add [r, g, b] field to triangle, so we can draw coloured objects (next: add ability to change current colour)

functional-core/app/triangles.sml

@@ -9,7 +9,7 @@ struct
 
   fun helpToVector (lst, acc, windowWidth, windowHeight, halfWidth, halfHeight) =
     case lst of
-      {x1, y1, x2, y2, x3, y3} :: tl =>
+      {x1, y1, x2, y2, x3, y3, r, g, b} :: tl =>
         let
           val x1 = Ndc.centreAlignX (x1, windowWidth, windowHeight, halfWidth)
           val x2 = Ndc.centreAlignX (x2, windowWidth, windowHeight, halfWidth)
@@ -22,10 +22,19 @@ struct
           val vec =
            #[ x1 / halfWidth
             , y1 / halfHeight
+            , r
+            , g
+            , b
             , x2 / halfWidth
             , y2 / halfHeight
+            , r
+            , g
+            , b
             , x3 / halfWidth
             , y3 / halfHeight
+            , r
+            , g
+            , b
             ]
           val acc = vec :: acc
         in