1 files changed, 144 insertions, 0 deletions
diff --git a/share/extensions/edge3d.py b/share/extensions/edge3d.py
new file mode 100755
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+++ b/share/extensions/edge3d.py
@@ -0,0 +1,144 @@
+#!/usr/bin/env python
+# coding=utf-8
+#
+# Copyright (C) 2007 Terry Brown, terry_n_brown@yahoo.com
+#
+# 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.
+#
+
+from math import atan2, degrees
+
+import inkex
+from inkex import ClipPath, Filter
+
+
+class Edge3D(inkex.EffectExtension):
+    """Generate a 3d edge"""
+
+    def add_arguments(self, pars):
+        pars.add_argument(
+            "--angle",
+            type=float,
+            default=45.0,
+            help="angle of illumination, clockwise, 45 = upper right",
+        )
+        pars.add_argument(
+            "--stddev", type=float, default=5.0, help="Gaussian Blur stdDeviation"
+        )
+        pars.add_argument(
+            "--blurheight", type=float, default=2.0, help="Gaussian Blur height"
+        )
+        pars.add_argument(
+            "--blurwidth", type=float, default=2.0, help="Gaussian Blur width"
+        )
+        pars.add_argument("--shades", type=int, default=2, help="Number of shades")
+        pars.add_argument("--bw", type=inkex.Boolean, help="Black and white")
+        pars.add_argument(
+            "--thick", type=float, default=10.0, help="stroke-width for pieces"
+        )
+
+    def angle_between(self, start, end, angle):
+        """Return true if angle (degrees, clockwise, 0 = up/north) is between
+        angles start and end"""
+
+        def f(x):
+            """Add 360 to x if x is less than 0"""
+            if x < 0:
+                return x + 360.0
+            return x
+
+        # rotate all inputs by start, => start = 0
+        a = f(f(angle) - f(start))
+        e = f(f(end) - f(start))
+        return a < e
+
+    def effect(self):
+        """Check each internode to see if it's in one of the wedges
+        for the current shade.  shade is a floating point 0-1 white-black"""
+        # size of a wedge for shade i, wedges come in pairs
+        delta = 360.0 / self.options.shades / 2.0
+        for node in self.svg.selection.filter(inkex.PathElement):
+            array = node.path.to_arrays()
+            group = None
+            filt = None
+            for shade in range(0, self.options.shades):
+                if self.options.bw and 0 < shade < self.options.shades - 1:
+                    continue
+                start = [self.options.angle - delta * (shade + 1)]
+                end = [self.options.angle - delta * shade]
+                start.append(self.options.angle + delta * shade)
+                end.append(self.options.angle + delta * (shade + 1))
+                level = float(shade) / float(self.options.shades - 1)
+                last = []
+                result = []
+                for cmd, params in array:
+                    if cmd == "Z":
+                        last = []
+                        continue
+                    if last:
+                        if cmd == "V":
+                            point = [last[0], params[-2:][0]]
+                        elif cmd == "H":
+                            point = [params[-2:][0], last[1]]
+                        else:
+                            point = params[-2:]
+                        ang = degrees(atan2(point[0] - last[0], point[1] - last[1]))
+                        if self.angle_between(
+                            start[0], end[0], ang
+                        ) or self.angle_between(start[1], end[1], ang):
+                            result.append(("M", last))
+                            result.append((cmd, params))
+                        ref = point
+                    else:
+                        ref = params[-2:]
+                    last = ref
+                if result:
+                    if group is None:
+                        group, filt = self.get_group(node)
+                    new_node = group.add(node.copy())
+                    new_node.path = result
+                    new_node.style = "fill:none;stroke-opacity:1;stroke-width:10"
+                    new_node.style += filt
+                    col = 255 - int(255.0 * level)
+                    new_node.style["stroke"] = inkex.Color((col, col, col))
+
+    def get_group(self, node):
+        """
+        make a clipped group, clip with clone of original, clipped group
+        include original and group of paths.
+        """
+        defs = self.svg.defs
+        clip = defs.add(ClipPath())
+        new_node = clip.add(node.copy())
+        clip_group = node.getparent().add(inkex.Group())
+        group = clip_group.add(inkex.Group())
+        clip_group.set("clip-path", clip.get_id(as_url=2))
+
+        # make a blur filter reference by the style of each path
+        filt = defs.add(
+            Filter(
+                x="-0.5",
+                y="-0.5",
+                height=str(self.options.blurheight),
+                width=str(self.options.blurwidth),
+            )
+        )
+
+        filt.add_primitive("feGaussianBlur", stdDeviation=self.options.stddev)
+        return group, inkex.Style(filter=filt.get_id(as_url=2))
+
+
+if __name__ == "__main__":
+    Edge3D().run()