### Compilation failed:

error: 1: invalid type
layout(binding=0) sampler2D test2D;
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
error: 2: invalid type
layout(binding=1) sampler2D test2DRect;
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
error: 4: 'main' must return: 'vec4', 'float4', or 'half4'
void main() {
^^^^^^^^^^^
error: 5: unknown identifier 'sk_FragColor'
    sk_FragColor = sample(test2D, float2(0.5));
    ^^^^^^^^^^^^
error: 5: unknown identifier 'sample'
    sk_FragColor = sample(test2D, float2(0.5));
                   ^^^^^^
error: 5: unknown identifier 'test2D'
    sk_FragColor = sample(test2D, float2(0.5));
                          ^^^^^^
error: 6: unknown identifier 'sk_FragColor'
    sk_FragColor = sample(test2DRect, float2(0.5));
    ^^^^^^^^^^^^
error: 6: unknown identifier 'sample'
    sk_FragColor = sample(test2DRect, float2(0.5));
                   ^^^^^^
error: 6: unknown identifier 'test2DRect'
    sk_FragColor = sample(test2DRect, float2(0.5));
                          ^^^^^^^^^^
error: 7: unknown identifier 'sk_FragColor'
    sk_FragColor = sample(test2DRect, float3(0.5));
    ^^^^^^^^^^^^
error: 7: unknown identifier 'sample'
    sk_FragColor = sample(test2DRect, float3(0.5));
                   ^^^^^^
error: 7: unknown identifier 'test2DRect'
    sk_FragColor = sample(test2DRect, float3(0.5));
                          ^^^^^^^^^^
12 errors