33 lines
1.0 KiB
Lua
33 lines
1.0 KiB
Lua
dofile("init.lua")
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-- This generates images necessary to colorize 16 Minetest nodes in 4096 colors.
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-- It serves as a demonstration of what you can achieve using colormapped nodes.
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-- It is be useful for grass or beam or glass nodes that need to blend smoothly.
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-- Sample depth rescaling is done according to the algorithm presented in:
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-- <https://www.w3.org/TR/2003/REC-PNG-20031110/#13Sample-depth-rescaling>
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local max_sample_in = math.pow(2, 4) - 1
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local max_sample_out = math.pow(2, 8) - 1
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for r = 0,15 do
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local pixels = {}
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for g = 0,15 do
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if nil == pixels[g + 1] then
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pixels[g + 1] = {}
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end
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for b = 0,15 do
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local color = {
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math.floor((r * max_sample_out / max_sample_in) + 0.5),
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math.floor((g * max_sample_out / max_sample_in) + 0.5),
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math.floor((b * max_sample_out / max_sample_in) + 0.5),
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}
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pixels[g + 1][b + 1] = color
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end
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end
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local filename = "colormap_" .. tostring(r) .. ".tga"
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tga_encoder.image(pixels):save(
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filename,
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{ color_format="A1R5G5B5" } -- waste less bits
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)
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end
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