feat!: Make arc_scale a combo field

KEYMAP_SPEC.md

@@ -133,6 +133,7 @@ This is an optional field that contains a list of combo specs, each of which is
 | `offset` (`o`)        | `float`                                           | `0.0`         | additional offset to `top`/`bottom`/`left`/`right` positioning, specified in units of key width/height: useful for combos that would otherwise overlap                            |
 | `dendron` (`d`)       | `null \| bool`                                    | `null`        | whether to draw dendrons going from combo to triggering key coordinates, default is to draw for non-`mid` alignments and draw for `mid` if key coordinates are far from the combo |
 | `slide` (`s`)         | `null \| float (-1 <= val <= 1)`                  | `null`        | slide the combo box along an axis between keys -- can be used for moving `top`/`bottom` combo boxes left/right, `left`/`right` boxes up/down, or `mid` combos between two keys    |
+| `arc_scale`           | `float`                                           | `1.0`         | scale the arcs going left/right for `top`/`bottom` or up/down for `left`/`right` aligned combos                                                                                   |
 | `type`                | `str`                                             | `"combo"`     | the styling of the key that corresponds to the [SVG class](keymap_drawer/config.py#L51), see `LayoutKey` definition above                                                         |
 
 [^5]: Key indices start from `0` on the first key position and increase by columns and then rows, corresponding to their ordering in the `layers` field. This matches the `key-positions` property in ZMK combo definitions.

keymap_drawer/config.py

@@ -39,9 +39,6 @@ class DrawConfig(BaseSettings, env_prefix="KEYMAP_", extra="ignore"):
     # curve radius for combo dendrons
     arc_radius: float = 6
 
-    # length multiplier for dendrons
-    arc_scale: float = 1.0
-
     # whether to add a colon after layer name while printing the layer header
     append_colon_to_layer_header: bool = True
 

keymap_drawer/draw.py

@@ -75,8 +75,12 @@ def _draw_glyph(self, p: Point, name: str, legend_type: LegendType, classes: Seq
             f'height="{height}" width="{width}"{self._to_class_str(classes)}/>\n'
         )
 
-    def _draw_arc_dendron(self, p_1: Point, p_2: Point, x_first: bool, shorten: float) -> None:
+    def _draw_arc_dendron(  # pylint: disable=too-many-arguments
+        self, p_1: Point, p_2: Point, x_first: bool, shorten: float, arc_scale: float
+    ) -> None:
         diff = p_2 - p_1
+
+        # check if the points are too close to draw an arc, if so draw a line instead
         if (x_first and abs(diff.x) < self.cfg.arc_radius) or (not x_first and abs(diff.y) < self.cfg.arc_radius):
             self._draw_line_dendron(p_1, p_2, shorten)
             return
@@ -86,11 +90,11 @@ def _draw_arc_dendron(self, p_1: Point, p_2: Point, x_first: bool, shorten: floa
         arc_y = copysign(self.cfg.arc_radius, diff.y)
         clockwise = (diff.x > 0) ^ (diff.y > 0)
         if x_first:
-            line_1 = f"h{self.cfg.arc_scale * diff.x - arc_x}"
+            line_1 = f"h{arc_scale * diff.x - arc_x}"
             line_2 = f"v{diff.y - arc_y - copysign(shorten, diff.y)}"
             clockwise = not clockwise
         else:
-            line_1 = f"v{self.cfg.arc_scale * diff.y - arc_y}"
+            line_1 = f"v{arc_scale * diff.y - arc_y}"
             line_2 = f"h{diff.x - arc_x - copysign(shorten, diff.x)}"
         arc = f"a{self.cfg.arc_radius},{self.cfg.arc_radius} 0 0 {int(clockwise)} {arc_x},{arc_y}"
         self.out.write(f'<path d="{start} {line_1} {arc} {line_2}" class="combo"/>\n')
@@ -225,11 +229,11 @@ def print_combo(self, p_0: Point, combo: ComboSpec) -> None:
                 case "top" | "bottom":
                     for k in p_keys:
                         offset = k.height / 5 if abs(p_0.x + k.pos.x - p.x) < self.cfg.combo_w / 2 else k.height / 3
-                        self._draw_arc_dendron(p, p_0 + k.pos, True, offset)
+                        self._draw_arc_dendron(p, p_0 + k.pos, True, offset, combo.arc_scale)
                 case "left" | "right":
                     for k in p_keys:
                         offset = k.width / 5 if abs(p_0.y + k.pos.y - p.y) < self.cfg.combo_h / 2 else k.width / 3
-                        self._draw_arc_dendron(p, p_0 + k.pos, False, offset)
+                        self._draw_arc_dendron(p, p_0 + k.pos, False, offset, combo.arc_scale)
                 case "mid":
                     for k in p_keys:
                         if combo.dendron is True or abs(p_0 + k.pos - p) >= k.width - 1:

keymap_drawer/keymap.py

@@ -58,6 +58,7 @@ class ComboSpec(BaseModel, allow_population_by_field_name=True):
     offset: float = Field(alias="o", default=0.0)
     dendron: bool | None = Field(alias="d", default=None)
     slide: float | None = Field(alias="s", default=None)
+    arc_scale: float = 1.0
     type: str = "combo"
 
     @classmethod