Method

VipsRegionprepare

Declaration [src]

int
vips_region_prepare (
  VipsRegion* reg,
  const VipsRect* r
)

Description [src]

Vips_region_prepare() fills reg with pixels. After calling, you can address at least the area r with VIPS_REGION_ADDR() and get valid pixels.

vips_region_prepare() runs in-line, that is, computation is done by the calling thread, no new threads are involved, and computation blocks until the pixels are ready.

Use vips_sink_screen() to calculate an area of pixels in the background.

See also: vips_sink_screen(), vips_region_prepare_to().

Parameters

`r`	`VipsRect`
	`VipsRect` of pixels you need to be able to address.
	The data is owned by the caller of the function.

Return value

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