android - 在 Android 中翻转两个面的硬币

Question

我正在使用这个 Rotate3dAnimation 类创建一个抛硬币动画，它也在移动和缩放。但我只能将它用于一个 ImageView 。只需在该 ImageView 上使用 startAnimation() 方法。

但我想做的是，使用硬币的两个面，这样它看起来就像一个真正的硬币，有两个不同的面正在翻转。有人可以帮助我了解如何做到这一点吗？

谢谢

    package com.example.movingcoin;



    import android.view.animation.Animation;
    import android.view.animation.Transformation;
    import android.graphics.Camera;
    import android.graphics.Matrix;

    /**
     * An animation that rotates the view on the Y axis between two specified angles.
     * This animation also adds a translation on the Z axis (depth) to improve the effect.
     */
    public class Rotate3dAnimation extends Animation {
    private final float mFromDegrees;
    private final float mToDegrees;
    private final float mCenterX;
    private final float mCenterY;
    private final float mDepthZ;
    private final boolean mReverse;
    private Camera mCamera;

    /**
     * Creates a new 3D rotation on the Y axis. The rotation is defined by its
     * start angle and its end angle. Both angles are in degrees. The rotation
     * is performed around a center point on the 2D space, definied by a pair
     * of X and Y coordinates, called centerX and centerY. When the animation
     * starts, a translation on the Z axis (depth) is performed. The length
     * of the translation can be specified, as well as whether the translation
     * should be reversed in time.
     *
     * @param fromDegrees the start angle of the 3D rotation
     * @param toDegrees the end angle of the 3D rotation
     * @param centerX the X center of the 3D rotation
     * @param centerY the Y center of the 3D rotation
     * @param reverse true if the translation should be reversed, false otherwise
     */
    public Rotate3dAnimation(float fromDegrees, float toDegrees,
            float centerX, float centerY, float depthZ, boolean reverse) {
        mFromDegrees = fromDegrees;
        mToDegrees = toDegrees;
        mCenterX = centerX;
        mCenterY = centerY;
        mDepthZ = depthZ;
        mReverse = reverse;
    }

    @Override
    public void initialize(int width, int height, int parentWidth, int parentHeight) {
        super.initialize(width, height, parentWidth, parentHeight);
        mCamera = new Camera();
    }

    @Override
    protected void applyTransformation(float interpolatedTime, Transformation t) {
        final float fromDegrees = mFromDegrees;
        float degrees = fromDegrees + ((mToDegrees - fromDegrees) * interpolatedTime);

        final float centerX = mCenterX;
        final float centerY = mCenterY;
        final Camera camera = mCamera;

        final Matrix matrix = t.getMatrix();

        camera.save();
        if (mReverse) {
            camera.translate(0.0f, 0.0f, mDepthZ * interpolatedTime);
        } else {
            camera.translate(0.0f, 0.0f, mDepthZ * (1.0f - interpolatedTime));
        }

//        camera.rotateY(degrees);
        camera.rotateX(degrees);

        camera.getMatrix(matrix);
        camera.restore();

        matrix.preTranslate(-centerX, -centerY);
        matrix.postTranslate(centerX, centerY);
    }
}

Answer 1

几天前遇到了同样的问题，在 FlipAnimator 类中找到了解决方案，您可以在这里找到:FlipAnimatorClass

实际上，这非常简单:您只需将硬币的两面传递给 FlipAnimator。我认为该类(class)非常容易理解，并且实际上是在执行 g00dy 在他上面的评论中建议的内容。