| Allegro CL version 8.2 Unrevised from 8.1 to 8.2. 8.1 version |
Arguments: window
Returns or sets with setf the stretch mode of window. The stretch mode determines how pixels are combined when using copy-pixels-to-stream to draw a pixmap on window such that the image is smaller in at least one direction. In that case, at least some pixels in the original image will map to a single displaced pixel. The stretch mode determines the color of those pixels.
The modes are:
:black-on-white
performs a Boolean AND
operation using the color values for the eliminated and existing
pixels. If the bitmap is a monochrome bitmap, this mode preserves
black pixels at the expense of white pixels.
:white-on-black
performs a Boolean OR
operation using the color values for the eliminated and existing
pixels. If the bitmap is a monochrome bitmap, this mode preserves
white pixels at the expense of black pixels.
:color-on-color
deletes the pixels. This
mode deletes all eliminated lines of pixels without trying to preserve
their information.
:halftone
maps pixels from the source
rectangle into blocks of pixels in the destination rectangle. The
average color over the destination block of pixels approximates the
color of the source pixels.
This option is not implemented on the GTK platform. GTK does not
appear to offer an option that is similar to the one that is built
into the Windows bitblitting functionality. Calling (setf stretch-mode) on GTK
will simply invoke the *gtk-compatibility-warning-action*
.
Copyright (c) 1998-2016, Franz Inc. Oakland, CA., USA. All rights reserved.
This page was not revised from the 8.1 page.
Created 2010.1.21.
| Allegro CL version 8.2 Unrevised from 8.1 to 8.2. 8.1 version |