Support colours for rendering the layer view

LayerData.py

@@ -1,4 +1,5 @@
 from UM.Mesh.MeshData import MeshData
+from UM.Math.Color import Color
 
 import numpy
 import math
@@ -7,16 +8,22 @@ class LayerData(MeshData):
     def __init__(self):
         super().__init__()
         self._layers = {}
+        self._element_counts = []
 
     def addPolygon(self, layer, type, data):
         if layer not in self._layers:
             self._layers[layer] = []
 
-        self._layers[layer].append(Polygon(self, type, data))
+        p = Polygon(self, type, data)
+        self._layers[layer].append(p)
+        self._element_counts.append(p.count)
 
     def getLayers(self):
         return self._layers
 
+    def getElementCounts(self):
+        return self._element_counts
+
 class Polygon():
     NoneType = 0
     Inset0Type = 1
@@ -30,11 +37,30 @@ class Polygon():
         self._type = type
         self._begin = mesh._vertex_count
         mesh.addVertices(data)
+        self._end = self._begin + len(data)
 
-        indices = [self._begin + i for i in range(len(data))]
+        color = None
+        if type == self.Inset0Type:
+            color = [1, 0, 0, 1]
+        elif type == self.InsetXType:
+            color = [0, 1, 0, 1]
+        elif type == self.SkinType:
+            color = [1, 1, 0, 1]
+        elif type == self.SupportType:
+            color = [0, 1, 1, 1]
+        elif type == self.SkirtType:
+            color = [0, 1, 1, 1]
+        else:
+            color = [1, 1, 1, 1]
 
+        colors = [color for i in range(len(data))]
+        mesh.addColors(numpy.array(colors, dtype=numpy.float32))
+
+        indices = []
+        for i in range(self._begin, self._end):
+            indices.append(i)
+            indices.append(i + 1)
         mesh.addIndices(numpy.array(indices, dtype=numpy.int32))
-        self._end = mesh._vertex_count
 
     @property
     def type(self):
@@ -43,3 +69,7 @@ class Polygon():
     @property
     def data(self):
         return self._data
+
+    @property
+    def count(self):
+        return self._end - self._begin