Merge pull request #223 from googlefonts/ungroup

Restructure processing of clip, transform, and group

README.md

@@ -8,8 +8,10 @@ Tool to simplify SVGs. Converts an input svg into a "pico" svg:
 
 * Exactly 1 `<defs>` element, first child of root
 * Only gradients defined under `<defs>`
-* Only `<path>` elements without stroke or clipping after the initial `<defs>`
+* After the initial `<defs>`, only `<g>` and `<path>`
+ * `<g>` is eliminated when possible, but may be retained for opacity
 * Only absolute coordinates
+* Only commands that specify full coordinates, no shorthand (H, S, etc)
 
 Clip paths and strokes are rendered into equivalent paths using [Skia](https://skia.org/) via [skia-pathops](https:/fonttools/skia-pathops), `<use>` references are materialized, etc.
 

src/picosvg/geometric_types.py

@@ -143,3 +143,8 @@ def _overlap(start1, end1, start2, end2):
  if x1 != x2 and y1 != y2:
  return Rect(x1, y1, x2 - x1, y2 - y1)
  return None
+
+ def normalized_diagonal(self):
+ # used for computing percentages of lengths relative to the SVG viewport:
+ # https://www.w3.org/TR/SVG2/coords.html#Units
+ return math.hypot(self.w, self.h) / math.sqrt(2)