网站基础服务,WordPress离线博客,网站搭建语言,网页开发需要学什么技术目录 先叨叨git信息关键代码VulkanEnv::FindHostVisitbaleMemoryTypeIndex()TestPipeLine::CreateFramebuffers() 与网上大多数文章不同#xff0c;其他文章基本上都使用窗口框架#xff08;X11、GLFW、WSL等#xff09;提供的surface来显示Vulkan渲染出的图像。我认为那样会… 目录 先叨叨git信息关键代码VulkanEnv::FindHostVisitbaleMemoryTypeIndex()TestPipeLine::CreateFramebuffers() 与网上大多数文章不同其他文章基本上都使用窗口框架X11、GLFW、WSL等提供的surface来显示Vulkan渲染出的图像。我认为那样会屏蔽很多细节因此我选择使用更原生的方式即让Vulkan渲染到一块内存中然后将内存读出再渲染到屏幕上。其实surface只不过是封装好的Image而以。 先叨叨
上一篇创建的RenderPass但还没有给RenderPass分配内存空间。本篇来介绍如何给RenderPass创建内存空间。RenderPass与内存的对应关系如下图 Vulkan的架构设计将RenderPass到Memeory的对应关系拉了一条很长的线路至于为什么和这么设计的好处我还理解不到。所以先死记硬背下来。
RenderPass中有很多个Attachment每个Attachment对应一块内存空间。Attachment用于指明该空间在渲染时具体起到的作用。如颜色缓存、深度缓存、模板缓存等。多个Attachment由一个Subpass进行关联指明一次渲染会用到Subpass中的所有的Attachment。比如将第一个Attachment当作颜色缓存将第二Attachment当作深度缓存。一个RenderPass对应一个FrameBuffer。而FrameBuffer中有多个ImageView每个ImageView对应一个RenderPass中的Attachment。。ImageView还不是真正的内存空间。ImageView会关联到一个Image。Image是对内存空间的描述但Image并不是真正的内存空间。真正的内存空间是MemoryMemory需要从Device上申请申请完后需要绑定到Image上。
git信息
repository: https://gitee.com/J8_series/easy-car-uitag: 09-CreateFrameBufferurl: https://gitee.com/J8_series/easy-car-ui/tree/09-CreateFrameBuffer
关键代码
VulkanEnv::FindHostVisitbaleMemoryTypeIndex()
上面介绍了Memory需要从Device上申请而Device可能有多个内存空间堆。我希望找到一个GPU和CPU都能访问的堆因为我想把渲染完的图片拷贝出来。渲染需要GPU访问而拷贝需要CPU访问。
void VulkanEnv::FindHostVisitbaleMemoryTypeIndex()
{VkPhysicalDeviceMemoryProperties pMemoryProperties;vkGetPhysicalDeviceMemoryProperties(m_selectedPhysicalDevice, pMemoryProperties);bool found false;for (uint32_t i 0; i pMemoryProperties.memoryTypeCount; i){if (pMemoryProperties.memoryTypes[i].propertyFlags VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT){m_hostVisitbaleMemoryTypeIndex i;found true;break;}}if (false found){throw std::runtime_error(To find host visiable memory is failed);}
}TestPipeLine::CreateFramebuffers()
本方法流程如下
创建Image申请Memory将Image和Memory 绑定到一起创建ImageView并关联到Image上创建FrameBuffer。framebufferInfo.pAttachments的值是一个ImageView数组数组里的元素顺序要与RenderPass中的Attachment顺序一致。Vulkan用这种方式实现了Attachment和ImageView的对应。 void TestPipeline::CreateFramebuffers(){//https://registry.khronos.org/vulkan/specs/latest/html/vkspec.html#VkImageCreateInfoVkImageCreateInfo imageCreateInfo{};imageCreateInfo.sType VK_STRUCTURE_TYPE_IMAGE_CREATE_INFO;imageCreateInfo.pNext nullptr;imageCreateInfo.flags;imageCreateInfo.imageType VK_IMAGE_TYPE_2D;imageCreateInfo.format VK_FORMAT_R8G8B8A8_UINT;imageCreateInfo.extent VkExtent3D{m_width, m_height, 1};imageCreateInfo.mipLevels 1;imageCreateInfo.arrayLayers 1;imageCreateInfo.samples VK_SAMPLE_COUNT_1_BIT;imageCreateInfo.tiling VK_IMAGE_TILING_LINEAR;imageCreateInfo.usage VK_IMAGE_USAGE_STORAGE_BIT | VK_IMAGE_USAGE_COLOR_ATTACHMENT_BIT;imageCreateInfo.sharingMode