gravity implemennted

body.lua

@@ -0,0 +1,60 @@
+BodyList = {}
+Body = class(nil,{type=0})
+
+function newBody(x,y,mass,color)
+  local o = {}
+  -- coordinates
+  o.x = x
+  o.y = y
+  -- velocities
+  o.vx = 0
+  o.vy = 0
+  -- accceleration
+  o.ax = 0
+  o.ay = 0
+  -- mass
+  o.mass = mass
+  -- color
+  o.color = color
+	table.insert(BodyList,o)
+end
+
+function UpdateBodiesAcceleration()
+  for n, body in pairs(BodyList) do
+    local ax = 0
+    local ay = 0
+    for o_n, other_body in pairs(BodyList) do
+      if n ~= o_n then
+
+        local dx = other_body.x - body.x
+        local dy = other_body.y - body.y
+
+        local d2 = dx*dx + dy*dy
+
+        local f =
+          (CONST_G * other_body.mass) /
+          d2 * math.sqrt(d2 + CONST_S)
+
+        ax = ax + dx * f
+        ay = ay + dy * f
+      end
+    end
+
+    body.ax = ax
+    body.ay = ay
+  end
+end
+
+function UpdateBodiesVelocity(dt)
+  for _, body in pairs(BodyList) do
+    body.vx = body.vx + body.ax * dt
+    body.vy = body.vy + body.ay * dt
+  end
+end
+
+function UpdateBodiesPosition(dt)
+  for _, body in pairs(BodyList) do
+    body.x = body.x + body.vx * dt
+    body.y = body.y + body.vy * dt
+  end
+end

class.lua

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+function class(super, self)
+	assert(super == nil or super.__index == super)
+	self = self or {}
+	self.__index = self
+	setmetatable(self, super)
+	return self
+end
+
+function getAncestors(self)
+	local family = self
+	local list = {}
+	while family ~= nil do
+		family = getmetatable(family)
+		table.insert(list,family)
+	end
+	return list
+end

conf.lua

@@ -0,0 +1,7 @@
+function love.conf(love)
+	love.title = "HSS"
+	love.version = "11.3"
+	love.window.width = 800
+	love.window.height = 800
+	love.window.resizable = true
+end

main.lua

@@ -0,0 +1,52 @@
+
+function love.load()
+	--options
+	love.graphics.setColor(1,1,1)
+	love.graphics.setDefaultFilter("nearest") -- good pixel
+
+  SCREEN_WIDTH = love.graphics.getWidth()
+  SCREEN_HEIGHT = love.graphics.getHeight()
+
+  -- simulation variables
+  CONST_G = 39.5
+  TIME_SPEED = 0.05
+  CONST_S = 0.15
+
+  T = 0
+
+  require "class"
+	require "body"
+
+	newBody(0,0,300,{1,0,0})
+	newBody(0,0.1,100,{0,1,0})
+	newBody(0.1,0,200,{0,0,1})
+	newBody(0.1,0.1,50,{1,1,0})
+	newBody(0.1,0.2,250,{1,0,1})
+	newBody(0.2,0.1,150,{0,1,1})
+
+end
+
+function love.update(dt)
+
+  T = T + dt
+  while T > TIME_SPEED do
+    UpdateBodiesAcceleration()
+    UpdateBodiesVelocity(dt)
+    UpdateBodiesPosition(dt)
+    T = T - TIME_SPEED
+  end
+end
+
+function love.draw()
+  -- draw bodies
+  for n, body in pairs(BodyList) do
+    love.graphics.setColor(body.color[1],body.color[2],body.color[3])
+    love.graphics.circle("line",body.x+SCREEN_WIDTH/2,body.y+SCREEN_HEIGHT/2,10)
+  end
+  -- draw info
+  love.graphics.setColor(1,1,1)
+  love.graphics.print(T.."/"..TIME_SPEED)
+  for n, body in pairs(BodyList) do
+    love.graphics.print("mass: "..body.mass.." x,y: "..body.x..", "..body.y,0,15*(n))
+  end
+end