progs/trivial/tri-unfilled-fog.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 GLint Width = 250, Height = 250;
  35
  36 GLenum doubleBuffer;
  37
  38 static void Init(void)
  39 {
  40    fprintf(stderr, "GL_RENDERER   = %s\n", (char *) glGetString(GL_RENDERER));
  41    fprintf(stderr, "GL_VERSION    = %s\n", (char *) glGetString(GL_VERSION));
  42    fprintf(stderr, "GL_VENDOR     = %s\n", (char *) glGetString(GL_VENDOR));
  43    fflush(stderr);
  44
  45    glClearColor(0.0, 0.0, 1.0, 0.0);
  46 }
  47
  48 static void Reshape(int width, int height)
  49 {
  50    glViewport(0, 0, (GLint)width, (GLint)height);
  51
  52    glMatrixMode(GL_PROJECTION);
  53    glLoadIdentity();
  54    glOrtho(-1.0, 1.0, -1.0, 1.0, -0.5, 1000.0);
  55    glMatrixMode(GL_MODELVIEW);
  56 }
  57
  58 static void Key(unsigned char key, int x, int y)
  59 {
  60    switch (key) {
  61       case 27:
  62          exit(1);
  63    }
  64
  65    glutPostRedisplay();
  66 }
  67
  68 static void Draw(void)
  69 {
  70    glClear(GL_COLOR_BUFFER_BIT);
  71
  72    glEnable(GL_FOG);
  73
  74    glPolygonMode(GL_FRONT, GL_FILL);
  75    glPolygonMode(GL_BACK, GL_FILL);
  76
  77    glBegin(GL_TRIANGLES);
  78    glColor3f(0,0,.7);
  79    glVertex3f( 0.7, -0.7, -30.0);
  80    glColor3f(.8,0,0);
  81    glVertex3f( 0.7,  0.7, -30.0);
  82    glColor3f(0,.9,0);
  83    glVertex3f(-0.7,  0.0, -30.0);
  84    glEnd();
  85
  86    glPolygonMode(GL_FRONT, GL_LINE);
  87    glPolygonMode(GL_BACK, GL_LINE);
  88
  89    glBegin(GL_TRIANGLES);
  90    glColor3f(0,0,.7);
  91    glVertex3f( 0.9, -0.9, -30.0);
  92    glColor3f(.8,0,0);
  93    glVertex3f( 0.9,  0.9, -30.0);
  94    glColor3f(0,.9,0);
  95    glVertex3f(-0.9,  0.0, -30.0);
  96    glEnd();
  97
  98    glDisable(GL_FOG);
  99
 100    glFlush();
 101
 102    if (doubleBuffer) {
 103       glutSwapBuffers();
 104    }
 105 }
 106
 107 static GLenum Args(int argc, char **argv)
 108 {
 109    GLint i;
 110
 111    doubleBuffer = GL_FALSE;
 112
 113    for (i = 1; i < argc; i++) {
 114       if (strcmp(argv[i], "-sb") == 0) {
 115          doubleBuffer = GL_FALSE;
 116       } else if (strcmp(argv[i], "-db") == 0) {
 117          doubleBuffer = GL_TRUE;
 118       } else {
 119          fprintf(stderr, "%s (Bad option).\n", argv[i]);
 120          return GL_FALSE;
 121       }
 122    }
 123    return GL_TRUE;
 124 }
 125
 126 int main(int argc, char **argv)
 127 {
 128    GLenum type;
 129
 130    glutInit(&argc, argv);
 131
 132    if (Args(argc, argv) == GL_FALSE) {
 133       exit(1);
 134    }
 135
 136    glutInitWindowPosition(100, 0); glutInitWindowSize(Width, Height);
 137
 138    type = GLUT_RGB;
 139    type |= (doubleBuffer) ? GLUT_DOUBLE : GLUT_SINGLE;
 140    glutInitDisplayMode(type);
 141
 142    if (glutCreateWindow(*argv) == GL_FALSE) {
 143       exit(1);
 144    }
 145
 146    Init();
 147
 148    glutReshapeFunc(Reshape);
 149    glutKeyboardFunc(Key);
 150    glutDisplayFunc(Draw);
 151    glutMainLoop();
 152    return 0;
 153 }