmdHelper = GetCommandData(commands.size() - 1);
 		cmdHelper->cmdBuffer.executeCommands(submitBuffers[currentImageId].size(), submitBuffers[currentImageId].data());
 		context.swapChainRenderPass.End(cmdHelper->cmdBuffer);
+		depthBufferQuery.Encode(cmdHelper->cmdBuffer);
 		uiRenderer.DrawUiFrame(cmdHelper->cmdBuffer);
 		cmdHelper->cmdBuffer.end();
 		std::array<vk::PipelineStageFlags, 2> stateFlags = { vk::PipelineStageFlags(vk::PipelineStageFlagBits::eColorAttachmentOutput), vk::PipelineStageFlags(vk::PipelineStageFlagBits::eColorAttachmentOutput) };

openVulkanoCpp/Vulkan/Renderer.hpp

@@ -16,6 +16,7 @@
 #include "CommandHelper.hpp"
 #include "Base/EngineConfiguration.hpp"
 #include "Resources/ResourceManager.hpp"
+#include "DepthBufferQuery.hpp"
 #include <vector>
 #include <thread>
 
@@ -40,9 +41,10 @@ namespace OpenVulkano::Vulkan
 		std::vector<std::vector<vk::CommandBuffer>> submitBuffers;
 		UiRenderer uiRenderer;
 		std::vector<ICloseable*> closeables;
+		DepthBufferQuery depthBufferQuery;
 
 	public:
-		Renderer() = default;
+		Renderer();
 		~Renderer() override = default;
 
 		void Init(IGraphicsAppManager* graphicsAppManager, IWindow* window) override;
@@ -86,5 +88,9 @@ namespace OpenVulkano::Vulkan
 		void UnregisterCloseable(ICloseable* closeable) { Utils::Remove(closeables, closeable); }
 
 		IResourceManager* GetIResourceManager() override { return &resourceManager; }
+
+
+		float GetLastQueriedDepthValue() override { return depthBufferQuery.GetQueriedValue(); }
+		void SetQueryDepthValue(const Math::Vector2f& depthCoordinates) override { depthBufferQuery.SetQueryCoordinates(depthCoordinates); }
 	};
 }

openVulkanoCpp/Vulkan/SwapChain.hpp

@@ -45,7 +45,7 @@ namespace OpenVulkano
 			vk::PresentModeKHR presentMode;
 			std::vector<vk::Semaphore> imageAvailableSemaphores;
 			uint32_t currentSemaphoreId = 0;
-			vk::Extent2D size{0,0};
+			vk::Extent2D size{ 0, 0 };
 
 		public:
 			vk::SwapchainKHR swapChain;
@@ -59,10 +59,7 @@ namespace OpenVulkano
 
 			void Resize(uint32_t newWidth, uint32_t newHeight);
 
-			[[nodiscard]] vk::Extent2D GetSize() const
-			{
-				return size;
-			}
+			[[nodiscard]] vk::Extent2D GetSize() const { return size; }
 			
 			uint32_t AcquireNextImage(const vk::Fence& fence = vk::Fence());
 
@@ -81,10 +78,7 @@ namespace OpenVulkano
 				}
 			}
 
-			[[nodiscard]] uint32_t GetImageCount() const
-			{
-				return images.size();
-			}
+			[[nodiscard]] uint32_t GetImageCount() const { return images.size(); }
 
 			vk::Semaphore& GetCurrentSemaphore() { return imageAvailableSemaphores[currentSemaphoreId]; }
 
@@ -96,10 +90,7 @@ namespace OpenVulkano
 			void DestroySwapChain();
 
 		protected:
-			vk::Format FindColorFormat() override
-			{
-				return surfaceFormat.format;
-			}
+			[[nodiscard]] vk::Format FindColorFormat() override { return surfaceFormat.format; }
 
 			virtual vk::PresentModeKHR ChosePresentMode();