progs/demos/winpos.c

   1 /* $Id: winpos.c,v 1.3 2000/12/24 22:53:54 pesco Exp $ */
   2
   3 /*
   4  * Example of how to use the GL_MESA_window_pos extension.
   5  * Brian Paul   This file is in the public domain.
   6  */
   7
   8
   9 /*
  10  * $Log: winpos.c,v $
  11  * Revision 1.3  2000/12/24 22:53:54  pesco
  12  * * demos/Makefile.am (INCLUDES): Added -I$(top_srcdir)/util.
  13  * * demos/Makefile.X11, demos/Makefile.BeOS-R4, demos/Makefile.cygnus:
  14  * Essentially the same.
  15  * Program files updated to include "readtex.c", not "../util/readtex.c".
  16  * * demos/reflect.c: Likewise for "showbuffer.c".
  17  *
  18  *
  19  * * Makefile.am (EXTRA_DIST): Added top-level regular files.
  20  *
  21  * * include/GL/Makefile.am (INC_X11): Added glxext.h.
  22  *
  23  *
  24  * * src/GGI/include/ggi/mesa/Makefile.am (EXTRA_HEADERS): Include
  25  * Mesa GGI headers in dist even if HAVE_GGI is not given.
  26  *
  27  * * configure.in: Look for GLUT and demo source dirs in $srcdir.
  28  *
  29  * * src/swrast/Makefile.am (libMesaSwrast_la_SOURCES): Set to *.[ch].
  30  * More source list updates in various Makefile.am's.
  31  *
  32  * * Makefile.am (dist-hook): Remove CVS directory from distribution.
  33  * (DIST_SUBDIRS): List all possible subdirs here.
  34  * (SUBDIRS): Only list subdirs selected for build again.
  35  * The above two applied to all subdir Makefile.am's also.
  36  *
  37  * Revision 1.2  2000/06/27 17:04:43  brianp
  38  * fixed compiler warnings
  39  *
  40  * Revision 1.1.1.1  1999/08/19 00:55:40  jtg
  41  * Imported sources
  42  *
  43  * Revision 3.3  1999/03/28 18:24:37  brianp
  44  * minor clean-up
  45  *
  46  * Revision 3.2  1998/11/05 04:34:04  brianp
  47  * moved image files to ../images/ directory
  48  *
  49  * Revision 3.1  1998/02/22 16:36:10  brianp
  50  * changed image file and set unpack alignment to 1
  51  *
  52  * Revision 3.0  1998/02/14 18:42:29  brianp
  53  * initial rev
  54  *
  55  */
  56
  57
  58 #include <math.h>
  59 #include <string.h>
  60 #include <stdlib.h>
  61 #include <stdio.h>
  62 #define GL_GLEXT_LEGACY
  63 #include "GL/glut.h"
  64
  65 #include "readtex.c"  /* a hack, I know */
  66
  67 #define IMAGE_FILE "../images/girl.rgb"
  68
  69
  70 #ifndef M_PI
  71 #  define M_PI 3.14159265
  72 #endif
  73
  74
  75
  76 static GLubyte *Image;
  77 static int ImgWidth, ImgHeight;
  78 static GLenum ImgFormat;
  79
  80
  81
  82 static void draw( void )
  83 {
  84    GLfloat angle;
  85    char *extensions;
  86
  87    extensions = (char *) glGetString( GL_EXTENSIONS );
  88    if (strstr( extensions, "GL_MESA_window_pos")==NULL) {
  89       printf("Sorry, GL_MESA_window_pos extension not available.\n");
  90       return;
  91    }
  92
  93    glClear( GL_COLOR_BUFFER_BIT );
  94
  95    for (angle = -45.0; angle <= 135.0; angle += 10.0) {
  96       GLfloat x = 50.0 + 200.0 * cos( angle * M_PI / 180.0 );
  97       GLfloat y = 50.0 + 200.0 * sin( angle * M_PI / 180.0 );
  98
  99       /* Don't need to worry about the modelview or projection matrices!!! */
 100 #ifdef GL_MESA_window_pos
 101       glWindowPos2fMESA( x, y );
 102 #endif
 103       glDrawPixels( ImgWidth, ImgHeight, ImgFormat, GL_UNSIGNED_BYTE, Image );
 104    }
 105 }
 106
 107
 108
 109
 110 static void key( unsigned char key, int x, int y )
 111 {
 112    (void) x;
 113    (void) y;
 114    switch (key) {
 115       case 27:
 116          exit(0);
 117    }
 118 }
 119
 120
 121
 122 /* new window size or exposure */
 123 static void reshape( int width, int height )
 124 {
 125    glViewport(0, 0, (GLint)width, (GLint)height);
 126 }
 127
 128
 129 static void init( void )
 130 {
 131    Image = LoadRGBImage( IMAGE_FILE, &ImgWidth, &ImgHeight, &ImgFormat );
 132    if (!Image) {
 133       printf("Couldn't read %s\n", IMAGE_FILE);
 134       exit(0);
 135    }
 136    glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
 137 }
 138
 139
 140
 141 int main( int argc, char *argv[] )
 142 {
 143    glutInitWindowPosition(0, 0);
 144    glutInitWindowSize(500, 500);
 145    glutInitDisplayMode( GLUT_RGB );
 146
 147    if (glutCreateWindow("winpos") <= 0) {
 148       exit(0);
 149    }
 150
 151    init();
 152
 153    glutReshapeFunc( reshape );
 154    glutKeyboardFunc( key );
 155    glutDisplayFunc( draw );
 156    glutMainLoop();
 157    return 0;
 158 }