test/shape.cxx

   1 //
   2 // "$Id: shape.cxx 8033 2010-12-15 12:11:16Z AlbrechtS $"
   3 //
   4 // Tiny OpenGL demo program for the Fast Light Tool Kit (FLTK).
   5 //
   6 // Copyright 1998-2010 by Bill Spitzak and others.
   7 //
   8 // This library is free software; you can redistribute it and/or
   9 // modify it under the terms of the GNU Library General Public
  10 // License as published by the Free Software Foundation; either
  11 // version 2 of the License, or (at your option) any later version.
  12 //
  13 // This library is distributed in the hope that it will be useful,
  14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16 // Library General Public License for more details.
  17 //
  18 // You should have received a copy of the GNU Library General Public
  19 // License along with this library; if not, write to the Free Software
  20 // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  21 // USA.
  22 //
  23 // Please report all bugs and problems on the following page:
  24 //
  25 //     http://www.fltk.org/str.php
  26 //
  27
  28 #include <config.h>
  29 #include <FL/Fl.H>
  30 #include <FL/Fl_Window.H>
  31 #include <FL/Fl_Hor_Slider.H>
  32 #include <FL/math.h>
  33
  34 #if HAVE_GL
  35
  36 #include <FL/gl.h>
  37 #include <FL/Fl_Gl_Window.H>
  38
  39 class shape_window : public Fl_Gl_Window {
  40   void draw();
  41 public:
  42   int sides;
  43   shape_window(int x,int y,int w,int h,const char *l=0);
  44 };
  45
  46 shape_window::shape_window(int x,int y,int w,int h,const char *l) :
  47 Fl_Gl_Window(x,y,w,h,l) {
  48   sides = 3;
  49 }
  50
  51 void shape_window::draw() {
  52 // the valid() property may be used to avoid reinitializing your
  53 // GL transformation for each redraw:
  54   if (!valid()) {
  55     valid(1);
  56     glLoadIdentity();
  57     glViewport(0, 0, w(), h());
  58   }
  59 // draw an amazing graphic:
  60   glClear(GL_COLOR_BUFFER_BIT);
  61   glColor3f(.5,.6,.7);
  62   glBegin(GL_POLYGON);
  63   for (int j=0; j<sides; j++) {
  64     double ang = j*2*M_PI/sides;
  65     glVertex3f(cos(ang),sin(ang),0);
  66   }
  67   glEnd();
  68 }
  69
  70 #else
  71
  72 #include <FL/Fl_Box.H>
  73 class shape_window : public Fl_Box {
  74 public:
  75   int sides;
  76   shape_window(int x,int y,int w,int h,const char *l=0)
  77     :Fl_Box(FL_DOWN_BOX,x,y,w,h,l){
  78       label("This demo does\nnot work without GL");
  79   }
  80 };
  81
  82 #endif
  83
  84 // when you change the data, as in this callback, you must call redraw():
  85 void sides_cb(Fl_Widget *o, void *p) {
  86   shape_window *sw = (shape_window *)p;
  87   sw->sides = int(((Fl_Slider *)o)->value());
  88   sw->redraw();
  89 }
  90
  91 int main(int argc, char **argv) {
  92
  93   Fl_Window window(300, 330);
  94
  95 // the shape window could be it's own window, but here we make it
  96 // a child window:
  97   shape_window sw(10, 10, 280, 280);
  98 // make it resize:
  99   window.resizable(&sw);
 100   //  window.size_range(300,330,0,0,1,1,1);
 101 // add a knob to control it:
 102   Fl_Hor_Slider slider(50, 295, window.w()-60, 30, "Sides:");
 103   slider.align(FL_ALIGN_LEFT);
 104   slider.callback(sides_cb,&sw);
 105   slider.value(sw.sides);
 106   slider.step(1);
 107   slider.bounds(3,40);
 108
 109   window.end();
 110   window.show(argc,argv);
 111
 112   return Fl::run();
 113 }
 114
 115 //
 116 // End of "$Id: shape.cxx 8033 2010-12-15 12:11:16Z AlbrechtS $".
 117 //