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| Allegro CL version 9.0 Unrevised from 8.2 to 9.0. 8.2 version

## mask-contents

Arguments: pixmap

Returns a value that specifies which pixels of a `pixmap` are transparent (if any). The value may be set either by calling (setf mask-contents) or by passing the `:mask-contents` initarg to make-instance when creating the pixmap.

pixmap should be a pixmap object. See cg-pixmaps.htm for an overview of pixmap functionality.

The value returned by mask-contents or passed to (setf mask-contents) is `nil` when the pixmap has no mask. Otherwise it is a list of lists, where each inner list represents a row of the pixmap and each member of an inner list represents a pixel in that row. Each row member should be 1 to make the pixmap transparent at that pixel, or 0 to make it opaque. In addition, each transparent pixel must have a 0 in the main texture of the pixmap.

The number of inner lists reflects the number of rows in the pixmap, and the number of members in each inner list (these should all be the same) reflect the number of columns. These sizes for the mask should match the sizes that were used to specify the main image via the contents or texture property.

The mask of a pixmap may alternately be specified either by passing a texture to (setf mask), or by calling generate-mask.

### Example

Here is how Common Graphics makes the `:default-leaf-with-mask` pixmap, which is used by leaf nodes of `outline` widgets.

    (cache-pixmap
     (make-instance 'pixmap
       :name :default-leaf-with-mask
       :contents
       '(( 0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0)
         ( 0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0)
         ( 0  0  0 15 15 15 15 15  0  0  0  0  0  0  0  0)
         ( 0  0  0 15 15 15 15 15  0 15  0  0  0  0  0  0)
         ( 0  0  0 15 15 15 15 15  0 15 15  0  0  0  0  0)
         ( 0  0  0 15 15 15 15 15  0 15 15 15  0  0  0  0)
         ( 0  0  0 15 15 15 15 15  0  0  0  0  0  0  0  0)
         ( 0  0  0 15 15 15 15 15 15 15 15 15 15  0  0  0)
         ( 0  0  0 15 15 15 15 15 15 15 15 15 15  0  0  0)
         ( 0  0  0 15 15 15 15 15 15 15 15 15 15  0  0  0)
         ( 0  0  0 15 15 15 15 15 15 15 15 15 15  0  0  0)
         ( 0  0  0 15 15 15 15 15 15 15 15 15 15  0  0  0)
         ( 0  0  0 15 15 15 15 15 15 15 15 15 15  0  0  0)
         ( 0  0  0 15 15 15 15 15 15 15 15 15 15  0  0  0)
         ( 0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0)
         ( 0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0))
       :mask-contents
       '((1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1)
         (1 1 0 0 0 0 0 0 0 1 1 1 1 1 1 1)
         (1 1 0 0 0 0 0 0 0 0 1 1 1 1 1 1)
         (1 1 0 0 0 0 0 0 0 0 0 1 1 1 1 1)
         (1 1 0 0 0 0 0 0 0 0 0 0 1 1 1 1)
         (1 1 0 0 0 0 0 0 0 0 0 0 0 1 1 1)
         (1 1 0 0 0 0 0 0 0 0 0 0 0 0 1 1)
         (1 1 0 0 0 0 0 0 0 0 0 0 0 0 1 1)
         (1 1 0 0 0 0 0 0 0 0 0 0 0 0 1 1)
         (1 1 0 0 0 0 0 0 0 0 0 0 0 0 1 1)
         (1 1 0 0 0 0 0 0 0 0 0 0 0 0 1 1)
         (1 1 0 0 0 0 0 0 0 0 0 0 0 0 1 1)
         (1 1 0 0 0 0 0 0 0 0 0 0 0 0 1 1)
         (1 1 0 0 0 0 0 0 0 0 0 0 0 0 1 1)
         (1 1 0 0 0 0 0 0 0 0 0 0 0 0 1 1)
         (1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1))))

mask-contents is a property of the `pixmap` and `texture` classes.

Copyright (c) 1998-2019, Franz Inc. Oakland, CA., USA. All rights reserved.
This page was not revised from the 8.2 page.
Created 2012.5.30.

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| Allegro CL version 9.0 Unrevised from 8.2 to 9.0. 8.2 version