create_similar_image_surface


Description:

[ Version ( since = "3.10" ) ]
public ImageSurface create_similar_image_surface (int format, int width, int height, int scale)

Create a new image surface that is efficient to draw on the given this.

Initially the surface contents are all 0 (transparent if contents have transparency, black otherwise.)

The width and height of the new surface are not affected by the scaling factor of the this , or by the scale argument; they are the size of the surface in device pixels. If you wish to create an image surface capable of holding the contents of this you can use:

  int scale = gdk_window_get_scale_factor (window);
int width = gdk_window_get_width (window) * scale;
int height = gdk_window_get_height (window) * scale;

// format is set elsewhere
cairo_surface_t *surface =
gdk_window_create_similar_image_surface (window,
format,
width, height,
scale);

Note that unlike Surface.similar_image, the new surface's device scale is set to scale, or to the scale factor of this if scale is 0.

Parameters:

this

window to make new surface similar to, or null if none

format

the format for the new surface

width

width of the new surface

height

height of the new surface

scale

the scale of the new surface, or 0 to use same as this

Returns:

a pointer to the newly allocated surface. The caller owns the surface and should call cairo_surface_destroy when done with it.

This function always returns a valid pointer, but it will return a pointer to a “nil” surface if other is already in an error state or any other error occurs.