Color tweaks. (#240)

* Color tweaks.

* Color tweaks bugfix.

* Style tweak and added test.

src/scenic/core/object_types.py

@@ -497,6 +497,11 @@ def _specify(cls, context, prop, value):
                     "Color property contains value not between 0 and 1 (inclusive)."
                 )
 
+            if len(value) == 3:
+                value = (value[0], value[1], value[2], 1)
+            elif len(value) != 4:
+                raise ValueError(f"Color property has incorrect length {len(value)}.")
+
         object.__setattr__(context, prop, value)
 
     def _register(self):
@@ -1555,7 +1560,8 @@ def show3D(self, viewer, highlight=False):
         if highlight:
             object_mesh.visual.face_colors = [30, 179, 0, 255]
         elif self.color is not None:
-            object_mesh.visual.face_colors = self.color
+            r, g, b, a = self.color
+            object_mesh.visual.face_colors = [255 * r, 255 * g, 255 * b, 255 * a]
 
         viewer.add_geometry(object_mesh)
 

src/scenic/simulators/utils/colors.py

@@ -88,7 +88,7 @@ def __init__(self, baseColor, hueNoise, satNoise, lightNoise):
     @staticmethod
     def addNoiseTo(color, hueNoise, lightNoise, satNoise):
         try:
-            hue, lightness, saturation = colorsys.rgb_to_hls(*color)
+            hue, lightness, saturation = colorsys.rgb_to_hls(*color[:3])
         except ZeroDivisionError:
             hue, lightness, saturation = 0.0, 1.0, 0.0
         hue = max(0, min(1, hue + hueNoise))

tests/syntax/test_specifiers.py

@@ -1136,3 +1136,30 @@ def test_shape():
 
     with pytest.raises(InvalidScenarioError):
         sampleEgoFrom(program, mode2D=True)
+
+
+# Color
+def test_color():
+    program = """
+        ego = new Object with color (0.5,0.5,0.5,0.5)
+        """
+    ego = sampleEgoFrom(program)
+    assert ego.color == (0.5, 0.5, 0.5, 0.5)
+
+    program = """
+        ego = new Object with color (0.5,0.5,0.5)
+        """
+    ego = sampleEgoFrom(program)
+    assert ego.color == (0.5, 0.5, 0.5, 1)
+
+    with pytest.raises(ValueError):
+        program = """
+            ego = new Object with color (255,0,0)
+            """
+        sampleEgoFrom(program)
+
+    with pytest.raises(ValueError):
+        program = """
+            ego = new Object with color (1,1,1,1,1)
+            """
+        sampleEgoFrom(program)