fixed issue with Color being mutable

 * improved README
 * Color is now frozen, so mutable issues with
 dataclass are avoided

README.md

@@ -41,31 +41,30 @@ The Mapsy library is designed to be simple to use. The following sections provid
 
 ### Creating a simple Map
 
-Here is an example of how to create a simple map with a filled polygon:
+Here is an example of how to create a simple map with a tiled raster layer:
 
 ```python
 import mapsy
+
 my_map = mapsy.Map()
 tile_layer = mapsy.TiledRasterLayer(
     [
         "https://tile.openstreetmap.org/{z}/{x}/{y}.png",
     ]
 )
 my_map.add_layer(tile_layer)
-my_map.add_layer(Attribution("© OpenStreetMap contributors"))
+my_map.add_layer(mapsy.Attribution("© OpenStreetMap contributors"))
 
 surf = my_map.render(
     mapsy.FixedScreenSize(
-        Box.from_lng_lat(5.988, 47.302, 15.016, 54.983), mapsy.ScreenSize(512, 512)
+        mapsy.Box.from_lng_lat(5.988, 47.302, 15.016, 54.983), mapsy.ScreenSize(512, 512)
     )
 )
 surf.write_to_png("my_map.png")
 
 ```
 
-If you want to use the map on a public place be sure to include proper attribution. This code will generate a map with a filled polygon and save it as `simple_map.png`.
-
-
+### Layers
 
 #### Background Layer
 A background layer provides a solid color background for the map.

mapsy/color.py

@@ -1,8 +1,9 @@
 import colorsys
 from dataclasses import dataclass
+from functools import cached_property
 
 
-@dataclass
+@dataclass(frozen=True)
 class Color:
     r: float
     g: float
@@ -11,27 +12,19 @@ class Color:
 
     @property
     def h(self) -> float:
-        self._ensure_hsv_exists()
         return self.hsv[0]
 
     @property
     def s(self) -> float:
-        self._ensure_hsv_exists()
-        return self.hsv[2]
+        return self.hsv[1]
 
     @property
     def v(self) -> float:
-        self._ensure_hsv_exists()
-        return self.hsv[3]
+        return self.hsv[2]
 
-    @property
+    @cached_property
     def hsv(self) -> tuple[float, float, float]:
-        self._ensure_hsv_exists()
-        return self.hsv
-
-    def _ensure_hsv_exists(self):
-        if self._hsv is None:
-            self._hsv = colorsys.rgb_to_hsv(self.r, self.g, self.b)
+        return colorsys.rgb_to_hsv(self.r, self.g, self.b)
 
     def float_rgb(self) -> tuple[float, float, float]:
         return self.r, self.g, self.b

mapsy/layer/symbol_layer.py

@@ -2,7 +2,7 @@
 from affine import Affine
 from shapely import MultiPoint, Point, affinity
 
-from mapsy.color import Color
+from mapsy.color import Color, Colors
 from mapsy.common import FontSlant, FontWeight, TextAnchor
 from mapsy.icon.icon import Icon
 from mapsy.layer.layer import Layer
@@ -22,7 +22,7 @@ class SymbolItem:
     text_offset: tuple[float, float] = (0, 0)
     text_font: str = "arial"
     text_size: float = 12
-    text_color: Color | None = Color(0, 0, 0)
+    text_color: Color | None = Colors.BLACK
     text_slant: FontSlant | None = None
     text_weight: FontWeight | None = None
     text_anchor: TextAnchor | None = None

pyproject.toml

@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "mapsy"
-version = "0.2.1"
+version = "0.3.0"
 description = "Mapsy is a Python library designed easily render static maps in python."
 authors = ["Felix Horvat <[email protected]>"]
 readme = "README.md"