Issue #11: move color utility to separate module.

roentgen/color.py

@@ -0,0 +1,38 @@
+from typing import Any, List
+
+from colour import Color
+
+from roentgen.util import MinMax
+
+
+def is_bright(color: Color) -> bool:
+    """
+    Is color bright enough to have black outline instead of white.
+    """
+    return (
+        0.2126 * color.red * 256 +
+        0.7152 * color.green * 256 +
+        0.0722 * color.blue * 256 > 200)
+
+
+def get_gradient_color(value: Any, bounds: MinMax, colors: List[Color]):
+    """
+    Get color from the color scale for the value.
+
+    :param value: given value (should be in bounds)
+    :param bounds: maximum and minimum values
+    :param colors: color scale
+    """
+    color_length: int = len(colors) - 1
+    scale = colors + [Color("black")]
+
+    coefficient: float = (
+        0 if bounds.max_ == bounds.min_ else
+        (value - bounds.min_) / (bounds.max_ - bounds.min_))
+    coefficient = min(1.0, max(0.0, coefficient))
+    m: int = int(coefficient * color_length)
+    color_coefficient = (coefficient - m / color_length) * color_length
+
+    return Color(rgb=[
+        scale[m].rgb[i] + color_coefficient *
+        (scale[m + 1].rgb[i] - scale[m].rgb[i]) for i in range(3)])

roentgen/constructor.py

@@ -15,7 +15,8 @@
 from roentgen.flinger import Flinger
 from roentgen.osm_reader import Map, OSMMember, OSMRelation, OSMWay, OSMNode, Tagged
 from roentgen.scheme import IconSet, Scheme
-from roentgen.util import MinMax, get_gradient_color
+from roentgen.util import MinMax
+from roentgen.color import get_gradient_color
 
 DEBUG: bool = False
 TIME_COLOR_SCALE: List[Color] = [

roentgen/mapper.py

@@ -25,7 +25,8 @@
 from roentgen.osm_reader import Map, OSMReader
 from roentgen.scheme import Scheme
 from roentgen.direction import DirectionSet, Sector
-from roentgen.util import MinMax, is_bright
+from roentgen.util import MinMax
+from roentgen.color import is_bright
 
 ICONS_FILE_NAME: str = "icons/icons.svg"
 TAGS_FILE_NAME: str = "data/tags.yml"

roentgen/util.py

@@ -1,8 +1,3 @@
-from typing import Any, List
-
-from colour import Color
-
-
 class MinMax:
     """
     Minimum and maximum.
@@ -29,36 +24,3 @@ def center(self):
         Get middle point between minimum and maximum.
         """
         return (self.min_ + self.max_) / 2
-
-
-def is_bright(color: Color) -> bool:
-    """
-    Is color bright enough to have black outline instead of white.
-    """
-    return (
-        0.2126 * color.red * 256 +
-        0.7152 * color.green * 256 +
-        0.0722 * color.blue * 256 > 200)
-
-
-def get_gradient_color(value: Any, bounds: MinMax, colors: List[Color]):
-    """
-    Get color from the color scale for the value.
-
-    :param value: given value (should be in bounds)
-    :param bounds: maximum and minimum values
-    :param colors: color scale
-    """
-    color_length: int = len(colors) - 1
-    scale = colors + [Color("black")]
-
-    coefficient: float = (
-        0 if bounds.max_ == bounds.min_ else
-        (value - bounds.min_) / (bounds.max_ - bounds.min_))
-    coefficient = min(1.0, max(0.0, coefficient))
-    m: int = int(coefficient * color_length)
-    color_coefficient = (coefficient - m / color_length) * color_length
-
-    return Color(rgb=[
-        scale[m].rgb[i] + color_coefficient *
-        (scale[m + 1].rgb[i] - scale[m].rgb[i]) for i in range(3)])