Updated construct and paintable_construct to use matrices for space c…

…oords.

construct.lua

@@ -2,6 +2,7 @@ require "middleclass" -- definition of useful class construction methods
 require 'constants'
 require 'spob'
 require 'segment'
+local matrix = require 'lua-matrix/lua/matrix'
 
 -- Construct class: Spob composed of multiple Segments
 
@@ -31,10 +32,14 @@ function Construct:initialize(host, n_segments, radius, height, thickness, perio
     stop  = { x = math.cos(s * angle_subtended) * self.radius, 
 	      y = math.sin(s * angle_subtended) * self.radius } 
     -- Walk out the points of the face in clockwise fashion
-    p1 = { x = start.x, y = start.y, z =  half_thickness }
-    p2 = { x = stop.x,  y = stop.y,  z =  half_thickness }
-    p3 = { x = stop.x,  y = stop.y,  z = -half_thickness }
-    p4 = { x = start.x, y = start.y, z = -half_thickness }
+--    p1 = { x = start.x, y = start.y, z =  half_thickness }
+--    p2 = { x = stop.x,  y = stop.y,  z =  half_thickness }
+--    p3 = { x = stop.x,  y = stop.y,  z = -half_thickness }
+--    p4 = { x = start.x, y = start.y, z = -half_thickness }
+    p1 = matrix{ start.x, start.y,  half_thickness }
+    p2 = matrix{ stop.x,  stop.y,   half_thickness }
+    p3 = matrix{ stop.x,  stop.y,   -half_thickness }
+    p4 = matrix{ start.x, start.y,  -half_thickness }
     faces = { { p1, p2, p3, p4 } }
     table.insert(self.segments, Segment:new(self, faces))
 

paintable_construct.lua

@@ -1,5 +1,6 @@
 require "middleclass" -- definition of useful class construction methods
 require "paintable"
+local matrix = require 'lua-matrix/lua/matrix'
 
 PaintableConstruct = Paintable:subclass('PaintableConstruct')
 
@@ -9,22 +10,28 @@ function PaintableConstruct:initialize(spob, color)
 end
 
 function PaintableConstruct:draw()
-  segments = self.spob.segments
+  local segments = self.spob.segments
 
   love.graphics.setColor(self.color.R, self.color.G, self.color.B)
 
-  construct_location = self.spob:getLocation()
+  local construct_location = self.spob:getLocation()
   for seg_i, segment in pairs(self.spob.segments) do
     for face_i, face in pairs(segment.faces) do
       polygon = {}
       for _, point in pairs(face) do
-	sin_theta = math.sin(self.spob.rotation_angle)
-	cos_theta = math.cos(self.spob.rotation_angle)
-	local rot_p = { x = point.x * cos_theta - point.y * sin_theta,
-			y = point.x * sin_theta + point.y * cos_theta }
-	local p = { x = rot_p.x + construct_location.x,
-		    y = rot_p.y + construct_location.y }
-        screen_x, screen_y = scale:screenCoords(p)
+	local theta = self.spob.rotation_angle
+	local sin_theta = math.sin(theta)
+	local cos_theta = math.cos(theta)
+	--local rot_p = { x = point.x * cos_theta - point.y * sin_theta,
+	--		y = point.x * sin_theta + point.y * cos_theta }
+	-- This is a 3D rotation matrix around the z axis
+	local rot_p = matrix{{cos_theta,-sin_theta,0},
+			     {sin_theta, cos_theta,0},
+			     {        0,         0,1}} * point    
+	--local p = { x = rot_p.x + construct_location.x,
+	--	    y = rot_p.y + construct_location.y }
+	local p = rot_p + construct_location -- yummy, I'm a matrix
+        local screen_x, screen_y = scale:screenCoords(p)
         table.insert(polygon, screen_x)
         table.insert(polygon, screen_y)
       end