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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 16:29:01 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 16:29:01 +0000 |
commit | 35a96bde514a8897f6f0fcc41c5833bf63df2e2a (patch) | |
tree | 657d15a03cc46bd099fc2c6546a7a4ad43815d9f /share/extensions/draw_from_triangle.py | |
parent | Initial commit. (diff) | |
download | inkscape-35a96bde514a8897f6f0fcc41c5833bf63df2e2a.tar.xz inkscape-35a96bde514a8897f6f0fcc41c5833bf63df2e2a.zip |
Adding upstream version 1.0.2.upstream/1.0.2upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'share/extensions/draw_from_triangle.py')
-rwxr-xr-x | share/extensions/draw_from_triangle.py | 395 |
1 files changed, 395 insertions, 0 deletions
diff --git a/share/extensions/draw_from_triangle.py b/share/extensions/draw_from_triangle.py new file mode 100755 index 0000000..32de00a --- /dev/null +++ b/share/extensions/draw_from_triangle.py @@ -0,0 +1,395 @@ +#!/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 various triangle constructions +It requires a path to be selected +It will use the first three nodes of this path + +Dimensions of a triangle__ + + /`__ + / a_c``--__ + / ``--__ s_a +s_b / ``--__ + /a_a a_b`--__ + /--------------------------------``B + A s_b +""" + +from math import acos, cos, pi, sin, sqrt, tan + +import inkex +from inkex import PathElement, Circle + +(X, Y) = range(2) + +# DRAWING ROUTINES + +# draw an SVG triangle given in trilinar coords +def draw_SVG_circle(rad, centre, params, style, name, parent): # draw an SVG circle with a given radius as trilinear coordinates + if rad == 0: # we want a dot + r = style.d_rad # get the dot width from the style + circ_style = {'stroke': style.d_col, 'stroke-width': str(style.d_th), 'fill': style.d_fill} + else: + r = rad # use given value + circ_style = {'stroke': style.c_col, 'stroke-width': str(style.c_th), 'fill': style.c_fill} + + cx, cy = get_cartesian_pt(centre, params) + circ_attribs = {'cx': str(cx), 'cy': str(cy), 'r': str(r)} + elem = parent.add(Circle(**circ_attribs)) + elem.style = circ_style + elem.label = name + + +# draw an SVG triangle given in trilinar coords +def draw_SVG_tri(vert_mat, params, style, name, parent): + p1, p2, p3 = get_cartesian_tri(vert_mat, params) # get the vertex matrix in cartesian points + elem = parent.add(PathElement()) + elem.path = 'M ' + str(p1[0]) + ',' + str(p1[1]) +\ + ' L ' + str(p2[0]) + ',' + str(p2[1]) +\ + ' L ' + str(p3[0]) + ',' + str(p3[1]) +\ + ' L ' + str(p1[0]) + ',' + str(p1[1]) + ' z' + elem.style = {'stroke': style.l_col, 'stroke-width': str(style.l_th), 'fill': style.l_fill} + elem.label = name + + +# draw an SVG line segment between the given (raw) points +def draw_SVG_line(a, b, style, name, parent): + (x1, y1) = a + (x2, y2) = b + line = parent.add(PathElement()) + line.style = {'stroke': style.l_col, 'stroke-width': str(style.l_th), 'fill': style.l_fill} + line.path = 'M ' + str(x1) + ',' + str(y1) + ' L ' + str(x2) + ',' + str(y2) + line.lavel = name + + +# lines from each vertex to a corresponding point in trilinears +def draw_vertex_lines(vert_mat, params, width, name, parent): + for i in range(3): + oppositepoint = get_cartesian_pt(vert_mat[i], params) + draw_SVG_line(params[3][-i % 3], oppositepoint, width, name + ':' + str(i), parent) + + +# MATHEMATICAL ROUTINES + +def distance(a, b): + """find the pythagorean distance""" + (x0, y0) = a + (x1, y1) = b + return sqrt((x0 - x1) * (x0 - x1) + (y0 - y1) * (y0 - y1)) + + +def vector_from_to(a, b): + """get the vector from (x0,y0) to (x1,y1)""" + return b[X] - a[X], b[Y], a[Y] + + +def get_cartesian_pt(t, p): # get the cartesian coordinates from a trilinear set + denom = p[0][0] * t[0] + p[0][1] * t[1] + p[0][2] * t[2] + c1 = p[0][1] * t[1] / denom + c2 = p[0][2] * t[2] / denom + return c1 * p[2][1][0] + c2 * p[2][0][0], c1 * p[2][1][1] + c2 * p[2][0][1] + + +def get_cartesian_tri(arg, params): + """get the cartesian points from a trilinear vertex matrix""" + (t11, t12, t13), (t21, t22, t23), (t31, t32, t33) = arg + p1 = get_cartesian_pt((t11, t12, t13), params) + p2 = get_cartesian_pt((t21, t22, t23), params) + p3 = get_cartesian_pt((t31, t32, t33), params) + return p1, p2, p3 + + +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 translate_string(string, os): # translates s_a, a_a, etc to params[x][y], with cyclic offset + string = string.replace('s_a', 'params[0][' + str((os + 0) % 3) + ']') # replace with ref. to the relvant values, + string = string.replace('s_b', 'params[0][' + str((os + 1) % 3) + ']') # cycled by i + string = string.replace('s_c', 'params[0][' + str((os + 2) % 3) + ']') + string = string.replace('a_a', 'params[1][' + str((os + 0) % 3) + ']') + string = string.replace('a_b', 'params[1][' + str((os + 1) % 3) + ']') + string = string.replace('a_c', 'params[1][' + str((os + 2) % 3) + ']') + string = string.replace('area', 'params[4][0]') + string = string.replace('semiperim', 'params[4][1]') + return string + + +def pt_from_tcf(tcf, params): # returns a trilinear triplet from a triangle centre function + trilin_pts = [] # will hold the final points + for i in range(3): + temp = tcf # read in the tcf + temp = translate_string(temp, i) + func = eval('lambda params: ' + temp.strip('"')) # the function leading to the trilinar element + trilin_pts.append(func(params)) # evaluate the function for the first trilinear element + return trilin_pts + + +# SVG DATA PROCESSING + +def get_n_points_from_path(node, n): + """returns a list of first n points (x,y) in an SVG path-representing node""" + points = list(node.path.control_points) + if len(points) < 3: + return [] + return points[:3] + +# EXTRA MATHS FUNCTIONS +def sec(x): # secant(x) + if x == pi / 2 or x == -pi / 2 or x == 3 * pi / 2 or x == -3 * pi / 2: # sec(x) is undefined + return 100000000000 + else: + return 1 / cos(x) + + +def csc(x): # cosecant(x) + if x == 0 or x == pi or x == 2 * pi or x == -2 * pi: # csc(x) is undefined + return 100000000000 + else: + return 1 / sin(x) + + +def cot(x): # cotangent(x) + if x == 0 or x == pi or x == 2 * pi or x == -2 * pi: # cot(x) is undefined + return 100000000000 + else: + return 1 / tan(x) + + +class Style(object): # container for style information + def __init__(self, svg): + # dot markers + self.d_rad = svg.unittouu('4px') # dot marker radius + self.d_th = svg.unittouu('2px') # stroke width + self.d_fill = '#aaaaaa' # fill colour + self.d_col = '#000000' # stroke colour + + # lines + self.l_th = svg.unittouu('2px') + self.l_fill = 'none' + self.l_col = '#000000' + + # circles + self.c_th = svg.unittouu('2px') + self.c_fill = 'none' + self.c_col = '#000000' + + +class DrawFromTriangle(inkex.EffectExtension): + def add_arguments(self, pars): + pars.add_argument("--tab") + # PRESET POINT OPTIONS + pars.add_argument("--circumcircle", type=inkex.Boolean, default=False) + pars.add_argument("--circumcentre", type=inkex.Boolean, default=False) + pars.add_argument("--incircle", type=inkex.Boolean, default=False) + pars.add_argument("--incentre", type=inkex.Boolean, default=False) + pars.add_argument("--contact_tri", type=inkex.Boolean, default=False) + pars.add_argument("--excircles", type=inkex.Boolean, default=False) + pars.add_argument("--excentres", type=inkex.Boolean, default=False) + pars.add_argument("--extouch_tri", type=inkex.Boolean, default=False) + pars.add_argument("--excentral_tri", type=inkex.Boolean, default=False) + pars.add_argument("--orthocentre", type=inkex.Boolean, default=False) + pars.add_argument("--orthic_tri", type=inkex.Boolean, default=False) + pars.add_argument("--altitudes", type=inkex.Boolean, default=False) + pars.add_argument("--anglebisectors", type=inkex.Boolean, default=False) + pars.add_argument("--centroid", type=inkex.Boolean, default=False) + pars.add_argument("--ninepointcentre", type=inkex.Boolean, default=False) + pars.add_argument("--ninepointcircle", type=inkex.Boolean, default=False) + pars.add_argument("--symmedians", type=inkex.Boolean, default=False) + pars.add_argument("--sym_point", type=inkex.Boolean, default=False) + pars.add_argument("--sym_tri", type=inkex.Boolean, default=False) + pars.add_argument("--gergonne_pt", type=inkex.Boolean, default=False) + pars.add_argument("--nagel_pt", type=inkex.Boolean, default=False) + # CUSTOM POINT OPTIONS + pars.add_argument("--mode", default='trilin') + pars.add_argument("--cust_str", default='s_a') + pars.add_argument("--cust_pt", type=inkex.Boolean, default=False) + pars.add_argument("--cust_radius", type=inkex.Boolean, default=False) + pars.add_argument("--radius", default='s_a') + pars.add_argument("--isogonal_conj", type=inkex.Boolean, default=False) + pars.add_argument("--isotomic_conj", type=inkex.Boolean, default=False) + + def effect(self): + so = self.options # shorthand + + pts = [] # initialise in case nothing is selected and following loop is not executed + for node in self.svg.selection.filter(inkex.PathElement).values(): + # find the (x,y) coordinates of the first 3 points of the path + pts = get_n_points_from_path(node, 3) + + if len(pts) == 3: # if we have right number of nodes, else skip and end program + st = Style(self.svg) # style for dots, lines and circles + + # CREATE A GROUP TO HOLD ALL GENERATED ELEMENTS IN + # Hold relative to point A (pt[0]) + layer = self.svg.get_current_layer().add(inkex.Group.new('TriangleElements')) + layer.transform = 'translate(' + str(pts[0][0]) + ',' + str(pts[0][1]) + ')' + + # GET METRICS OF THE TRIANGLE + # vertices in the local coordinates (set pt[0] to be the origin) + vtx = [[0, 0], + [pts[1][0] - pts[0][0], pts[1][1] - pts[0][1]], + [pts[2][0] - pts[0][0], pts[2][1] - pts[0][1]]] + + s_a = distance(vtx[1], vtx[2]) # get the scalar side lengths + s_b = distance(vtx[0], vtx[1]) + s_c = distance(vtx[0], vtx[2]) + sides = (s_a, s_b, s_c) # side list for passing to functions easily and for indexing + + a_a = angle_from_3_sides(s_b, s_c, s_a) # angles in radians + a_b = angle_from_3_sides(s_a, s_c, s_b) + a_c = angle_from_3_sides(s_a, s_b, s_c) + angles = (a_a, a_b, a_c) + + ab = vector_from_to(vtx[0], vtx[1]) # vector from a to b + ac = vector_from_to(vtx[0], vtx[2]) # vector from a to c + bc = vector_from_to(vtx[1], vtx[2]) # vector from b to c + vecs = (ab, ac) # vectors for finding cartesian point from trilinears + + semiperim = (s_a + s_b + s_c) / 2.0 # semiperimeter + area = sqrt(semiperim * (semiperim - s_a) * (semiperim - s_b) * (semiperim - s_c)) # area of the triangle by heron's formula + uvals = (area, semiperim) # useful values + + params = (sides, angles, vecs, vtx, uvals) # all useful triangle parameters in one object + + # BEGIN DRAWING + if so.circumcentre or so.circumcircle: + r = s_a * s_b * s_c / (4 * area) + pt = (cos(a_a), cos(a_b), cos(a_c)) + if so.circumcentre: + draw_SVG_circle(0, pt, params, st, 'Circumcentre', layer) + if so.circumcircle: + draw_SVG_circle(r, pt, params, st, 'Circumcircle', layer) + + if so.incentre or so.incircle: + pt = [1, 1, 1] + if so.incentre: + draw_SVG_circle(0, pt, params, st, 'Incentre', layer) + if so.incircle: + r = area / semiperim + draw_SVG_circle(r, pt, params, st, 'Incircle', layer) + + if so.contact_tri: + t1 = s_b * s_c / (-s_a + s_b + s_c) + t2 = s_a * s_c / (s_a - s_b + s_c) + t3 = s_a * s_b / (s_a + s_b - s_c) + v_mat = ((0, t2, t3), (t1, 0, t3), (t1, t2, 0)) + draw_SVG_tri(v_mat, params, st, 'ContactTriangle', layer) + + if