我如何使用抛物线将球投向特定角度？

Question

我使用过这种方法，但根据我的要求不能正常工作，请建议我

public void applyTransformation(float interpolatedTime, Transformation t) {
    float dx = 0, dy = 0;
    if (mFromXValue != mToXValue) {

        dx = (float) ((1.0 - interpolatedTime) * (1.0 - interpolatedTime)
                * mFromXValue + 2.0 * interpolatedTime
                * (1.0 - interpolatedTime) * mBezierXDelta + interpolatedTime
                * interpolatedTime * mToXValue);
    }

    if (mFromYValue != mToYValue) {

        dy = (float) ((1.0 - interpolatedTime) * (1.0 - interpolatedTime)
                * mFromYValue + 2.0 * interpolatedTime
                * (1.0 - interpolatedTime) * mBezierYDelta + interpolatedTime
                * interpolatedTime * mToYValue);
    }

    t.getMatrix().setTranslate(dx, dy);

  }

Answer 1

在sprite类中使用这个方法它会帮助你......

public void paintFromCenter(float angle, Canvas c) {
    Bitmap b = sprite;
    Matrix matrix = new Matrix();
    matrix.postRotate(angle, b.getWidth() / 2, b.getHeight());
    matrix.postTranslate(getX(), getY());

    Bitmap bmp2 = Bitmap.createBitmap(b, 0, 0, frameWidth, frameHeight,
            matrix, true);
    c.drawBitmap(b, matrix, null);

}