direct: Fix DirectGrid alpha issue and getVertexColor error (#1793)

Fixes #1292

direct/src/directtools/DirectGeometry.py

@@ -79,8 +79,8 @@ class LineNodePath(NodePath):
     def getVertex(self, index):
         return self.lineSegs.getVertex(index)
 
-    def getVertexColor(self):
-        return self.lineSegs.getVertexColor()
+    def getVertexColor(self, index):
+        return self.lineSegs.getVertexColor(index)
 
     def drawArrow(self, sv, ev, arrowAngle, arrowLength):
         """

direct/src/directtools/DirectGrid.py

@@ -33,7 +33,7 @@ class DirectGrid(NodePath, DirectObject):
 
         self.centerLines = LineNodePath(self.lines)
         self.centerLines.lineNode.setName('centerLines')
-        self.centerLines.setColor(VBase4(1, 0, 0, 0))
+        self.centerLines.setColor(VBase4(1, 0, 0, 1))
         self.centerLines.setThickness(3)
 
         # Small marker to hilight snap-to-grid point