[added] colour.distance_rgb and distance_packed_rgb

This commit is contained in:
Max Cahill 2020-08-18 19:54:24 +10:00
parent 324a5b4783
commit e957a4502f

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@ -112,4 +112,27 @@ end
--todo: hsv, other colour spaces
--colour distance functions
--distance of one colour to another (linear space)
--can be used for finding nearest colours for palette mapping, for example
function colour.distance_rgb(
ar, ag, ab,
br, bg, bb
)
local dr, dg, db = ar - br, ag - bg, ab - bb
return math.sqrt(dr * dr + dg * dg + db * db)
end
function colour.distance_packed_rgb(a, b)
local ar, ag, ab = colour.unpack_rgb(a)
local br, bg, bb = colour.unpack_rgb(b)
return colour.distance_rgb(
ar, ag, ab,
br, bg, bb
)
end
--todo: rgba and various other unpacks
return colour