VK_SHARING_MODE_EXCLUSIVE;imageCreateInfo.queueFamilyIndexCount 0;imageCreateInfo.pQueueFamilyIndices nullptr;imageCreateInfo.initialLayout VK_IMAGE_LAYOUT_UNDEFINED;if (VK_SUCCESS ! vkCreateImage(m_device, imageCreateInfo, nullptr, m_image)){throw std::runtime_error(To create image is failed!);}// https://registry.khronos.org/vulkan/specs/latest/html/vkspec.html#VkMemoryAllocateInfoVkMemoryAllocateInfo memoryAllocationInfo;memoryAllocationInfo.sType VK_STRUCTURE_TYPE_MEMORY_ALLOCATE_INFO;memoryAllocationInfo.pNext nullptr;memoryAllocationInfo.memoryTypeIndex m_memroyTypeIndex;memoryAllocationInfo.allocationSize m_width * m_height * 4;// https://registry.khronos.org/vulkan/specs/latest/html/vkspec.html#vkAllocateMemoryif (VK_SUCCESS ! vkAllocateMemory(m_device, memoryAllocationInfo, nullptr, m_imageMemory)){throw std::runtime_error(To allocate memory is failed!);}// https://registry.khronos.org/vulkan/specs/latest/html/vkspec.html#vkBindImageMemoryif (VK_SUCCESS ! vkBindImageMemory(m_device, m_image, m_imageMemory, 0)){throw std::runtime_error(To bind memory is failed!);}//https://registry.khronos.org/vulkan/specs/latest/html/vkspec.html#VkImageViewCreateInfoVkImageViewCreateInfo imageViewCreateInfo{};imageViewCreateInfo.sType VK_STRUCTURE_TYPE_IMAGE_VIEW_CREATE_INFO;imageViewCreateInfo.pNext nullptr;imageViewCreateInfo.flags 0;imageViewCreateInfo.image m_image;imageViewCreateInfo.viewType VK_IMAGE_VIEW_TYPE_2D;imageViewCreateInfo.format VK_FORMAT_R8G8B8A8_UINT;imageViewCreateInfo.components.r VK_COMPONENT_SWIZZLE_IDENTITY;imageViewCreateInfo.components.g VK_COMPONENT_SWIZZLE_IDENTITY;imageViewCreateInfo.components.b VK_COMPONENT_SWIZZLE_IDENTITY;imageViewCreateInfo.components.a VK_COMPONENT_SWIZZLE_IDENTITY;imageViewCreateInfo.subresourceRange.aspectMask VK_IMAGE_ASPECT_COLOR_BIT;imageViewCreateInfo.subresourceRange.baseMipLevel 0;imageViewCreateInfo.subresourceRange.levelCount 1;imageViewCreateInfo.subresourceRange.baseArrayLayer 0;imageViewCreateInfo.subresourceRange.layerCount 1;if (VK_SUCCESS ! vkCreateImageView(m_device, imageViewCreateInfo, nullptr, m_imageView)){throw std::runtime_error(To create image view is failed!);}VkFramebufferCreateInfo framebufferInfo{};framebufferInfo.sType VK_STRUCTURE_TYPE_FRAMEBUFFER_CREATE_INFO;framebufferInfo.renderPass m_renderPass;framebufferInfo.attachmentCount 1;framebufferInfo.pAttachments m_imageView;framebufferInfo.width m_width;framebufferInfo.height m_height;framebufferInfo.layers 1;//https://registry.khronos.org/vulkan/specs/latest/html/vkspec.html#vkCreateFramebufferif (VK_SUCCESS ! vkCreateFramebuffer(m_device, framebufferInfo, nullptr, m_framebuffer)) {throw std::runtime_error(To create framebuffer is failed!);}}
