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/* cairo - a vector graphics library with display and print output
*
* Copyright © 2006 Keith Packard
* Copyright © 2006 Red Hat, Inc
*
* This library is free software; you can redistribute it and/or
* modify it either under the terms of the GNU Lesser General Public
* License version 2.1 as published by the Free Software Foundation
* (the "LGPL") or, at your option, under the terms of the Mozilla
* Public License Version 1.1 (the "MPL"). If you do not alter this
* notice, a recipient may use your version of this file under either
* the MPL or the LGPL.
*
* You should have received a copy of the LGPL along with this library
* in the file COPYING-LGPL-2.1; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
* You should have received a copy of the MPL along with this library
* in the file COPYING-MPL-1.1
*
* The contents of this file are subject to the Mozilla Public License
* Version 1.1 (the "License"); you may not use this file except in
* compliance with the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY
* OF ANY KIND, either express or implied. See the LGPL or the MPL for
* the specific language governing rights and limitations.
*
* The Original Code is the cairo graphics library.
*
* The Initial Developer of the Original Code is University of Southern
* California.
*
* Contributor(s):
* Carl D. Worth <cworth@cworth.org>
* Keith Packard <keithp@keithp.com>
*/
#include "cairoint.h"
/* The analysis here assumes destination alpha semantics (that is
* CAIRO_CONTENT_COLOR_ALPHA). More things can be considered opaque
* otherwise (CAIRO_CONTENT_COLOR) so we'll probably want to add a
* cairo_content_t parameter to this function
*
* We also need a definition of what "opaque" means. Is it, "does not
* requiring 'knowing' the original contents of destination, nor does
* it set the destination alpha to anything but 1.0" ?
*/
cairo_bool_t
_cairo_operator_always_opaque (cairo_operator_t op)
{
switch (op) {
case CAIRO_OPERATOR_CLEAR:
return FALSE;
case CAIRO_OPERATOR_SOURCE:
return FALSE;
case CAIRO_OPERATOR_OVER:
case CAIRO_OPERATOR_IN:
case CAIRO_OPERATOR_OUT:
case CAIRO_OPERATOR_ATOP:
return FALSE;
case CAIRO_OPERATOR_DEST:
return TRUE;
case CAIRO_OPERATOR_DEST_OVER:
case CAIRO_OPERATOR_DEST_IN:
case CAIRO_OPERATOR_DEST_OUT:
case CAIRO_OPERATOR_DEST_ATOP:
return FALSE;
case CAIRO_OPERATOR_XOR:
case CAIRO_OPERATOR_ADD:
case CAIRO_OPERATOR_SATURATE:
return FALSE;
}
return FALSE;
}
/* As above, we'll probably want to add a cairo_content_t parameter to
* this function
*
* We also need a definition of what "translucent" means.
*/
cairo_bool_t
_cairo_operator_always_translucent (cairo_operator_t op)
{
switch (op) {
case CAIRO_OPERATOR_CLEAR:
return TRUE;
case CAIRO_OPERATOR_SOURCE:
return FALSE;
case CAIRO_OPERATOR_OVER:
case CAIRO_OPERATOR_IN:
case CAIRO_OPERATOR_OUT:
case CAIRO_OPERATOR_ATOP:
return FALSE;
case CAIRO_OPERATOR_DEST:
return FALSE;
case CAIRO_OPERATOR_DEST_OVER:
case CAIRO_OPERATOR_DEST_IN:
case CAIRO_OPERATOR_DEST_OUT:
case CAIRO_OPERATOR_DEST_ATOP:
return FALSE;
case CAIRO_OPERATOR_XOR:
case CAIRO_OPERATOR_ADD:
case CAIRO_OPERATOR_SATURATE:
return TRUE;
}
return TRUE;
}
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