fltk/src/fl_overlay_visual.cxx
Greg Ercolano 4f4a8fc3c7 Modifications to all LGPL headers for STR #2685.
(to clarify static exception LGPL by changing license references)



git-svn-id: file:///fltk/svn/fltk/branches/branch-1.3@8864 ea41ed52-d2ee-0310-a9c1-e6b18d33e121
2011-07-19 04:49:30 +00:00

97 lines
2.7 KiB
C++

//
// "$Id$"
//
// X overlay support for the Fast Light Tool Kit (FLTK).
//
// Copyright 1998-2010 by Bill Spitzak and others.
//
// This library is free software. Distribution and use rights are outlined in
// the file "COPYING" which should have been included with this file. If this
// file is missing or damaged, see the license at:
//
// http://www.fltk.org/COPYING.php
//
// Please report all bugs and problems on the following page:
//
// http://www.fltk.org/str.php
//
// Return an overlay visual, if any. Also allocate a colormap and
// record the depth for fl_color() to use.
// Another disgusting X interface, based on code extracted and
// purified with great difficulty from XLayerUtil.cxx:
#include <config.h>
#if HAVE_OVERLAY
#include <FL/Fl.H>
#include <FL/x.H>
// SERVER_OVERLAY_VISUALS property element:
struct OverlayInfo {
long overlay_visual;
long transparent_type;
long value;
long layer;
};
extern Colormap fl_overlay_colormap;
extern XVisualInfo* fl_overlay_visual;
extern ulong fl_transparent_pixel;
XVisualInfo *fl_find_overlay_visual() {
static char beenhere;
if (beenhere) return fl_overlay_visual;
beenhere = 1;
fl_open_display();
Atom overlayVisualsAtom =
XInternAtom(fl_display,"SERVER_OVERLAY_VISUALS",1);
if (!overlayVisualsAtom) return 0;
OverlayInfo *overlayInfo;
ulong sizeData, bytesLeft;
Atom actualType;
int actualFormat;
if (XGetWindowProperty(fl_display, RootWindow(fl_display, fl_screen),
overlayVisualsAtom, 0L, 10000L, False,
overlayVisualsAtom, &actualType, &actualFormat,
&sizeData, &bytesLeft,
(unsigned char **) &overlayInfo)) return 0;
if (actualType == overlayVisualsAtom && actualFormat == 32) {
int n = int(sizeData/4);
XVisualInfo* v = 0;
// find the greatest depth that has a transparent pixel:
for (int i = 0; i < n; i++) {
if (overlayInfo[i].transparent_type != 1) continue;
if (overlayInfo[i].layer <= 0) continue;
XVisualInfo templt;
templt.visualid = overlayInfo[i].overlay_visual;
int num;
XVisualInfo *v1=XGetVisualInfo(fl_display, VisualIDMask, &templt, &num);
if (v1->screen == fl_screen && v1->c_class == PseudoColor
&& (!v || v1->depth > v->depth && v1->depth <= 8)) {
if (v) XFree((char*)v);
v = v1;
fl_transparent_pixel = overlayInfo[i].value;
} else {
XFree((char*)v1);
}
}
if (v) {
fl_overlay_visual = v;
fl_overlay_colormap =
XCreateColormap(fl_display, RootWindow(fl_display, fl_screen),
v->visual, AllocNone);
}
}
XFree((char*)overlayInfo);
//printf("overlay visual %ld selected\n", fl_overlay_visual->visualid);
return fl_overlay_visual;
}
#endif
//
// End of "$Id$".
//