From cca66b9ec4e494c1d919bff0f71a820d8afab1fa Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 20:24:48 +0200 Subject: Adding upstream version 1.2.2. Signed-off-by: Daniel Baumann --- src/live_effects/lpe-gears.cpp | 277 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 277 insertions(+) create mode 100644 src/live_effects/lpe-gears.cpp (limited to 'src/live_effects/lpe-gears.cpp') diff --git a/src/live_effects/lpe-gears.cpp b/src/live_effects/lpe-gears.cpp new file mode 100644 index 0000000..d636654 --- /dev/null +++ b/src/live_effects/lpe-gears.cpp @@ -0,0 +1,277 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) Johan Engelen 2007 + * Copyright 2006 Michael G. Sloan + * Copyright 2006 Aaron Spike + * + * Released under GNU GPL v2+, read the file 'COPYING' for more information. + */ + +#include "live_effects/lpe-gears.h" +#include <2geom/bezier-to-sbasis.h> +// TODO due to internal breakage in glibmm headers, this must be last: +#include + +using namespace Geom; + +class Gear { +public: + // pitch circles touch on two properly meshed gears + // all measurements are taken from the pitch circle + double pitch_diameter() {return (_number_of_teeth * _module) / M_PI;} + double pitch_radius() {return pitch_diameter() / 2.0;} + void pitch_radius(double R) {_module = (2 * M_PI * R) / _number_of_teeth;} + + // base circle serves as the basis for the involute toothe profile + double base_diameter() {return pitch_diameter() * cos(_pressure_angle);} + double base_radius() {return base_diameter() / 2.0;} + + // diametrical pitch + double diametrical_pitch() {return _number_of_teeth / pitch_diameter();} + + // height of the tooth above the pitch circle + double addendum() {return 1.0 / diametrical_pitch();} + // depth of the tooth below the pitch circle + double dedendum() {return addendum() + _clearance;} + + // root circle specifies the bottom of the fillet between teeth + double root_radius() {return pitch_radius() - dedendum();} + double root_diameter() {return root_radius() * 2.0;} + + // outer circle is the outside diameter of the gear + double outer_radius() {return pitch_radius() + addendum();} + double outer_diameter() {return outer_radius() * 2.0;} + + // angle covered by the tooth on the pitch circle + double tooth_thickness_angle() {return M_PI / _number_of_teeth;} + + Geom::Point centre() {return _centre;} + void centre(Geom::Point c) {_centre = c;} + + double angle() {return _angle;} + void angle(double a) {_angle = a;} + + int number_of_teeth() {return _number_of_teeth;} + + Geom::Path path(); + Gear spawn(Geom::Point p); + + Gear(int n, double m, double phi) + : _number_of_teeth(n) + , _pressure_angle(phi) + , _module(m) + { + } +private: + int _number_of_teeth; + double _pressure_angle; + double _module; + double _clearance = 0.0; + double _angle = 0.0; + Geom::Point _centre; + D2 _involute(double start, double stop) { + D2 B; + D2 I; + Linear bo = Linear(start,stop); + + B[0] = cos(bo,2); + B[1] = sin(bo,2); + + I = B - Linear(0,1) * derivative(B); + I = I*base_radius() + _centre; + return I; + } + D2 _arc(double start, double stop, double R) { + D2 B; + Linear bo = Linear(start,stop); + + B[0] = cos(bo,2); + B[1] = sin(bo,2); + + B = B*R + _centre; + return B; + } + // angle of the base circle used to create the involute to a certain radius + double involute_swath_angle(double R) { + if (R <= base_radius()) return 0.0; + return sqrt(R*R - base_radius()*base_radius())/base_radius(); + } + + // angle of the base circle between the origin of the involute and the intersection on another radius + double involute_intersect_angle(double R) { + if (R <= base_radius()) return 0.0; + return (sqrt(R*R - base_radius()*base_radius())/base_radius()) - acos(base_radius()/R); + } +}; + +static void +makeContinuous(D2 &a, Point const b) { + for(unsigned d=0;d<2;d++) + a[d][0][0] = b[d]; +} + +Geom::Path Gear::path() { + Geom::Path pb; + + // angle covered by a full tooth and fillet + double tooth_rotation = 2.0 * tooth_thickness_angle(); + // angle covered by an involute + double involute_advance = involute_intersect_angle(outer_radius()) - involute_intersect_angle(root_radius()); + // angle covered by the tooth tip + double tip_advance = tooth_thickness_angle() - (2 * (involute_intersect_angle(outer_radius()) - involute_intersect_angle(pitch_radius()))); + // angle covered by the toothe root + double root_advance = (tooth_rotation - tip_advance) - (2.0 * involute_advance); + // begin drawing the involute at t if the root circle is larger than the base circle + double involute_t = involute_swath_angle(root_radius())/involute_swath_angle(outer_radius()); + + //rewind angle to start drawing from the leading edge of the tooth + double