b582afeb1f
This updates the VoxeLibre documentation by replacing "Minetest" with "Luanti" and updating links. Done: * Update "Minetest" in documentation and comments to "Luanti" * Update links to forums, ContentDB and Luanti project web page Reviewed-on: https://git.minetest.land/VoxeLibre/VoxeLibre/pulls/4706 Reviewed-by: the-real-herowl <the-real-herowl@noreply.git.minetest.land> Co-authored-by: teknomunk <teknomunk@protonmail.com> Co-committed-by: teknomunk <teknomunk@protonmail.com> |
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| .. | ||
| tools | ||
| colormap_generator.lua | ||
| donut.lua | ||
| examples.lua | ||
| init.lua | ||
| LICENSE | ||
| logo.lua | ||
| mod.conf | ||
| README.md | ||
tga_encoder
A TGA Encoder written in Lua without the use of external Libraries.
Created by fleckenstein for VoxeLibre, then improved by erlehmann.
May be used as a Luanti mod.
See examples.lua for example code and usage hints.
Use Cases for tga_encoder
Encoding Textures for Editing
TGA images of types 1/2/3 consist of header data followed by a pixel array.
This makes it trivial to parse TGA files – and even edit pixels in-place.
No checksums need to be updated on any kind of in-place texture editing.
Tip: When storing an editable image in item meta, use zlib compression.
Legacy Luanti Texture Encoding
Luanti 5.4 did not include minetest.encode_png() (or any equvivalent).
Since tga_encoder is written in pure Lua, it does not need engine support.
Tip: Look at examples.lua and the Luanti mod mcl_maps for guidance.
Advanced Texture Format Control
The function minetest.encode_png() always encodes images as 32bpp RGBA.
tga_encoder allows saving images as grayscale, 16bpp RGBA and 24bpp RGB.
For generating maps from terrain, color-mapped formats can be more useful.
Encoding Very Small Textures
Images of size 8×8 or below are often smaller than an equivalent PNG file.
Note that on many filesystems files use at least 4096 bytes (i.e. 64×64).
Therefore, saving bytes on files up to a few 100 bytes is often useless.
Encoding Reference Textures
TGA is a simple format, which makes it easy to create reference textures.
Using a hex editor, one can trivially see how all the pixels are stored.
Supported Image Types
For all types, images are encoded in a fast single pass (i.e. append-only).
Color-Mapped Images (Type 1)
These images contain a palette, followed by pixel data.
A1R5G5B5(8bpp RGB)B8G8R8(8bpp RGB)B8G8R8A8(8bpp RGBA)
True-Color Images (Type 2)
These images contain uncompressed RGB(A) pixel data.
A1R5G5B5(16bpp RGBA)B8G8R8(24bpp RGB)B8G8R8A8(32bpp RGBA)
Grayscale Images (Type 3)
Y8(8bpp grayscale)
Run-Length Encoded (RLE), True-Color Images (Type 10)
These images contain compressed RGB(A) pixel data.
A1R5G5B5(16bpp RGBA)B8G8R8(24bpp RGB)B8G8R8A8(32bpp RGBA)
TODO
- Actually support
R8G8B8A8input forA1R5G5B5output - Add both zoomable and explorable maps to
mcl_maps.