Fix add_cube

Author: can-lehmann

src/geometryutils/render3.nim

@@ -272,9 +272,12 @@ proc add_cube*(wireframe: Wireframe, pos, size: Vec3) =
         ))
 
   wireframe.lines &= [
-    [0, 1], [2, 3], [4, 5], [6, 7],
-    [0, 4], [2, 6], [1, 5], [3, 7],
-    [0, 2], [4, 6], [5, 7], [1, 3]
+    [idx + 0, idx + 1], [idx + 2, idx + 3],
+    [idx + 4, idx + 5], [idx + 6, idx + 7],
+    [idx + 0, idx + 4], [idx + 2, idx + 6],
+    [idx + 1, idx + 5], [idx + 3, idx + 7],
+    [idx + 0, idx + 2], [idx + 4, idx + 6],
+    [idx + 5, idx + 7], [idx + 1, idx + 3]
   ]
 
 proc new_cube_wireframe*(pos, size: Vec3): Wireframe =
@@ -333,7 +336,7 @@ type
         ambient*: float64
 
   Render3* = object
-    window: BaseWindow
+    window*: BaseWindow
 
     shader_prog: ShaderProgram
     wireframe_shader_prog: ShaderProgram

src/geometryutils/serialize.nim

@@ -143,7 +143,7 @@ proc load*[T](stream: Stream, items: var seq[T]) =
 proc load*[K, V](stream: Stream, items: var Table[K, V]) =
   mixin load
   var length: int64
-  stream.load(length)  
+  stream.load(length)
   items = init_table[K, V]()
   for it in 0..<int(length):
     var