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//
// "$Id: gl_overlay.cxx 4288 2005-04-16 00:13:17Z mike $"
//
// OpenGL overlay test program for the Fast Light Tool Kit (FLTK).
//
// Copyright 1998-2005 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 on the following page:
//
// http://www.fltk.org/str.php
//
#include "config.h"
#include <FL/Fl.H>
#include <FL/Fl_Window.H>
#include <FL/Fl_Hor_Slider.H>
#include <FL/Fl_Toggle_Button.H>
#include <FL/math.h>
#if !HAVE_GL
#include <FL/Fl_Box.H>
class shape_window : public Fl_Box {
public:
int sides;
shape_window(int x,int y,int w,int h,const char *l=0)
:Fl_Box(FL_DOWN_BOX,x,y,w,h,l){
label("This demo does\nnot work without GL");
}
};
#else
#include <FL/gl.h>
#include <FL/Fl_Gl_Window.H>
class shape_window : public Fl_Gl_Window {
void draw();
void draw_overlay();
public:
int sides;
int overlay_sides;
shape_window(int x,int y,int w,int h,const char *l=0);
};
shape_window::shape_window(int x,int y,int w,int h,const char *l) :
Fl_Gl_Window(x,y,w,h,l) {
sides = overlay_sides = 3;
}
void shape_window::draw() {
// the valid() property may be used to avoid reinitializing your
// GL transformation for each redraw:
if (!valid()) {
valid(1);
glLoadIdentity();
glViewport(0,0,w(),h());
}
// draw an amazing but slow graphic:
glClear(GL_COLOR_BUFFER_BIT);
// for (int j=1; j<=1000; j++) {
glBegin(GL_POLYGON);
for (int i=0; i<sides; i++) {
double ang = i*2*M_PI/sides;
glColor3f(float(i)/sides,float(i)/sides,float(i)/sides);
glVertex3f(cos(ang),sin(ang),0);
}
glEnd();
// }
}
void shape_window::draw_overlay() {
// the valid() property may be used to avoid reinitializing your
// GL transformation for each redraw:
if (!valid()) {
valid(1);
glLoadIdentity();
glViewport(0,0,w(),h());
}
// draw an amazing graphic:
gl_color(FL_RED);
glBegin(GL_LINE_LOOP);
for (int i=0; i<overlay_sides; i++) {
double ang = i*2*M_PI/overlay_sides;
glVertex3f(cos(ang),sin(ang),0);
}
glEnd();
}
#endif
// when you change the data, as in this callback, you must call redraw():
void sides_cb(Fl_Widget *o, void *p) {
shape_window *sw = (shape_window *)p;
sw->sides = int(((Fl_Slider *)o)->value());
sw->redraw();
}
#if HAVE_GL
void overlay_sides_cb(Fl_Widget *o, void *p) {
shape_window *sw = (shape_window *)p;
sw->overlay_sides = int(((Fl_Slider *)o)->value());
sw->redraw_overlay();
}
#endif
#include <stdio.h>
int main(int argc, char **argv) {
Fl_Window window(300, 370);
shape_window sw(10, 75, window.w()-20, window.h()-90);
//sw.mode(FL_RGB);
window.resizable(&sw);
Fl_Hor_Slider slider(60, 5, window.w()-70, 30, "Sides:");
slider.align(FL_ALIGN_LEFT);
slider.callback(sides_cb,&sw);
slider.value(sw.sides);
slider.step(1);
slider.bounds(3,40);
Fl_Hor_Slider oslider(60, 40, window.w()-70, 30, "Overlay:");
oslider.align(FL_ALIGN_LEFT);
#if HAVE_GL
oslider.callback(overlay_sides_cb,&sw);
oslider.value(sw.overlay_sides);
#endif
oslider.step(1);
oslider.bounds(3,40);
window.end();
window.show(argc,argv);
#if HAVE_GL
printf("Can do overlay = %d\n", sw.can_do_overlay());
sw.show();
sw.redraw_overlay();
#else
sw.show();
#endif
return Fl::run();
}
//
// End of "$Id: gl_overlay.cxx 4288 2005-04-16 00:13:17Z mike $".
//
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