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