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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:24:48 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:24:48 +0000 |
commit | cca66b9ec4e494c1d919bff0f71a820d8afab1fa (patch) | |
tree | 146f39ded1c938019e1ed42d30923c2ac9e86789 /src/object/sp-spiral.cpp | |
parent | Initial commit. (diff) | |
download | inkscape-upstream.tar.xz inkscape-upstream.zip |
Adding upstream version 1.2.2.upstream/1.2.2upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/object/sp-spiral.cpp')
-rw-r--r-- | src/object/sp-spiral.cpp | 569 |
1 files changed, 569 insertions, 0 deletions
diff --git a/src/object/sp-spiral.cpp b/src/object/sp-spiral.cpp new file mode 100644 index 0000000..f8b8065 --- /dev/null +++ b/src/object/sp-spiral.cpp @@ -0,0 +1,569 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/** \file + * <sodipodi:spiral> implementation + */ +/* + * Authors: + * Mitsuru Oka <oka326@parkcity.ne.jp> + * Lauris Kaplinski <lauris@kaplinski.com> + * Abhishek Sharma + * Jon A. Cruz <jon@joncruz.org> + * + * Copyright (C) 1999-2002 Lauris Kaplinski + * Copyright (C) 2000-2001 Ximian, Inc. + * + * Released under GNU GPL v2+, read the file 'COPYING' for more information. + */ + +#include "live_effects/effect.h" +#include "svg/svg.h" +#include "attributes.h" +#include <2geom/bezier-utils.h> +#include <2geom/pathvector.h> +#include "display/curve.h" +#include <glibmm/i18n.h> +#include "xml/repr.h" +#include "document.h" + +#include "sp-spiral.h" + +SPSpiral::SPSpiral() + : SPShape() + , cx(0) + , cy(0) + , exp(1) + , revo(3) + , rad(1) + , arg(0) + , t0(0) +{ +} + +SPSpiral::~SPSpiral() = default; + +void SPSpiral::build(SPDocument * document, Inkscape::XML::Node * repr) { + SPShape::build(document, repr); + + this->readAttr(SPAttr::SODIPODI_CX); + this->readAttr(SPAttr::SODIPODI_CY); + this->readAttr(SPAttr::SODIPODI_EXPANSION); + this->readAttr(SPAttr::SODIPODI_REVOLUTION); + this->readAttr(SPAttr::SODIPODI_RADIUS); + this->readAttr(SPAttr::SODIPODI_ARGUMENT); + this->readAttr(SPAttr::SODIPODI_T0); +} + +Inkscape::XML::Node* SPSpiral::write(Inkscape::XML::Document *xml_doc, Inkscape::XML::Node *repr, guint flags) { + if ((flags & SP_OBJECT_WRITE_BUILD) && !repr) { + repr = xml_doc->createElement("svg:path"); + } + + if (flags & SP_OBJECT_WRITE_EXT) { + /* Fixme: we may replace these attributes by + * sodipodi:spiral="cx cy exp revo rad arg t0" + */ + repr->setAttribute("sodipodi:type", "spiral"); + repr->setAttributeSvgDouble("sodipodi:cx", this->cx); + repr->setAttributeSvgDouble("sodipodi:cy", this->cy); + repr->setAttributeSvgDouble("sodipodi:expansion", this->exp); + repr->setAttributeSvgDouble("sodipodi:revolution", this->revo); + repr->setAttributeSvgDouble("sodipodi:radius", this->rad); + repr->setAttributeSvgDouble("sodipodi:argument", this->arg); + repr->setAttributeSvgDouble("sodipodi:t0", this->t0); + } + + // make sure the curve is rebuilt with all up-to-date parameters + this->set_shape(); + + // Nulls might be possible if this called iteratively + if (!this->_curve) { + //g_warning("sp_spiral_write(): No path to copy\n"); + return nullptr; + } + + repr->setAttribute("d", sp_svg_write_path(this->_curve->get_pathvector())); + + SPShape::write(xml_doc, repr, flags | SP_SHAPE_WRITE_PATH); + + return repr; +} + +void SPSpiral::set(SPAttr key, gchar const* value) { + /// \todo fixme: we should really collect updates + switch (key) { + case SPAttr::SODIPODI_CX: + if (!sp_svg_length_read_computed_absolute (value, &this->cx)) { + this->cx = 0.0; + } + + this->requestDisplayUpdate(SP_OBJECT_MODIFIED_FLAG); + break; + + case SPAttr::SODIPODI_CY: + if (!sp_svg_length_read_computed_absolute (value, &this->cy)) { + this->cy = 0.0; + } + + this->requestDisplayUpdate(SP_OBJECT_MODIFIED_FLAG); + break; + + case SPAttr::SODIPODI_EXPANSION: + if (value) { + /** \todo + * FIXME: check that value looks like a (finite) + * number. Create a routine that uses strtod, and + * accepts a default value (if strtod finds an error). + * N.B. atof/sscanf/strtod consider "nan" and "inf" + * to be valid numbers. + */ + this->exp = g_ascii_strtod (value, nullptr); + this->exp = CLAMP (this->exp, 0.0, 1000.0); + } else { + this->exp = 1.0; + } + + this->requestDisplayUpdate(SP_OBJECT_MODIFIED_FLAG); + break; + + case SPAttr::SODIPODI_REVOLUTION: + if (value) { + this->revo = g_ascii_strtod (value, nullptr); + this->revo = CLAMP (this->revo, 0.05, 1024.0); + } else { + this->revo = 3.0; + } + + this->requestDisplayUpdate(SP_OBJECT_MODIFIED_FLAG); + break; + + case SPAttr::SODIPODI_RADIUS: + if (!sp_svg_length_read_computed_absolute (value, &this->rad)) { + this->rad = MAX (this->rad, 0.001); + } + + this->requestDisplayUpdate(SP_OBJECT_MODIFIED_FLAG); + break; + + case SPAttr::SODIPODI_ARGUMENT: + if (value) { + this->arg = g_ascii_strtod (value, nullptr); + /** \todo + * FIXME: We still need some bounds on arg, for + * numerical reasons. E.g., we don't want inf or NaN, + * nor near-infinite numbers. I'm inclined to take + * modulo 2*pi. If so, then change the knot editors, + * which use atan2 - revo*2*pi, which typically + * results in very negative arg. + */ + } else { + this->arg = 0.0; + } + + this->requestDisplayUpdate(SP_OBJECT_MODIFIED_FLAG); + break; + + case SPAttr::SODIPODI_T0: + if (value) { + this->t0 = g_ascii_strtod (value, nullptr); + this->t0 = CLAMP (this->t0, 0.0, 0.999); + /** \todo + * Have shared constants for the allowable bounds for + * attributes. There was a bug here where we used -1.0 + * as the minimum (which leads to NaN via, e.g., + * pow(-1.0, 0.5); see sp_spiral_get_xy for + * requirements. + */ + } else { + this->t0 = 0.0; + } + + this->requestDisplayUpdate(SP_OBJECT_MODIFIED_FLAG); + break; + + default: + SPShape::set(key, value); + break; + } +} + +void SPSpiral::update(SPCtx *ctx, guint flags) { + if (flags & (SP_OBJECT_MODIFIED_FLAG | SP_OBJECT_STYLE_MODIFIED_FLAG | SP_OBJECT_VIEWPORT_MODIFIED_FLAG)) { + this->set_shape(); + } + + SPShape::update(ctx, flags); +} + +const char* SPSpiral::typeName() const { + return "spiral"; +} + +const char* SPSpiral::displayName() const { + return _("Spiral"); +} + +gchar* SPSpiral::description() const { + // TRANSLATORS: since turn count isn't an integer, please adjust the + // string as needed to deal with an localized plural forms. + return g_strdup_printf (_("with %3f turns"), this->revo); +} + +/** + * Fit beziers