Adding upstream version 1.2.2.upstream/1.2.2upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 181 insertions, 0 deletions

diff --git a/share/extensions/render_gears.py b/share/extensions/render_gears.py
new file mode 100755
index 0000000..b160bc0
--- /dev/null
+++ b/share/extensions/render_gears.py
@@ -0,0 +1,181 @@
+#!/usr/bin/env python
+#
+# Copyright (C) 2007 Aaron Spike  (aaron @ ekips.org)
+# Copyright (C) 2007 Tavmjong Bah (tavmjong @ free.fr)
+#
+# 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.
+#
+"""
+Generate gears in SVG
+"""
+
+from math import acos, cos, pi, radians, sin, sqrt
+
+import inkex
+from inkex import PathElement
+
+
+def involute_intersect_angle(Rb, R):
+    Rb, R = float(Rb), float(R)
+    return (sqrt(R**2 - Rb**2) / Rb) - (acos(Rb / R))
+
+
+def point_on_circle(radius, angle):
+    x = radius * cos(angle)
+    y = radius * sin(angle)
+    return x, y
+
+
+def points_to_svgd(p):
+    f = p[0]
+    p = p[1:]
+    svgd = "M{:.5f},{:.5f}".format(f[0], f[1])
+    for x in p:
+        svgd += " L{:.5f},{:.5f}".format(x[0], x[1])
+    svgd += "z"
+    return svgd
+
+
+class Gears(inkex.GenerateExtension):
+    container_label = "Rendered Gears"
+
+    def add_arguments(self, pars):
+        pars.add_argument("--teeth", type=int, default=24, help="Number of teeth")
+        pars.add_argument("--pitch", type=float, default=20.0, help="Circular Pitch")
+        pars.add_argument("--angle", type=float, default=20.0, help="Pressure Angle")
+        pars.add_argument(
+            "--centerdiameter", type=float, default=20.0, help="Diameter of hole"
+        )
+        pars.add_argument(
+            "--unit", default="px", help="unit for pitch and center diameter"
+        )
+
+    def generate(self):
+        teeth = self.options.teeth
+        pitch = self.svg.unittouu(str(self.options.pitch) + self.options.unit)
+        angle = (
+            self.options.angle
+        )  # Angle of tangent to tooth at circular pitch wrt radial line.
+        centerdiameter = self.svg.unittouu(
+            str(self.options.centerdiameter) + self.options.unit
+        )
+
+        # print >>sys.stderr, "Teeth: %s\n"        % teeth
+
+        two_pi = 2.0 * pi
+
+        # Pitch (circular pitch): Length of the arc from one tooth to the next)
+        # Pitch diameter: Diameter of pitch circle.
+        pitch_diameter = float(teeth) * pitch / pi
+        pitch_radius = pitch_diameter / 2.0
+
+        # Base Circle
+        base_diameter = pitch_diameter * cos(radians(angle))
+        base_radius = base_diameter / 2.0
+
+        # Diametrial pitch: Number of teeth per unit length.
+        pitch_diametrial = float(teeth) / pitch_diameter
+
+        # Addendum: Radial distance from pitch circle to outside circle.
+        addendum = 1.0 / pitch_diametrial
+
+        # Outer Circle
+        outer_radius = pitch_radius + addendum
+        outer_diameter = outer_radius * 2.0
+
+        # Tooth thickness: Tooth width along pitch circle.
+        tooth = (pi * pitch_diameter) / (2.0 * float(teeth))
+
+        # Undercut?
+        undercut = 2.0 / (sin(radians(angle)) ** 2)
+        needs_undercut = teeth < undercut
+
+        # Clearance: Radial distance between top of tooth on one gear to bottom of gap on another.
+        clearance = 0.0
+
+        # Dedendum: Radial distance from pitch circle to root diameter.
+        dedendum = addendum + clearance
+
+        # Root diameter: Diameter of bottom of tooth spaces.
+        root_radius = pitch_radius - dedendum
+        root_diameter = root_radius * 2.0
+
+        half_thick_angle = two_pi / (4.0 * float(teeth))
+        pitch_to_base_angle = involute_intersect_angle(base_radius, pitch_radius)
+        pitch_to_outer_angle = (
+            involute_intersect_angle(base_radius, outer_radius) - pitch_to_base_angle
+        )
+
+        centers = [(x * two_pi / float(teeth)) for x in range(teeth)]
+
+        points = []
+
+        for c in centers:
+
+            # Angles
+            pitch1 = c - half_thick_angle
+            base1 = pitch1 - pitch_to_base_angle
+            outer1 = pitch1 + pitch_to_outer_angle
+
+            pitch2 = c + half_thick_angle
+            base2 = pitch2 + pitch_to_base_angle
+            outer2 = pitch2 - pitch_to_outer_angle
+
+            # Points
+            b1 = point_on_circle(base_radius, base1)
+            p1 = point_on_circle(pitch_radius, pitch1)
+            o1 = point_on_circle(outer_radius, outer1)
+
+            b2 = point_on_circle(base_radius, base2)
+            p2 = point_on_circle(pitch_radius, pitch2)
+            o2 = point_on_circle(outer_radius, outer2)
+
+            if root_radius > base_radius:
+                pitch_to_root_angle = pitch_to_base_angle - involute_intersect_angle(
+                    base_radius, root_radius
+                )
+                root1 = pitch1 - pitch_to_root_angle
+                root2 = pitch2 + pitch_to_root_angle
+                r1 = point_on_circle(root_radius, root1)
+                r2 = point_on_circle(root_radius, root2)
+                p_tmp = [r1, p1, o1, o2, p2, r2]
+            else:
+                r1 = point_on_circle(root_radius, base1)
+                r2 = point_on_circle(root_radius, base2)
+                p_tmp = [r1, b1, p1, o1, o2, p2, b2, r2]
+
+            points.extend(p_tmp)
+
+        path = points_to_svgd(points)
+
+        # Create SVG Path for gear
+        style = {
+            "stroke": "#000000",
+            "fill": "none",
+            "stroke-width": str(self.svg.unittouu("1px")),
+        }
+        gear = PathElement()
+        gear.style = style
+        gear.path = path
+        yield gear
+
+        if centerdiameter > 0.0:
+            arc = PathElement.arc((0, 0), centerdiameter / 2)
+            arc.style = style
+            yield arc
+
+
+if __name__ == "__main__":
+    Gears().run()