android - 在 Android Studio 中旋转移动位图

Question

我正在尝试构建一个简单的“flappybird”游戏，我需要鸟的图像倾斜，向上时指向上方，反之亦然。但是，当旋转我的图像时，它会在稍微下落或点击屏幕后部分或完全从屏幕上消失。有人可以告诉我如何解决这个问题吗？

        matrix = new Matrix();
        if(angle > minAngle && angle < maxAngle && !boosting) {
            angle+=avel;
            matrix.postRotate(angle);
        }
        if(boosting) {
            angle = -20;
            matrix.postRotate(angle);
            speed = -30;
        }
        rotatedBitmap = Bitmap.createBitmap(bitmap, 0, 0, 50, 50, matrix, true);
        bitmap = rotatedBitmap;
        //Now the player object gets this rotated image and adds it to the Canvas

Answer 1

private Bitmap rotation(Bitmap myBitmap) {

    int rotate = 90; // degree of rotation;


            Matrix matrix = new Matrix();
            matrix.postRotate(rotate);
            if (myBitmap != null) {
                return   myBitmap = Bitmap.createBitmap(myBitmap, 0, 0, myBitmap.getWidth(),
                        myBitmap.getHeight(), matrix, true);
            }

    return myBitmap;
}