+ // if this is a wxGLApp (derived from wxApp), and we've already
+ // chosen a specific visual, then derive the GdkVisual from that
+ if (m_glVisualInfo != NULL)
+ {
+#ifdef __WXGTK20__
+ // seems gtk_widget_set_default_visual no longer exists?
+ GdkVisual* vis = gtk_widget_get_default_visual();
+#else
+ GdkVisual* vis = gdkx_visual_get(
+ ((XVisualInfo *) m_glVisualInfo) ->visualid );
+ gtk_widget_set_default_visual( vis );
+#endif
+
+ GdkColormap *colormap = gdk_colormap_new( vis, FALSE );
+ gtk_widget_set_default_colormap( colormap );
+
+ visual = vis;
+ }
+
+ // On some machines, the default visual is just 256 colours, so
+ // we make sure we get the best. This can sometimes be wasteful.
+
+ else
+ if ((gdk_visual_get_best() != gdk_visual_get_system()) && (m_useBestVisual))
+ {
+#ifdef __WXGTK20__
+ /* seems gtk_widget_set_default_visual no longer exists? */
+ GdkVisual* vis = gtk_widget_get_default_visual();
+#else
+ GdkVisual* vis = gdk_visual_get_best();
+ gtk_widget_set_default_visual( vis );
+#endif
+
+ GdkColormap *colormap = gdk_colormap_new( vis, FALSE );
+ gtk_widget_set_default_colormap( colormap );
+
+ visual = vis;
+ }
+
+ // Nothing to do for 15, 16, 24, 32 bit displays
+ if (visual->depth > 8) return TRUE;
+
+ // initialize color cube for 8-bit color reduction dithering
+
+ GdkColormap *cmap = gtk_widget_get_default_colormap();
+
+ m_colorCube = (unsigned char*)malloc(32 * 32 * 32);
+
+ for (int r = 0; r < 32; r++)
+ {
+ for (int g = 0; g < 32; g++)
+ {
+ for (int b = 0; b < 32; b++)
+ {
+ int rr = (r << 3) | (r >> 2);
+ int gg = (g << 3) | (g >> 2);
+ int bb = (b << 3) | (b >> 2);
+
+ int index = -1;
+
+ GdkColor *colors = cmap->colors;
+ if (colors)
+ {
+ int max = 3 * 65536;
+
+ for (int i = 0; i < cmap->size; i++)
+ {
+ int rdiff = ((rr << 8) - colors[i].red);
+ int gdiff = ((gg << 8) - colors[i].green);
+ int bdiff = ((bb << 8) - colors[i].blue);
+ int sum = ABS (rdiff) + ABS (gdiff) + ABS (bdiff);
+ if (sum < max)
+ {
+ index = i; max = sum;
+ }
+ }
+ }
+ else
+ {
+ // assume 8-bit true or static colors. this really exists
+ GdkVisual* vis = gdk_colormap_get_visual( cmap );
+ index = (r >> (5 - vis->red_prec)) << vis->red_shift;
+ index |= (g >> (5 - vis->green_prec)) << vis->green_shift;
+ index |= (b >> (5 - vis->blue_prec)) << vis->blue_shift;
+ }
+ m_colorCube[ (r*1024) + (g*32) + b ] = index;
+ }
+ }
+ }
+
+ return TRUE;
+}
+
+GdkVisual *wxApp::GetGdkVisual()