title: SpriteKit shaders on iOS 16 - Y-axis is inverted
body: <p>My SpriteKit app, which uses several GLSL fragment shaders, is showing different shader behaviour on iOS 16 as compared to iOS 15 and earlier. On iOS 15 the y-axis increased in the direction of the bottom of the screen, but now suddenly iOS 16 appears to have inverted this and now the y-axis is increasing in the direction of the top of the screen.</p>
  <p>The fact that this change is occurring only in my fragment shaders while SpriteKit node positioning remains unchanged between iOS 15 and 16 leads me to believe that this might be a change made in Metal 3.</p>
  <p>Is there an elegant solution to achieving consistent behaviour between iOS versions here? I would prefer not to have to detect the user's iOS version and supply a shader uniform to invert the y-axis manually, on a per-shader basis.</p>