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
  44    glClearColor(0.3, 0.1, 0.3, 0.0);
  45 }
  46
  47 static void Reshape(int width, int height)
  48 {
  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(0);
  63       default:
  64          glutPostRedisplay();
  65          return;
  66    }
  67 }
  68
  69 static void Draw(void)
  70 {
  71    glClear(GL_COLOR_BUFFER_BIT);
  72
  73    glBegin(GL_TRIANGLES);
  74    glColor3f(.8,0,0);
  75    glVertex3f(-0.9, -0.9, -30.0);
  76    glColor3f(0,.9,0);
  77    glVertex3f( 0.9, -0.9, -30.0);
  78    glColor3f(0,0,.7);
  79    glVertex3f( 0.0,  0.9, -30.0);
  80    glEnd();
  81
  82
  83    glLineWidth(4.0);
  84
  85    glEnable(GL_BLEND);
  86    glEnable(GL_COLOR_LOGIC_OP);
  87    glLogicOp(GL_XOR);
  88
  89    glBegin(GL_LINES);
  90    glColor3f(.1,.7,.1);
  91    glVertex3f( 0.5, -0.5, -30.0);
  92    glVertex3f( 0.5,  0.5, -30.0);
  93
  94    glColor3f(.1,.1,.8);
  95    glVertex3f( 0.5,  0.5, -30.0);
  96    glVertex3f(-0.5,  0.5, -30.0);
  97
  98    glColor3f(.5,.1,.1);
  99    glVertex3f(-0.5,  0.5, -30.0);
 100    glVertex3f(-0.5, -0.5, -30.0);
 101
 102    glColor3f(.8,.8,.8);
 103    glVertex3f(-0.5, -0.5, -30.0);
 104    glVertex3f( 0.5, -0.5, -30.0);
 105    glEnd();
 106
 107 //   glLineWidth(12.0);
 108
 109    /* Redraw parts of the lines to remove them:
 110     */
 111    glBegin(GL_LINES);
 112    glColor3f(.1,.7,.1);
 113    glVertex3f( 0.5, -0.2, -30.0);
 114    glVertex3f( 0.5,  0.2, -30.0);
 115
 116    glColor3f(.1,.1,.8);
 117    glVertex3f( 0.2,  0.5, -30.0);
 118    glVertex3f(-0.2,  0.5, -30.0);
 119
 120    glColor3f(.5,.1,.1);
 121    glVertex3f(-0.5,  0.2, -30.0);
 122    glVertex3f(-0.5, -0.2, -30.0);
 123
 124    glColor3f(.8,.8,.8);
 125    glVertex3f(-0.2, -0.5, -30.0);
 126    glVertex3f( 0.2, -0.5, -30.0);
 127    glEnd();
 128
 129
 130
 131    glDisable(GL_COLOR_LOGIC_OP);
 132    glDisable(GL_BLEND);
 133
 134    glFlush();
 135
 136    if (doubleBuffer) {
 137       glutSwapBuffers();
 138    }
 139 }
 140
 141 static GLenum Args(int argc, char **argv)
 142 {
 143    GLint i;
 144
 145    for (i = 1; i < argc; i++) {
 146       if (strcmp(argv[i], "-sb") == 0) {
 147          doubleBuffer = GL_FALSE;
 148       } else if (strcmp(argv[i], "-db") == 0) {
 149          doubleBuffer = GL_TRUE;
 150       } else {
 151          fprintf(stderr, "%s (Bad option).\n", argv[i]);
 152          return GL_FALSE;
 153       }
 154    }
 155    return GL_TRUE;
 156 }
 157
 158 int main(int argc, char **argv)
 159 {
 160    GLenum type;
 161
 162    glutInit(&argc, argv);
 163
 164    if (Args(argc, argv) == GL_FALSE) {
 165       exit(1);
 166    }
 167
 168    glutInitWindowPosition(0, 0); glutInitWindowSize( 250, 250);
 169
 170    type = GLUT_RGB | GLUT_ALPHA;
 171    type |= (doubleBuffer) ? GLUT_DOUBLE : GLUT_SINGLE;
 172    glutInitDisplayMode(type);
 173
 174    win = glutCreateWindow(*argv);
 175    if (!win) {
 176       exit(1);
 177    }
 178
 179    Init();
 180
 181    glutReshapeFunc(Reshape);
 182    glutKeyboardFunc(Key);
 183    glutDisplayFunc(Draw);
 184    glutMainLoop();
 185    return 0;
 186 }