progs/trivial/quad-tex-2d.c

   1 /*
   2  * Copyright (c) 1991, 1992, 1993 Silicon Graphics, Inc.
   3  *
   4  * Permission to use, copy, modify, distribute, and sell this software and
   5  * its documentation for any purpose is hereby granted without fee, provided
   6  * that (i) the above copyright notices and this permission notice appear in
   7  * all copies of the software and related documentation, and (ii) the name of
   8  * Silicon Graphics may not be used in any advertising or
   9  * publicity relating to the software without the specific, prior written
  10  * permission of Silicon Graphics.
  11  *
  12  * THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF
  13  * ANY KIND,
  14  * EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY
  15  * WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
  16  *
  17  * IN NO EVENT SHALL SILICON GRAPHICS BE LIABLE FOR
  18  * ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND,
  19  * OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
  20  * WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF
  21  * LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
  22  * OF THIS SOFTWARE.
  23  */
  24
  25 #include <stdio.h>
  26 #include <string.h>
  27 #include <stdlib.h>
  28 #include <GL/glut.h>
  29
  30
  31 #define CI_OFFSET_1 16
  32 #define CI_OFFSET_2 32
  33
  34 GLenum doubleBuffer;
  35
  36 static void Init(void)
  37 {
  38    fprintf(stderr, "GL_RENDERER   = %s\n", (char *) glGetString(GL_RENDERER));
  39    fprintf(stderr, "GL_VERSION    = %s\n", (char *) glGetString(GL_VERSION));
  40    fprintf(stderr, "GL_VENDOR     = %s\n", (char *) glGetString(GL_VENDOR));
  41
  42    glClearColor(0.0, 0.0, 1.0, 0.0);
  43
  44 #define SIZE 16
  45    {
  46       GLubyte tex2d[SIZE][SIZE][3];
  47       GLint s, t;
  48
  49       for (s = 0; s < SIZE; s++) {
  50          for (t = 0; t < SIZE; t++) {
  51 #if 0
  52             tex2d[t][s][0] = (s < SIZE/2) ? 0 : 255;
  53             tex2d[t][s][1] = (t < SIZE/2) ? 0 : 255;
  54             tex2d[t][s][2] = 0;
  55 #else
  56             tex2d[t][s][0] = s*255/(SIZE-1);
  57             tex2d[t][s][1] = t*255/(SIZE-1);
  58             tex2d[t][s][2] = 0;
  59 #endif
  60          }
  61       }
  62
  63       glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
  64       glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_R, GL_REPEAT);
  65       glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
  66       glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
  67
  68       glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
  69       glTexImage2D(GL_TEXTURE_2D, 0, 3, SIZE, SIZE, 0,
  70                    GL_RGB, GL_UNSIGNED_BYTE, tex2d);
  71       glPixelStorei(GL_UNPACK_ALIGNMENT, 4);
  72       glEnable(GL_TEXTURE_2D);
  73    }
  74
  75 }
  76
  77 static void Reshape(int width, int height)
  78 {
  79
  80     glViewport(0, 0, (GLint)width, (GLint)height);
  81
  82     glMatrixMode(GL_PROJECTION);
  83     glLoadIdentity();
  84     glOrtho(-1.0, 1.0, -1.0, 1.0, -0.5, 1000.0);
  85     glMatrixMode(GL_MODELVIEW);
  86 }
  87
  88 static void Key(unsigned char key, int x, int y)
  89 {
  90
  91     switch (key) {
  92       case 27:
  93         exit(1);
  94       default:
  95         return;
  96     }
  97
  98     glutPostRedisplay();
  99 }
 100
 101 static void Draw(void)
 102 {
 103    glClear(GL_COLOR_BUFFER_BIT);
 104
 105    glBegin(GL_QUADS);
 106    glTexCoord2f(1,0);
 107    glVertex3f( 0.9, -0.9, -30.0);
 108    glTexCoord2f(1,1);
 109    glVertex3f( 0.9,  0.9, -30.0);
 110    glTexCoord2f(0,1);
 111    glVertex3f(-0.9,  0.9, -30.0);
 112    glTexCoord2f(0,0);
 113    glVertex3f(-0.9,  -0.9, -30.0);
 114    glEnd();
 115
 116    glFlush();
 117
 118    if (doubleBuffer) {
 119       glutSwapBuffers();
 120    }
 121 }
 122
 123 static GLenum Args(int argc, char **argv)
 124 {
 125     GLint i;
 126
 127     doubleBuffer = GL_FALSE;
 128
 129     for (i = 1; i < argc; i++) {
 130         if (strcmp(argv[i], "-sb") == 0) {
 131             doubleBuffer = GL_FALSE;
 132         } else if (strcmp(argv[i], "-db") == 0) {
 133             doubleBuffer = GL_TRUE;
 134         } else {
 135             fprintf(stderr, "%s (Bad option).\n", argv[i]);
 136             return GL_FALSE;
 137         }
 138     }
 139     return GL_TRUE;
 140 }
 141
 142 int main(int argc, char **argv)
 143 {
 144     GLenum type;
 145
 146     glutInit(&argc, argv);
 147
 148     if (Args(argc, argv) == GL_FALSE) {
 149         exit(1);
 150     }
 151
 152     glutInitWindowPosition(0, 0); glutInitWindowSize( 250, 250);
 153
 154     type = GLUT_RGB;
 155     type |= (doubleBuffer) ? GLUT_DOUBLE : GLUT_SINGLE;
 156     glutInitDisplayMode(type);
 157
 158     if (glutCreateWindow("First Tri") == GL_FALSE) {
 159         exit(1);
 160     }
 161
 162     Init();
 163
 164     glutReshapeFunc(Reshape);
 165     glutKeyboardFunc(Key);
 166     glutDisplayFunc(Draw);
 167     glutMainLoop();
 168         return 0;
 169 }