DVD-Hostile File Formats
Seriously, who came up with the brilliant idea of storing the mip levels of a texture bigger-to-smaller after the header in a DDS file? This way, when you want to load just, say, mip level 256×256 and all the smaller ones, you need to do two disjoint reads from the file - one to parse the DDS header, and another for the mip subchain. Nothing would be simpler than storing them smaller-to-bigger - this way you’d be able to read with a single read operation, or, at worst, with two adjacent ones. When you’re trying to read asynchronously textures, the bigger-to-smaller order forces you to either keep a preloaded table of all the DDS headers in your game (which is a bad idea in many ways - it consumes memory proportionally to the entire data set of the game, instead of the currently needed data set, introduces additional asset build steps, and messes with the ability to let artists change texture formats and size on the fly while the game is running), or to two two asynchronous reads, doubling the latency for textures appearing on the screen.
I try hard not to be one of those not-invented-here guys who insist on having their own data processing tools and file formats for everything, but it’s not easy…