summaryrefslogtreecommitdiffstats
path: root/src/kwin/misc.cpp
blob: f05097530b4019051c7fc8eadb0ad8006a9ec0d9 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
/* Plastik KWin window decoration
  Copyright (C) 2003 Sandro Giessl <[email protected]>

  based on the window decoration "Web":
  Copyright (C) 2001 Rik Hemsley (rikkus) <[email protected]>

  This program is free software; you can redistribute it and/or
  modify it under the terms of the GNU General Public
  License as published by the Free Software Foundation; either
  version 2 of the License, or (at your option) any later version.

  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program; see the file COPYING.  If not, write to
  the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  Boston, MA 02110-1301, USA.
 */

#include <kpixmap.h>
#include <kpixmapeffect.h>

#include <qcolor.h>
#include <qimage.h>
#include <qpainter.h>

#include "misc.h"

QColor alphaBlendColors(const QColor &bgColor, const QColor &fgColor, const int a)
{

    // normal button...
    QRgb rgb = bgColor.rgb();
    QRgb rgb_b = fgColor.rgb();
    int alpha = a;
    if(alpha>255) alpha = 255;
    if(alpha<0) alpha = 0;
    int inv_alpha = 255 - alpha;

    QColor result  = QColor( qRgb(qRed(rgb_b)*inv_alpha/255 + qRed(rgb)*alpha/255,
                                  qGreen(rgb_b)*inv_alpha/255 + qGreen(rgb)*alpha/255,
                                  qBlue(rgb_b)*inv_alpha/255 + qBlue(rgb)*alpha/255) );

    return result;
}