summaryrefslogtreecommitdiff
path: root/progs/demos/winpos.c
blob: 7001165deeffb9ab0ef84835e93505e5dcad22b6 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
/* $Id: winpos.c,v 1.2 2000/06/27 17:04:43 brianp Exp $ */

/*
 * Example of how to use the GL_MESA_window_pos extension.
 * Brian Paul   This file is in the public domain.
 */


/*
 * $Log: winpos.c,v $
 * Revision 1.2  2000/06/27 17:04:43  brianp
 * fixed compiler warnings
 *
 * Revision 1.1.1.1  1999/08/19 00:55:40  jtg
 * Imported sources
 *
 * Revision 3.3  1999/03/28 18:24:37  brianp
 * minor clean-up
 *
 * Revision 3.2  1998/11/05 04:34:04  brianp
 * moved image files to ../images/ directory
 *
 * Revision 3.1  1998/02/22 16:36:10  brianp
 * changed image file and set unpack alignment to 1
 *
 * Revision 3.0  1998/02/14 18:42:29  brianp
 * initial rev
 *
 */


#include <math.h>
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#define GL_GLEXT_LEGACY
#include "GL/glut.h"

#include "../util/readtex.c"  /* a hack, I know */

#define IMAGE_FILE "../images/girl.rgb"


#ifndef M_PI
#  define M_PI 3.14159265
#endif



static GLubyte *Image;
static int ImgWidth, ImgHeight;
static GLenum ImgFormat;



static void draw( void )
{
   GLfloat angle;
   char *extensions;

   extensions = (char *) glGetString( GL_EXTENSIONS );
   if (strstr( extensions, "GL_MESA_window_pos")==NULL) {
      printf("Sorry, GL_MESA_window_pos extension not available.\n");
      return;
   }

   glClear( GL_COLOR_BUFFER_BIT );

   for (angle = -45.0; angle <= 135.0; angle += 10.0) {
      GLfloat x = 50.0 + 200.0 * cos( angle * M_PI / 180.0 );
      GLfloat y = 50.0 + 200.0 * sin( angle * M_PI / 180.0 );

      /* Don't need to worry about the modelview or projection matrices!!! */
#ifdef GL_MESA_window_pos
      glWindowPos2fMESA( x, y );
#endif
      glDrawPixels( ImgWidth, ImgHeight, ImgFormat, GL_UNSIGNED_BYTE, Image );
   }
}




static void key( unsigned char key, int x, int y )
{
   (void) x;
   (void) y;
   switch (key) {
      case 27:
         exit(0);
   }
}



/* new window size or exposure */
static void reshape( int width, int height )
{
   glViewport(0, 0, (GLint)width, (GLint)height);
}


static void init( void )
{
   Image = LoadRGBImage( IMAGE_FILE, &ImgWidth, &ImgHeight, &ImgFormat );
   if (!Image) {
      printf("Couldn't read %s\n", IMAGE_FILE);
      exit(0);
   }
   glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
}



int main( int argc, char *argv[] )
{
   glutInitWindowPosition(0, 0);
   glutInitWindowSize(500, 500);
   glutInitDisplayMode( GLUT_RGB );

   if (glutCreateWindow("winpos") <= 0) {
      exit(0);
   }

   init();

   glutReshapeFunc( reshape );
   glutKeyboardFunc( key );
   glutDisplayFunc( draw );
   glutMainLoop();
   return 0;
}