Question

排队缩放事件时遇到问题：

ScaleGestureDetector.OnScaleGestureListener fingerScaleGestureListener = new ScaleGestureDetector.OnScaleGestureListener() {

    @Override
    public void onScaleEnd(ScaleGestureDetector detector) {
        //GESTURE finger scale-end
        Log.d(TAG+".scale.end", Float.toString(detector.getScaleFactor()));
    }

    @Override
    public boolean onScaleBegin(ScaleGestureDetector detector) {
        //GESTURE finger scale-begin
        Log.d(TAG+".scale.begin", Float.toString(detector.getScaleFactor()));
        return true;
    }

    @Override
    public boolean onScale(final ScaleGestureDetector detector) {
        //GESTURE finger onscale
        Log.d(TAG+".scale.on", Float.toString(detector.getScaleFactor()));

        glSurfaceView.queueEvent(new Runnable() {

            @Override
            public void run() {
                renderer.zoom(detector.getScaleFactor());

            }
        });

        return true;
    }
};

根据LogCat输出，它工作正常。

renderer.zoom（）的实现：

public void zoom(float ratio)
{
    Log.d(TAG+".zoom", Float.toString(ratio));

    float dx = eyeX - centerX;
    float dy = eyeY - centerY;
    float dz = eyeZ - centerZ;
    dx*=ratio;
    dy*=ratio;
    dz*=ratio;
    eyeX = centerX + dx;
    eyeY = centerY + dy;
    eyeZ = centerZ + dz;

    Matrix.perspectiveM(projectionMatrix, 0, fovy, aspect, zNear, zFar);
    Matrix.setLookAtM(viewMatrix, 0, eyeX, eyeY, eyeZ, centerX, centerY, centerZ, upX, upY, upZ);
    Matrix.multiplyMM(MVPMatrix, 0, projectionMatrix, 0, viewMatrix, 0);


}

缩放手势期间的LogCat：

04-09 19:57:47.057: D/MainActivity.scale.begin(21916): 1.0
04-09 19:57:47.072: D/MainActivity.scale.on(21916): 1.0305684
04-09 19:57:47.072: D/GLRenderer.zoom(21916): 1.0
04-09 19:57:47.087: D/MainActivity.scale.on(21916): 1.0367821
04-09 19:57:47.092: D/GLRenderer.zoom(21916): 1.0
04-09 19:57:47.102: D/MainActivity.scale.on(21916): 1.0497419
04-09 19:57:47.107: D/GLRenderer.zoom(21916): 1.0
04-09 19:57:47.122: D/MainActivity.scale.on(21916): 1.0489701
04-09 19:57:47.122: D/GLRenderer.zoom(21916): 1.0
04-09 19:57:47.137: D/MainActivity.scale.on(21916): 1.035543
04-09 19:57:47.137: D/GLRenderer.zoom(21916): 1.0
04-09 19:57:47.147: D/MainActivity.scale.end(21916): 1.0

为什么缩放功能始终为1.0f？

Answer 1

您依靠detector.getScaleFactor()获取在您的情况下不正确的比例因子：）

getScaleFactor()返回相对于上次调用onScale()

的比例因子

解决方案就像维护float成员变量（初始化为1.0f）一样简单，只需要像

那样

public void run() {
    mScale *= detector.getScaleFactor();
    renderer.zoom(mScale);
}

queueEvent奇怪的行为

1 个答案: