C Specification

To enqueue a command to copy a 2D or 3D rectangular region from the buffer object identified by src_buffer to a 2D or 3D region in the buffer object identified by dst_buffer, call the function

// Provided by CL_VERSION_1_1
cl_int clEnqueueCopyBufferRect(
    cl_command_queue command_queue,
    cl_mem src_buffer,
    cl_mem dst_buffer,
    const size_t* src_origin,
    const size_t* dst_origin,
    const size_t* region,
    size_t src_row_pitch,
    size_t src_slice_pitch,
    size_t dst_row_pitch,
    size_t dst_slice_pitch,
    cl_uint num_events_in_wait_list,
    const cl_event* event_wait_list,
    cl_event* event);
clEnqueueCopyBufferRect is missing before version 1.1.

Parameters

  • command_queue refers to the host command-queue in which the copy command will be queued. The OpenCL context associated with command_queue, src_buffer and dst_buffer must be the same.

  • src_origin defines the (x, y, z) offset in the memory region associated with src_buffer. For a 2D rectangle region, the z value given by src_origin[2] should be 0. The offset in bytes is computed as src_origin[2] × src_slice_pitch + src_origin[1] × src_row_pitch + src_origin[0].

  • dst_origin defines the (x, y, z) offset in the memory region associated with dst_buffer. For a 2D rectangle region, the z value given by dst_origin[2] should be 0. The offset in bytes is computed as dst_origin[2] × dst_slice_pitch + dst_origin[1] × dst_row_pitch + dst_origin[0].

  • region defines the (width in bytes, height in rows, depth in slices) of the 2D or 3D rectangle being copied. For a 2D rectangle, the depth value given by region[2] should be 1. The values in region cannot be 0.

  • src_row_pitch is the length of each row in bytes to be used for the memory region associated with src_buffer. If src_row_pitch is 0, src_row_pitch is computed as region[0].

  • src_slice_pitch is the length of each 2D slice in bytes to be used for the memory region associated with src_buffer. If src_slice_pitch is 0, src_slice_pitch is computed as region[1] × src_row_pitch.

  • dst_row_pitch is the length of each row in bytes to be used for the memory region associated with dst_buffer. If dst_row_pitch is 0, dst_row_pitch is computed as region[0].

  • dst_slice_pitch is the length of each 2D slice in bytes to be used for the memory region associated with dst_buffer. If dst_slice_pitch is 0, dst_slice_pitch is computed as region[1] × dst_row_pitch.

  • event_wait_list and num_events_in_wait_list specify events that need to complete before this particular command can be executed. If event_wait_list is NULL, then this particular command does not wait on any event to complete. If event_wait_list is NULL, num_events_in_wait_list must be 0. If event_wait_list is not NULL, the list of events pointed to by event_wait_list must be valid and num_events_in_wait_list must be greater than 0. The events specified in event_wait_list act as synchronization points. The context associated with events in event_wait_list and command_queue must be the same. The memory associated with event_wait_list can be reused or freed after the function returns.

  • event returns an event object that identifies this copy command and can be used to query or queue a wait for this command to complete. If event is NULL or the enqueue is unsuccessful, no event will be created and therefore it will not be possible to query the status of this command or to wait for this command to complete. If event_wait_list and event are not NULL, event must not refer to an element of the event_wait_list array.

Description

Copying begins at the source offset and destination offset which are computed as described below in the description for src_origin and dst_origin. Each byte of the region’s width is copied from the source offset to the destination offset. After copying each width, the source and destination offsets are incremented by their respective source and destination row pitches. After copying each 2D rectangle, the source and destination offsets are incremented by their respective source and destination slice pitches.

If src_buffer and dst_buffer are the same buffer object, src_row_pitch must equal dst_row_pitch and src_slice_pitch must equal dst_slice_pitch.

