1### Compilation failed: 2 3error: 1: 'main' must return: 'vec4', 'float4', or 'half4' 4void main() { 5^^^^^^^^^^^ 6error: 2: unknown identifier 'sk_FragColor' 7 sk_FragColor.xy = half2(sk_FragCoord.yx); 8 ^^^^^^^^^^^^ 92 errors 10