windows-nt/Source/XPSP1/NT/multimedia/opengl/test/demos/stonehen/point.cxx
2020-09-26 16:20:57 +08:00

148 lines
4.4 KiB
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* Unpublished-- rights reserved under the copyright laws of the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 <windows.h>
#include <GL/gl.h>
#include <math.h>
#include <stdio.h>
#ifdef WIN32
#include "stonehen.h"
#endif
#define POINT_EXTERN
#include "Point.h"
Point Point::rotate_abouty(GLfloat c, GLfloat s)
{
val.pt[0] = c*pt[0] + s*pt[2];
val.pt[1] = pt[1];
val.pt[2] = -s*pt[0] + c*pt[2];
return val;
}
Point Point::rotate_aboutz(GLfloat c, GLfloat s)
{
val.pt[0] = c*pt[0] - s*pt[1];
val.pt[1] = s*pt[0] + c*pt[1];
val.pt[2] = pt[2];
return val;
}
void Point::refract_self(Point light, Point N, GLfloat I)
{
GLfloat t;
Point dlight;
dlight = refract_direction(light, N, I);
t = -pt[2] / dlight.pt[2];
pt[0] = pt[0] + dlight.pt[0]*t;
pt[1] = pt[1] + dlight.pt[1]*t;
pt[2] = 0;
}
Point Point::refract_direction(Point light, Point N, GLfloat I)
{
GLfloat cos1, sin1, cos2, sin2, m;
GLfloat dlight[3], dN[3], axis[3];
/* dlight = (light - *this).unit() * -1.0; */
dlight[0] = pt[0] - light.pt[0];
dlight[1] = pt[1] - light.pt[1];
dlight[2] = pt[2] - light.pt[2];
m = sqrt(dlight[0]*dlight[0] + dlight[1]*dlight[1] + dlight[2]*dlight[2]);
dlight[0] /= m;
dlight[1] /= m;
dlight[2] /= m;
// dN = N * -1.0;
dN[0] = -N.pt[0];
dN[1] = -N.pt[1];
dN[2] = -N.pt[2];
// cos1 = dN.dot(dlight);
cos1 = dN[0]*dlight[0] + dN[1]*dlight[1] + dN[2]*dlight[2];
if (1.0 - cos1*cos1 < point_fudge) {
val = dN;
return val;
}
// axis = ((dN * dlight) * dN).unit();
val.pt[0] = dN[1]*dlight[2] - dlight[1]*dN[2];
val.pt[1] = dN[2]*dlight[0] - dlight[2]*dN[0];
val.pt[2] = dN[0]*dlight[1] - dN[1]*dlight[0];
axis[0] = val.pt[1]*dN[2] - dN[1]*val.pt[2];
axis[1] = val.pt[2]*dN[0] - dN[2]*val.pt[0];
axis[2] = val.pt[0]*dN[1] - val.pt[1]*dN[0];
m = sqrt(axis[0]*axis[0] + axis[1]*axis[1] + axis[2]*axis[2]);
axis[0] /= m;
axis[1] /= m;
axis[2] /= m;
if (axis[0]*axis[0] > point_fudge)
sin1 = (dlight[0] - dN[0] * cos1) / axis[0];
else if (axis[1]*axis[1] > point_fudge)
sin1 = (dlight[1] - dN[1] * cos1) / axis[1];
else sin1 = dlight[2] - dN[2] * cos1;
sin2 = sin1 / I;
cos2 = (sin1*sin1 < 1.0) ? sqrt(1.0 - sin2*sin2) : 0;
dlight[0] = dN[0]*cos2 + axis[0]*sin2;
dlight[1] = dN[1]*cos2 + axis[1]*sin2;
dlight[2] = dN[2]*cos2 + axis[2]*sin2;
/* I'm not sure this is quite legal */
if (dlight[2] > 0.0) dlight[2] = -dlight[2];
val = dlight;
return val;
}
void Point::print()
{
print("%f %f %f\n");
}
void Point::print(const char *format)
{
printf(format, this->pt[0], this->pt[1], this->pt[2], 1.0);
}