- // Get information on all the screens which are available.
- _screenInfoList.reserve(ScreenCount(_display));
- for (int i = 0; i < ScreenCount(_display); ++i)
- _screenInfoList.push_back(ScreenInfo(i));
+ /*
+ If the default depth is at least 8 we will use that,
+ otherwise we try to find the largest TrueColor visual.
+ Preference is given to 24 bit over larger depths if 24 bit is an option.
+ */
+
+ int screen = DefaultScreen(_display);
+ _depth = DefaultDepth(_display, screen);
+ _visual = DefaultVisual(_display, screen);
+ _colormap = DefaultColormap(_display, screen);
+
+ if (_depth < 8) {
+ // search for a TrueColor Visual... if we can't find one...
+ // we will use the default visual for the screen
+ XVisualInfo vinfo_template, *vinfo_return;
+ int vinfo_nitems;
+ int best = -1;
+
+ vinfo_template.screen = screen;
+ vinfo_template.c_class = TrueColor;
+
+ vinfo_return = XGetVisualInfo(_display,
+ VisualScreenMask | VisualClassMask,
+ &vinfo_template, &vinfo_nitems);
+ if (vinfo_return) {
+ int max_depth = 1;
+ for (int i = 0; i < vinfo_nitems; ++i) {
+ if (vinfo_return[i].depth > max_depth) {
+ if (max_depth == 24 && vinfo_return[i].depth > 24)
+ break; // prefer 24 bit over 32
+ max_depth = vinfo_return[i].depth;
+ best = i;
+ }
+ }
+ if (max_depth < _depth) best = -1;
+ }
+
+ if (best != -1) {
+ _depth = vinfo_return[best].depth;
+ _visual = vinfo_return[best].visual;
+ _colormap = XCreateColormap(_display, RootWindow(_display, screen),
+ _visual, AllocNone);
+ }