vulkan 中 渲染通道創建相對獨立 ,不依賴其他的渲染組件。
typedef struct VkRenderPassCreateInfo {
VkStructureType sType;
const void* pNext;
VkRenderPassCreateFlags flags;
uint32_t attachmentCount;
const VkAttachmentDescription* pAttachments;
uint32_t subpassCount;
const VkSubpassDescription* pSubpasses;
uint32_t dependencyCount;
const VkSubpassDependency* pDependencies;
} VkRenderPassCreateInfo;
主要有 1. 關聯附件的數量,描述指針
2. 子通道數量,描述指針
3. 依賴數量,指針。
他們的相關描述
使用通道的地方 主要有三處
- 創建VkFramebufferCreateInfo 要指定framebuffer 屬於那個通道,一個通道可以指定多個 framebuffer
typedef struct VkFramebufferCreateInfo {
VkStructureType sType;
const void* pNext;
VkFramebufferCreateFlags flags;
VkRenderPass renderPass;
uint32_t attachmentCount;
const VkImageView* pAttachments;
uint32_t width;
uint32_t height;
uint32_t layers;
} VkFramebufferCreateInfo;
- 創建VkGraphicsPipelineCreateInfo 時,同樣 一個通道可以創建多個管線。
typedef struct VkGraphicsPipelineCreateInfo {
VkStructureType sType;
const void* pNext;
VkPipelineCreateFlags flags;
uint32_t stageCount;
const VkPipelineShaderStageCreateInfo* pStages;
const VkPipelineVertexInputStateCreateInfo* pVertexInputState;
const VkPipelineInputAssemblyStateCreateInfo* pInputAssemblyState;
const VkPipelineTessellationStateCreateInfo* pTessellationState;
const VkPipelineViewportStateCreateInfo* pViewportState;
const VkPipelineRasterizationStateCreateInfo* pRasterizationState;
const VkPipelineMultisampleStateCreateInfo* pMultisampleState;
const VkPipelineDepthStencilStateCreateInfo* pDepthStencilState;
const VkPipelineColorBlendStateCreateInfo* pColorBlendState;
const VkPipelineDynamicStateCreateInfo* pDynamicState;
VkPipelineLayout layout;
VkRenderPass renderPass;
uint32_t subpass;
VkPipeline basePipelineHandle;
int32_t basePipelineIndex;
} VkGraphicsPipelineCreateInfo;
- 開始寫入 命令緩衝 時,renderPassBeginInfo需要在vkCmdBeginRenderPass 作爲參數。
VKAPI_ATTR void VKAPI_CALL vkCmdBeginRenderPass(
VkCommandBuffer commandBuffer,
const VkRenderPassBeginInfo* pRenderPassBegin,
VkSubpassContents contents);
typedef struct VkRenderPassBeginInfo {
VkStructureType sType;
const void* pNext;
VkRenderPass renderPass;
VkFramebuffer framebuffer;
VkRect2D renderArea;
uint32_t clearValueCount;
const VkClearValue* pClearValues;
} VkRenderPassBeginInfo;
需要注意 由於 一個VkRenderPass 可以指定多個 framebuffer 和 pipeline 。所以在每次寫入渲染命令時 需要重新指定當前要使用的 framebuffer 和 pipeline。 framebuffer 就寫入上面的結構體裏,pipeline 用 vkCmdBindPipeline 重新綁定。