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/*
* facet.cc -- Utility classes for shaded surface plotting
*
* This file is part of ePiX, a C++ library for creating high-quality
* figures in LaTeX
*
* Version 1.2.2
* Last Change: December 06, 2007
*/
/*
* Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007
* Andrew D. Hwang <rot 13 nujnat at zngupf dot ubylpebff dot rqh>
* Department of Mathematics and Computer Science
* College of the Holy Cross
* Worcester, MA, 01610-2395, USA
*/
/*
* ePiX is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* ePiX is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
* License for more details.
*
* You should have received a copy of the GNU General Public License
* along with ePiX; if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <cmath>
#include "constants.h"
#include "errors.h"
#include "functions.h"
#include "frame.h"
#include "camera.h"
#include "Color.h"
#include "paint_style.h"
#include "facet.h"
namespace ePiX {
facet::facet(P f(double, double),
double u0, double v0,
double du, double dv,
const unsigned int N1, const unsigned int N2)
: m_tint(the_paint_style().fill_color()),
m_line(the_paint_style().line_pen()),
m_fill(the_paint_style().fill_flag()),
pt1(f(u0, v0)),
pt2(f(u0 + N1*du, v0)),
pt3(f(u0 + N1*du, v0 + N2*dv)),
pt4(f(u0, v0 + N2*dv)),
center(0.25*(pt1 + pt2 + pt3 + pt4)),
direction(center-cam().viewpt()),
distance(norm(direction))
{
perp = ((pt1 - center)*(pt2 - center));
if (norm(perp) < EPIX_EPSILON)
perp = (pt3 - center)*(pt4 - center);
perp *= recip(norm(perp));
// bottom edge
for (unsigned int i=0; i<N1; ++i)
bd.pt(f(u0 + i*du, v0));
// right edge
for (unsigned int j=0; j<N2; ++j)
bd.pt(f(u0 + N1*du, v0 + j*dv));
// top edge (backward)
for (unsigned int i=0; i<N1; ++i)
bd.pt(f(u0 + (N1-i)*du, v0 + N2*dv));
// left edge (downward)
for (unsigned int j=0; j<N2; ++j)
bd.pt(f(u0, v0 + (N2-j)*dv));
bd.close().fill(!m_tint.is_unset());
}
// facet constructor for f(double, double, double)
facet::facet(P f(double, double, double),
double u0, double v0, double w0,
double du, double dv, double dw,
const unsigned int N1, const unsigned int N2)
: m_tint(the_paint_style().fill_color()),
m_line(the_paint_style().line_pen()),
m_fill(the_paint_style().fill_flag()),
pt1(f(u0, v0, w0))
{
if (du == 0) // (y,z)
{
// bottom edge
for (unsigned int i=0; i<N1; ++i)
bd.pt(f(u0, v0 + i*dv, w0));
// right edge
for (unsigned int j=0; j<N2; ++j)
bd.pt(f(u0, v0 + N1*dv, w0 + j*dw));
// top edge (backward)
for (unsigned int i=0; i<N1; ++i)
bd.pt(f(u0, v0 + (N1-i)*dv, w0 + N2*dw));
// left edge (downward)
for (unsigned int j=0; j<N2; ++j)
bd.pt(f(u0, v0, w0 + (N2-j)*dw));
// use corners to approximate distance to camera
pt2 = f(u0, v0 + N1*dv, w0);
pt3 = f(u0, v0 + N1*dv, w0 + N2*dw);
pt4 = f(u0, v0, w0 + N2*dw);
}
else if (dv == 0) // (x,z)
{
// bottom edge
for (unsigned int i=0; i<N1; ++i)
bd.pt(f(u0 + i*du, v0, w0));
// right edge
for (unsigned int j=0; j<N2; ++j)
bd.pt(f(u0 + N1*du, v0, w0 + j*dw));
// top edge (backward)
for (unsigned int i=0; i<N1; ++i)
