Note.

This is older code from when Lua was still new to me, you'd be better off looking at the Coracle package in the Calx game repo for a more up-to-date and better written version of this project. This repo will be improved with updated examples and code once Calx has shipped.

Coracle for Playdate

A port of Coracle to Lua to run on the Playdate.

Usage

Clone and open in Nova, change the drawing import in main.lua to switch drawings.

Drawings

These are ported from the Kotlin Coracle framework.


Hello, Coracle	Shapes

Gravity	Avoid Closest

Perlin Flow Field	Self Organising

Example

--[[
  A port of Coracle Gravity: https://orllewin.github.io/coracle/drawings/vector/gravity/
]]
import 'Vector'
import 'SECL.lua'

local maxSpeed = 2.2
local bodyCount = 5

local blackhole = Vector:create(width/2, height/2)
local blackholeSize = 35
local blackholeMass = 0.4
local bodies = {}

function setup()
  for i = 1 , bodyCount do
    local boid = class:new()
    boid.location = Vector:create(math.random(width), math.random(height))
    boid.velocity = Vector:create(0, 0)
    table.insert(bodies, boid)
  end
end

function draw()
  background()
  
  fill(0.25)
  circle(blackhole.x, blackhole.y, blackholeSize)
  
  fill(1.0)
  
  for i = 1, bodyCount do
    circle(bodies[i].location.x, bodies[i].location.y, 5)
  end
  
  update()
end

function update()
  for i = 1, bodyCount do
    
    local body = bodies[i]
    
    local blackholeDirection = vectorMinus(blackhole, body.location)
    blackholeDirection:normalise()
    blackholeDirection:times(blackholeMass)
    
    body.velocity:plus(blackholeDirection)
    body.location:plus(body.velocity)
    
    for ii = 1, bodyCount do
      if (i ~= ii) then
        local other = bodies[ii]
        
        bodyDirection = vectorMinus(body.location, other.location)
        bodyDirection:normalise()
        bodyDirection:times(0.03)
        body.velocity:plus(bodyDirection)
        body.velocity:limit(3.0)
        body.location:plus(body.velocity)

      end
    end
  end
  
  if(crankUp())then
    blackholeSize = blackholeSize + 0.5
    blackholeMass = blackholeMass + 0.005
  end
  
  if(crankDown())then
    blackholeSize = blackholeSize - 0.5
    blackholeMass = blackholeMass - 0.005
  end
end

License

zlib