Java Array Cross Product crossEndForLineVectorAlgebra(double x1, double y1, double x2, double y2, double margin, double width)

Description

Calculate cross end for given line with vector algebra:
---------------x--
Cross points:
      C D
A---------------x--B
      E F
Usage code:

License

Apache License

Parameter

Parameter	Description
x1	line start A X
y1	line start A Y
x2	line end B X
y2	line end B Y
margin	cross from B
width	of cross

Return

arrays of calculated cross points: cross's points: [C x, D x, E x, F x] [C y, D y, E y, F y]

Declaration

public static double[][] crossEndForLineVectorAlgebra(double x1, double y1, double x2, double y2, double margin,
        double width) 

Method Source Code

//package com.java2s;
/*/*www. j a  v a 2 s.c  o  m*/
 * Beigesoft ?
 * 
 * Licensed under the Apache License, Version 2.0
 * 
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 */

public class Main {
    /**
     * Calculate cross end for given line with vector algebra:<br>
     * ---------------x--<br>
     * Cross points:<br>
     * &emsp;&emsp;&emsp;&emsp;&emsp;&emsp;C&emsp;D<br>
     * A---------------x--B<br>
     * &emsp;&emsp;&emsp;&emsp;&emsp;&emsp;E&emsp;F<br>
     * 
     * Usage code:
     * <pre>
     * </pre>
     * @param x1 line start A X
     * @param y1 line start A Y
     * @param x2 line end B X
     * @param y2 line end B Y
     * @param margin cross from B
     * @param width of cross
     * @return arrays of calculated cross points:
     * cross's points:  
     * [C x, D x, E x, F x]
     * [C y, D y, E y, F y]</li>
     * </ul>
     */
    public static double[][] crossEndForLineVectorAlgebra(double x1, double y1, double x2, double y2, double margin,
            double width) {
        double[][] result = new double[2][4];
        double[] baseVector = { x2 - x1, y2 - y1 };
        double baseVectorLenght = Math.sqrt(baseVector[0] * baseVector[0] + baseVector[1] * baseVector[1]);
        double[] baseUnitVector = { baseVector[0] / baseVectorLenght, baseVector[1] / baseVectorLenght };
        double[] normal = { -baseUnitVector[1], baseUnitVector[0] };
        //Point C:
        result[0][0] = x2 - baseUnitVector[0] * (margin + width / 2) - normal[0] * width / 2;
        result[1][0] = y2 - baseUnitVector[1] * (margin + width / 2) - normal[1] * width / 2;
        //Point D:
        result[0][1] = x2 - baseUnitVector[0] * (margin - width / 2) - normal[0] * width / 2;
        result[1][1] = y2 - baseUnitVector[1] * (margin - width / 2) - normal[1] * width / 2;
        //Point E:
        result[0][2] = x2 - baseUnitVector[0] * (margin + width / 2) + normal[0] * width / 2;
        result[1][2] = y2 - baseUnitVector[1] * (margin + width / 2) + normal[1] * width / 2;
        //Point F:
        result[0][3] = x2 - baseUnitVector[0] * (margin - width / 2) + normal[0] * width / 2;
        result[1][3] = y2 - baseUnitVector[1] * (margin - width / 2) + normal[1] * width / 2;
        return result;
    }
}

Related

1. cross(int x1, int y1, int x2, int y2)
2. cross2D(final float[] v1, final float[] v2)
3. cross2D(int[] v, int[] u)
4. cross3(double x1, double y1, double z1, double x2, double y2, double z2)
5. cross33(float u[], float v[])
6. crossMuliply(double a, double b, double c)
7. crossMult(int value, int maximum, int coefficient)
8. crossProduct(double x1, double y1, double x2, double y2, double x3, double y3)
9. crossProduct(double[] output, double[] a, double[] b)