/*---

    iGeo - http://igeo.jp

    Copyright (c) 2002-2013 Satoru Sugihara

    This file is part of iGeo.

    iGeo is free software: you can redistribute it and/or modify
    it under the terms of the GNU Lesser General Public License as
    published by the Free Software Foundation, version 3.

    iGeo 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 Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with iGeo.  If not, see <http://www.gnu.org/licenses/>.

---*/

package igeo;

import java.util.ArrayList;

/**
   A subclass of IMap defined by two value to generate gradient map in v direction.
   
   @author Satoru Sugihara
*/
public class IVLinearMap extends IMap{
    public double start, end; //vval1, vval2;
    public ArrayList<Double> domains;
    public ArrayList<Double> values;
    
    public IVLinearMap(){ start = 0; end = 0; }
    public IVLinearMap(double value){ start = value; end = value; }
    public IVLinearMap(double v0, double v1){ start = v0; end = v1; }
    public IVLinearMap(double v0, double v05, double v1){
	start = v0; end = v1;
	domains = new ArrayList<Double>();
	values =  new ArrayList<Double>();
	domains.add(0.5);
	values.add(v05);
    }
    public IVLinearMap(double v0, double v033, double v066, double v1){
	start = v0; end = v1;
	domains = new ArrayList<Double>();
	values =  new ArrayList<Double>();
	domains.add(1./3);
	values.add(v033);
	domains.add(2./3);
	values.add(v066);
    }
    
    /**
       adding (inserting) value between the domain of 0 - 1
    */
    public IVLinearMap add(double v, double value){
	if(IG.eq(v, 0.0, IConfig.parameterTolerance)){ start = value; return this; }
	if(IG.eq(v, 1.0, IConfig.parameterTolerance)){ end = value; return this; }
	
	if(v < 0.0 || v > 1.0){ IOut.err("v ("+v+") is out of range. skipped"); return this; }
	
	if(domains==null){
	    domains = new ArrayList<Double>();
	    values = new ArrayList<Double>();
	    domains.add(v);
	    values.add(value);
	    return this;
	}
	
	for(int i=0; i<domains.size(); i++){
	    if(IG.eq(v, domains.get(i), IConfig.parameterTolerance)){
		domains.set(i, v);
		values.set(i, value);
		return this;
	    }
	    else if(v < domains.get(i)){
		domains.add(i, v);
		values.add(i, value);
		return this;
	    }
	}
	domains.add(v);
	values.add(value);
	return this;
    }
    /** alias of add(double,double) */
    public IVLinearMap addValue(double v, double value){ return add(v,value); }
    /** alias of add(double,double) */
    public IVLinearMap insert(double v, double value){ return add(v,value); }
    
    
    public double get(double u, double v){ return get(v); }
    
    public double get(double x){
	if(x < 0.) return start;
	if(x > 1.) return end;
	if(domains==null || domains.size()==0) return (end-start)*x+start;
	
	if( x <= domains.get(0) ){
	    return (values.get(0)-start)*x/domains.get(0) + start;
	}
	int num = domains.size();
	if( x >= domains.get(num-1) ){
	    return (end-values.get(num-1))* (x-domains.get(num-1))/(1.0-domains.get(num-1)) + values.get(num-1);
	}
	for(int i=0; i<num-1; i++){
	    if(x>=domains.get(i) && x<domains.get(i+1))
		return (values.get(i+1)-values.get(i))*
		    (x-domains.get(i))/(domains.get(i+1)-domains.get(i)) + values.get(i);
	}
	
	return end; // error?
	//return values.get(values.size()-1);
	//return 0;
    }
    
    
    public IVLinearMap flipV(){
	double tmp = start; start = end; end = tmp;
	if(domains!=null && domains.size()>1){
	    ArrayList<Double> newdomains = new ArrayList<Double>();
	    ArrayList<Double> newvalues = new ArrayList<Double>();
	    for(int i=domains.size()-1; i>=0; i--){
		newdomains.add(1.0-domains.get(i));
		newvalues.add(values.get(i));
	    }
	    domains = newdomains;
	    values = newvalues;
	}
	return this;
    }
}
