forked from Yonokid/YataiDONNijiiro
TaikoZhongandClaude Opus 5.5
2f7291d4ec
The collab backdrops (and the default donbg band) replay exported movies
whose per-frame channels were Lua tables of numbers: 38 MB that Lua
compiled on every song start (0.7 s for the TOHO pack; game screen init
1.5-1.6 s -> 0.9-1.0 s in-game), plus ~19 MB of Lua memory per pack.
Each per-frame array is now {base, step, width, "digits"}: value = base +
step * n, n being the frame's width chars in base 92 (printable ASCII
without '"' and '\'). One string constant compiles in a fraction of the
time; bg_objects/packed_channel.lua decodes the frame being drawn.
Quantization: 0.05 px, 0.005 deg, 5e-5 scale, 1/1024 alpha and tint;
every value of all 77 files checked against the original within half a
step.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
30 lines
1.0 KiB
Lua
30 lines
1.0 KiB
Lua
-- A channel of an exported cabinet movie (bg_data/bg_anim, bg_data/donbg_anim) at loop frame i
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-- (1-based). A channel is a number (constant), a table with one value per frame, or a packed
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-- table {base, step, width, digits}: value = base + step * n, n being frame i's `width` chars of
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-- `digits` in base 92 (printable ASCII without '"' and '\'). The packed form compiles several
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-- times faster than a table of numbers and takes a fraction of the memory.
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-- Written by scratchpad/arcade_collab/pack_channels.py.
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local byte = string.byte
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local DIGIT = {}
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do
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local d = 0
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for c = 33, 126 do
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if c ~= 34 and c ~= 92 then
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DIGIT[c] = d
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d = d + 1
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end
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end
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end
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return function(v, i)
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if type(v) == "number" then return v end
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local s = v[4]
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if type(s) ~= "string" then return v[i] end -- a plain table: one value per frame
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local w = v[3]
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local p = (i - 1) * w
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local n = DIGIT[byte(s, p + 1)]
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for k = p + 2, p + w do n = n * 92 + DIGIT[byte(s, k)] end
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return v[1] + v[2] * n
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end
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