progs/trivial/tri-logicop-xor.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 = 1;
  36 int win;
  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(0.3, 0.1, 0.3, 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    switch (key) {
  62       case 27:
  63          exit(0);
  64       default:
  65          glutPostRedisplay();
  66          return;
  67    }
  68 }
  69
  70 static void Draw(void)
  71 {
  72    glClear(GL_COLOR_BUFFER_BIT);
  73
  74    glBegin(GL_TRIANGLES);
  75    glColor3f(.8,0,0);
  76    glVertex3f(-0.9, -0.9, -30.0);
  77    glColor3f(0,.9,0);
  78    glVertex3f( 0.9, -0.9, -30.0);
  79    glColor3f(0,0,.7);
  80    glVertex3f( 0.0,  0.9, -30.0);
  81    glEnd();
  82
  83
  84    glLineWidth(4.0);
  85
  86    glEnable(GL_BLEND);
  87    glEnable(GL_COLOR_LOGIC_OP);
  88    glLogicOp(GL_XOR);
  89
  90    glBegin(GL_LINES);
  91    glColor3f(.1,.7,.1);
  92    glVertex3f( 0.5, -0.5, -30.0);
  93    glVertex3f( 0.5,  0.5, -30.0);
  94
  95    glColor3f(.1,.1,.8);
  96    glVertex3f( 0.5,  0.5, -30.0);
  97    glVertex3f(-0.5,  0.5, -30.0);
  98
  99    glColor3f(.5,.1,.1);
 100    glVertex3f(-0.5,  0.5, -30.0);
 101    glVertex3f(-0.5, -0.5, -30.0);
 102
 103    glColor3f(.8,.8,.8);
 104    glVertex3f(-0.5, -0.5, -30.0);
 105    glVertex3f( 0.5, -0.5, -30.0);
 106    glEnd();
 107
 108    /* glLineWidth(12.0); */
 109
 110    /* Redraw parts of the lines to remove them:
 111     */
 112    glBegin(GL_LINES);
 113    glColor3f(.1,.7,.1);
 114    glVertex3f( 0.5, -0.2, -30.0);
 115    glVertex3f( 0.5,  0.2, -30.0);
 116
 117    glColor3f(.1,.1,.8);
 118    glVertex3f( 0.2,  0.5, -30.0);
 119    glVertex3f(-0.2,  0.5, -30.0);
 120
 121    glColor3f(.5,.1,.1);
 122    glVertex3f(-0.5,  0.2, -30.0);
 123    glVertex3f(-0.5, -0.2, -30.0);
 124
 125    glColor3f(.8,.8,.8);
 126    glVertex3f(-0.2, -0.5, -30.0);
 127    glVertex3f( 0.2, -0.5, -30.0);
 128    glEnd();
 129
 130
 131
 132    glDisable(GL_COLOR_LOGIC_OP);
 133    glDisable(GL_BLEND);
 134
 135    glFlush();
 136
 137    if (doubleBuffer) {
 138       glutSwapBuffers();
 139    }
 140 }
 141
 142 static GLenum Args(int argc, char **argv)
 143 {
 144    GLint i;
 145
 146    for (i = 1; i < argc; i++) {
 147       if (strcmp(argv[i], "-sb") == 0) {
 148          doubleBuffer = GL_FALSE;
 149       } else if (strcmp(argv[i], "-db") == 0) {
 150          doubleBuffer = GL_TRUE;
 151       } else {
 152          fprintf(stderr, "%s (Bad option).\n", argv[i]);
 153          return GL_FALSE;
 154       }
 155    }
 156    return GL_TRUE;
 157 }
 158
 159 int main(int argc, char **argv)
 160 {
 161    GLenum type;
 162
 163    glutInit(&argc, argv);
 164
 165    if (Args(argc, argv) == GL_FALSE) {
 166       exit(1);
 167    }
 168
 169    glutInitWindowPosition(0, 0); glutInitWindowSize( 250, 250);
 170
 171    type = GLUT_RGB | GLUT_ALPHA;
 172    type |= (doubleBuffer) ? GLUT_DOUBLE : GLUT_SINGLE;
 173    glutInitDisplayMode(type);
 174
 175    win = glutCreateWindow(*argv);
 176    if (!win) {
 177       exit(1);
 178    }
 179
 180    Init();
 181
 182    glutReshapeFunc(Reshape);
 183    glutKeyboardFunc(Key);
 184    glutDisplayFunc(Draw);
 185    glutMainLoop();
 186    return 0;
 187 }