mirrors/fltk
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Pre-multiply alpha on cursors on X11, as required by XRender.

Browse Source 
git-svn-id: file:///fltk/svn/fltk/branches/branch-1.4@12177 ea41ed52-d2ee-0310-a9c1-e6b18d33e121
This commit is contained in:
Pierre Ossman 2017-02-20 12:40:50 +00:00
parent a2f22358cd
commit cebc3d71be
1 changed files with 21 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

25
src/Fl_x.cxx
View File

@ -2755,20 +2755,37 @@ int Fl_X11_Window_Driver::set_cursor(const Fl_RGB_Image *image, int hotx, int ho
XcursorPixel *o = cursor->pixels;
for (int y = 0;y < image->h();y++) {
for (int x = 0;x < image->w();x++) {
uchar r, g, b, a;
switch (image->d()) {
case 1:
*o = (0xff<<24) | (i[0]<<16) | (i[0]<<8) | i[0];
r = g = b = i[0];
a = 0xff;
break;
case 2:
*o = (i[1]<<24) | (i[0]<<16) | (i[0]<<8) | i[0];
r = g = b = i[0];
a = i[1];
break;
case 3:
*o = (0xff<<24) | (i[0]<<16) | (i[1]<<8) | i[2];
r = i[0];
g = i[1];
b = i[2];
a = 0xff;
break;
case 4:
*o = (i[3]<<24) | (i[0]<<16) | (i[1]<<8) | i[2];
r = i[0];
g = i[1];
b = i[2];
a = i[3];
break;
default:
return 0;
}
// Alpha needs to be pre-multiplied for X11
r = (uchar)((unsigned)r * a / 255);
g = (uchar)((unsigned)g * a / 255);
b = (uchar)((unsigned)b * a / 255);
*o = (a<<24) | (r<<16) | (g<<8) | b;
i += image->d();
o++;
}