nuclear@12: /*
nuclear@12: glviewvol is an OpenGL 3D volume data viewer
nuclear@12: Copyright (C) 2014  John Tsiombikas <nuclear@member.fsf.org>
nuclear@12: 
nuclear@12: This program is free software: you can redistribute it and/or modify
nuclear@12: it under the terms of the GNU General Public License as published by
nuclear@12: the Free Software Foundation, either version 3 of the License, or
nuclear@12: (at your option) any later version.
nuclear@12: 
nuclear@12: This program is distributed in the hope that it will be useful,
nuclear@12: but WITHOUT ANY WARRANTY; without even the implied warranty of
nuclear@12: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
nuclear@12: GNU General Public License for more details.
nuclear@12: 
nuclear@12: You should have received a copy of the GNU General Public License
nuclear@12: along with this program.  If not, see <http://www.gnu.org/licenses/>.
nuclear@12: */
nuclear@4: #include <algorithm>
nuclear@4: #include "curve.h"
nuclear@4: 
nuclear@4: #define CLAMP(x, low, high)	std::min<float>(std::max<float>(x, low), high)
nuclear@4: #define INDEX(x) ((x) * 65535.0)
nuclear@4: 
nuclear@4: void Curve::set_point(float t, float val)
nuclear@4: {
nuclear@4: 	uint16_t x = INDEX(CLAMP(t, 0.0, 1.0));
nuclear@4: 	set_point_int(x, val);
nuclear@4: }
nuclear@4: 
nuclear@4: static bool cpcmp(const CurvePoint &a, const CurvePoint &b)
nuclear@4: {
nuclear@4: 	return a.t_int < b.t_int;
nuclear@4: }
nuclear@4: 
nuclear@4: void Curve::set_point_int(uint16_t ti, float val)
nuclear@4: {
nuclear@4: 	CurvePoint *p = get_point_at(ti);
nuclear@4: 	if(p) {
nuclear@4: 		p->value = val;
nuclear@4: 	} else {
nuclear@4: 		CurvePoint p;
nuclear@4: 		p.t_int = ti;
nuclear@4: 		p.value = val;
nuclear@4: 		cp.push_back(p);
nuclear@4: 		std::sort(cp.begin(), cp.end(), cpcmp);
nuclear@4: 	}
nuclear@4: }
nuclear@4: 
nuclear@4: bool Curve::delete_point(uint16_t ti)
nuclear@4: {
nuclear@4: 	int sz = (int)cp.size();
nuclear@4: 	for(int i=0; i<sz; i++) {
nuclear@4: 		if(cp[i].t_int == ti) {
nuclear@4: 			cp.erase(cp.begin() + i);
nuclear@4: 			return true;
nuclear@4: 		}
nuclear@4: 	}
nuclear@4: 	return false;
nuclear@4: }
nuclear@4: 
nuclear@4: CurvePoint *Curve::get_point(int idx)
nuclear@4: {
nuclear@7: 	if(idx < 0 || idx >= (int)cp.size()) {
nuclear@4: 		return 0;
nuclear@4: 	}
nuclear@4: 	return &cp[idx];
nuclear@4: }
nuclear@4: 
nuclear@4: const CurvePoint *Curve::get_point(int idx) const
nuclear@4: {
nuclear@7: 	if(idx < 0 || idx >= (int)cp.size()) {
nuclear@4: 		return 0;
nuclear@4: 	}
nuclear@4: 	return &cp[idx];
nuclear@4: }
nuclear@4: 
nuclear@4: int Curve::get_num_points() const
nuclear@4: {
nuclear@4: 	return (int)cp.size();
nuclear@4: }
nuclear@4: 
nuclear@4: CurvePoint *Curve::get_point_at(uint16_t ti)
nuclear@4: {
nuclear@4: 	int sz = (int)cp.size();
nuclear@4: 	for(int i=0; i<sz; i++) {
nuclear@4: 		if(cp[i].t_int == ti) {
nuclear@4: 			return &cp[i];
nuclear@4: 		}
nuclear@4: 	}
nuclear@4: 	return 0;
nuclear@4: }
nuclear@4: 
nuclear@4: const CurvePoint *Curve::get_point_at(uint16_t ti) const
nuclear@4: {
nuclear@4: 	int sz = (int)cp.size();
nuclear@4: 	for(int i=0; i<sz; i++) {
nuclear@4: 		if(cp[i].t_int == ti) {
nuclear@4: 			return &cp[i];
nuclear@4: 		}
nuclear@4: 	}
nuclear@4: 	return 0;
nuclear@4: }
nuclear@4: 
nuclear@4: float Curve::value(float t) const
nuclear@4: {
nuclear@4: 	uint16_t x = INDEX(CLAMP(t, 0.0, 1.0));
nuclear@4: 	return value_int(x);
nuclear@4: }
nuclear@4: 
nuclear@4: float Curve::value_int(uint16_t ti) const
nuclear@4: {
nuclear@4: 	CurvePoint p = { ti, 0 };
nuclear@4: 	std::vector<CurvePoint>::const_iterator it;
nuclear@4: 	it = std::lower_bound(cp.begin(), cp.end(), p, cpcmp);
nuclear@4: 	if(ti >= it->t_int || it == cp.begin()) {
nuclear@4: 		return it->value;
nuclear@4: 	}
nuclear@4: 
nuclear@4: 	std::vector<CurvePoint>::const_iterator prev = it - 1;
nuclear@4: 
nuclear@4: 	float t = (float)(ti - prev->t_int) / (float)(it->t_int - prev->t_int);
nuclear@4: 	return prev->value + (it->value - prev->value) * t;
nuclear@4: }