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 static float Rot = 0;
  34
  35 static void Init(void)
  36 {
  37    fprintf(stderr, "GL_RENDERER   = %s\n", (char *) glGetString(GL_RENDERER));
  38    fprintf(stderr, "GL_VERSION    = %s\n", (char *) glGetString(GL_VERSION));
  39    fprintf(stderr, "GL_VENDOR     = %s\n", (char *) glGetString(GL_VENDOR));
  40
  41    glClearColor(0.0, 0.0, 1.0, 0.0);
  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       if (Target == GL_TEXTURE_1D)
  65          glTexImage1D(Target, 0, 3, SIZE, 0, GL_RGB, GL_UNSIGNED_BYTE, tex2d);
  66       else
  67          glTexImage2D(Target, 0, 3, SIZE, SIZE, 0,
  68                       GL_RGB, GL_UNSIGNED_BYTE, tex2d);
  69
  70       glEnable(Target);
  71       glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
  72       glTexParameterf(Target, GL_TEXTURE_WRAP_R, GL_REPEAT);
  73       glTexParameterf(Target, GL_TEXTURE_MIN_FILTER, Filter);
  74       glTexParameterf(Target, GL_TEXTURE_MAG_FILTER, Filter);
  75
  76       glPixelStorei(GL_UNPACK_ALIGNMENT, 4);
  77    }
  78 }
  79
  80 static void Reshape(int width, int height)
  81 {
  82    glViewport(0, 0, (GLint)width, (GLint)height);
  83    glMatrixMode(GL_PROJECTION);
  84    glLoadIdentity();
  85 #if 0
  86    glOrtho(-1.0, 1.0, -1.0, 1.0, -0.5, 1000.0);
  87 #else
  88    glFrustum(-1, 1, -1, 1, 10, 20);
  89 #endif
  90    glMatrixMode(GL_MODELVIEW);
  91    glTranslatef(0, 0, -15);
  92 }
  93
  94 static void Key(unsigned char key, int x, int y)
  95 {
  96    switch (key) {
  97    case 'r':
  98       Rot += 10.0;
  99       break;
 100    case 'R':
 101       Rot -= 10.0;
 102       break;
 103    case 27:
 104       exit(0);
 105    default:
 106       return;
 107    }
 108    glutPostRedisplay();
 109 }
 110
 111 static void Draw(void)
 112 {
 113    glClear(GL_COLOR_BUFFER_BIT);
 114
 115    glPushMatrix();
 116    glRotatef(Rot, 0, 1, 0);
 117
 118    glBegin(GL_QUADS);
 119    glTexCoord2f(1,0);
 120    glVertex3f( 0.9, -0.9, 0.0);
 121    glTexCoord2f(1,1);
 122    glVertex3f( 0.9,  0.9, 0.0);
 123    glTexCoord2f(0,1);
 124    glVertex3f(-0.9,  0.9, 0.0);
 125    glTexCoord2f(0,0);
 126    glVertex3f(-0.9,  -0.9, 0.0);
 127    glEnd();
 128
 129    glPopMatrix();
 130
 131    glFlush();
 132
 133    if (doubleBuffer) {
 134       glutSwapBuffers();
 135    }
 136 }
 137
 138 static GLenum Args(int argc, char **argv)
 139 {
 140     GLint i;
 141
 142     doubleBuffer = GL_FALSE;
 143
 144     for (i = 1; i < argc; i++) {
 145         if (strcmp(argv[i], "-sb") == 0) {
 146             doubleBuffer = GL_FALSE;
 147         } else if (strcmp(argv[i], "-db") == 0) {
 148             doubleBuffer = GL_TRUE;
 149         } else {
 150             fprintf(stderr, "%s (Bad option).\n", argv[i]);
 151             return GL_FALSE;
 152         }
 153     }
 154     return GL_TRUE;
 155 }
 156
 157 int main(int argc, char **argv)
 158 {
 159     GLenum type;
 160
 161     glutInit(&argc, argv);
 162
 163     if (Args(argc, argv) == GL_FALSE) {
 164         exit(1);
 165     }
 166
 167     glutInitWindowPosition(0, 0); glutInitWindowSize( 250, 250);
 168
 169     type = GLUT_RGB;
 170     type |= (doubleBuffer) ? GLUT_DOUBLE : GLUT_SINGLE;
 171     glutInitDisplayMode(type);
 172
 173     if (glutCreateWindow("First Tri") == GL_FALSE) {
 174         exit(1);
 175     }
 176
 177     Init();
 178
 179     glutReshapeFunc(Reshape);
 180     glutKeyboardFunc(Key);
 181     glutDisplayFunc(Draw);
 182     glutMainLoop();
 183     return 0;
 184 }