VkCommandBuffer

A VkCommandBuffer is a fundamental object in the Vulkan graphics API, used to record a sequence of graphics and compute commands. Think of it as a list of instructions that the GPU will execute. Command buffers are typically recorded on the CPU and then submitted to the GPU for execution.

There are several stages to using a VkCommandBuffer. First, it must be created from a VkCommandPool. This pool manages the memory and resources for command buffers. Once created, a command buffer is in a recording state. During this state, you can issue commands to it, such as setting pipelines, binding descriptor sets, drawing geometry, or dispatching compute work. After all commands are recorded, the command buffer must be ended, transitioning it to a executable state.

Executable command buffers can then be submitted to a VkQueue for execution on the GPU. A single queue can execute multiple command buffers, either sequentially or concurrently depending on the queue's capabilities. For synchronization, Vulkan provides semaphores and fences to signal when command buffer execution has completed.

Command buffers can be recorded once and executed multiple times, which is highly efficient. They can also be reset, allowing their contents to be overwritten. The ability to record commands ahead of time and submit them efficiently is a key performance advantage of Vulkan.