Adding upstream version 1.0.2.upstream/1.0.2upstream

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

1 files changed, 188 insertions, 0 deletions

diff --git a/share/extensions/triangle.py b/share/extensions/triangle.py
new file mode 100755
index 0000000..dc8d6f2
--- /dev/null
+++ b/share/extensions/triangle.py
@@ -0,0 +1,188 @@
+#!/usr/bin/env python
+# coding=utf-8
+#
+# Copyright (C) 2007 John Beard john.j.beard@gmail.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.
+#
+"""
+This extension allows you to draw a triangle given certain information
+ about side length or angles.
+
+Measurements of the triangle
+
+         C(x_c,y_c)
+        /`__
+       / a_c``--__
+      /           ``--__ s_a
+ s_b /                  ``--__
+    /a_a                    a_b`--__
+   /--------------------------------``B(x_b, y_b)
+  A(x_a,y_a)         s_b
+"""
+
+import sys
+from math import acos, asin, cos, pi, sin, sqrt
+
+import inkex
+
+X, Y = range(2)
+
+def draw_SVG_tri(point1, point2, point3, offset, width, name, parent):
+    style = {'stroke': '#000000', 'stroke-width': str(width), 'fill': 'none'}
+    elem = parent.add(inkex.PathElement())
+    elem.update(**{
+        'style': style,
+        'inkscape:label': name,
+         'd': 'M ' + str(point1[X] + offset[X]) + ',' + str(point1[Y] + offset[Y]) +
+              ' L ' + str(point2[X] + offset[X]) + ',' + str(point2[Y] + offset[Y]) +
+              ' L ' + str(point3[X] + offset[X]) + ',' + str(point3[Y] + offset[Y]) +
+              ' L ' + str(point1[X] + offset[X]) + ',' + str(point1[Y] + offset[Y]) + ' z'})
+    return elem
+
+
+def angle_from_3_sides(a, b, c):  # return the angle opposite side c
+    cosx = (a * a + b * b - c * c) / (2 * a * b)  # use the cosine rule
+    return acos(cosx)
+
+
+def third_side_from_enclosed_angle(s_a, s_b, a_c):  # return the side opposite a_c
+    c_squared = s_a * s_a + s_b * s_b - 2 * s_a * s_b * cos(a_c)
+    if c_squared > 0:
+        return sqrt(c_squared)
+    else:
+        return 0  # means we have an invalid or degenerate triangle (zero is caught at the drawing stage)
+
+
+def pt_on_circ(radius, angle):  # return the x,y coordinate of the polar coordinate
+    x = radius * cos(angle)
+    y = radius * sin(angle)
+    return [x, y]
+
+
+def v_add(point1, point2):  # add an offset to coordinates
+    return [point1[X] + point2[X], point1[Y] + point2[Y]]
+
+
+def is_valid_tri_from_sides(a, b, c):  # check whether triangle with sides a,b,c is valid
+    return (a + b) > c and (a + c) > b and (b + c) > a and a > 0 and b > 0 and c > 0  # two sides must always be greater than the third
+    # no zero-length sides, no degenerate case
+
+
+def draw_tri_from_3_sides(s_a, s_b, s_c, offset, width, parent):  # draw a triangle from three sides (with a given offset
+    if is_valid_tri_from_sides(s_a, s_b, s_c):
+        a_b = angle_from_3_sides(s_a, s_c, s_b)
+
+        a = (0, 0)  # a is the origin
+        b = v_add(a, (s_c, 0))  # point B is horizontal from the origin
+        c = v_add(b, pt_on_circ(s_a, pi - a_b))  # get point c
+        c[1] = -c[1]
+
+        offx = max(b[0], c[0]) / 2  # b or c could be the furthest right
+        offy = c[1] / 2  # c is the highest point
+        offset = (offset[0] - offx, offset[1] - offy)  # add the centre of the triangle to the offset
+
+        draw_SVG_tri(a, b, c, offset, width, 'Triangle', parent)
+    else:
+        inkex.errormsg('Invalid Triangle Specifications.')
+
+
+class Triangle(inkex.EffectExtension):
+    def add_arguments(self, pars):
+        pars.add_argument("--s_a", type=float, default=100.0, help="Side Length a")
