本文实例讲述了Android开发实现的几何图形工具类GeometryUtil。分享给大家供大家参考，具体如下：

package com.android.imooc.goo;

import android.graphics.PointF;

/**

* 几何图形工具

*/

public class GeometryUtil {

/**

* As meaning of method name. 获得两点之间的距离

*

* @param p0

* @param p1

* @return

*/

public static float getDistanceBetween2Points(PointF p0, PointF p1) {

float distance = (float) Math.sqrt(Math.pow(p0.y - p1.y, 2) + Math.pow(p0.x - p1.x, 2));

return distance;

}

/**

* Get middle point between p1 and p2. 获得两点连线的中点

*

* @param p1

* @param p2

* @return

*/

public static PointF getMiddlePoint(PointF p1, PointF p2) {

return new PointF((p1.x + p2.x) / 2.0f, (p1.y + p2.y) / 2.0f);

}

/**

* Get point between p1 and p2 by percent. 根据百分比获取两点之间的某个点坐标

*

* @param p1

* @param p2

* @param percent

* @return

*/

public static PointF getPointByPercent(PointF p1, PointF p2, float percent) {

return new PointF(evaluateValue(percent, p1.x, p2.x), evaluateValue(percent, p1.y, p2.y));

}

/**

* 根据分度值，计算从start到end中，fraction位置的值。fraction范围为0 -> 1

*

* @param fraction

* @param start

* @param end

* @return

*/

public static float evaluateValue(float fraction, Number start, Number end) {

return start.floatValue() + (end.floatValue() - start.floatValue()) * fraction;

}

/**

* Get the point of intersection between circle and line. 获取

* 通过指定圆心，斜率为lineK的直线与圆的交点。

*

* @param pMiddle

* The circle center point.

* @param radius

* The circle radius.

* @param lineK

* The slope of line which cross the pMiddle.

* @return

*/

public static PointF[] getIntersectionPoints(PointF pMiddle, float radius, Double lineK) {

PointF[] points = new PointF[2];

float radian, xOffset = 0, yOffset = 0;

if (lineK != null) {

radian = (float) Math.atan(lineK);

xOffset = (float) (Math.sin(radian) * radius);

yOffset = (float) (Math.cos(radian) * radius);

} else {

xOffset = radius;

yOffset = 0;

}

points[0] = new PointF(pMiddle.x + xOffset, pMiddle.y - yOffset);

points[1] = new PointF(pMiddle.x - xOffset, pMiddle.y + yOffset);

return points;

}

}

希望本文所述对大家Android程序设计有所帮助。