Java tutorial
//package com.java2s; /** * Copyright 2015 bingoogolapple * <p/> * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * <p/> * http://www.apache.org/licenses/LICENSE-2.0 * <p/> * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ import android.graphics.PointF; public class Main { 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; } }