[color] Add helper functions for HSV and HSL color conversion

This commit is contained in:
Lorenzo Cogotti 2024-01-26 16:23:55 +01:00
parent 2b7c1dd829
commit 41954aff63
1 changed files with 44 additions and 0 deletions

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@ -38,6 +38,50 @@ function Color.lighten(r, g, b, amount)
return r, g, b return r, g, b
end end
function Color.hsl(h, s, l, a)
a = a or 1
if s <= 0 then return 1, 1, 1, a end
h = h * 6
local abs = math.abs
local c = (1 - abs(l*2 - 1))*s
local x = (1 - abs(h%2 - 1))*c
local m = l - c*0.5
local r, g, b
if h < 1 then r, g, b = c, x, 0
elseif h < 2 then r, g, b = x, c, 0
elseif h < 3 then r, g, b = 0, c, x
elseif h < 4 then r, g, b = 0, x, c
elseif h < 5 then r, g, b = x, 0, c
else r, g, b = c, 0, x
end
return r+m, g+m, b+m, a
end
function Color.hsv(h, s, v, a)
a = a or 1
if s <= 0 then return v, v, v, a end
h = h * 6
local c = v * s
local x = (1 - math.abs(h%2 - 1))*c
local m = v - c
local r, g, b
if h < 1 then r, g, b = c, x, 0
elseif h < 2 then r, g, b = x, c, 0
elseif h < 3 then r, g, b = 0, c, x
elseif h < 4 then r, g, b = 0, x, c
elseif h < 5 then r, g, b = x, 0, c
else r, g, b = c, 0, x
end
return r+m, g+m, b+m, a
end
--- Given two RGB colors, calculate fade by the specified amount. --- Given two RGB colors, calculate fade by the specified amount.
-- --
-- @number cr first color, red channel -- @number cr first color, red channel