There was confusion in the lighting code between light indexes and sun indexes. These are usually the same, but not always. This makes several changes to fix light/sun handling.
1. Clarify the distinction between lights and suns and add a `sun_index` field
2. Add a flags field and assign the `dual_cone` boolean to it, as well as a new glare flag
3. Determine light glare by checking the light flag, not the sun (which never worked in the first place as the `stars_sun_has_glare` function checked bitmaps rather than suns)
* Create the ingame options game state
* Base working version of in-game options
* Cleanup + Optimization
* Localization pass
* more cleanup + documentation
* tooltips on option hover
* documentation and better inbounds check
* match case
* format strings instead of direct strings
* unused parameter
* address feedback
* localization id conflict with master
* Add this line back in
* pass the new option flags as well
* resolve xstr id conflict
Use a single canonical `frametime` value for all HUD rendering, in both `hud_render_preprocess` and `hud_render_all`. Previously, certain functions called through `hud_render_preprocess` were using the full frametime, rather than the half frametime needed for VR when the HUD is rendered twice.
Fixes#5882.
Convert additional timestamps to use the new timestamp system. This covers all timestamps referred to in freespace.cpp. For purposes of organization, the fade-in/fade-out timestamps have been moved to light.h|cpp and the training timestamps have been moved to missiontraining.h|cpp.
There are also several related code enhancements:
1. `FadeType` has been converted from `enum` to `enum class`
2. Initialization of the various training variables has been added to `training_mission_init` (previously they had never been reset between missions)
3. Validity checks have been added to the relevant locations for these timestamps
Some of the `frand_range` calls were used for integer calculations, so we can use `Random::next` now.
This also reduces the number of C-style casts in the codebase.
* Add a divide by zero check
For coverity 1107324. Keeps framecount from dividing by zero in very rare circumstances.
* Add a clarifying comment
This marks isNaturalNumberFactor() so that we know it is the best way to get whether a number is a natural number.
Modulo division is slower and gives the same results.
* Spoiled by Rust
Goober5000