bd.pt(f(u0 + (N1-i)*du, v0, w0 + N2*dw));
// left edge (downward)
for (unsigned int j=0; j<N2; ++j)
bd.pt(f(u0, v0, w0 + (N2-j)*dw));
// use corners to approximate distance to camera
pt2 = f(u0 + N1*du, v0, w0);
pt3 = f(u0 + N1*du, v0, w0 + N2*dw);
pt4 = f(u0, v0, w0 + N2*dw);
}
else if (dw == 0) // (x,y)
{
// bottom edge
for (unsigned int i=0; i<N1; ++i)
bd.pt(f(u0 + i*du, v0, w0));
// right edge
for (unsigned int j=0; j<N2; ++j)
bd.pt(f(u0 + N1*du, v0 + j*dv, w0));
// top edge (backward)
for (unsigned int i=0; i<N1; ++i)
bd.pt(f(u0 + (N1-i)*du, v0 + N2*dv, w0));
// left edge (downward)
for (unsigned int j=0; j<N2; ++j)
bd.pt(f(u0, v0 + (N2-j)*dv, w0));
// use corners to approximate distance to camera
pt2 = f(u0 + N1*du, v0, w0);
pt3 = f(u0 + N1*du, v0 + N2*dv, w0);
pt4 = f(u0, v0 + N2*dv, w0);
}
else
epix_error("Bad call to facet constructor"); // exits
bd.close().fill(!m_tint.is_unset());
center = 0.25*(pt1 + pt2 + pt3 + pt4);
direction = center-cam().viewpt();
distance = norm(direction);
perp = ((pt1 - center)*(pt2 - center));
if (norm(perp) < EPIX_EPSILON)
perp = (pt3 - center)*(pt4 - center);
perp *= recip(norm(perp));
} // end of facet(f(double, double, double), ...)
// for surface of rotation
facet::facet(double f(double), double g(double),
double u0, double v0,
double du, double dv,
const unsigned int N1, const unsigned int N2,
const frame& coords)
: m_tint(the_paint_style().fill_color()),
m_line(the_paint_style().line_pen()),
m_fill(the_paint_style().fill_flag()),
pt1(f(u0)*coords.sea() +
g(u0)*Cos(v0)*coords.sky() +
g(u0)*Sin(v0)*coords.eye()),
pt2(f(u0 + N1*du)*coords.sea() +
g(u0 + N1*du)*Cos(v0)*coords.sky() +
g(u0 + N1*du)*Sin(v0)*coords.eye()),
pt3(f(u0 + N1*du)*coords.sea() +
g(u0 + N1*du)*Cos(v0 + N2*dv)*coords.sky() +
g(u0 + N1*du)*Sin(v0 + N2*dv)*coords.eye()),
pt4(f(u0)*coords.sea() +
g(u0)*Cos(v0 + N2*dv)*coords.sky() +
g(u0)*Sin(v0 + N2*dv)*coords.eye()),
center(0.25*(pt1 + pt2 + pt3 + pt4)),
direction(center-cam().viewpt()), distance(norm(direction))
{
perp = ((pt1 - center)*(pt2 - center));
if (norm(perp) < EPIX_EPSILON)
perp = (pt3 - center)*(pt4 - center);
perp *= recip(norm(perp));
// bottom edge
for (unsigned int i=0; i<N1; ++i)
bd.pt(f(u0 + i*du)*coords.sea() +
g(u0 + i*du)*Cos(v0)*coords.sky() +
g(u0 + i*du)*Sin(v0)*coords.eye());
// right edge
for (unsigned int j=0; j<N2; ++j)
bd.pt(f(u0 + N1*du)*coords.sea() +
g(u0 + N1*du)*Cos(v0 + j*dv)*coords.sky() +
g(u0 + N1*du)*Sin(v0 + j*dv)*coords.eye());
// top edge (backward)
for (unsigned int i=0; i<N1; ++i)
bd.pt(f(u0 + (N1-i)*du)*coords.sea() +
g(u0 + (N1-i)*du)*Cos(v0 + N2*dv)*coords.sky() +
g(u0 + (N1-i)*du)*Sin(v0 + N2*dv)*coords.eye());
// left edge (downward)
for (unsigned int j=0; j<N2; ++j)
bd.pt(f(u0)*coords.sea() +
g(u0)*Cos(v0 + (N2-j)*dv)*coords.sky() +
g(u0)*Sin(v0 + (N2-j)*dv)*coords.eye());
bd.close().fill(!m_tint.is_unset());
}
//// Color-dependent constructors
facet::facet(P f(double, double),
double u0, double v0,
double du, double dv,
const unsigned int N1, const unsigned int N2,
const Color& tint)
: m_tint(tint), m_line(the_paint_style().line_pen()),
