progs/trivial/tri-viewport.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 GLenum doubleBuffer = 1;
  31 int win;
  32
  33 static void Init(void)
  34 {
  35    fprintf(stderr, "GL_RENDERER   = %s\n", (char *) glGetString(GL_RENDERER));
  36    fprintf(stderr, "GL_VERSION    = %s\n", (char *) glGetString(GL_VERSION));
  37    fprintf(stderr, "GL_VENDOR     = %s\n", (char *) glGetString(GL_VENDOR));
  38    fflush(stderr);
  39
  40    glClearColor(0.3, 0.1, 0.3, 0.0);
  41 }
  42
  43 static void Reshape(int width, int height)
  44 {
  45    glViewport(width / -2.0, height / -2.0, width, height);
  46
  47    glMatrixMode(GL_PROJECTION);
  48    glLoadIdentity();
  49    glOrtho(-1.0, 1.0, -1.0, 1.0, -0.5, 1000.0);
  50    glMatrixMode(GL_MODELVIEW);
  51    glLoadIdentity();
  52 }
  53
  54 static void Key(unsigned char key, int x, int y)
  55 {
  56    switch (key) {
  57       case 27:
  58          exit(0);
  59       default:
  60          glutPostRedisplay();
  61          return;
  62    }
  63 }
  64
  65 static void Draw(void)
  66 {
  67    glClear(GL_COLOR_BUFFER_BIT);
  68
  69    glBegin(GL_TRIANGLES);
  70    glColor3f(.8,0,0);
  71    glVertex3f(-0.9,  0.9, -30.0);
  72    glColor3f(0,.9,0);
  73    glVertex3f( 0.9,  0.9, -30.0);
  74    glColor3f(0,0,.7);
  75    glVertex3f( 0.0, -0.9, -30.0);
  76    glEnd();
  77
  78    glFlush();
  79
  80    if (doubleBuffer) {
  81       glutSwapBuffers();
  82    }
  83 }
  84
  85 static GLenum Args(int argc, char **argv)
  86 {
  87    GLint i;
  88
  89    for (i = 1; i < argc; i++) {
  90       if (strcmp(argv[i], "-sb") == 0) {
  91          doubleBuffer = GL_FALSE;
  92       } else if (strcmp(argv[i], "-db") == 0) {
  93          doubleBuffer = GL_TRUE;
  94       } else {
  95          fprintf(stderr, "%s (Bad option).\n", argv[i]);
  96          return GL_FALSE;
  97       }
  98    }
  99    return GL_TRUE;
 100 }
 101
 102 int main(int argc, char **argv)
 103 {
 104    GLenum type;
 105
 106    glutInit(&argc, argv);
 107
 108    if (Args(argc, argv) == GL_FALSE) {
 109       exit(1);
 110    }
 111
 112    glutInitWindowPosition(0, 0); glutInitWindowSize( 250, 250);
 113
 114    type = GLUT_RGB | GLUT_ALPHA;
 115    type |= (doubleBuffer) ? GLUT_DOUBLE : GLUT_SINGLE;
 116    glutInitDisplayMode(type);
 117
 118    win = glutCreateWindow(*argv);
 119    if (!win) {
 120       exit(1);
 121    }
 122
 123    Init();
 124
 125    glutReshapeFunc(Reshape);
 126    glutKeyboardFunc(Key);
 127    glutDisplayFunc(Draw);
 128    glutMainLoop();
 129    return 0;
 130 }