Draft: Cord reimplementation

[namishere]

I've ultimately come to the conclusion that trying to expose the base game's cord system isn't worth it. It would be a monumental task trying to reverse engineer them given how little readily available information there is, and there's a good chance they won't be flexible enough to cover every use case someone might come up with. Now that BeamRenderer is fairly well understood, I've started working on a total reimplementation of cords.

What's needed for vanilla parity:

• [x] Automatically calculate the appropriate spritesheet coordinates of each point

  • This will require tweaking later on for dynamic Point addition & removal

• [x] Automatically handle updating point positions via an Update() call

• [x] Automatically handle rendering with BeamRenderer via a Render() call

  • Currently requires feeding in Sprite, LayerID, UseOverlayData. Will handle storage of these later.

• [ ] Automatically generate and remove new Points to handle variable rope distances

  • Currently has a fixed Point count

What's needed for developers:

1. Container class for Points

• [x] Retrieval of class from Cord (implemented as PointDeque)

  • Beam returns PointDeque for GetPoints() now, SetPoints() still takes a table

• [ ] Exposure of deque functions to lua

  • Currently have [Push/Pop][Front/Back]
  • Will definitely need __len, erase, Point getter/setter

2. Game state interactions

• [ ] Handling for connecting both ends of a Cord to Entities

  • Currently takes an Entity as a source, but the other end is free-floating
  • Might also want to allow an arbitrary Vector source/target (would need to be updated before calling Update()
  • Do I want to handle restricting target Entity movement? Maybe make this optional?

3. Documentation

• [ ] Pages for Cord, PointDeque
• [ ] Update Beam page for PointDeque
• [ ] Tutorial, example mod
• [ ] Changelog entry

What'd be nice:

• [ ] Snap points to nearest entity/grid
• [ ] Handle edge cases where large angle changes between points causes visual distortion
• [ ] Rope & Point mass

Test script:

mod = RegisterMod("REPENTOTEST", 1)
local spritesheetHeight = 64

local sprite = Sprite()
sprite:Load("gfx/1000.193_anima chain.anm2", true)
sprite:Play("Idle", false)
local layer = sprite:GetLayer("chain")
layer:SetWrapSMode(1)
layer:SetWrapTMode(0)

mod:AddCallback(ModCallbacks.MC_POST_PLAYER_INIT, function(_, player)
    local cord = Cord(player, Vector(80, 160), 12)
    player:GetData().cord = cord
end)

mod:AddCallback(ModCallbacks.MC_POST_PLAYER_UPDATE, function(_, player)
    if player:GetData().cord ~= nil then
        player:GetData().cord:Update()
    end
end)

mod:AddCallback(ModCallbacks.MC_POST_PLAYER_RENDER, function(_, player)
    if player:GetData().cord ~= nil then
        player:GetData().cord:Render(sprite, 1, false)
    end
end)