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; } }
更多关于Android相关内容感兴趣的读者可查看本站专题：《Android图形与图像处理技巧总结》、《Android开发入门与进阶教程》、《Android调试技巧与常见问题解决方法汇总》、《Android基本组件用法总结》、《Android视图View技巧总结》、《Android布局layout技巧总结》及《Android控件用法总结》
希望本文所述对大家Android程序设计有所帮助。