Copyright Mark Kilgard 1994 Copyright 1993 Silicon Graphics Inc ALL RI

/* Copyright (c) Mark J. Kilgard, 1994. */

/**
* (c) Copyright 1993, Silicon Graphics, Inc.
* ALL RIGHTS RESERVED
* Permission to use, copy, modify, and distribute this software for
* any purpose and without fee is hereby granted, provided that the above
* copyright notice appear in all copies and that both the copyright notice
* and this permission notice appear in supporting documentation, and that
* the name of Silicon Graphics, Inc. not be used in advertising
* or publicity pertaining to distribution of the software without specific,
* written prior permission.
*
* THE MATERIAL EMBODIED ON THIS SOFTWARE IS PROVIDED TO YOU "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, INC.  BE LIABLE TO YOU OR ANYONE ELSE FOR ANY DIRECT,
* SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY
* KIND, OR ANY DAMAGES WHATSOEVER, INCLUDING WITHOUT LIMITATION,
* LOSS OF PROFIT, LOSS OF USE, SAVINGS OR REVENUE, OR THE CLAIMS OF
* THIRD PARTIES, WHETHER OR NOT SILICON GRAPHICS, INC.  HAS BEEN
* ADVISED OF THE POSSIBILITY OF SUCH LOSS, HOWEVER CAUSED AND ON
* ANY THEORY OF LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE
* POSSESSION, USE OR PERFORMANCE OF THIS SOFTWARE.
*
* US Government Users Restricted Rights
* Use, duplication, or disclosure by the Government is subject to
* restrictions set forth in FAR 52.227.19(c)(2) or subparagraph
* (c)(1)(ii) of the Rights in Technical Data and Computer Software
* clause at DFARS 252.227-7013 and/or in similar or successor
* clauses in the FAR or the DOD or NASA FAR Supplement.
* Unpublished-- rights reserved under the copyright laws of the
* United States.  Contractor/manufacturer is Silicon Graphics,
* Inc., 2011 N.  Shoreline Blvd., Mountain View, CA 94039-7311.
*
* OpenGL(TM) is a trademark of Silicon Graphics, Inc.
*/

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <GL/glut.h>

GLboolean doubleBuffer;

/* ARGSUSED1 */
static void
Key(unsigned char key, int x, int y)
{
	switch (key) {
	case 27:
		exit(0);
	}
}

static void
Draw(void)
{
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);

	glStencilFunc(GL_ALWAYS, 1, 0);
	glStencilOp(GL_KEEP, GL_KEEP, GL_REPLACE);

	glColor3f(0.0, 1.0, 0);
	glPushMatrix();
		glRotatef(45, 1, 0, 0);
		glRotatef(30, 0, 1, 0);
		glutSolidCube(2.5);
	glPopMatrix();

	/* red triangle */

	glStencilFunc(GL_ALWAYS, 2, 0);
	glStencilOp(GL_KEEP, GL_KEEP, GL_REPLACE);
	glColor3ub(200, 0, 0);
	glutSolidSphere(1.5,50,50);
	/* green square */

	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

	glStencilFunc(GL_EQUAL, 1, 255);
	glStencilOp(GL_KEEP, GL_KEEP, GL_KEEP);
	glPushMatrix();
	glRotatef(45, 1, 0, 0);
	glRotatef(30, 0, 1, 0);
	glutSolidCube(2.5);
	glPopMatrix();

	glRotated(0.1, 1, 0, 0);
	glutSwapBuffers();
	
}

void resize(int width, int height)
{
	glViewport(0, 0, width, height);
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	glOrtho(-5, 5, -5, 5, 2, 12);
	gluLookAt(0, 0, 5, 0, 0, 0, 0, 1, 0);
	glMatrixMode(GL_MODELVIEW);
}

static void Args(int argc, char **argv)
{
	GLint i;

	doubleBuffer = GL_TRUE;
	for (i = 1; i < argc; i++) {
		if (strcmp(argv[i], "-sb") == 0) {
			doubleBuffer = GL_FALSE;
		}
		else if (strcmp(argv[i], "-db") == 0) {
			doubleBuffer = GL_TRUE;
		}
	}
}

int
main(int argc, char **argv)
{
	GLenum type;
	float pos[4] = { 3, 3, 3, 1 };
	float dir[3] = { -1, -1, -1 };
	GLfloat mat_specular[] = { 1, 1, 1, 1 };
	glutInit(&argc, argv);
	Args(argc, argv);

	type = GLUT_RGB | GLUT_STENCIL;
	type |= (doubleBuffer) ? GLUT_DOUBLE : GLUT_SINGLE;
	glutInitDisplayMode(type);
	glutCreateWindow("Stencil Test");

	glEnable(GL_DEPTH_TEST);

	glEnable(GL_COLOR_MATERIAL);

	glEnable(GL_LIGHTING);
	glEnable(GL_LIGHT0);

	glLightfv(GL_LIGHT0, GL_POSITION, pos);
	glLightfv(GL_LIGHT0, GL_SPOT_DIRECTION, dir);

	glMaterialfv(GL_FRONT, GL_SPECULAR, mat_specular);
	glMaterialf(GL_FRONT, GL_SHININESS, 128.0);

	glClearColor(0.0, 0.0, 0.0, 0.0);
	glClearStencil(0);
	glStencilMask(1);
	glEnable(GL_STENCIL_TEST);

	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	glOrtho(-5.0, 5.0, -5.0, 5.0, -5.0, 5.0);
	glMatrixMode(GL_MODELVIEW);

	glutKeyboardFunc(Key);
	glutDisplayFunc(Draw);
	glutMainLoop();
	return 0;             /* ANSI C requires main to return int. */
}