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/*
* camera.h -- the ePiX camera class
*
* This file is part of ePiX, a preprocessor for creating high-quality
* line figures in LaTeX
*
* Version 1.0.15
* Last Change: October 10, 2006
*/
/*
* Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006
* 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
*/
/*
* ePiX uses a camera metaphor to view points in R^3. The camera consists
* of:
* - a frame ({sea, sky, eye}, with the intuitive meanings:)
* - a point to look at (the "target")
* - the distance from the camera to the target
* - a projection mapping from R^3 to R^2 (the "lens")
*
* While specific behavior is determined by the lens, the idea is that the
* viewer sits at given <distance> from the <target>, in the direction of
* the <eye>. The vectors <sea> and <sky> point horizontally to the right
* and vertically upward on the screen. A <distance> of zero is taken to
* mean "infinitely far away"; for example, point projection (<shadow>)
* becomes orthogonal projection along the <eye> axis. Again, a specific
* lens can override this behavior, for example by ignoring the distance.
*
*
* This file provides:
*
* - the camera class and routines:
* void rotate_sea(double); // change camera orientation
* void rotate_sky(double); // about respective axes
* void rotate_eye(double);
*
* void range(double d); // set distance from camera to origin
* void look_at(P arg); // set target (center of field of view)
* void lens(pair (*screen_projection(P))); // set projection mapping
*
* pair shoot(P arg); // project a point to the screen ("take a photo")
*/
#ifndef EPIX_CAMERA
#define EPIX_CAMERA
#include "pairs.h"
#include "triples.h"
#include "frame.h"
namespace ePiX {
// screen projection mappings ("lenses")
pair shadow(const P& arg);
pair fisheye(const P& arg);
pair bubble(const P& arg);
class epix_camera {
public:
// defaults to orthog projection on (x,y) plane from pos z-axis
epix_camera();
P get_viewpt() const;
P get_target() const;
double get_range() const;
// get frame vectors
P sea() const;
P sky() const;
P eye() const;
// adjust position, orientation, and target
// pitch: rotate camera up/down
epix_camera& rotate_sea(double angle);
// yaw: rotate camera left/right
epix_camera& rotate_sky(double angle);
// roll: rotate camera about viewing axis
epix_camera& rotate_eye(double angle);
// fix target, move viewpt radially along eye()
epix_camera& range(double d);
// fix viewpt, move target radially along eye()
epix_camera& focus(double d);
// fix target, set viewpt arbitrarily
epix_camera& at(const P& arg);
epix_camera& at(const double, const double, const double);
// fix viewpt, set target arbitrarily
epix_camera& look_at(const P& arg);
epix_camera& look_at(const double, const double, const double);
// set projection mapping
epix_camera& lens(pair proj(const P&));
// project a point to the screen ("shoot a photo")
pair operator() (const P&) const;
private:
P viewpt;
P target;
frame orient;
double distance;
pair (*screen_projection)(const P&);
}; // end of class epix_camera
extern epix_camera camera;
// set global camera's location
void viewpoint(const P&);
void viewpoint(double a1, double a2, double a3);
} // end of namespace
#endif /* EPIX_CAMERA */
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