cairo-image-surface-create-for-data (data format width height stride)

data -- a pointer to a buffer supplied by the application in which to write contents, this pointer must be suitably aligned for any kind of variable, for example, a pointer returned by malloc
format -- a value of the cairo-format-t enumeration for the format of pixels in the buffer
width -- an integer with the width of the image to be stored in the buffer
height -- an integer with the height of the image to be stored in the buffer
stride -- an integer with the number of bytes between the start of rows in the buffer as allocated, this value should always be computed by the function cairo-format-stride-for-width before allocating the data buffer

A pointer to the newly created surface. The caller owns the surface and should call the function cairo-surface-destroy when done with it. This function always returns a valid pointer, but it will return a pointer to a "nil" surface in the case of an error such as out of memory or an invalid stride value. In case of invalid stride value the error status of the returned surface will be :invalid-stride. You can use the function cairo-surface-status to check for this. See the function cairo-surface-set-user-data for a means of attaching a destroy-notification fallback to the surface if necessary.

Creates an image surface for the provided pixel data. The output buffer must be kept around until the Cairo surface is destroyed or the function cairo-surface-finish is called on the surface. The initial contents of data will be used as the initial image contents; you must explicitly clear the buffer, using, for example, the functions cairo-rectangle and cairo-fill if you want it cleared.

Note that the stride may be larger than width*bytes per pixel to provide proper alignment for each pixel and row. This alignment is required to allow high-performance rendering within Cairo. The correct way to obtain a legal stride value is to call the function cairo-format-stride-for-width with the desired format and maximum image width value, and then use the resulting stride value to allocate the data and to create the image surface. See the function cairo-format-stride-for-width for example code.