Minor cleanup in GCoder

printrun/gcoder.py

@@ -109,22 +109,22 @@ class Layer(list):
                     y = current_y + (y or 0)
                     z = current_z + (z or 0)
                 else:
-                    if line.x: x = line.x + offset_x
-                    if line.y: y = line.y + offset_y
-                    if line.z: z = line.z + offset_z
+                    if x is not None: x = x + offset_x
+                    if y is not None: y = y + offset_y
+                    if z is not None: z = z + offset_z
 
                 current_x = x or current_x
                 current_y = y or current_y
                 current_z = z or current_z
 
                 if line.e or not ignore_noe:
-                    if x:
+                    if x is not None:
                         xmin = min(xmin, x)
                         xmax = max(xmax, x)
-                    if y:
+                    if y is not None:
                         ymin = min(ymin, y)
                         ymax = max(ymax, y)
-                    if current_z:
+                    if current_z is not None:
                         zmin = min(zmin, current_z)
                         zmax = max(zmax, current_z)
 
@@ -132,9 +132,9 @@ class Layer(list):
                 if not any([line.x, line.y, line.z]):
                     current_x = current_y = current_z = 0
                 else:
-                    if line.x: current_x = 0
-                    if line.y: current_y = 0
-                    if line.z: current_z = 0
+                    if line.x is not None: current_x = 0
+                    if line.y is not None: current_y = 0
+                    if line.z is not None: current_z = 0
 
             elif line.command == "G92":
                 if host_mode:
@@ -142,9 +142,9 @@ class Layer(list):
                     current_y = line.y or current_y
                     current_z = line.z or current_z
                 else:
-                    if line.x: offset_x = current_x - line.x
-                    if line.y: offset_y = current_y - line.y
-                    if line.z: offset_z = current_z - line.z
+                    if line.x is not None: offset_x = current_x - line.x
+                    if line.y is not None: offset_y = current_y - line.y
+                    if line.z is not None: offset_z = current_z - line.z
 
             line.current_x = current_x
             line.current_y = current_y