The usage information which indicates whether the memory object can be read or written by a kernel and/or the host and is given by the cl_mem_flags argument value specified when src_buffer or dst_buffer is created is ignored by clEnqueueCopyBufferRect.

clEnqueueCopyBufferRect returns CL_SUCCESS if the function is executed successfully. Otherwise, it returns one of the following errors:

  • CL_INVALID_COMMAND_QUEUE

    • if command_queue is not a valid host command-queue

  • CL_INVALID_CONTEXT

    • if the context associated with command_queue and src_buffer are not the same

    • if the context associated with command_queue and dst_buffer are not the same

    • if the context associated with command_queue and events in event_wait_list are not the same

  • CL_INVALID_MEM_OBJECT

    • if src_buffer is not a valid buffer object

    • if dst_buffer is not a valid buffer object

  • CL_MISALIGNED_SUB_BUFFER_OFFSET

    • if src_buffer is a sub-buffer object and the offset specified when the sub-buffer object was created is not aligned to the CL_DEVICE_MEM_BASE_ADDR_ALIGN value for the device associated with command_queue. This error code is missing before version 1.1.

    • if dst_buffer is a sub-buffer object and the offset specified when the sub-buffer object was created is not aligned to the CL_DEVICE_MEM_BASE_ADDR_ALIGN value for the device associated with command_queue. This error code is missing before version 1.1.

  • CL_INVALID_VALUE

    • if src_origin, dst_origin, or region is NULL

    • if the region specified by src_origin, region, src_row_pitch, and src_slice_pitch is out of bounds of src_buffer

    • if the region specified by dst_origin, region, dst_row_pitch, and dst_slice_pitch is out of bounds of dst_buffer

    • if any region array element is zero

    • if src_row_pitch is not equal to zero and is less than region[0]

    • if src_slice_pitch is not equal to zero and is less than region[1] times src_row_pitch

    • if src_slice_pitch is not equal to zero and is not a multiple of src_row_pitch

    • if dst_row_pitch is not equal to zero and is less than region[0]

    • if dst_slice_pitch is not equal to zero and is less than region[1] times dst_row_pitch

    • if dst_slice_pitch is not equal to zero and is not a multiple of dst_row_pitch

    • if src_buffer and dst_buffer are the same buffer object and src_row_pitch is not equal to dst_row_pitch

    • if src_buffer and dst_buffer are the same buffer object and src_slice_pitch is not equal to dst_slice_pitch

  • CL_INVALID_EVENT_WAIT_LIST

    • if event_wait_list is NULL and num_events_in_wait_list is greater than zero

    • if event_wait_list is not NULL and num_events_in_wait_list is zero

    • if event objects in event_wait_list are not valid events

  • CL_MEM_COPY_OVERLAP

    • if src_buffer and dst_buffer are the same buffer or sub-buffer object and the source and destination regions overlap

    • if src_buffer and dst_buffer are different sub-buffers of the same associated buffer object and they overlap

    • Refer to Checking for Memory Copy Overlap for details on how to determine if source and destination regions overlap.

  • CL_MEM_OBJECT_ALLOCATION_FAILURE

    • if there is a failure to allocate memory for the data store associated with src_buffer or dst_buffer

  • CL_INVALID_OPERATION

    • if dst_buffer was created with CL_MEM_IMMUTABLE_EXT

  • CL_OUT_OF_RESOURCES

    • if there is a failure to allocate resources required by the OpenCL implementation on the device

  • CL_OUT_OF_HOST_MEMORY

    • if there is a failure to allocate resources required by the OpenCL implementation on the host

See Also

CL_VERSION_1_1, cl_command_queue, cl_event, cl_mem, cl_uint

Document Notes

For more information, see the OpenCL Specification

This page is extracted from the OpenCL Specification. Fixes and changes should be made to the Specification, not directly.

Copyright

Copyright 2014-2026 The Khronos Group Inc.

SPDX-License-Identifier: CC-BY-4.0