ref: 182dda4dd9335704b78347f74c37f7343c4c65cd
dir: /DoConfig/fltk/src/Fl_visual.cxx/
// // "$Id$" // // Visual 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 // // Set the default visual according to passed switches: #include <config.h> #include <FL/Fl.H> #include <FL/x.H> /** \fn Fl::visual(int flags) Selects a visual so that your graphics are drawn correctly. This is only allowed before you call show() on any windows. This does nothing if the default visual satisfies the capabilities, or if no visual satisfies the capabilities, or on systems that don't have such brain-dead notions. <P>Only the following combinations do anything useful: <UL> <LI>Fl::visual(FL_RGB) <BR>Full/true color (if there are several depths FLTK chooses the largest). Do this if you use fl_draw_image for much better (non-dithered) output. <BR> </LI> <LI>Fl::visual(FL_RGB8) <BR>Full color with at least 24 bits of color. FL_RGB will always pick this if available, but if not it will happily return a less-than-24 bit deep visual. This call fails if 24 bits are not available. <BR> </LI> <LI>Fl::visual(FL_DOUBLE|FL_INDEX) <BR>Hardware double buffering. Call this if you are going to use Fl_Double_Window. <BR> </LI> <LI>Fl::visual(FL_DOUBLE|FL_RGB)</LI> <LI>Fl::visual(FL_DOUBLE|FL_RGB8) <BR>Hardware double buffering and full color. </UL> <P>This returns true if the system has the capabilities by default or FLTK suceeded in turing them on. Your program will still work even if this returns false (it just won't look as good). */ #ifdef WIN32 int Fl::visual(int flags) { fl_GetDC(0); if (flags & FL_DOUBLE) return 0; if (!(flags & FL_INDEX) && GetDeviceCaps(fl_gc,BITSPIXEL) <= 8) return 0; if ((flags & FL_RGB8) && GetDeviceCaps(fl_gc,BITSPIXEL)<24) return 0; return 1; } #elif defined(__APPLE__) // \todo Mac : need to implement Visual flags int Fl::visual(int flags) { (void)flags; return 1; } #else #if USE_XDBE #include <X11/extensions/Xdbe.h> #endif static int test_visual(XVisualInfo& v, int flags) { if (v.screen != fl_screen) return 0; #if USE_COLORMAP if (!(flags & FL_INDEX)) { if (v.c_class != StaticColor && v.c_class != TrueColor) return 0; if (v.depth <= 8) return 0; // fltk will work better in colormap mode } if (flags & FL_RGB8) { if (v.depth < 24) return 0; } // for now, fltk does not like colormaps of more than 8 bits: if ((v.c_class&1) && v.depth > 8) return 0; #else // simpler if we can't use colormapped visuals at all: if (v.c_class != StaticColor && v.c_class != TrueColor) return 0; #endif #if USE_XDBE if (flags & FL_DOUBLE) { static XdbeScreenVisualInfo *xdbejunk; if (!xdbejunk) { int event_base, error_base; if (!XdbeQueryExtension(fl_display, &event_base, &error_base)) return 0; Drawable root = RootWindow(fl_display,fl_screen); int numscreens = 1; xdbejunk = XdbeGetVisualInfo(fl_display,&root,&numscreens); if (!xdbejunk) return 0; } for (int j = 0; ; j++) { if (j >= xdbejunk->count) return 0; if (xdbejunk->visinfo[j].visual == v.visualid) break; } } #endif return 1; } int Fl::visual(int flags) { #if USE_XDBE == 0 if (flags & FL_DOUBLE) return 0; #endif fl_open_display(); // always use default if possible: if (test_visual(*fl_visual, flags)) return 1; // get all the visuals: XVisualInfo vTemplate; int num; XVisualInfo *visualList = XGetVisualInfo(fl_display, 0, &vTemplate, &num); // find all matches, use the one with greatest depth: XVisualInfo *found = 0; for (int i=0; i<num; i++) if (test_visual(visualList[i], flags)) { if (!found || found->depth < visualList[i].depth) found = &visualList[i]; } if (!found) {XFree((void*)visualList); return 0;} fl_visual = found; fl_colormap = XCreateColormap(fl_display, RootWindow(fl_display,fl_screen), fl_visual->visual, AllocNone); return 1; } #endif // // End of "$Id$". //