first_tooth_angle = _angle - ((0.5 * tip_advance) + involute_advance); + + Geom::Point prev; + for (int i=0; i < _number_of_teeth; i++) + { + double cursor = first_tooth_angle + (i * tooth_rotation); + + D2 leading_I = compose(_involute(cursor, cursor + involute_swath_angle(outer_radius())), Linear(involute_t,1)); + if(i != 0) makeContinuous(leading_I, prev); + pb.append(SBasisCurve(leading_I)); + cursor += involute_advance; + prev = leading_I.at1(); + + D2 tip = _arc(cursor, cursor+tip_advance, outer_radius()); + makeContinuous(tip, prev); + pb.append(SBasisCurve(tip)); + cursor += tip_advance; + prev = tip.at1(); + + cursor += involute_advance; + D2 trailing_I = compose(_involute(cursor, cursor - involute_swath_angle(outer_radius())), Linear(1,involute_t)); + makeContinuous(trailing_I, prev); + pb.append(SBasisCurve(trailing_I)); + prev = trailing_I.at1(); + + if (base_radius() > root_radius()) { + Geom::Point leading_start = trailing_I.at1(); + Geom::Point leading_end = (root_radius() * unit_vector(leading_start - _centre)) + _centre; + prev = leading_end; + pb.appendNew(leading_end); + } + + D2 root = _arc(cursor, cursor+root_advance, root_radius()); + makeContinuous(root, prev); + pb.append(SBasisCurve(root)); + //cursor += root_advance; + prev = root.at1(); + + if (base_radius() > root_radius()) { + Geom::Point trailing_start = root.at1(); + Geom::Point trailing_end = (base_radius() * unit_vector(trailing_start - _centre)) + _centre; + pb.appendNew(trailing_end); + prev = trailing_end; + } + } + + return pb; +} + +Gear Gear::spawn(Geom::Point p) { + double radius = Geom::distance(this->centre(), p) - this->pitch_radius(); + int N = (int) floor( (radius / this->pitch_radius()) * this->number_of_teeth() ); + + Gear gear(N, _module, _pressure_angle); + gear.centre(p); + + double a = atan2(p - this->centre()); + double new_angle = 0.0; + if (gear.number_of_teeth() % 2 == 0) + new_angle -= gear.tooth_thickness_angle(); + new_angle -= (_angle) * (pitch_radius() / gear.pitch_radius()); + new_angle += (a) * (pitch_radius() / gear.pitch_radius()); + gear.angle(new_angle + a); + return gear; +} + + + +// ################################################################# + + + +namespace Inkscape { +namespace LivePathEffect { + + +LPEGears::LPEGears(LivePathEffectObject *lpeobject) : + Effect(lpeobject), + teeth(_("_Teeth:"), _("The number of teeth"), "teeth", &wr, this, 10), + phi(_("_Phi:"), _("Tooth pressure angle (typically 20-25 deg). The ratio of teeth not in contact."), "phi", &wr, this, 5), + min_radius(_("Min Radius:"), _("Minimum radius, low values can be slow"), "min_radius", &wr, this, 5.0) +{ + /* Tooth pressure angle: The angle between the tooth profile and a perpendicular to the pitch + * circle, usually at the point where the pitch circle meets the tooth profile. Standard angles + * are 20 and 25 degrees. The pressure angle affects the force that tends to separate mating + * gears. A high pressure angle means that higher ratio of teeth not in contact. However, this + * allows the teeth to have higher capacity and also allows fewer teeth without undercutting. + */ + + teeth.param_make_integer(); + teeth.param_set_range(3, 1e10); + min_radius.param_set_range(0.01, std::numeric_limits::max()); + registerParameter(&teeth); + registerParameter(&phi); + registerParameter(&min_radius); +} + +LPEGears::~LPEGears() += default; + +Geom::PathVector +LPEGears::doEffect_path (Geom::PathVector const &path_in) +{ + Geom::PathVector path_out; + Geom::Path gearpath = path_in[0]; + + Geom::Path::iterator it(gearpath.begin()); + if ( it == gearpath.end() ) return path_out; + + Gear * gear = new Gear(teeth, 200.0, phi * M_PI / 180); + Geom::Point gear_centre = (*it).finalPoint(); + gear->centre(gear_centre); + gear->angle(atan2((*it).initialPoint() - gear_centre)); + + ++it; + if ( it == gearpath.end() ) return path_out; + double radius = Geom::distance(gear_centre, (*it).finalPoint()); + radius = radius < min_radius?min_radius:radius; + gear->pitch_radius(radius); + + path_out.push_back( gear->path()); + + for (++it; it != gearpath.end() ; ++it) { + if (are_near((*it).initialPoint(), (*it).finalPoint())) { + continue; + } + // iterate through Geom::Curve in path_in + Gear* gearnew = new Gear(gear->spawn( (*it).finalPoint() )); + path_out.push_back( gearnew->path() ); + delete gear; + gear = gearnew; + } + delete gear; + + return path_out; +} + +} // namespace LivePathEffect +} /* namespace Inkscape */ + +/* + Local Variables: + mode:c++ + c-file-style:"stroustrup" + c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +)) + indent-tabs-mode:nil + fill-column:99 + End: +*/ +// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 : -- cgit v1.2.3