support rect rx and ry for svg

src/pixie/fileformats/svg.nim

@@ -169,8 +169,32 @@ proc draw(
       width = parseFloat(node.attr("width"))
       height = parseFloat(node.attr("height"))
 
+    var rx, ry: float32
+    if node.attr("rx").len > 0:
+      rx = max(parseFloat(node.attr("rx")), 0)
+    if node.attr("ry").len > 0:
+      ry = max(parseFloat(node.attr("ry")), 0)
+
     var path: Path
-    path.rect(x, y, width, height)
+    if rx > 0 or ry > 0:
+      if rx == 0:
+        rx = ry
+      elif ry == 0:
+        ry = rx
+      rx = min(rx, width / 2)
+      ry = min(ry, height / 2)
+
+      path.moveTo(x + rx, y)
+      path.lineTo(x + width - rx, y)
+      path.ellipticalArcTo(rx, ry, 0, false, true, x + width, y + ry)
+      path.lineTo(x + width, y + height - ry)
+      path.ellipticalArcTo(rx, ry, 0, false, true, x + width - rx, y + height)
+      path.lineTo(x + rx, y + height)
+      path.ellipticalArcTo(rx, ry, 0, false, true, x, y + height - ry)
+      path.lineTo(x, y + ry)
+      path.ellipticalArcTo(rx, ry, 0, false, true, x + rx, y)
+    else:
+      path.rect(x, y, width, height)
 
     if ctx.fill != ColorRGBA():
       img.fillPath(path, ctx.fill, ctx.transform)

src/pixie/paths.nim

@@ -353,6 +353,21 @@ proc arcTo*(path: var Path, ctrl1, ctrl2: Vec2, radius: float32) {.inline.} =
 proc arcTo*(path: var Path, x1, y1, x2, y2, radius: float32) =
   path.arcTo(vec2(x1, y1), vec2(x2, y2), radius)
 
+proc ellipticalArcTo*(
+  path: var Path,
+  rx, ry: float32,
+  xAxisRotation: float32,
+  largeArcFlag, sweepFlag: bool,
+  x, y: float32
+) =
+  path.commands.add(PathCommand(
+    kind: Arc,
+    numbers: @[
+      rx, ry, xAxisRotation, largeArcFlag.float32, sweepFlag.float32, x, y
+    ]
+  ))
+  path.at = vec2(x, y)
+
 proc rect*(path: var Path, x, y, w, h: float32, clockwise = true) =
   if clockwise:
     path.moveTo(x, y)