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/*
* This file is part of din.
*
* din is copyright (c) 2006 - 2012 S Jagannathan <jag@dinisnoise.org>
* For more information, please visit http://dinisnoise.org
*
* din 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.
*
* din 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 din. If not, see <http://www.gnu.org/licenses/>.
*
*/
#ifndef _CURVE
#define _CURVE
#include <list>
#include <vector>
#include "crvpt.h"
#include "point.h"
struct curve {
float x[2], y[2]; // start/end points
float tx[2], ty[2]; // start/end tangents
std::list <crvpt> lpts; // for generation (faster bcos recursive subdivision inserts points)
std::vector<crvpt> vpts; // for draw & solve (faster bcos no inserts after generation)
curve ();
curve (float x1, float y1, float x2, float y2, float tx1, float ty1, float tx2, float ty2, float d = 1);
curve (const curve& c);
curve& operator= (const curve& c);
void copy (const curve& c);
/*
* din generates points on the bezier curve using recursive subdivision:
*
* find midpoint of line joining end points
* if distance between midpoint on this line and point on the bezier curve > limit
* insert point and repeat else stop
*/
float limit2; // square of limit distance
void set_limit (float l);
// evaluation means generation of points of the curve
enum {EVAL_REQUIRED, EVAL_COMPLETE};
int eval_state;
void eval ();
inline void tangent (int i, float xt, float yt) {
tx[i] = xt;
ty[i] = yt;
eval_state = EVAL_REQUIRED;
}
inline void get_tangent (int i, float& xt, float& yt) {
xt = tx[i];
yt = ty[i];
}
inline void vertex (int i, float xv, float yv) {
x[i] = xv;
y[i] = yv;
eval_state = EVAL_REQUIRED;
}
inline void get_vertex (int i, float& xv, float& yv) {
xv = x[i];
yv = y[i];
}
inline int eval_required () {
return (eval_state == EVAL_REQUIRED);
}
};
#endif
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