# SDL_MapGPUTransferBuffer Maps a transfer buffer into application address space. ## Header File Defined in [<SDL3/SDL_gpu.h>](https://github.com/libsdl-org/SDL/blob/main/include/SDL3/SDL_gpu.h) ## Syntax ```c void * SDL_MapGPUTransferBuffer( SDL_GPUDevice *device, SDL_GPUTransferBuffer *transfer_buffer, bool cycle); ``` ## Function Parameters | | | | | ------------------------------------------------ | ------------------- | ----------------------------------------------------------- | | [SDL_GPUDevice](SDL_GPUDevice) * | **device** | a GPU context. | | [SDL_GPUTransferBuffer](SDL_GPUTransferBuffer) * | **transfer_buffer** | a transfer buffer. | | bool | **cycle** | if true, cycles the transfer buffer if it is already bound. | ## Return Value (void *) Returns the address of the mapped transfer buffer memory, or NULL on failure; call [SDL_GetError](SDL_GetError)() for more information. ## Remarks You must unmap the transfer buffer before encoding upload commands. The memory is owned by the graphics driver - do NOT call [SDL_free](SDL_free)() on the returned pointer. ## Version This function is available since SDL 3.2.0. ---- [CategoryAPI](CategoryAPI), [CategoryAPIFunction](CategoryAPIFunction), [CategoryGPU](CategoryGPU)