Aegisub/automation/include/karaskel.lua

--[[
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-- Aegisub Automation include file
-- The purpose of this include file is to provide a default skeleton for Automation scripts,
-- where you, as a scripter, can just override the functions you need to override.

-- The following functions can be overridden:
--   do_syllable - called for each syllable in a line
--   do_line_decide - called to decide whether to process a line or not
--   do_line_start - called at the beginning of each line
--   do_line_end - called at the end of each line
--   do_line - Process an entire line
-- By default, these functions are all assigned to the following default functions
-- Your functions should obviously use the same parameter lists etc.
-- Note that if you override do_line, none of the other functions will be called!


-- All the functions mentioned here are, however, wrapped in some code that pre-calculates some
-- extra data for the lines and syllables.

-- The following fields are added to lines:
--   i - The index of the line in the file, 0 being the first
--   width - Rendered width of the line in pixels (using the line style, overrides are not taken into account)
--   height - Rendered height of the line in pixels (note that rotation isn't taken into account either)
--   ascent - Height of the ascenders, in pixels (notice that this looks like the output of text_extents?)
--   extlead - External leading of the font, in pixels (well, it is!)
--   centerleft - Pixel position of the left edge of the line, when horisontally centered on screen
--   centerright - Pixel pisition of the right edge of the line, when horisontally centered on screen
--   duration - Duration of the line in miliseconds
--   styleref - The actual style table for the style this line has

-- The following fields are added to syllables:
--   i - The index of the syllable in the line, 0 being the first (and usually empty) one
--   width, height, ascent, extlead - Same as for lines
--   left - Left pixel position of the syllable, relative to the start of the line
--   center - Center pixel position of the syllable, also relative to the start of the line
--   right - Right pixel position of the syllable, relative again
--   start_time - Start time of the syllable, in miliseconds, relative to the start of the line
--   end_time - End time of the syllable, similar to start_time

include("karaskel-base.lua")

-- Return a replacement text for a syllable
function karaskel.do_syllable(meta, styles, config, line, syl)
	karaskel.trace("default_do_syllable")
	return syl.text
end

-- Decide whether or not to process a line
function karaskel.do_line_decide(meta, styles, config, line)
	karaskel.trace("default_do_line_decide")
	return line.kind == "dialogue"
end

-- Return a text to prefix the line
function karaskel.do_line_start(meta, styles, config, line)
	karaskel.trace("default_do_line_start")
	return ""
end

-- Return a text to suffix the line
function karaskel.do_line_end(meta, styles, config, line)
	karaskel.trace("default_do_line_end")
	return ""
end

-- Process an entire line (which has pre-calculated extra data in it already)
-- Return a table of replacement lines
function karaskel.do_line(meta, styles, config, line)
	karaskel.trace("default_do_line")
	
	-- Check if the line should be processed at all
	if not do_line_decide(meta, styles, config, line) then
		return {n=0}
	end
	karaskel.trace("default_do_line:2")
	
	-- Create a new local var for the line replacement text, set it to line prefix
	-- This is to make sure the actual line text isn't replaced before the line has been completely processed
	local newtext = do_line_start(meta, styles, config, line)
	karaskel.trace("default_do_line:3")
	
	-- Loop over the syllables
	for i = 0, line.karaoke.n-1 do
		karaskel.trace("default_do_line:4:"..i)
		-- Append the replacement for each syllable onto the line
		newtext = newtext .. do_syllable(meta, styles, config, line, line.karaoke[i])
	end
	karaskel.trace("default_do_line:5")
	
	-- Append line suffix
	newtext = newtext .. do_line_end(meta, styles, config, line)
	karaskel.trace("default_do_line:6")
	
	-- Now replace the line text
	line.text = newtext
	
	-- And return a table with one entry
	return {n=1; [1]=line}
end

-- Now assign all the default functions to the names that are actually called
do_syllable = karaskel.do_syllable
do_line_decide = karaskel.do_line_decide
do_line_start = karaskel.do_line_start
do_line_end = karaskel.do_line_end
do_line = karaskel.do_line