functioning model

treemodel/main.lua

@@ -0,0 +1,87 @@
+local screen_width, screen_height = 960, 540
+love.window.setMode(screen_width, screen_height)
+local game_time = os.time()
+love.math.setRandomSeed(game_time)
+
+local star = {
+  x = 0, y = 0, orbital_radius = 0,
+  children = {
+    {
+      orbital_radius = 100,
+      children = {
+        {
+          orbital_radius = 10,
+        }
+      }
+    },
+    {
+      orbital_radius = 50
+    },
+    {
+      orbital_radius = 200,
+      children = {
+        {
+          orbital_radius = 25,
+          children = {
+            {
+              orbital_radius = 5
+            }
+          }
+        }
+      }
+    }
+  }
+}
+local set_offsets
+set_offsets = function(object)
+  object.rotation_offset = math.pi * 2 * love.math.random()
+  if object.children then
+    for i = 1, #object.children do
+      set_offsets(object.children[i])
+    end
+  end
+end
+set_offsets(star)
+
+function love.update(dt)
+  game_time = game_time + dt
+
+  local update_object_position
+  update_object_position = function(object, parent_x, parent_y)
+    local temporary_speed_up = 100
+    local argument = game_time / object.orbital_radius^1.337 * temporary_speed_up + object.rotation_offset
+    if (argument == math.huge) or (argument ~= argument) then
+      argument = 0
+    end
+    object.x, object.y = parent_x + object.orbital_radius * math.cos(argument), parent_y + object.orbital_radius * math.sin(argument)
+    if object.children then
+      for i = 1, #object.children do
+        update_object_position(object.children[i], object.x, object.y)
+      end
+    end
+  end
+  update_object_position(star, 0, 0)
+end
+
+function love.draw()
+  love.graphics.setColor(1, 1, 1, 1)
+  love.graphics.translate(screen_width / 2, screen_height / 2)
+
+  local draw_object
+  draw_object = function(object, parent_x, parent_y)
+    love.graphics.circle("fill", object.x, object.y, 3)
+    love.graphics.circle("line", parent_x, parent_y, object.orbital_radius)
+    if object.children then
+      for i = 1, #object.children do
+        draw_object(object.children[i], object.x, object.y)
+      end
+    end
+  end
+  draw_object(star, 0, 0)
+end
+
+function love.keypressed(key)
+  if key == "escape" then
+    love.event.quit()
+  end
+end