layout(builtin=15) float4 sk_FragCoord;

// Today, we continue to allow all versions of sample from any runtime effect.
// When shader and colorFilter are different program kinds, move these declarations into separate
// modules so that each stage can only see the permitted versions.
// Ultimately, these declarations can go away, when we support invoking children like functions
// (using the same arguments here, eg shader_name(coords) rather than sample(shader, coords)).
// skbug.com/11813

half4 sample(shader s);
half4 sample(shader s, float3x3 transform);
half4 sample(shader s, float2 coords);

half4 sample(colorFilter f);