Simple-Physics-Engine/world.lua at main · imtheproxy/Simple-Physics-Engine · GitHub

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World = {}
World.__index = World

local sx, sy = guiGetScreenSize()

function World.new(gravity)
	local self = setmetatable({}, World)

	self.objects = {}
	self.gravity = gravity

	return self
end

function World:add(obj)
	table.insert(self.objects, obj)
end

function World:remove(obj)
	for i, v in ipairs(self.objects) do
		if v == obj then table.remove(self.objects, i) end
	end
end

function World:step(delta)
	self:resolve_collision(delta)

	for _, obj in ipairs(self.objects) do
		obj.force = {
			obj.force[1] + (obj.mass * self.gravity[1]),
			obj.force[2] + (obj.mass * self.gravity[2]),
		}

		obj.velocity = {
			obj.velocity[1] + (obj.force[1] / obj.mass * delta),
			obj.velocity[2] + (obj.force[2] / obj.mass * delta)
		}

		obj.transform.position = {
			obj.transform.position[1] + (obj.velocity[1] * delta),
			obj.transform.position[2] + (obj.velocity[2] * delta)
		}

		obj.force = { 0, 0 }
	end
end

function World:resolve_collision(delta)
	local collisions = {}

	for _, a in ipairs(self.objects) do
		for _, b in ipairs(self.objects) do
			if (a == b) then break end

			AABB(a, b)
		end
	end
end