src/sksl/sksl_public.sksl

// SkSL intrinsics that are not part of GLSL

// Color space transformation, between the working (destination) space and fixed (known) spaces:
$pure half3 toLinearSrgb(half3 color);
$pure half3 fromLinearSrgb(half3 color);

// SkSL intrinsics that reflect Skia's C++ object model:
      half4 $eval(float2 coords, shader s);
      half4 $eval(half4 color, colorFilter f);
      half4 $eval(half4 src, half4 dst, blender b);