Make Atlas terrain texture previews work with force_s3tc_enable

[Philip Taylor]

The game mostly works on Linux with compressed textures if you set DRI's force_s3tc_enable flag. But the terrain previews in Atlas don't work - they're just black squares. (They do work fine if the libtxc_dxtn library is installed, but it's a pain to expect users to install that.)

(See tools/atlas/GameInterface/Handlers/TerrainHandlers.cpp for the code that reads the textures and sends them to Atlas.)

So Atlas needs to do something different. Maybe the engine should just use its own software S3TC decoder - that would additionally save the cost of loading every terrain texture into a full GL texture, since we only actually need to decode a small chunk of a single mipmap level.

[Philip Taylor]

Duped by #474 (which has a broader scope).

[(none)]

Milestone Unclassified deleted