CODEWITHSUNDEEP
androidanimationopengl-es
Sleeper9
Sleeper9

Reputation: 1779

Android OpenGL error during Camera animation

I found the following code that I use to flip two CardViews containing a chart (I use MPAndroidCharts lib), creating a 3D card flip effect:

public class FlipAnimation extends Animation {

...

@Override
protected void applyTransformation(float interpolatedTime, Transformation t) {
    // Angle around the y-axis of the rotation at the given time
    // calculated both in radians and degrees.
    final double radians = Math.PI * interpolatedTime;
    float degrees = (float) (180.0 * radians / Math.PI);

    // Once we reach the midpoint in the animation, we need to hide the
    // source view and show the destination view. We also need to change
    // the angle by 180 degrees so that the destination does not come in
    // flipped around
    if (interpolatedTime >= 0.5f) {
        degrees -= 180.f;
        fromView.setVisibility(View.GONE);
        toView.setVisibility(View.VISIBLE);
    }

    if (forward)
        degrees = -degrees; //determines direction of rotation when flip begins

    final Matrix matrix = t.getMatrix();
    camera.save();
    if(horizontal){
        camera.rotateX(degrees);
    } else {
        camera.rotateY(degrees);
    }
    camera.getMatrix(matrix);
    camera.restore();
    matrix.preTranslate(-centerX, -centerY);
    matrix.postTranslate(centerX, centerY);
}

The original code was only able to flip along the vertical center axis, so I added that little if when a boolean is set, then the animation is made along the horizontal center axis. Now sometimes during the animation, the following weird error crashes my app:

03-20 16:37:26.369 551-579/c.f.q.android.demo A/OpenGLRenderer: Error: Spot pair overflow!!! used 30, total 22
03-20 16:37:26.370 551-579/c.f.q.android.demo A/libc: Fatal signal 6 (SIGABRT), code -6 in tid 579 (hwuiTask1)

It seems that this error only happens when I rotate along the horizontal axis, but even this case, the error does not happen consistently (e.g. sometimes it works countless times and sometimes it crashes on the second flip).

Upvotes: 1

Views: 672

Answers (1)

MarutiB
MarutiB

Reputation: 934

Does your card view need a shadow ? I was able to fix my error by setting elevation of CardView to 0dp. So in xml :- 

<android.support.v7.widget.CardView xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    app:cardElevation="0dp"
    app:cardUseCompatPadding="true">

Some other open source projects were also seeing this error :- https://github.com/AnderWeb/discreteSeekBar/issues/73 .

Upvotes: 3

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