m_fill(the_paint_style().fill_flag()),
pt1(f(u0, v0)),
pt2(f(u0 + N1*du, v0)),
pt3(f(u0 + N1*du, v0 + N2*dv)),
pt4(f(u0, v0 + N2*dv)),
center(0.25*(pt1 + pt2 + pt3 + pt4)),
direction(center-cam().viewpt()),
distance(norm(direction))
{
perp = ((pt1 - center)*(pt2 - center));
if (norm(perp) < EPIX_EPSILON)
perp = (pt3 - center)*(pt4 - center);
perp *= recip(norm(perp));
// bottom edge
for (unsigned int i=0; i<N1; ++i)
bd.pt(f(u0 + i*du, v0));
// right edge
for (unsigned int j=0; j<N2; ++j)
bd.pt(f(u0 + N1*du, v0 + j*dv));
// top edge (backward)
for (unsigned int i=0; i<N1; ++i)
bd.pt(f(u0 + (N1-i)*du, v0 + N2*dv));
// left edge (downward)
for (unsigned int j=0; j<N2; ++j)
bd.pt(f(u0, v0 + (N2-j)*dv));
bd.close().fill(!m_tint.is_unset());
}
// facet constructor for f(double, double, double)
facet::facet(P f(double, double, double),
double u0, double v0, double w0,
double du, double dv, double dw,
const unsigned int N1, const unsigned int N2,
const Color& tint)
: m_tint(tint), m_line(the_paint_style().line_pen()),
m_fill(the_paint_style().fill_flag()),
pt1(f(u0, v0, w0))
{
if (du == 0) // (y,z)
{
// bottom edge
for (unsigned int i=0; i<N1; ++i)
bd.pt(f(u0, v0 + i*dv, w0));
// right edge
for (unsigned int j=0; j<N2; ++j)
bd.pt(f(u0, v0 + N1*dv, w0 + j*dw));
// top edge (backward)
for (unsigned int i=0; i<N1; ++i)
bd.pt(f(u0, v0 + (N1-i)*dv, w0 + N2*dw));
// left edge (downward)
for (unsigned int j=0; j<N2; ++j)
bd.pt(f(u0, v0, w0 + (N2-j)*dw));
// use corners to approximate distance to camera
pt2 = f(u0, v0 + N1*dv, w0);
pt3 = f(u0, v0 + N1*dv, w0 + N2*dw);
pt4 = f(u0, v0, w0 + N2*dw);
}
else if (dv == 0) // (x,z)
{
// bottom edge
for (unsigned int i=0; i<N1; ++i)
bd.pt(f(u0 + i*du, v0, w0));
// right edge
for (unsigned int j=0; j<N2; ++j)
bd.pt(f(u0 + N1*du, v0, w0 + j*dw));
// top edge (backward)
for (unsigned int i=0; i<N1; ++i)
bd.pt(f(u0 + (N1-i)*du, v0, w0 + N2*dw));
// left edge (downward)
for (unsigned int j=0; j<N2; ++j)
bd.pt(f(u0, v0, w0 + (N2-j)*dw));
// use corners to approximate distance to camera
pt2 = f(u0 + N1*du, v0, w0);
pt3 = f(u0 + N1*du, v0, w0 + N2*dw);
pt4 = f(u0, v0, w0 + N2*dw);
}
else if (dw == 0) // (x,y)
{
// bottom edge
for (unsigned int i=0; i<N1; ++i)
bd.pt(f(u0 + i*du, v0, w0));
// right edge
for (unsigned int j=0; j<N2; ++j)
bd.pt(f(u0 + N1*du, v0 + j*dv, w0));
// top edge (backward)
for (unsigned int i=0; i<N1; ++i)
bd.pt(f(u0 + (N1-i)*du, v0 + N2*dv, w0));
// left edge (downward)
for (unsigned int j=0; j<N2; ++j)
bd.pt(f(u0, v0 + (N2-j)*dv, w0));
// use corners to approximate distance to camera
pt2 = f(u0 + N1*du, v0, w0);
pt3 = f(u0 + N1*du, v0 + N2*dv, w0);
pt4 = f(u0, v0 + N2*dv, w0);
}
else
epix_error("Bad call to facet constructor"); // exits
bd.close().fill(!m_tint.is_unset());
center = 0.25*(pt1 + pt2 + pt3 + pt4);
direction = center-cam().viewpt();
distance = norm(direction);
perp = ((pt1 - center)*(pt2 - center));
if (norm(perp) < EPIX_EPSILON)
perp = (pt3 - center)*(pt4 - center);
perp *= recip(norm(perp));
} // end of facet(f(double, double, double), ...)
