progs/trivial/tri-tex.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
  32 GLenum doubleBuffer;
  33
  34 static void Init(void)
  35 {
  36    fprintf(stderr, "GL_RENDERER   = %s\n", (char *) glGetString(GL_RENDERER));
  37    fprintf(stderr, "GL_VERSION    = %s\n", (char *) glGetString(GL_VERSION));
  38    fprintf(stderr, "GL_VENDOR     = %s\n", (char *) glGetString(GL_VENDOR));
  39
  40     glClearColor(0.0, 0.0, 1.0, 0.0);
  41
  42
  43 #define SIZE 32
  44    {
  45       GLubyte tex2d[SIZE][SIZE][3];
  46       GLint s, t;
  47
  48       for (s = 0; s < SIZE; s++) {
  49          for (t = 0; t < SIZE; t++) {
  50 #if 0
  51             tex2d[t][s][0] = (s < SIZE/2) ? 0 : 255;
  52             tex2d[t][s][1] = (t < SIZE/2) ? 0 : 255;
  53             tex2d[t][s][2] = 0;
  54 #else
  55             tex2d[t][s][0] = s*255/(SIZE-1);
  56             tex2d[t][s][1] = t*255/(SIZE-1);
  57             tex2d[t][s][2] = 0;
  58 #endif
  59          }
  60       }
  61
  62       glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
  63
  64       glTexImage2D(GL_TEXTURE_2D, 0, 3, SIZE, SIZE, 0,
  65                    GL_RGB, GL_UNSIGNED_BYTE, tex2d);
  66
  67       glEnable(GL_TEXTURE_2D);
  68       glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
  69       glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_R, GL_REPEAT);
  70       glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
  71       glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
  72
  73       glPixelStorei(GL_UNPACK_ALIGNMENT, 4);
  74    }
  75
  76 }
  77
  78 static void Reshape(int width, int height)
  79 {
  80
  81     glViewport(0, 0, (GLint)width, (GLint)height);
  82
  83     glMatrixMode(GL_PROJECTION);
  84     glLoadIdentity();
  85 /*     glOrtho(-1.0, 1.0, -1.0, 1.0, -0.5, 1000.0); */
  86     glMatrixMode(GL_MODELVIEW);
  87 }
  88
  89 static void Key(unsigned char key, int x, int y)
  90 {
  91
  92     switch (key) {
  93       case 27:
  94         exit(1);
  95       default:
  96         return;
  97     }
  98
  99     glutPostRedisplay();
 100 }
 101
 102 static void Draw(void)
 103 {
 104    glClear(GL_COLOR_BUFFER_BIT);
 105
 106    glBegin(GL_TRIANGLES);
 107    glTexCoord2f(1,-1);
 108    glVertex3f( 0.9, -0.9, -0.0);
 109    glTexCoord2f(1,1);
 110    glVertex3f( 0.9,  0.9, -0.0);
 111    glTexCoord2f(-1,0);
 112    glVertex3f(-0.9,  0.0, -0.0);
 113    glEnd();
 114
 115    glFlush();
 116
 117    if (doubleBuffer) {
 118       glutSwapBuffers();
 119    }
 120 }
 121
 122 static GLenum Args(int argc, char **argv)
 123 {
 124     GLint i;
 125
 126     doubleBuffer = GL_FALSE;
 127
 128     for (i = 1; i < argc; i++) {
 129         if (strcmp(argv[i], "-sb") == 0) {
 130             doubleBuffer = GL_FALSE;
 131         } else if (strcmp(argv[i], "-db") == 0) {
 132             doubleBuffer = GL_TRUE;
 133         } else {
 134             fprintf(stderr, "%s (Bad option).\n", argv[i]);
 135             return GL_FALSE;
 136         }
 137     }
 138     return GL_TRUE;
 139 }
 140
 141 int main(int argc, char **argv)
 142 {
 143     GLenum type;
 144
 145     glutInit(&argc, argv);
 146
 147     if (Args(argc, argv) == GL_FALSE) {
 148         exit(1);
 149     }
 150
 151     glutInitWindowPosition(0, 0); glutInitWindowSize( 250, 250);
 152
 153     type = GLUT_RGB | GLUT_ALPHA;
 154     type |= (doubleBuffer) ? GLUT_DOUBLE : GLUT_SINGLE;
 155     glutInitDisplayMode(type);
 156
 157     if (glutCreateWindow(*argv) == GL_FALSE) {
 158         exit(1);
 159     }
 160
 161     Init();
 162
 163     glutReshapeFunc(Reshape);
 164     glutKeyboardFunc(Key);
 165     glutDisplayFunc(Draw);
 166     glutMainLoop();
 167         return 0;
 168 }