222 lines
6.3 KiB
Text
222 lines
6.3 KiB
Text
-- Copyright (c) 2005-2010, Niels Martin Hansen, Rodrigo Braz Monteiro
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-- Copyright (c) 2013, Thomas Goyne <plorkyeran@aegisub.org>
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--
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-- Permission to use, copy, modify, and distribute this software for any
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-- purpose with or without fee is hereby granted, provided that the above
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-- copyright notice and this permission notice appear in all copies.
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--
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-- THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
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-- WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
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-- MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
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-- ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
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-- WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
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-- ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
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-- OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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error = error
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pairs = pairs
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select = select
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sformat = string.format
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tonumber = tonumber
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type = type
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local *
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-- Make a shallow copy of a table
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copy = (tbl) -> {k, v for k, v in pairs tbl}
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-- Make a deep copy of a table
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-- Retains equality of table references inside the copy and handles self-referencing structures
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deep_copy = (tbl) ->
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seen = {}
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copy = (val) ->
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return val if type(val) != 'table'
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return seen[val] if seen[val]
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seen[val] = val
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{k, copy(v) for k, v in pairs val}
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copy tbl
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-- Generates ASS hexadecimal string from R, G, B integer components, in &HBBGGRR& format
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ass_color = (r, g, b) -> sformat "&H%02X%02X%02X&", b, g, r
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-- Format an alpha-string for \Xa style overrides
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ass_alpha = (a) -> sformat "&H%02X&", a
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-- Format an ABGR string for use in style definitions (these don't end with & either)
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ass_style_color = (r, g, b, a) -> sformat "&H%02X%02X%02X%02X", a, b, g, r
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-- Extract colour components of an ASS colour
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extract_color = (s) ->
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local a, b, g, r
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-- Try a style first
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a, b, g, r = s\match '&H(%x%x)(%x%x)(%x%x)(%x%x)'
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if a then
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return tonumber(r, 16), tonumber(g, 16), tonumber(b, 16), tonumber(a, 16)
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-- Then a colour override
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b, g, r = s\match '&H(%x%x)(%x%x)(%x%x)&'
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if b then
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return tonumber(r, 16), tonumber(g, 16), tonumber(b, 16), 0
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-- Then an alpha override
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a = s\match '&H(%x%x)&'
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if a then
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return 0, 0, 0, tonumber(a, 16)
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-- Ok how about HTML format then?
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r, g, b, a = s\match '#(%x%x)(%x?%x?)(%x?%x?)(%x?%x?)'
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if r then
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return tonumber(r, 16), tonumber(g, 16) or 0, tonumber(b, 16) or 0, tonumber(a, 16) or 0
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-- Create an alpha override code from a style definition colour code
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alpha_from_style = (scolor) -> ass_alpha select 4, extract_color scolor
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-- Create an colour override code from a style definition colour code
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color_from_style = (scolor) ->
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r, g, b = extract_color scolor
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ass_color r or 0, g or 0, b or 0
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-- Converts HSV (Hue, Saturation, Value) to RGB
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HSV_to_RGB = (H, S, V) ->
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r, g, b = 0, 0, 0
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-- Saturation is zero, make grey
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if S == 0
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r = clamp(V*255, 0, 255)
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g = r
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b = r
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-- Else, calculate color
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else
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-- Calculate subvalues
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H = math.abs(H) % 360 -- Put H in range [0, 360)
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Hi = math.floor(H/60)
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f = H/60.0 - Hi
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p = V*(1-S)
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q = V*(1-f*S)
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t = V*(1-(1-f)*S)
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-- Do math based on hue index
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if Hi == 0
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r = V*255.0
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g = t*255.0
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b = p*255.0
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elseif Hi == 1
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r = q*255.0
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g = V*255.0
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b = p*255.0
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elseif Hi == 2
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r = p*255.0
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g = V*255.0
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b = t*255.0
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elseif Hi == 3
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r = p*255.0
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g = q*255.0
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b = V*255.0
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elseif Hi == 4
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r = t*255.0
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g = p*255.0
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b = V*255.0
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elseif Hi == 5
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r = V*255.0
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g = p*255.0
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b = q*255.0
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else
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error "math.floor(H % 360 / 60) should be [0, 6), is #{Hi}?"
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return r, g, b
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-- Convert HSL (Hue, Saturation, Luminance) to RGB
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-- Contributed by Gundamn
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HSL_to_RGB = (H, S, L) ->
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local r, g, b
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-- Make sure input is in range
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H = math.abs(H) % 360
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S = clamp(S, 0, 1)
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L = clamp(L, 0, 1)
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if S == 0 -- Simple case if saturation is 0, all grey
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r = L
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g = L
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b = L
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else
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-- More common case, saturated colour
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Q = if L < 0.5
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L * (1.0 + S)
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else
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L + S - (L * S)
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P = 2.0 * L - Q
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Hk = H / 360
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local Tr, Tg, Tb
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if Hk < 1/3
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Tr = Hk + 1/3
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Tg = Hk
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Tb = Hk + 2/3
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elseif Hk > 2/3
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Tr = Hk - 2/3
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Tg = Hk
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Tb = Hk - 1/3
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else
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Tr = Hk + 1/3
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Tg = Hk
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Tb = Hk - 1/3
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get_component = (T) ->
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if T < 1/6
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P + ((Q - P) * 6.0 * T)
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elseif 1/6 <= T and T < 1/2
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Q
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elseif 1/2 <= T and T < 2/3
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P + ((Q - P) * (2/3 - T) * 6.0)
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else
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P
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r = get_component(Tr)
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g = get_component(Tg)
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b = get_component(Tb)
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return math.floor(r*255+0.5), math.floor(g*255+0.5), math.floor(b*255+0.5)
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-- Removes spaces at the start and end of string
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trim = (s) -> s\gsub '^%s*(.-)%s*$', '%1'
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-- Get the 'head' and 'tail' of a string, treating it as a sequence of words separated by one or more space-characters
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headtail = (s) ->
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a, b, head, tail = s\find '(.-)%s+(.*)'
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if a then head, tail else s, ''
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-- Iterator function for headtail
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words = (s) -> ->
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return if s == ''
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head, tail = headtail s
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s = tail
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head
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-- Clamp a number value to a range
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clamp = (val, min, max) ->
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if val < min then min elseif val > max then max else val
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-- Interpolate between two numbers
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interpolate = (pct, min, max) ->
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if pct <= 0 then min elseif pct >= 1 then max else pct * (max - min) + min
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-- Interpolate between two colour values, given in either style definition or style override format
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-- Return in style override format
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interpolate_color = (pct, first, last) ->
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r1, g1, b1 = extract_color first
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r2, g2, b2 = extract_color last
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r, g, b = interpolate(pct, r1, r2), interpolate(pct, g1, g2), interpolate(pct, b1, b2)
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ass_color r, g, b
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-- Interpolate between two alpha values, given either in style override or as part as a style definition colour
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-- Return in style override format
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interpolate_alpha = (pct, first, last) ->
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ass_alpha interpolate pct, select(4, extract_color first), select(4, extract_color last)
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{ :copy, :deep_copy, :ass_color, :ass_alpha, :ass_style_color,
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:extract_color, :alpha_from_style, :color_from_style, :HSV_to_RGB,
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:HSL_to_RGB, :trim, :headtail, :words, :clamp, :interpolate,
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:interpolate_color, :interpolate_alpha }
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