Method

VipsImagegenerate

Declaration [src]

int
vips_image_generate (
  VipsImage* image,
  VipsStartFn start_fn,
  VipsGenerateFn generate_fn,
  VipsStopFn stop_fn,
  void* a,
  void* b
)

Description [src]

Generates an image. The action depends on the image type.

For images created with vips_image_new(), vips_image_generate() just attaches the start/generate/stop callbacks and returns.

For images created with vips_image_new_memory(), memory is allocated for the whole image and it is entirely generated using vips_sink_memory().

For images created with vips_image_new_temp_file() and friends, memory for a few scanlines is allocated and vips_sink_disc() used to generate the image in small chunks. As each chunk is generated, it is written to disc.

::: seealso vips_sink_memory(), vips_image_new(), vips_region_prepare().

Parameters

`start_fn`	`VipsStartFn`
	Start sequences with this function.
`generate_fn`	`VipsGenerateFn`
	Generate pixels with this function.
`stop_fn`	`VipsStopFn`
	Stop sequences with this function.
`a`	`void*`
	User data.
	The argument can be `NULL`.
	The data is owned by the caller of the function.
`b`	`void*`
	User data.
	The argument can be `NULL`.
	The data is owned by the caller of the function.

Return value

Returns:	`int`
	0 on success, or -1 on error.