+        pars.add_argument("--s_b", type=float, default=100.0, help="Side Length b")
+        pars.add_argument("--s_c", type=float, default=100.0, help="Side Length c")
+        pars.add_argument("--a_a", type=float, default=60.0, help="Angle a")
+        pars.add_argument("--a_b", type=float, default=30.0, help="Angle b")
+        pars.add_argument("--a_c", type=float, default=90.0, help="Angle c")
+        pars.add_argument("--mode", default='3_sides', help="Side Length c")
+
+    def effect(self):
+        tri = self.svg.get_current_layer()
+        offset = self.svg.namedview.center
+        self.options.s_a = self.svg.unittouu(str(self.options.s_a) + 'px')
+        self.options.s_b = self.svg.unittouu(str(self.options.s_b) + 'px')
+        self.options.s_c = self.svg.unittouu(str(self.options.s_c) + 'px')
+        stroke_width = self.svg.unittouu('2px')
+
+        if self.options.mode == '3_sides':
+            s_a = self.options.s_a
+            s_b = self.options.s_b
+            s_c = self.options.s_c
+            draw_tri_from_3_sides(s_a, s_b, s_c, offset, stroke_width, tri)
+
+        elif self.options.mode == 's_ab_a_c':
+            s_a = self.options.s_a
+            s_b = self.options.s_b
+            a_c = self.options.a_c * pi / 180  # in rad
+
+            s_c = third_side_from_enclosed_angle(s_a, s_b, a_c)
+            draw_tri_from_3_sides(s_a, s_b, s_c, offset, stroke_width, tri)
+
+        elif self.options.mode == 's_ab_a_a':
+            s_a = self.options.s_a
+            s_b = self.options.s_b
+            a_a = self.options.a_a * pi / 180  # in rad
+
+            if (a_a < pi / 2.0) and (s_a < s_b) and (s_a > s_b * sin(a_a)):  # this is an ambiguous case
+                ambiguous = True  # we will give both answers
+            else:
+                ambiguous = False
+
+            sin_a_b = s_b * sin(a_a) / s_a
+
+            if (sin_a_b <= 1) and (sin_a_b >= -1):  # check the solution is possible
+                a_b = asin(sin_a_b)  # acute solution
+                a_c = pi - a_a - a_b
+                error = False
+            else:
+                sys.stderr.write('Error:Invalid Triangle Specifications.\n')  # signal an error
+                error = True
+
+            if not error and (a_b < pi) and (a_c < pi):  # check that the solution is valid, if so draw acute solution
+                s_c = third_side_from_enclosed_angle(s_a, s_b, a_c)
+                draw_tri_from_3_sides(s_a, s_b, s_c, offset, stroke_width, tri)
+
+            if not error and ((a_b > pi) or (a_c > pi) or ambiguous):  # we want the obtuse solution
+                a_b = pi - a_b
+                a_c = pi - a_a - a_b
+                s_c = third_side_from_enclosed_angle(s_a, s_b, a_c)
+                draw_tri_from_3_sides(s_a, s_b, s_c, offset, stroke_width, tri)
+
+        elif self.options.mode == 's_a_a_ab':
+            s_a = self.options.s_a
+            a_a = self.options.a_a * pi / 180  # in rad
+            a_b = self.options.a_b * pi / 180  # in rad
+
+            a_c = pi - a_a - a_b
+            s_b = s_a * sin(a_b) / sin(a_a)
+            s_c = s_a * sin(a_c) / sin(a_a)
+
+            draw_tri_from_3_sides(s_a, s_b, s_c, offset, stroke_width, tri)
+
+        elif self.options.mode == 's_c_a_ab':
+            s_c = self.options.s_c
+            a_a = self.options.a_a * pi / 180  # in rad
+            a_b = self.options.a_b * pi / 180  # in rad
+
+            a_c = pi - a_a - a_b
+            s_a = s_c * sin(a_a) / sin(a_c)
+            s_b = s_c * sin(a_b) / sin(a_c)
+
+            draw_tri_from_3_sides(s_a, s_b, s_c, offset, stroke_width, tri)
+
+
+if __name__ == '__main__':
+    Triangle().run()