together to spiral and draw it. + * + * \pre dstep \> 0. + * \pre is_unit_vector(*hat1). + * \post is_unit_vector(*hat2). + **/ +void SPSpiral::fitAndDraw(SPCurve* c, double dstep, Geom::Point darray[], Geom::Point const& hat1, Geom::Point& hat2, double* t) const { +#define BEZIER_SIZE 4 +#define FITTING_MAX_BEZIERS 4 +#define BEZIER_LENGTH (BEZIER_SIZE * FITTING_MAX_BEZIERS) + + g_assert (dstep > 0); + g_assert (is_unit_vector (hat1)); + + Geom::Point bezier[BEZIER_LENGTH]; + double d; + int depth, i; + + for (d = *t, i = 0; i <= SAMPLE_SIZE; d += dstep, i++) { + darray[i] = this->getXY(d); + + /* Avoid useless adjacent dups. (Otherwise we can have all of darray filled with + the same value, which upsets chord_length_parameterize.) */ + if ((i != 0) && (darray[i] == darray[i - 1]) && (d < 1.0)) { + i--; + d += dstep; + /** We mustn't increase dstep for subsequent values of + * i: for large spiral.exp values, rate of growth + * increases very rapidly. + */ + /** \todo + * Get the function itself to decide what value of d + * to use next: ensure that we move at least 0.25 * + * stroke width, for example. The derivative (as used + * for get_tangent before normalization) would be + * useful for estimating the appropriate d value. Or + * perhaps just start with a small dstep and scale by + * some small number until we move >= 0.25 * + * stroke_width. Must revert to the original dstep + * value for next iteration to avoid the problem + * mentioned above. + */ + } + } + + double const next_t = d - 2 * dstep; + /* == t + (SAMPLE_SIZE - 1) * dstep, in absence of dups. */ + + hat2 = -this->getTangent(next_t); + + /** \todo + * We should use better algorithm to specify maximum error. + */ + depth = Geom::bezier_fit_cubic_full (bezier, nullptr, darray, SAMPLE_SIZE, + hat1, hat2, + SPIRAL_TOLERANCE*SPIRAL_TOLERANCE, + FITTING_MAX_BEZIERS); + + g_assert(depth * BEZIER_SIZE <= gint(G_N_ELEMENTS(bezier))); + +#ifdef SPIRAL_DEBUG + if (*t == spiral->t0 || *t == 1.0) + g_print ("[%s] depth=%d, dstep=%g, t0=%g, t=%g, arg=%g\n", + debug_state, depth, dstep, spiral->t0, *t, spiral->arg); +#endif + + if (depth != -1) { + for (i = 0; i < 4*depth; i += 4) { + c->curveto(bezier[i + 1], + bezier[i + 2], + bezier[i + 3]); + } + } else { +#ifdef SPIRAL_VERBOSE + g_print ("cant_fit_cubic: t=%g\n", *t); +#endif + for (i = 1; i < SAMPLE_SIZE; i++) + c->lineto(darray[i]); + } + + *t = next_t; + + g_assert (is_unit_vector (hat2)); +} + +void SPSpiral::set_shape() { + if (checkBrokenPathEffect()) { + return; + } + + Geom::Point darray[SAMPLE_SIZE + 1]; + + this->requestModified(SP_OBJECT_MODIFIED_FLAG); + + auto c = std::make_unique<SPCurve>(); + +#ifdef SPIRAL_VERBOSE + g_print ("cx=%g, cy=%g, exp=%g, revo=%g, rad=%g, arg=%g, t0=%g\n", + this->cx, + this->cy, + this->exp, + this->revo, + this->rad, + this->arg, + this->t0); +#endif + + /* Initial moveto. */ + c->moveto(this->getXY(this->t0)); + + double const tstep = SAMPLE_STEP / this->revo; + double const dstep = tstep / (SAMPLE_SIZE - 1); + + Geom::Point hat1 = this->getTangent(this->t0); + Geom::Point hat2; + + double t; + for (t = this->t0; t < (1.0 - tstep);) { + this->fitAndDraw(c.get(), dstep, darray, hat1, hat2, &t); + + hat1 = -hat2; + } + + if ((1.0 - t) > SP_EPSILON) { + this->fitAndDraw(c.get(), (1.0 - t) / (SAMPLE_SIZE - 1.0), darray, hat1, hat2, &t); + } + + if (prepareShapeForLPE(c.get())) { + return; + } + + // This happends on undo, fix bug:#1791784 + setCurveInsync(std::move(c)); +} + +/** + * Set spiral properties and update display. + */ +void SPSpiral::setPosition(gdouble cx, gdouble cy, gdouble exp, gdouble revo, gdouble rad, gdouble arg, gdouble t0) { + /** \todo + * Consider applying CLAMP or adding in-bounds assertions for + * some of these parameters. + */ + this->cx = cx; + this->cy = cy; + this->exp = exp; + this->revo = revo; + this->rad = MAX (rad, 0.0); + this->arg = arg; + this->t0 = CLAMP(t0, 0.0, 0.999); + + this->requestDisplayUpdate(SP_OBJECT_MODIFIED_FLAG); +} + +void SPSpiral::snappoints(std::vector<Inkscape::SnapCandidatePoint> &p, Inkscape::SnapPreferences const *snapprefs) const { + // We will determine the spiral's midpoint ourselves, instead of trusting on the base class + // Therefore snapping to object midpoints is temporarily disabled + Inkscape::SnapPreferences local_snapprefs = *snapprefs; + local_snapprefs.setTargetSnappable(Inkscape::SNAPTARGET_OBJECT_MIDPOINT, false); + + SPShape::snappoints(p, &local_snapprefs); + + if (snapprefs->isTargetSnappable(Inkscape::SNAPTARGET_OBJECT_MIDPOINT)) { + Geom::Affine const i2dt (this->i2dt_affine ()); + + p.emplace_back(Geom::Point(this->cx, this->cy) * i2dt, Inkscape::SNAPSOURCE_OBJECT_MIDPOINT, Inkscape::SNAPTARGET_OBJECT_MIDPOINT); + // This point is the start-point of the spiral, which is also returned when _snap_to_itemnode has been set + // in the object snapper. In that case we will get a duplicate! + } +} + +/** + * Set spiral transform + */ +Geom::Affine SPSpiral::set_transform(Geom::Affine const &xform) +{ + if (pathEffectsEnabled() && !optimizeTransforms()) { + return xform; + } + // Only set transform with proportional scaling + if (!xform.withoutTranslation().isUniformScale()) { + return xform; + } + /* Calculate spiral start in parent coords. */ + Geom::Point pos( Geom::Point(this->cx, this->cy) * xform ); + + /* This function takes care of translation and scaling, we return whatever parts we can't + handle. */ + Geom::Affine ret(Geom::Affine(xform).withoutTranslation()); + gdouble const s = hypot(ret[0], ret[1]); + if (s > 1e-9) { + ret[0] /= s; + ret[1] /= s; + ret[2] /= s; + ret[3] /= s; + } else { + ret[0] = 1.0; + ret[1] = 0.0; + ret[2] = 0.0; + ret[3] = 1.0; + } + + this->rad *= s; + + /* Find start in item coords */ + pos = pos * ret.inverse(); + this->cx = pos[Geom::X]; + this->cy = pos[Geom::Y]; + + this->set_shape(); + + // Adjust stroke width + this->adjust_stroke(s); + + // Adjust pattern fill + this->adjust_pattern(xform * ret.inverse()); + + // Adjust gradient fill + this->adjust_gradient(xform * ret.inverse()); + + return ret; +} + +void SPSpiral::update_patheffect(bool write) { + SPShape::update_patheffect(write); +} + +/** + * Return one of the points on the spiral. + * + * \param t specifies how far along the spiral. + * \pre \a t in [0.0, 2.03]. (It doesn't make sense for t to be much more + * than 1.0, though some callers go slightly beyond 1.0 for curve-fitting + * purposes.) + */ +Geom::Point SPSpiral::getXY(gdouble t) const { + g_assert (this->exp >= 0.0); + /* Otherwise we get NaN for t==0. */ + g_assert (this->exp <= 1000.0); + /* Anything much more results in infinities. Even allowing 1000 is somewhat overkill. */ + g_assert (t >= 0.0); + /* Any callers passing -ve t will have a bug for non-integral values of exp. */ + + double const rad = this->rad * pow(t, (double)this->exp); + double const arg = 2.0 * M_PI * this->revo * t + this->arg; + + return Geom::Point(rad * cos(arg) + this->cx, rad * sin(arg) + this->cy); +} + + +/** + * Returns the derivative of sp_spiral_get_xy with respect to t, + * scaled to a unit vector. + * + * \pre spiral != 0. + * \pre 0 \<= t. + * \pre p != NULL. + * \post is_unit_vector(*p). + */ +Geom::Point SPSpiral::getTangent(gdouble t) const { + Geom::Point ret(1.0, 0.0); + + g_assert (t >= 0.0); + g_assert (this->exp >= 0.0); + /* See above for comments on these assertions. */ + + double const t_scaled = 2.0 * M_PI * this->revo * t; + double const arg = t_scaled + this->arg; + double const s = sin(arg); + double const c = cos(arg); + + if (this->exp == 0.0) { + ret = Geom::Point(-s, c); + } else if (t_scaled == 0.0) { + ret = Geom::Point(c, s); + } else { + Geom::Point unrotated(this->exp, t_scaled); + double const s_len = L2 (unrotated); + g_assert (s_len != 0); + /** \todo + * Check that this isn't being too hopeful of the hypot + * function. E.g. test with numbers around 2**-1070 + * (denormalized numbers), preferably on a few different + * platforms. However, njh says that the usual implementation + * does handle both very big and very small numbers. + */ + unrotated /= s_len; + + /* ret = spiral->exp * (c, s) + t_scaled * (-s, c); + alternatively ret = (spiral->exp, t_scaled) * (( c, s), + (-s, c)).*/ + ret = Geom::Point(dot(unrotated, Geom::Point(c, -s)), + dot(unrotated, Geom::Point(s, c))); + /* ret should already be approximately normalized: the + matrix ((c, -s), (s, c)) is orthogonal (it just + rotates by arg), and unrotated has been normalized, + so ret is already of unit length other than numerical + error in the above matrix multiplication. */ + + /** \todo + * I haven't checked how important it is for ret to be very + * near unit length; we could get rid of the below. + */ + + ret.normalize(); + /* Proof that ret length is non-zero: see above. (Should be near 1.) */ + } + + g_assert (is_unit_vector(ret)); + return ret; +} + +/** + * Compute rad and/or arg for point on spiral. + */ +void SPSpiral::getPolar(gdouble t, gdouble* rad, gdouble* arg) const { + if (rad) { + *rad = this->rad * pow(t, (double)this->exp); + } + + if (arg) { + *arg = 2.0 * M_PI * this->revo * t + this->arg; + } +} + +/** + * Return true if spiral has properties that make it invalid. + */ +bool SPSpiral::isInvalid() const { + gdouble rad; + + this->getPolar(0.0, &rad, nullptr); + + if (rad < 0.0 || rad > SP_HUGE) { + g_print("rad(t=0)=%g\n", rad); + return true; + } + + this->getPolar(1.0, &rad, nullptr); + + if (rad < 0.0 || rad > SP_HUGE) { + g_print("rad(t=1)=%g\n", rad); + return true; + } + + return false; +} + +/* + 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:fileencoding=utf-8:textwidth=99 : |