resources/sksl/wgsl/OutParams.sksl

/*#pragma settings NoInline*/
uniform half uFloat;

// Reference a pipeline I/O parameter and a global uniform. This tests that all parameter variations
// are injected correctly.
void various_parameter_types(half a, out half b, inout half c) {
    sk_FragColor = half4(a, b, c, uFloat);  // `b` has an undefined value but should compile OK.
    b = a;
    c = uFloat;
}

void one_out_param(out half h) {
    h = 2;
}

void one_out_param_indirect(out half h) {
    one_out_param(h);
}

struct S {
    half4 v;
};

void main() {
    // local float
    half x = 1;
    one_out_param(x);
    one_out_param_indirect(x);
    various_parameter_types(x + 1, x, x);

    // local vector
    half4 v;
    various_parameter_types(x + 1, v.x, v.x);
    various_parameter_types(x + 1, v.y, v.y);
    various_parameter_types(x + 1, v.x, v.y);

    // local struct
    S s;
    various_parameter_types(x + 1, s.v.x, x);
    various_parameter_types(x + 1, s.v.y, x);
}

// TODO(skbug.com/40044196): test the case in which a pipeline IO parameter is passed as out-param,
//                   directly and indirectly
// TODO(skbug.com/40044196): module-private out-param
// TODO(skbug.com/40044196): access an IO parameter while also passing it as an out-param
// TODO(skbug.com/40044196): mixing out params with in and inout
// TODO(skbug.com/40044196): swizzle assignment when that's supported