| /* |
| * Copyright (C) 2015 The Android Open Source Project |
| * |
| * 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 |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * 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 |
| */ |
| |
| package com.android.systemui.classifier; |
| |
| public class Point { |
| public float x; |
| public float y; |
| public long timeOffsetNano; |
| |
| public Point(float x, float y) { |
| this.x = x; |
| this.y = y; |
| this.timeOffsetNano = 0; |
| } |
| |
| public Point(float x, float y, long timeOffsetNano) { |
| this.x = x; |
| this.y = y; |
| this.timeOffsetNano = timeOffsetNano; |
| } |
| |
| public boolean equals(Point p) { |
| return x == p.x && y == p.y; |
| } |
| |
| public float dist(Point a) { |
| return (float) Math.hypot(a.x - x, a.y - y); |
| } |
| |
| /** |
| * Calculates the cross product of vec(this, a) and vec(this, b) where vec(x,y) is the |
| * vector from point x to point y |
| */ |
| public float crossProduct(Point a, Point b) { |
| return (a.x - x) * (b.y - y) - (a.y - y) * (b.x - x); |
| } |
| |
| /** |
| * Calculates the dot product of vec(this, a) and vec(this, b) where vec(x,y) is the |
| * vector from point x to point y |
| */ |
| public float dotProduct(Point a, Point b) { |
| return (a.x - x) * (b.x - x) + (a.y - y) * (b.y - y); |
| } |
| |
| /** |
| * Calculates the angle in radians created by points (a, this, b). If any two of these points |
| * are the same, the method will return 0.0f |
| * |
| * @return the angle in radians |
| */ |
| public float getAngle(Point a, Point b) { |
| float dist1 = dist(a); |
| float dist2 = dist(b); |
| |
| if (dist1 == 0.0f || dist2 == 0.0f) { |
| return 0.0f; |
| } |
| |
| float crossProduct = crossProduct(a, b); |
| float dotProduct = dotProduct(a, b); |
| float cos = Math.min(1.0f, Math.max(-1.0f, dotProduct / dist1 / dist2)); |
| float angle = (float) Math.acos(cos); |
| if (crossProduct < 0.0) { |
| angle = 2.0f * (float) Math.PI - angle; |
| } |
| return angle; |
| } |
| } |