// for surface of rotation
facet::facet(double f(double), double g(double),
double u0, double v0,
double du, double dv,
const unsigned int N1, const unsigned int N2,
const Color& tint, const frame& coords)
: m_tint(tint), m_line(the_paint_style().line_pen()),
m_fill(the_paint_style().fill_flag()),
pt1(f(u0)*coords.sea() +
g(u0)*Cos(v0)*coords.sky() +
g(u0)*Sin(v0)*coords.eye()),
pt2(f(u0 + N1*du)*coords.sea() +
g(u0 + N1*du)*Cos(v0)*coords.sky() +
g(u0 + N1*du)*Sin(v0)*coords.eye()),
pt3(f(u0 + N1*du)*coords.sea() +
g(u0 + N1*du)*Cos(v0 + N2*dv)*coords.sky() +
g(u0 + N1*du)*Sin(v0 + N2*dv)*coords.eye()),
pt4(f(u0)*coords.sea() +
g(u0)*Cos(v0 + N2*dv)*coords.sky() +
g(u0)*Sin(v0 + N2*dv)*coords.eye()),
center(0.25*(pt1 + pt2 + pt3 + pt4)),
direction(center-cam().viewpt()), distance(norm(direction))
{
perp = ((pt1 - center)*(pt2 - center));
if (norm(perp) < EPIX_EPSILON)
perp = (pt3 - center)*(pt4 - center);
perp *= recip(norm(perp));
// bottom edge
for (unsigned int i=0; i<N1; ++i)
bd.pt(f(u0 + i*du)*coords.sea() +
g(u0 + i*du)*Cos(v0)*coords.sky() +
g(u0 + i*du)*Sin(v0)*coords.eye());
// right edge
for (unsigned int j=0; j<N2; ++j)
bd.pt(f(u0 + N1*du)*coords.sea() +
g(u0 + N1*du)*Cos(v0 + j*dv)*coords.sky() +
g(u0 + N1*du)*Sin(v0 + j*dv)*coords.eye());
// top edge (backward)
for (unsigned int i=0; i<N1; ++i)
bd.pt(f(u0 + (N1-i)*du)*coords.sea() +
g(u0 + (N1-i)*du)*Cos(v0 + N2*dv)*coords.sky() +
g(u0 + (N1-i)*du)*Sin(v0 + N2*dv)*coords.eye());
// left edge (downward)
for (unsigned int j=0; j<N2; ++j)
bd.pt(f(u0)*coords.sea() +
g(u0)*Cos(v0 + (N2-j)*dv)*coords.sky() +
g(u0)*Sin(v0 + (N2-j)*dv)*coords.eye());
bd.close().fill(!m_tint.is_unset());
}
facet* facet::clone() const
{
return new facet(*this);
}
double facet::how_far() const { return distance; }
bool facet::front_facing() const
{
return (-direction|perp) > -EPIX_EPSILON;
}
// N.B. We assume the fill state is stored by our caller
void facet::draw(int cull) const
{
if (( cull == 1 && front_facing() ) || ( cull == -1 && !front_facing() ))
return;
// else
Color paint(m_tint);
if (paint.is_unset())
paint = White();
Color ink(m_line.color());
if (ink.is_unset())
ink = paint;
if (m_fill)
{
// calculate cosine^2 of normal angle
// Magic formula (simulated ambient lighting)
const double dens(0.5*(1+pow(perp|(recip(distance)*direction), 2)));
paint *= dens;
ink *= dens;
}
bd.draw(paint, pen_data(ink, m_line.width()));
} // end of facet::draw(bool, int)
bool by_distance::operator() (const facet& arg1, const facet& arg2)
{
return arg1.how_far() > arg2.how_far();
}
bool by_distance::operator() (const facet* arg1, const facet* arg2)
{
return arg1->how_far() > arg2->how_far();
}
} // end of namespace
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