so.extouch_tri: + t1 = (-s_a + s_b + s_c) / s_a + t2 = (s_a - s_b + s_c) / s_b + t3 = (s_a + s_b - s_c) / s_c + v_mat = ((0, t2, t3), (t1, 0, t3), (t1, t2, 0)) + draw_SVG_tri(v_mat, params, st, 'ExtouchTriangle', layer) + + if so.orthocentre: + pt = pt_from_tcf('cos(a_b)*cos(a_c)', params) + draw_SVG_circle(0, pt, params, st, 'Orthocentre', layer) + + if so.orthic_tri: + v_mat = [[0, sec(a_b), sec(a_c)], [sec(a_a), 0, sec(a_c)], [sec(a_a), sec(a_b), 0]] + draw_SVG_tri(v_mat, params, st, 'OrthicTriangle', layer) + + if so.centroid: + pt = [1 / s_a, 1 / s_b, 1 / s_c] + draw_SVG_circle(0, pt, params, st, 'Centroid', layer) + + if so.ninepointcentre or so.ninepointcircle: + pt = [cos(a_b - a_c), cos(a_c - a_a), cos(a_a - a_b)] + if so.ninepointcentre: + draw_SVG_circle(0, pt, params, st, 'NinePointCentre', layer) + if so.ninepointcircle: + r = s_a * s_b * s_c / (8 * area) + draw_SVG_circle(r, pt, params, st, 'NinePointCircle', layer) + + if so.altitudes: + v_mat = [[0, sec(a_b), sec(a_c)], [sec(a_a), 0, sec(a_c)], [sec(a_a), sec(a_b), 0]] + draw_vertex_lines(v_mat, params, st, 'Altitude', layer) + + if so.anglebisectors: + v_mat = ((0, 1, 1), (1, 0, 1), (1, 1, 0)) + draw_vertex_lines(v_mat, params, st, 'AngleBisectors', layer) + + if so.excircles or so.excentres or so.excentral_tri: + v_mat = ((-1, 1, 1), (1, -1, 1), (1, 1, -1)) + if so.excentral_tri: + draw_SVG_tri(v_mat, params, st, 'ExcentralTriangle', layer) + for i in range(3): + if so.excircles: + r = area / (semiperim - sides[i]) + draw_SVG_circle(r, v_mat[i], params, st, 'Excircle:' + str(i), layer) + if so.excentres: + draw_SVG_circle(0, v_mat[i], params, st, 'Excentre:' + str(i), layer) + + if so.sym_tri or so.symmedians: + v_mat = ((0, s_b, s_c), (s_a, 0, s_c), (s_a, s_b, 0)) + if so.sym_tri: + draw_SVG_tri(v_mat, params, st, 'SymmedialTriangle', layer) + if so.symmedians: + draw_vertex_lines(v_mat, params, st, 'Symmedian', layer) + + if so.sym_point: + pt = (s_a, s_b, s_c) + draw_SVG_circle(0, pt, params, st, 'SymmmedianPoint', layer) + + if so.gergonne_pt: + pt = pt_from_tcf('1/(s_a*(s_b+s_c-s_a))', params) + draw_SVG_circle(0, pt, params, st, 'GergonnePoint', layer) + + if so.nagel_pt: + pt = pt_from_tcf('(s_b+s_c-s_a)/s_a', params) + draw_SVG_circle(0, pt, params, st, 'NagelPoint', layer) + + if so.cust_pt or so.cust_radius or so.isogonal_conj or so.isotomic_conj: + pt = [] # where we will store the point in trilinears + if so.mode == 'trilin': # if we are receiving from trilinears + for i in range(3): + strings = so.cust_str.split(':') # get split string + strings[i] = translate_string(strings[i], 0) + func = eval('lambda params: ' + strings[i].strip('"')) # the function leading to the trilinar element + pt.append(func(params)) # evaluate the function for the trilinear element + else: # we need a triangle function + string = so.cust_str # don't need to translate, as the pt_from_tcf function does that for us + pt = pt_from_tcf(string, params) # get the point from the tcf directly + + if so.cust_pt: # draw the point + draw_SVG_circle(0, pt, params, st, 'CustomTrilinearPoint', layer) + if so.cust_radius: # draw the circle with given radius + strings = translate_string(so.radius, 0) + func = eval('lambda params: ' + strings.strip('"')) # the function leading to the radius + r = func(params) + draw_SVG_circle(r, pt, params, st, 'CustomTrilinearCircle', layer) + if so.isogonal_conj: + isogonal = [0, 0, 0] + for i in range(3): + isogonal[i] = 1 / pt[i] + draw_SVG_circle(0, isogonal, params, st, 'CustomIsogonalConjugate', layer) + if so.isotomic_conj: + isotomic = [0, 0, 0] + for i in range(3): + isotomic[i] = 1 / (params[0][i] * params[0][i] * pt[i]) + draw_SVG_circle(0, isotomic, params, st, 'CustomIsotomicConjugate', layer) + + +if __name__ == '__main__': + DrawFromTriangle().run() |