Address `Map Scalars` usability issues
The following needs to be done to make it less confusing when Map Scalars is checked/unchecked.
- Map Scalars should only be un-checkable when direct coloring is possible i.e.
- for surface rendering, if the integral in range [0,255] or floating point in range [0.0, 1.0] and has number components between 1 and 4 (see
vtkScalarToColorsfor interpretation for various components when using
- for volume rendering, only 2 and 4 components would be supported with component interpretation matching that of surface rendering.
- When Map Scalars is unchecked, the following should happen:
- the color selection combo-box in the toolbar and on the Display properties panel, should disable the component selection. Components cannot be selected when map-scalars is off.
- The Color Map editor should not show anything. There's no transfer function being set/used.
- The color legend should not be shown.