/*

 * This file is part of libbluray

 * Copyright (C) 2014  libbluray

 *

 * This library 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; either

 * version 2.1 of the License, or (at your option) any later version.

 *

 * This library 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 this library. If not, see

 * <http://www.gnu.org/licenses/>.

 */

package java.awt;

class PolyEdge {

    private int x1;

    private int y1;

    //private int x2;

    private int y2;

    private float m;

    private float c;

    private boolean vertical;

    PolyEdge(int x1, int y1, int x2, int y2) {

        // sort lowest to highest

        if (y2 < y1) {

            int swap;

            swap = x1; x1 = x2; x2 = swap;

            swap = y1; y1 = y2; y2 = swap;

        }

        this.x1 = x1;

        this.y1 = y1;

        //this.x2 = x2;

        this.y2 = y2;

        if (x1 == x2) {

            vertical = true;

            m = 0;

        } else {

            m = (float)(y2 - y1) / (float)(x2 - x1);

            c = (-x1 * m) + y1;

            vertical = false;

        }

    }

    public boolean intersects(int y) {

        if (y <= y2 && y >= y1 && y1 != y2) {

            return true;

        }

        return false;

    }

    public int intersectionX(int y) {

        if (vertical) {

            return x1;

        }

        return (int)(((y - c) / m) + 0.5f);

    }

}