Taking the Development Ahead - Learn OpenGL ES: For Mobile Game and Graphics Development - page 221

public boolean onTouch(View v, MotionEvent event) {
if (event.getAction() == MotionEvent.ACTION_DOWN) {
_touchedX = event.getX();
} else if (event.getAction() ==
MotionEvent.ACTION_MOVE) {
float touchedX = event.getX();
float dx = Math.abs(_touchedX - touchedX);
_dxFiltered = _dxFiltered * (1.0f -
_filterSensitivity) + dx
* _filterSensitivity;
if (touchedX < _touchedX) {
_zAngle = (2 * _dxFiltered / _width) *
_TOUCH_SENSITIVITY
* _ANGLE_SPAN;
_zAngleFiltered = _zAngleFiltered * (1.0f -
_filterSensitivity)
+ _zAngle * _filterSensitivity;
GLES20Renderer.setZAngle(GLES20Renderer.getZAngle()
+ _zAngleFiltered);
_surfaceView.requestRender();
} else {
_zAngle = (2 * _dxFiltered / _width) *
_TOUCH_SENSITIVITY
* _ANGLE_SPAN;
_zAngleFiltered = _zAngleFiltered * (1.0f -
_filterSensitivity)
+ _zAngle * _filterSensitivity;
GLES20Renderer.setZAngle(GLES20Renderer.getZAngle()
- _zAngleFiltered);
_surfaceView.requestRender();
}
}
return true;
}