Programatically setting the pitch to 0 via the camera also moves the map

[maciekish]

If i run the following code in your test app (via make iproj) and the pitch isn't already 0, it will jump to some arbitrary coordinate.

[self.mapView setCamera:[MGLMapCamera cameraLookingAtCenterCoordinate:self.mapView.centerCoordinate fromDistance:self.mapView.camera.altitude pitch:0 heading:0] animated:NO];

As you can see I'm reusing the current centerCoordinate and altitude. All i want is to set the pitch to 0. Am i doing it wrong or is this a bug?

If you just expose the mbgl::Map->setPitch function it works perfectly fine.

- (void)setPitch:(double)pitch
{
    _mbglMap->setPitch(pitch);
}

cc @Zakay

[1ec5]

Can you provide a coordinate pair and pitch to test with? I do see that the map effectively zooms out when starting out tilted, due to #2139 and the use of “fit bounds” when applying a camera, but the center coordinate stays fixed.

[maciekish]

It appears like this was caused by my new userConstrain function. I updated my PR with a bugfix #2341. I was incorrectly assuming that Cc and Bc in TransformState always correspond to the current zoom level, but it appears like they sometimes change before constrain and userConstrain are called which produced incorrect x_ and y_.