progs/trivial/point-wide.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
  35 GLenum doubleBuffer;
  36 static GLboolean smooth = GL_FALSE;
  37
  38
  39 static void Init(void)
  40 {
  41    fprintf(stderr, "GL_RENDERER   = %s\n", (char *) glGetString(GL_RENDERER));
  42    fprintf(stderr, "GL_VERSION    = %s\n", (char *) glGetString(GL_VERSION));
  43    fprintf(stderr, "GL_VENDOR     = %s\n", (char *) glGetString(GL_VENDOR));
  44
  45     glClearColor(0.0, 0.0, 1.0, 0.0);
  46 }
  47
  48 static void Reshape(int width, int height)
  49 {
  50
  51     glViewport(0, 0, (GLint)width, (GLint)height);
  52
  53     glMatrixMode(GL_PROJECTION);
  54     glLoadIdentity();
  55     glOrtho(-1.0, 1.0, -1.0, 1.0, -0.5, 1000.0);
  56     glMatrixMode(GL_MODELVIEW);
  57 }
  58
  59 static void Key(unsigned char key, int x, int y)
  60 {
  61
  62     switch (key) {
  63      case 's':
  64         smooth = !smooth;
  65         break;
  66       case 27:
  67         exit(1);
  68       default:
  69         return;
  70     }
  71
  72     glutPostRedisplay();
  73 }
  74
  75 static void Draw(void)
  76 {
  77    glClear(GL_COLOR_BUFFER_BIT);
  78
  79    glPointSize(8.0);
  80
  81    if (smooth) {
  82       glEnable(GL_POINT_SMOOTH);
  83       glEnable(GL_BLEND);
  84       glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
  85    }
  86    else {
  87       glDisable(GL_POINT_SMOOTH);
  88       glDisable(GL_BLEND);
  89    }
  90
  91    glBegin(GL_POINTS);
  92    glColor3f(1,0,0);
  93    glVertex3f( 0.9, -0.9, -30.0);
  94    glColor3f(1,1,0);
  95    glVertex3f( 0.9,  0.9, -30.0);
  96    glColor3f(1,0,1);
  97    glVertex3f(-0.9,  0.9, -30.0);
  98    glColor3f(0,1,1);
  99    glVertex3f(-0.9,  -0.9, -30.0);
 100    glEnd();
 101
 102    glFlush();
 103
 104    if (doubleBuffer) {
 105       glutSwapBuffers();
 106    }
 107 }
 108
 109 static GLenum Args(int argc, char **argv)
 110 {
 111     GLint i;
 112
 113     doubleBuffer = GL_FALSE;
 114
 115     for (i = 1; i < argc; i++) {
 116         if (strcmp(argv[i], "-sb") == 0) {
 117             doubleBuffer = GL_FALSE;
 118         } else if (strcmp(argv[i], "-db") == 0) {
 119             doubleBuffer = GL_TRUE;
 120         } else {
 121             fprintf(stderr, "%s (Bad option).\n", argv[i]);
 122             return GL_FALSE;
 123         }
 124     }
 125     return GL_TRUE;
 126 }
 127
 128 int main(int argc, char **argv)
 129 {
 130     GLenum type;
 131
 132     glutInit(&argc, argv);
 133
 134     if (Args(argc, argv) == GL_FALSE) {
 135         exit(1);
 136     }
 137
 138     glutInitWindowPosition(0, 0); glutInitWindowSize( 250, 250);
 139
 140     type = GLUT_RGB | GLUT_ALPHA;
 141     type |= (doubleBuffer) ? GLUT_DOUBLE : GLUT_SINGLE;
 142     glutInitDisplayMode(type);
 143
 144     if (glutCreateWindow("First Tri") == GL_FALSE) {
 145         exit(1);
 146     }
 147
 148     Init();
 149
 150     glutReshapeFunc(Reshape);
 151     glutKeyboardFunc(Key);
 152     glutDisplayFunc(Draw);
 153     glutMainLoop();
 154         return 0;
 155 }