| /* |
| * Copyright (C) 2017 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.egg.octo; |
| |
| import android.graphics.Canvas; |
| import android.graphics.Paint; |
| import android.graphics.Path; |
| import android.graphics.PathMeasure; |
| import android.os.Debug; |
| |
| import java.util.Arrays; |
| |
| public class TaperedPathStroke { |
| static float sMinStepPx = 4f; |
| static PathMeasure pm = new PathMeasure(); |
| static float[] pos = {0,0}; |
| static float[] tan = {0,0}; |
| static float lerp(float t, float a, float b) { |
| return a + t*(b-a); |
| } |
| public static void setMinStep(float px) { |
| sMinStepPx = px; |
| } |
| |
| // it's the variable-width brush algorithm from the Markers app, basically |
| public static void drawPath(Canvas c, Path p, float r1, float r2, Paint pt) { |
| pm.setPath(p,false); |
| final float len = pm.getLength(); |
| float t=0; |
| boolean last=false; |
| while (true) { |
| if (t>=len) { |
| t=len; |
| last=true; |
| } |
| pm.getPosTan(t, pos, tan); |
| float r = len > 0 ? lerp(t/len, r1, r2) : r1; |
| c.drawCircle(pos[0], pos[1], r, pt); |
| t += Math.max(r*0.25f, sMinStepPx); // walk forward 1/4 radius, not too small though |
| if (last) break; |
| } |
| } |
| } |