README.md

annotex

A command line tool to generate DDS BC7/BC1 textures with LOD for Anno. It is based on bc7enc.

The reason I made this is because I needed a CPU-based encoder to run Modding Tools for Anno in GitHub actions. Otherwise I would have chosen texconv.

How to use

To generate a BC7 DDS texture with LOD from 0 to 2 simply call:

annotex.exe townhall_diff.png -l=3

The output will be 3 files including mipmaps:

• townhall_diff_0.dds
• townhall_diff_1.dds
• townhall_diff_2.dds

Usage: annotex.exe [options] input.png

-f=<format>  Specify encoding format. Default: auto
   auto: Select below formats based on file ending.
   diff: Encode to BC7 (default).
   mask: Encode to BC1.
         Extension for auto: '_mask.png'.
   rga:  Encode normal map to BC7. Converts blue to alpha (glossiness).
         Extension for auto: '_rga.png'.
         Optional: uses blue channel from '_r_a+b.png' for glow.
   r_a:  Encode metal map to BC7. Converts blue to alpha (ambient occlusion).
         Extension for auto: '_r_a.png' or '_r_a+b.png'
-l=<0-9>  Number of LOD to generate with '_<LOD>.png' ending.
          0 will disable LODs (default)
-v  verbose

Downscale Algorithm

Mipmap and LOD generation are scaled down with a simple box downscale that relies on power of 2 textures (1024, 2048, ...). A sum of two power of 2 sizes is also OK (e.g. 1536 = 1024 + 512).

Width and height can be different.

Other sizes will work, but ignore odd pixels when downscaling.

Changes

1.2

• Added _r_a.png, _r_a+b.png to _metal.dds conversion
• Fixed non-square maps with _rga.

1.1

• Added _rga.png to _norm.dds conversion

Notes & License

The original code in this repository is unmodified to enable me to rebase to newer bc7enc if I need to. Only annotex.cpp, annotex/ has been added.

New code has been checked with VS 2019 only.

bc7enc: MIT License, Copyright(c) 2020-2021 Richard Geldreich, Jr.

annotex: MIT, Jakob Harder