xavilpergis/universemod

WIP Minecraft mod about exploring the universe!

Ultraviolet

I'm not sure I'll actually end up sticking with this name :P

Code Overview

• A lot of the custom rendering in this mod is done through separate OpenGL wrappers, rather than relying on what vanilla gives us. This may have been the wrong choice lol.
• Custom math types that dont sucks so much to use: Vec3, Vec3i, Quat, Color, etc. These are located currently in net/xavil/util/math

CelestialNode

CelestialNode in net/xavil/common/universe/system and its related classes are representations of celestial bodies and their children. Orbits are defined per-child, instead of per-node, meaning you have to use CelestialNodeChild to get orbital information about a celestial body.

• CelestialNodes form trees, and to enable efficient lootkups, each node in the tree is assigned an id that is greater than all of its children's ids. IDs are not assigned automatically as you insert nodes into the tree, so you must call assignIds on the root node before using them in certain places. Some operations do not actually need the tree IDs to be in place to work.
• Orbits are simple keplerian orbits, not a fully nbody gravity simulation, and can be derived solely from time, using the updatePositions method.
• Currently, CelesialNode has readNbt and writeNbt so that they can be serialized over the network.

Networking

Some mixins in ConnectionProtocol fire an event that allows this mod to register custom network packets without the overhead of ServerboundCustomPayloadPacket, which needs to include an entire ass string channel ID in every packet. I'm not sure how compatible these changes are with other mods, but I doubt it would be too terrible. If it proves too much of a problem, I can look into it later. It shouldn't mess with the ability to connect to vanilla servers either, since packet IDs are assigned linearly, and we insert new packet types after vanilla finishes adding its packet types. Packets can be registered with ModNetworking.REGISTER_PACKETS_EVENT.

IDs

• SystemNodeId
  • Full-resolution ID that allows identifying a single celestial node, given no prior context.
• GalaxySectorId
  • ID that allows identifying a star system, given a galaxy as prior context.
• SystemId
  • ID that allows identifying a star system, given no prior context.
• UniverseSectorId
  • ID that allows identifying a galaxy, given no prior context.

GalaxySector, SectorManager, SectorTicket, SystemTicket, SectorPos

GalaxySectors are octree nodes that span 10ly in each axis at the "base" level. These octrees are limited to 8 levels of depth. They primarily store basic info about star systems, like their position and context needed for more in-depth generation of the star system. Within a galaxy, SectorPoses are used to identify GalaxySectors. GalaxySectors are loaded, unloaded, and stored by SectorManager, which is responsible for keeping track of tickets that were issued by it, loading and unloading sectors/systems as needed. SystemTickets load a single star system in its entirety, as well as the sector that the system resides within. SectorTickets may load multiple sectors, and come in a few different flavors. They can either load a single sector given a SectorPos, or they can load a region of sectors around a point, given a "base radius", and a description of how that radius changes for each level higher in the octree. For both kinds of tickets, the contents of what they are loading can be modified at any point, and the sector manager will reflect that. For example, you can keep a single system ticket around, and simply change ticket.id to load a different system. null is also a valid ID, and will make the SectorManager unload anything that ticket has loaded. The SectorManager will do all its generation in a background threadpool, but it is also possible to wait until a ticket has completed being loaded.

UniverseSector and UniverseSectorManager

Very similar to ther galaxy counterparts, just that they refer to sectors that contain galaxies instead of sectors that contain star systems, and are attached to a Universe instead of a Galaxy.

Galaxy

Galaxies primarily act as a host for a GalaxySectorManager, but are also responsible for actually generating star system sectors. They contain a list of GalaxyGenerationLayers, which each contribute a set of stars to the generating sector. Every galaxy gets a BaseGalaxyGenerationLayer attached to it, which does all the heavy lifting. The galaxy that the starting system resides in gets an additional StartingSystemGalaxyGenerationLayer that simply places the starting system in the correct location. There are also plans for adding authored systems, which would probably be its own generation layer.

Universe

Like Minecraft's Level, ServerLevel, and ClientLevel, Universe is split between itself, ServerUniverse, and ClientUniverse. Like Galaxy, Universe serves as a context for generating galaxies, and also stores the results of that generation within itself. The generation process does not happen in the same way that star system generation does.

There are two types of seed: common and unique. The common seed is shared between everyone that uses the mod (this will be configurable in the future) and the unique seed is unique per world. The common seed drives the actual universe generation: the distribution of galaxies, the shape of those galaxies, the distribution of stars within those galaxies, and the layout of star systems. The unique seed drives starting system placement. This means that for the default common seed, two beings may share universe coordinates and be able to talk about the same planet/system/galaxy, even on worlds with different vanilla seeds. The reason the seeds are shared is so that the client can generate its own copy of the galaxies in the universe and the starts in a galaxy, so that the server doesn't need to stream a huge amount of data to the client when they, say, need to rebuild the background stars, or move around in the galaxy map view.

Rendering

WindowMixin redirects some GLFW hints to get it to provide us an OpenGL 4.5 context, because I want to use all the fancy DSA functions