//// "$Id: fl_overlay.cxx,v 1.1.1.1 2003/08/07 21:18:41 jasonk Exp $"//// Overlay support for the Fast Light Tool Kit (FLTK).//// Copyright 1998-1999 by Bill Spitzak and others.//// This library is free software; you can redistribute it and/or// modify it under the terms of the GNU Library General Public// License as published by the Free Software Foundation; either// version 2 of the License, or (at your option) any later version.//// This library is distributed in the hope that it will be useful,// but WITHOUT ANY WARRANTY; without even the implied warranty of// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU// Library General Public License for more details.//// You should have received a copy of the GNU Library General Public// License along with this library; if not, write to the Free Software// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307// USA.//// Please report all bugs and problems to "fltk-bugs@easysw.com".//// Extremely limited "overlay" support.  You can use this to drag out// a rectangle in response to mouse events.  It is your responsibility// to erase the overlay before drawing anything that might intersect// it.#include <FL/x.H>#include <FL/fl_draw.H>static int px,py,pw,ph;static void draw_current_rect() {#ifdef WIN32  int old = SetROP2(fl_gc, R2_NOT);  fl_rect(px, py, pw, ph);  SetROP2(fl_gc, old);#else#ifdef NANO_X //tanghao        GR_GC_ID temp_gc = GrCopyGC(fl_gc);        GrSetGCMode(temp_gc,GR_MODE_XOR);	GrSetGCForeground(temp_gc,0xffffff);	GrRect(fl_window,temp_gc,px,py,pw,ph);	GrDestroyGC(temp_gc);#else  XSetFunction(fl_display, fl_gc, GXxor);  XSetForeground(fl_display, fl_gc, 0xffffffff);  XDrawRectangle(fl_display, fl_window, fl_gc, px, py, pw, ph);  XSetFunction(fl_display, fl_gc, GXcopy);#endif #endif}void fl_overlay_clear() {  if (pw > 0) {draw_current_rect(); pw = 0;}}void fl_overlay_rect(int x, int y, int w, int h) {  if (w < 0) {x += w; w = -w;} else if (!w) w = 1;  if (h < 0) {y += h; h = -h;} else if (!h) h = 1;  if (pw > 0) {    if (x==px && y==py && w==pw && h==ph) return;    draw_current_rect();  }  px = x; py = y; pw = w; ph = h;  draw_current_rect();}//// End of "$Id: fl_overlay.cxx,v 1.1.1.1 2003/08/07 21:18:41 jasonk Exp $".//