/*
 * Pixel Dungeon
 * Copyright (C) 2012-2015  Oleg Dolya
 *
 * Shattered Pixel Dungeon
 * Copyright (C) 2014-2019 Evan Debenham
 *
 * This program 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 3 of the License, or
 * (at your option) any later version.
 *
 * This program 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 this program.  If not, see <http://www.gnu.org/licenses/>
 */

package com.watabou.utils;

public class ColorMath {
	
	public static int interpolate( int A, int B, float p ) {
		
		if (p <= 0) {
			return A;
		} else if (p >= 1) {
			return B;
		}
		
		int ra = A >> 16;
		int ga = (A >> 8) & 0xFF;
		int ba = A & 0xFF;
		
		int rb = B >> 16;
		int gb = (B >> 8) & 0xFF;
		int bb = B & 0xFF;
		
		float p1 = 1 - p;
		
		int r = (int)(p1 * ra + p * rb);
		int g = (int)(p1 * ga + p * gb);
		int b = (int)(p1 * ba + p * bb);
		
		return (r << 16) + (g << 8) + b;
	}
	
	public static int interpolate( float p,  int... colors ) {
		if (p <= 0) {
			return colors[0];
		} else if (p >= 1) {
			return colors[colors.length-1];
		}
		int segment = (int)((colors.length-1) * p);
		return interpolate( colors[segment], colors[segment+1], (p * (colors.length - 1)) % 1 );
	}
	
	public static int random( int a, int b ) {
		return interpolate( a, b, Random.Float() );
	}

}
