summaryrefslogtreecommitdiffstats
path: root/share/extensions/spirograph.py
diff options
context:
space:
mode:
Diffstat (limited to '')
-rwxr-xr-xshare/extensions/spirograph.py152
1 files changed, 152 insertions, 0 deletions
diff --git a/share/extensions/spirograph.py b/share/extensions/spirograph.py
new file mode 100755
index 0000000..69e6995
--- /dev/null
+++ b/share/extensions/spirograph.py
@@ -0,0 +1,152 @@
+#! /usr/bin/env python
+# coding=utf-8
+#
+# Copyright (C) 2007 Joel Holdsworth joel@airwebreathe.org.uk
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+#
+
+import math
+import inkex
+
+
+class Spirograph(inkex.EffectExtension):
+ def add_arguments(self, pars):
+ pars.add_argument(
+ "--primaryr", type=float, default=100.0, help="The radius of the outer gear"
+ )
+ pars.add_argument(
+ "--secondaryr",
+ type=float,
+ default=60.0,
+ help="The radius of the inner gear",
+ )
+ pars.add_argument(
+ "--penr",
+ type=float,
+ default=50.0,
+ help="The distance of the pen from the inner gear",
+ )
+ pars.add_argument(
+ "--gearplacement",
+ default="inside",
+ help="Selects whether the gear is inside or outside the ring",
+ )
+ pars.add_argument(
+ "--rotation",
+ type=float,
+ default=0.0,
+ help="The number of degrees to rotate the image by",
+ )
+ pars.add_argument(
+ "--quality",
+ type=int,
+ default=16,
+ help="The quality of the calculated output",
+ )
+
+ def effect(self):
+ self.options.primaryr = self.svg.unittouu(str(self.options.primaryr) + "px")
+ self.options.secondaryr = self.svg.unittouu(str(self.options.secondaryr) + "px")
+ self.options.penr = self.svg.unittouu(str(self.options.penr) + "px")
+
+ if self.options.secondaryr == 0:
+ return
+ if self.options.quality == 0:
+ return
+
+ if self.options.gearplacement.strip(" ").lower().startswith("outside"):
+ a = self.options.primaryr + self.options.secondaryr
+ flip = -1
+ else:
+ a = self.options.primaryr - self.options.secondaryr
+ flip = 1
+
+ ratio = a / self.options.secondaryr
+ if ratio == 0:
+ return
+ scale = 2 * math.pi / (ratio * self.options.quality)
+
+ rotation = -math.pi * self.options.rotation / 180
+
+ new = inkex.PathElement()
+ new.style = inkex.Style(stroke="#000000", fill="none", stroke_width="1.0")
+
+ path_string = ""
+ maxPointCount = 1000
+
+ for i in range(maxPointCount):
+
+ theta = i * scale
+
+ view_center = self.svg.namedview.center
+ x = (
+ a * math.cos(theta + rotation)
+ + self.options.penr * math.cos(ratio * theta + rotation) * flip
+ + view_center[0]
+ )
+ y = (
+ a * math.sin(theta + rotation)
+ - self.options.penr * math.sin(ratio * theta + rotation)
+ + view_center[1]
+ )
+
+ dx = (
+ (
+ -a * math.sin(theta + rotation)
+ - ratio
+ * self.options.penr
+ * math.sin(ratio * theta + rotation)
+ * flip
+ )
+ * scale
+ / 3
+ )
+ dy = (
+ (
+ a * math.cos(theta + rotation)
+ - ratio * self.options.penr * math.cos(ratio * theta + rotation)
+ )
+ * scale
+ / 3
+ )
+
+ if i <= 0:
+ path_string += "M {},{} C {},{} ".format(
+ str(x), str(y), str(x + dx), str(y + dy)
+ )
+ else:
+ path_string += "{},{} {},{}".format(
+ str(x - dx), str(y - dy), str(x), str(y)
+ )
+
+ if (
+ math.fmod(i / ratio, self.options.quality) == 0
+ and i % self.options.quality == 0
+ ):
+ path_string += "Z"
+ break
+ else:
+ if i == maxPointCount - 1:
+ pass # we reached the allowed maximum of points, stop here
+ else:
+ path_string += " C {},{} ".format(str(x + dx), str(y + dy))
+
+ new.path = path_string
+ self.svg.get_current_layer().append(new)
+
+
+if __name__ == "__main__":
+ Spirograph().run()