android 贝塞尔曲线画脸

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一个简单的例子，效果就是从一张笑脸过渡到一张哭脸 :) -> :(

package com.android.facelove;

import android.animation.ObjectAnimator;
import android.animation.ValueAnimator;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Path;
import android.util.AttributeSet;
import android.util.Log;
import android.view.View;

/**
 * Created by ding_qili on 15/10/20.
 */
public class FaceView extends View {
    public FaceView(Context context) {
        super(context);
        init();
    }

    public FaceView(Context context, AttributeSet attrs) {
        super(context, attrs);
        init();
    }

    public FaceView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        init();
    }


    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        drawFace(canvas);
        drawEyes(canvas);
        drawMouth(canvas);
        signature(canvas);

    }

    private void  init(){
        path = new Path();
        paint = new Paint();
        paint.setColor(Color.BLACK);
        paint.setAntiAlias(true);
        paint.setStyle(Paint.Style.STROKE);
    }

    private Path path;
    private Paint paint;
    private static final int FaceSize = 150;
    private static final int EyeSize = 50;
    private static final int MouthSize = 70;

    private final int smileeyeBézier = 20;
    private final int smilemouthBézier = 30;
    private final int unhappyeyeBézier = 0;
    private final int unhappymouthBézier = -30;

    private int curreyeBézier =unhappyeyeBézier;
    private int currmouthBézier =unhappymouthBézier;

    private ObjectAnimator eyeanim;
    private ObjectAnimator mouthanim;

    //画脸
    private void drawFace(Canvas canvas){
        paint.setStrokeWidth(2.0f);
        canvas.drawCircle(canvas.getWidth()/2, canvas.getHeight()/2, FaceSize, paint);// 脸
    }
    //画眼睛
    private void drawEyes(Canvas canvas){
        drawLeftEye(canvas);
        drawRightEye(canvas);
    }
    private void drawLeftEye(Canvas canvas){
        paint.setStrokeWidth(1.0f);
        path.reset();// 重置path
        int x = canvas.getWidth()/2-FaceSize/2;
        int y = canvas.getHeight()/2;
        path.moveTo(x-EyeSize/2,y);
        // 设置贝赛尔曲线的操作点以及终止点
        path.quadTo(x, y-curreyeBézier, x+EyeSize/2, y);
        // 绘制贝赛尔曲线（Path）
        canvas.drawPath(path, paint);
    }
    private void drawRightEye(Canvas canvas){
        paint.setStrokeWidth(1.0f);
        path.reset();// 重置path
        int x = canvas.getWidth()/2+FaceSize/2;
        int y = canvas.getHeight()/2;
        path.moveTo(x-EyeSize/2,y);
        // 设置贝赛尔曲线的操作点以及终止点
        path.quadTo(x, y-curreyeBézier, x+EyeSize/2, y);
        // 绘制贝赛尔曲线（Path）
        canvas.drawPath(path, paint);
    }

    //画嘴巴
    private void drawMouth(Canvas canvas){
        paint.setStrokeWidth(1.0f);
        path.reset();// 重置path
        int x = canvas.getWidth()/2;
        int y = canvas.getHeight()/2+FaceSize/2;
        path.moveTo(x-MouthSize/2,y);
        // 设置贝赛尔曲线的操作点以及终止点
        path.quadTo(x, y+currmouthBézier, x+EyeSize/2, y);
        // 绘制贝赛尔曲线（Path）
        canvas.drawPath(path, paint);
    }


    private void signature(Canvas canvas){
        paint.setUnderlineText(true);
        paint.setTextSize(30);
        canvas.drawText("ding_qili", 50, 50, paint);// 画文本
        paint.setUnderlineText(false);
    }


    public void smileAnimRun()
    {
        if(eyeanim !=null){
            eyeanim.cancel();
        }
        if(mouthanim !=null){
            mouthanim.cancel();
        }
        eyeanim = ObjectAnimator//
                .ofFloat(this, "smileEye", curreyeBézier, smileeyeBézier)//
                .setDuration(500);//
        eyeanim.start();
        eyeanim.addUpdateListener(new ValueAnimator.AnimatorUpdateListener()
        {
            @Override
            public void onAnimationUpdate(ValueAnimator animation)
            {
                float currmouthBézierF = (Float)animation.getAnimatedValue();
                curreyeBézier = (int) currmouthBézierF;
                FaceView.this.invalidate();
            }
        });

        mouthanim = ObjectAnimator//
                .ofFloat(this, "mouthEye", currmouthBézier, smilemouthBézier)//
                .setDuration(500);//
        mouthanim.start();
        mouthanim.addUpdateListener(new ValueAnimator.AnimatorUpdateListener()
        {
            @Override
            public void onAnimationUpdate(ValueAnimator animation)
            {
                float currmouthBézierF = (Float)animation.getAnimatedValue();
                currmouthBézier = (int) currmouthBézierF;
                FaceView.this.invalidate();
            }
        });
    }

    public void unHappyAnimRun()
    {
        if(eyeanim !=null){
            eyeanim.cancel();
        }
        if(mouthanim !=null){
            mouthanim.cancel();
        }
         eyeanim = ObjectAnimator//
                .ofFloat(this, "smileEye", curreyeBézier, unhappyeyeBézier)//
                .setDuration(500);//
        eyeanim.start();
        eyeanim.addUpdateListener(new ValueAnimator.AnimatorUpdateListener()
        {
            @Override
            public void onAnimationUpdate(ValueAnimator animation)
            {
                float currmouthBézierF = (Float)animation.getAnimatedValue();
                curreyeBézier = (int) currmouthBézierF;
                FaceView.this.invalidate();
            }
        });

        mouthanim = ObjectAnimator//
                .ofFloat(this, "mouthEye", currmouthBézier, unhappymouthBézier)//
                .setDuration(500);//
        mouthanim.start();
        mouthanim.addUpdateListener(new ValueAnimator.AnimatorUpdateListener()
        {
            @Override
            public void onAnimationUpdate(ValueAnimator animation)
            {
                float currmouthBézierF = (Float)animation.getAnimatedValue();
                currmouthBézier = (int) currmouthBézierF;
                FaceView.this.invalidate();
            }
        });
    }
}