D11-Android自定义控件之动画篇3-插值器与估值器

mPainter = PainterEnum.INSTANCE.getInstance(canvas);
mPainter.draw(sa.deepClone()
        .r(mCircleR).ang(360)
        .fs(mColor).p(mCircleR, -mCircleR).coo(0, 1600).p(currentPoint));

public class PosX2Evaluator implements TypeEvaluator {

    @Override
    public Object evaluate(float fraction, Object startValue, Object endValue) {
        //初始点
        Pos startPos = (Pos) startValue;
        //结束点
        Pos endPos = (Pos) endValue;
        //计算每次更新时的x坐标
        float x = startPos.x + fraction * (endPos.x - startPos.x);
        //将y坐标进行联动
        float y = x * x / 800;
        //返回更新后的点
        return endPos.clone(x, y);
    }
}

Pos startP = currentPoint;//初始值（起点）
Pos endP = new Pos(1000, mCircleR);//结束值（终点）
ValueAnimator animator = ValueAnimator.ofObject(new PosX2Evaluator(), startP, endP);
animator.setRepeatCount(-1);
animator.setRepeatMode(ValueAnimator.REVERSE);
animator.setDuration(5000);
animator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
    @Override
    public void onAnimationUpdate(ValueAnimator animation) {
        currentPoint = (Pos) animation.getAnimatedValue();
        postInvalidate();
    }
});
animator.start();

public class PosLogEvaluator implements TypeEvaluator {

    @Override
    public Object evaluate(float fraction, Object startValue, Object endValue) {
        //初始点
        Pos startPos = (Pos) startValue;
        //结束点
        Pos endPos = (Pos) endValue;
        //计算每次更新时的x坐标
        float x = startPos.x + fraction * (endPos.x - startPos.x);
        //将y坐标进行联动
        float y = (float) (Math.log10(x) * 200);
        //返回更新后的点
        return endPos.clone(x, y);
    }
}

public class PosSinEvaluator implements TypeEvaluator {

    @Override
    public Object evaluate(float fraction, Object startValue, Object endValue) {

        //初始点
        Pos startPos = (Pos) startValue;
        //结束点
        Pos endPos = (Pos) endValue;
        //计算每次更新时的x坐标
        float x = startPos.x + fraction * (endPos.x - startPos.x);
        //将y坐标进行联动
        float y =  (float) (Math.sin(x * Math.PI / 180) * 200);
        //返回更新后的点
        return endPos.clone(x, y);
    }
}

/**
 * 作者：张风捷特烈
 * 时间：2018/7/9:10:08
 * 邮箱：1981462002@qq.com
 * 说明：sin函数实现加速插值器
 */
public class D_Sin_Inter implements TimeInterpolator {
    @Override
    public float getInterpolation(float input) {
        //input是一个从0~1均匀变化的值
        //从0到PI/2均匀变化的值
        float rad = Logic.rad(90 * input);
        //返回这个弧度的sin值--sin曲线在0~PI/2区域是增长越来越缓慢，是的小球运动越来越缓慢
        return (float) (Math.sin(rad));
    }
}

 animator.setInterpolator(new D_Sin_Inter());

/**
 * 作者：张风捷特烈
 * 时间：2018/7/9:10:08
 * 邮箱：1981462002@qq.com
 * 说明：log函数实现加速插值器
 */
public class D_Log_Inter implements TimeInterpolator {
    @Override
    public float getInterpolation(float input) {
        return (float) (Math.log10(1 + 10 * input));
    }
}

//初始画笔
mPaint = new Paint();
mPaint.setStrokeWidth(5);
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setAntiAlias(true);
mPaint.setColor(Color.RED);
//实例路径
mPath =new ShapeStar(ShapeStar.MODE_REGULAR).num(8).R(200).formPath();
//测量路径
pathMeasure = new PathMeasure(mPath, false);

//动画设置
ValueAnimator pathAnimator = ValueAnimator.ofFloat(1, 0);
pathAnimator.setDuration(5000);
pathAnimator.setInterpolator(new D_Sin_Inter());
pathAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
    @Override
    public void onAnimationUpdate(ValueAnimator animation) {
        float value = (Float) animation.getAnimatedValue();
        DashPathEffect effect = new DashPathEffect(
                new float[]{
                        pathMeasure.getLength(),
                        pathMeasure.getLength()},
                value * pathMeasure.getLength());
        mPaint.setPathEffect(effect);
        invalidate();
    }
});
pathAnimator.start();

//绘制路径
canvas.drawPath(mPath, mPaint);