/* * Copyright (c) 1991, 1992, 1993 Silicon Graphics, Inc. * * Permission to use, copy, modify, distribute, and sell this software and * its documentation for any purpose is hereby granted without fee, provided * that (i) the above copyright notices and this permission notice appear in * all copies of the software and related documentation, and (ii) the name of * Silicon Graphics may not be used in any advertising or * publicity relating to the software without the specific, prior written * permission of Silicon Graphics. * * THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF * ANY KIND, * EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY * WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. * * IN NO EVENT SHALL SILICON GRAPHICS BE LIABLE FOR * ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND, * OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, * WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF * LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE * OF THIS SOFTWARE. */ #include <stdio.h> #include <stdlib.h> #include <string.h> #include <math.h> #include <GL/glut.h> static void Init(void) { glShadeModel(GL_FLAT); glClearColor(0.0, 0.0, 0.0, 0.0); glClearStencil(0); glStencilMask(1); glEnable(GL_STENCIL_TEST); } static void Reshape(int width, int height) { glViewport(0, 0, (GLint)width, (GLint)height); glMatrixMode(GL_PROJECTION); glLoadIdentity(); glOrtho(-5.0, 5.0, -5.0, 5.0, -5.0, 5.0); glMatrixMode(GL_MODELVIEW); } static void Key(unsigned char key, int x, int y) { switch (key) { case 27: exit(1); } } static void Draw(void) { glClear(GL_COLOR_BUFFER_BIT|GL_STENCIL_BUFFER_BIT); glStencilFunc(GL_ALWAYS, 1, 1); glStencilOp(GL_KEEP, GL_KEEP, GL_REPLACE); glColor3ub(200, 0, 0); glBegin(GL_POLYGON); glVertex3i(-4, -4, 0); glVertex3i( 4, -4, 0); glVertex3i( 0, 4, 0); glEnd(); glStencilFunc(GL_EQUAL, 1, 1); glStencilOp(GL_INCR, GL_KEEP, GL_DECR); glColor3ub(0, 200, 0); glBegin(GL_POLYGON); glVertex3i(3, 3, 0); glVertex3i(-3, 3, 0); glVertex3i(-3, -3, 0); glVertex3i(3, -3, 0); glEnd(); glStencilFunc(GL_EQUAL, 1, 1); glStencilOp(GL_KEEP, GL_KEEP, GL_KEEP); glColor3ub(0, 0, 200); glBegin(GL_POLYGON); glVertex3i(3, 3, 0); glVertex3i(-3, 3, 0); glVertex3i(-3, -3, 0); glVertex3i(3, -3, 0); glEnd(); glFlush(); } static GLenum Args(int argc, char **argv) { GLint i; for (i = 1; i < argc; i++) { if (strcmp(argv[i], "-dr") == 0) { } else { printf("%s (Bad option).\n", argv[i]); return GL_FALSE; } } return GL_TRUE; } int main(int argc, char **argv) { GLenum type; glutInit(&argc, argv); if (Args(argc, argv) == GL_FALSE) { exit(1); } glutInitWindowPosition(0, 0); glutInitWindowSize( 300, 300); type = GLUT_RGB | GLUT_SINGLE | GLUT_STENCIL; glutInitDisplayMode(type); if (glutCreateWindow("Stencil Test") == GL_FALSE) { exit(1); } Init(); glutReshapeFunc(Reshape); glutKeyboardFunc(Key); glutDisplayFunc(Draw); glutMainLoop(); return 0; }