1. There is no small logo. Simply use 2 variables.
2. The medium logo is much smaller as PCX:
* Hellfire (`ui_art\hf_logo2.pcx`): 1591816 bytes -> 195850 bytes
* Diablo (`ui_art\smlogo.pcx`): 341923 bytes -> 333099 bytes
* Move `ArtLogoBig` to `title.cpp`
It is only ever used there
1. Do not modify the map after loading. Instead, return string views
(guaranteed to be null-terminated) from look up functions and return
the key directly if not found.
2. Use an `unorded_map` instead of `map` where available (C++20).
Saves a bit of RAM (~50 KiB) and improves lookup performance.
The backgrounds can be quite large, for example
the Hellfire title background is a 2.4 MiB PCX file.
Previously, we converted all background to SDL surfaces.
This required extra memory, e.g. the 2.4 MiB Hellfire
title background uses 4.6 MiB as an SDL surface.
Changes the background to render directly from PCX instead
to reduce the allocator pressure.
Using optional arguments where possible so that all use cases can share the same constructor. Also moving member initialisation to the initialiser list syntax as this makes it clear that the derived class is only setting properties on that class, leaving the parent constructor to initialise members of the parent class.
Gleb Mazovetskiy