Adding upstream version 1.2.2.upstream/1.2.2upstream

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

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 :