progs/trivial/point-wide-smooth.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
  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
  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 27:
  64         exit(1);
  65       default:
  66         break;
  67     }
  68
  69     glutPostRedisplay();
  70 }
  71
  72 static void Draw(void)
  73 {
  74    glClear(GL_COLOR_BUFFER_BIT);
  75
  76    glPointSize(8.0);
  77
  78    glEnable(GL_POINT_SMOOTH);
  79    glEnable(GL_BLEND);
  80    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
  81
  82    glBegin(GL_POINTS);
  83    glColor3f(1,0,0);
  84    glVertex3f( 0.9, -0.9, -30.0);
  85    glColor3f(1,1,0);
  86    glVertex3f( 0.9,  0.9, -30.0);
  87    glColor3f(1,0,1);
  88    glVertex3f(-0.9,  0.9, -30.0);
  89    glColor3f(0,1,1);
  90    glVertex3f(-0.9,  -0.9, -30.0);
  91    glEnd();
  92
  93    glFlush();
  94
  95    if (doubleBuffer) {
  96       glutSwapBuffers();
  97    }
  98 }
  99
 100 static GLenum Args(int argc, char **argv)
 101 {
 102     GLint i;
 103
 104     doubleBuffer = GL_FALSE;
 105
 106     for (i = 1; i < argc; i++) {
 107         if (strcmp(argv[i], "-sb") == 0) {
 108             doubleBuffer = GL_FALSE;
 109         } else if (strcmp(argv[i], "-db") == 0) {
 110             doubleBuffer = GL_TRUE;
 111         } else {
 112             fprintf(stderr, "%s (Bad option).\n", argv[i]);
 113             return GL_FALSE;
 114         }
 115     }
 116     return GL_TRUE;
 117 }
 118
 119 int main(int argc, char **argv)
 120 {
 121     GLenum type;
 122
 123     glutInit(&argc, argv);
 124
 125     if (Args(argc, argv) == GL_FALSE) {
 126         exit(1);
 127     }
 128
 129     glutInitWindowPosition(0, 0); glutInitWindowSize( 250, 250);
 130
 131     type = GLUT_RGB | GLUT_ALPHA;
 132     type |= (doubleBuffer) ? GLUT_DOUBLE : GLUT_SINGLE;
 133     glutInitDisplayMode(type);
 134
 135     if (glutCreateWindow(*argv) == GL_FALSE) {
 136         exit(1);
 137     }
 138
 139     Init();
 140
 141     glutReshapeFunc(Reshape);
 142     glutKeyboardFunc(Key);
 143     glutDisplayFunc(Draw);
 144     glutMainLoop();
 145         return 0;
 146 }