What Doesn't Get Compressed?

Speaking of compression, X-Plane doesn't compress all textures...even if "texture compression" is on, we leave uncompressed certain textures that are flagged. A rough list:

• Most textures in the sky, like clouds and color stripes, have a lot of alpha and get wrecked by compression. They get exempted.
• Anything related to the 2-d panel, maps, and the UI get exempted.
• Some of the overlays like rain and snow, smoke puffs, and lights.
  
• Taxiway signs get exempted...S3TC does a number on letters and numbers.