main.lua, turtle.lua

turtle.lua

@@ -0,0 +1,80 @@
+
+
+local function fd(x, y, ang, steps, penDown)
+   local x2, y2 = x+math.sin(ang)*steps, y-math.cos(ang)*steps
+   if penDown then
+      love.graphics.line(x, y, x2, y2)
+   end
+   return x2, y2
+end
+
+local deg2rad = math.pi/180
+function mkTurtle(x,y,degrees,orig)
+   local penDown = true
+   if x == nil then x = 0 end
+   if y == nil then y = 0 end
+   if degrees == nil then degrees = 0 end
+
+   local self
+   self = {
+      fd = function(steps)
+	 x, y = fd(x, y, degrees*deg2rad, steps, penDown)
+	 return self
+      end,
+
+      bk = function(steps)
+	 x, y = fd(x, y, degrees*deg2rad, -steps, penDown)
+	 return self
+      end,
+
+      rt = function(deg)
+	 degrees = degrees + deg
+	 return self
+      end,
+
+      lt = function(deg)
+	 degrees = degrees - deg
+	 return self
+      end,
+
+      pd = function(isDown)
+	 penDown = isDown
+	 return self
+      end,
+
+      col = function(color)
+	 -- FIXME
+	 return self
+      end,
+
+      dup = function(orig)
+	 return mkTurtle(x, y, degrees, orig)
+      end,
+
+      parent = function()
+	 return orig
+      end,
+
+      inline = function(env, func)
+	 local stub = {}
+	 local meta = {
+	    __index = function(table, key)
+	       if env[key] ~= nil then
+		  return env[key]
+	       end
+	       if _ENV ~= nil and _ENV[key] ~= nil then
+		  return _ENV[key]
+	       end
+	       return nil
+	    end,
+	 }
+	 setmetatable(stub, meta)
+	 setfenv(func, stub)
+	 return func()
+      end,
+   }
+   return self
+end
+
+return mkTurtle
+