SpriteKit shader crash iOS 9: SKDefaultShading, gl_FragCoord

Question

Just installed the iOS 9 open beta (version 3) and now I\'m having loads of problems with SpriteKit shaders. On iOS 8 the following code worked just fine:

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Answer 1

I had this problem too with iOS9. gl_FragCoord stopped working on real devices, but works in the iOS simulator.

Work around.

Create a node with shader

let shader = SKShader(fileNamed: "polka.fsh")
let uniform = SKUniform(name: "u_spriteSize", floatVector2: GLKVector2Make(Float(200), Float(200)))
shader.uniforms.append(uniform)

Update the uniform

if let uniform = shader.uniformNamed("u_spriteSize") {
    let size = frame.size
    uniform.floatVector2Value = GLKVector2Make(Float(size.width * screenScale), Float(size.height * screenScale))
}

Shader

vec2 xy = v_tex_coord * u_spriteSize - u_polkaCenter; // new code
//vec2 xy = gl_FragCoord.xy - u_polkaCenter;  // old code that worked before iOS9