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 static GLenum Target = GL_TEXTURE_2D;
  31 static GLenum Filter = GL_NEAREST;
  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 #define SIZE 32
  43    {
  44       GLubyte tex2d[SIZE][SIZE][3];
  45       GLint s, t;
  46
  47       for (s = 0; s < SIZE; s++) {
  48          for (t = 0; t < SIZE; t++) {
  49 #if 0
  50             tex2d[t][s][0] = (s < SIZE/2) ? 0 : 255;
  51             tex2d[t][s][1] = (t < SIZE/2) ? 0 : 255;
  52             tex2d[t][s][2] = 0;
  53 #else
  54             tex2d[t][s][0] = s*255/(SIZE-1);
  55             tex2d[t][s][1] = t*255/(SIZE-1);
  56             tex2d[t][s][2] = 0;
  57 #endif
  58          }
  59       }
  60
  61       glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
  62
  63       if (Target == GL_TEXTURE_1D)
  64          glTexImage1D(Target, 0, 3, SIZE, 0, GL_RGB, GL_UNSIGNED_BYTE, tex2d);
  65       else
  66          glTexImage2D(Target, 0, 3, SIZE, SIZE, 0,
  67                       GL_RGB, GL_UNSIGNED_BYTE, tex2d);
  68
  69       glEnable(Target);
  70       glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
  71       glTexParameterf(Target, GL_TEXTURE_WRAP_R, GL_REPEAT);
  72       glTexParameterf(Target, GL_TEXTURE_MIN_FILTER, Filter);
  73       glTexParameterf(Target, GL_TEXTURE_MAG_FILTER, Filter);
  74
  75       glPixelStorei(GL_UNPACK_ALIGNMENT, 4);
  76    }
  77 }
  78
  79 static void Reshape(int width, int height)
  80 {
  81    glViewport(0, 0, (GLint)width, (GLint)height);
  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    switch (key) {
  91    case 27:
  92       exit(0);
  93    default:
  94       return;
  95    }
  96    glutPostRedisplay();
  97 }
  98
  99 static void Draw(void)
 100 {
 101    glClear(GL_COLOR_BUFFER_BIT);
 102
 103    glBegin(GL_QUADS);
 104    glTexCoord2f(1,0);
 105    glVertex3f( 0.9, -0.9, -30.0);
 106    glTexCoord2f(1,1);
 107    glVertex3f( 0.9,  0.9, -30.0);
 108    glTexCoord2f(0,1);
 109    glVertex3f(-0.9,  0.9, -30.0);
 110    glTexCoord2f(0,0);
 111    glVertex3f(-0.9,  -0.9, -30.0);
 112    glEnd();
 113
 114    glFlush();
 115
 116    if (doubleBuffer) {
 117       glutSwapBuffers();
 118    }
 119 }
 120
 121 static GLenum Args(int argc, char **argv)
 122 {
 123     GLint i;
 124
 125     doubleBuffer = GL_FALSE;
 126
 127     for (i = 1; i < argc; i++) {
 128         if (strcmp(argv[i], "-sb") == 0) {
 129             doubleBuffer = GL_FALSE;
 130         } else if (strcmp(argv[i], "-db") == 0) {
 131             doubleBuffer = GL_TRUE;
 132         } else {
 133             fprintf(stderr, "%s (Bad option).\n", argv[i]);
 134             return GL_FALSE;
 135         }
 136     }
 137     return GL_TRUE;
 138 }
 139
 140 int main(int argc, char **argv)
 141 {
 142     GLenum type;
 143
 144     glutInit(&argc, argv);
 145
 146     if (Args(argc, argv) == GL_FALSE) {
 147         exit(1);
 148     }
 149
 150     glutInitWindowPosition(0, 0); glutInitWindowSize( 250, 250);
 151
 152     type = GLUT_RGB;
 153     type |= (doubleBuffer) ? GLUT_DOUBLE : GLUT_SINGLE;
 154     glutInitDisplayMode(type);
 155
 156     if (glutCreateWindow("First Tri") == GL_FALSE) {
 157         exit(1);
 158     }
 159
 160     Init();
 161
 162     glutReshapeFunc(Reshape);
 163     glutKeyboardFunc(Key);
 164     glutDisplayFunc(Draw);
 165     glutMainLoop();
 166     return 0;
 167 }