[[stage(fragment)]] fn main([[location(0)]] none : f32, [[location(1), interpolate(flat)]] flat : f32, [[location(2), interpolate(perspective, center)]] perspective_center : f32, [[location(3), interpolate(perspective, centroid)]] perspective_centroid : f32, [[location(4), interpolate(perspective, sample)]] perspective_sample : f32, [[location(5), interpolate(linear, center)]] linear_center : f32, [[location(6), interpolate(linear, centroid)]] linear_centroid : f32, [[location(7), interpolate(linear, sample)]] linear_sample : f32) { }