windows-nt/Source/XPSP1/NT/multimedia/opengl/test/samples/tstencil.c

/*
 * (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 * Unpublished-- rights reserved under the copyright laws of the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 <string.h>
#include <math.h>
#include "tk.h"


GLenum directRender;


static void Init(void)
{

    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 GLenum Key(int key, GLenum mask)
{

    switch (key) {
      case TK_ESCAPE:
	tkQuit();
    }
    return GL_FALSE;
}

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;

    directRender = GL_FALSE;

    for (i = 1; i < argc; i++) {
	if (strcmp(argv[i], "-dr") == 0) {
	    directRender = GL_TRUE;
	} else if (strcmp(argv[i], "-ir") == 0) {
	    directRender = GL_FALSE;
	} else {
	    printf("%s (Bad option).\n", argv[i]);
	    return GL_FALSE;
	}
    }
    return GL_TRUE;
}

void main(int argc, char **argv)
{
    GLenum type;

    if (Args(argc, argv) == GL_FALSE) {
	tkQuit();
    }

    tkInitPosition(0, 0, 300, 300);

    type = TK_RGB | TK_SINGLE | TK_STENCIL;
    type |= (directRender) ? TK_DIRECT : TK_INDIRECT;
    tkInitDisplayMode(type);

    if (tkInitWindow("Stencil Test") == GL_FALSE) {
	tkQuit();
    }

    Init();

    tkExposeFunc(Reshape);
    tkReshapeFunc(Reshape);
    tkKeyDownFunc(Key);
    tkDisplayFunc(Draw);
    tkExec();
}