In-Game HUD: Health, Armor, Flashlight and Ammo

[JJL772]

Health, armor, flashlight and ammo HUDs

Typical Half-Life style HUD elements for mods that want this sorta thing.

Pretty much self-explanatory, these should roughly match up with the HL2 UI. Some ✨pizzazz✨ for these elements is very welcome too.

Implementation relies on #43 and #42

• Ammo
• Health
• Flashlight
• Armor

[JJL772]

Completed the health and ammo HUDs.

See basic implementation on feat/hud-ammo-and-health. It's ready for a UI dev to pick up.