UUM-9480 Workaround

UnityView+iOS.h

#pragma once

@interface UnityView (iOS)

// will simply update content orientation (it might be tweaked in layoutSubviews, due to disagreement between unity and view controller)
- (void)willRotateToOrientation:(UIInterfaceOrientation)toOrientation fromOrientation:(UIInterfaceOrientation)fromOrientation;
// will recreate gles backing if needed and repaint once to make sure we dont have black frame creeping in
- (void)didRotate;

- (void)touchesBegan:(NSSet*)touches withEvent:(UIEvent*)event;
- (void)touchesEnded:(NSSet*)touches withEvent:(UIEvent*)event;
- (void)touchesCancelled:(NSSet*)touches withEvent:(UIEvent*)event;
- (void)touchesMoved:(NSSet*)touches withEvent:(UIEvent*)event;
- (BOOL)is10thGenIpad;

@end

UnityView+iOS.mm

#if PLATFORM_IOS

#import "UnityView.h"
#import "UnityAppController+Rendering.h"
#include "OrientationSupport.h"

extern bool _unityAppReady;

@interface UnityView ()
@property (nonatomic, readwrite) ScreenOrientation contentOrientation;
@end

@implementation UnityView (iOS)
- (void)willRotateToOrientation:(UIInterfaceOrientation)toOrientation fromOrientation:(UIInterfaceOrientation)fromOrientation;
{
    // to support the case of interface and unity content orientation being different
    // we will cheat a bit:
    // we will calculate transform between interface orientations and apply it to unity view orientation
    // you can still tweak unity view as you see fit in AppController, but this is what you want in 99% of cases

    ScreenOrientation to    = ConvertToUnityScreenOrientation(toOrientation);
    ScreenOrientation from  = ConvertToUnityScreenOrientation(fromOrientation);

    if (fromOrientation == UIInterfaceOrientationUnknown)
        _curOrientation = to;
    else
        _curOrientation = OrientationAfterTransform(_curOrientation, TransformBetweenOrientations(from, to));

    _viewIsRotating = YES;
}

- (void)didRotate
{
    BOOL is10thGenIpad = [self is10thGenIpad];

    //https://issuetracker.unity3d.com/issues/ios-rendering-freezes-when-the-orientation-is-changed
    //Theres a bug in 10th gen ipads that fails to load the proper dimensions at the right time
    //so _shouldRecreateView never gets set.  Short circuit that here.  Side effects may be we
    //recreate the rendering surface more often than we should when rotating
    //Moreover, a long delay is required upon rotation.  Haven't tracked down why, but without approx
    //500ms sleep above the rendering will stop working seemingly at the OS level (even minimizing the
    //app takes 10+ seconds to refresh)

    if (is10thGenIpad)
    {
        [NSThread sleepForTimeInterval:0.5f];
    }

    if (_shouldRecreateView || is10thGenIpad)
    {
        [self recreateRenderingSurface];
    }

    _viewIsRotating = NO;
}

- (BOOL) is10thGenIpad
{
    static BOOL hasCheckedIf10thGen = NO;
    static BOOL is10thGen = NO;

    if (hasCheckedIf10thGen)
        return is10thGen;

    NSString * modelStr = [NSString stringWithUTF8String:UnityDeviceModel()];
    is10thGen = [modelStr hasPrefix:@"iPad13,"];
    hasCheckedIf10thGen = true;

    return is10thGen;
}

- (void)touchesBegan:(NSSet*)touches withEvent:(UIEvent*)event      { UnitySendTouchesBegin(touches, event); }
- (void)touchesEnded:(NSSet*)touches withEvent:(UIEvent*)event      { UnitySendTouchesEnded(touches, event); }
- (void)touchesCancelled:(NSSet*)touches withEvent:(UIEvent*)event  { UnitySendTouchesCancelled(touches, event); }
- (void)touchesMoved:(NSSet*)touches withEvent:(UIEvent*)event      { UnitySendTouchesMoved(touches, event); }

@end

#endif // PLATFORM_IOS