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-rw-r--r--src/object/sp-gradient.cpp1208
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diff --git a/src/object/sp-gradient.cpp b/src/object/sp-gradient.cpp
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+// SPDX-License-Identifier: GPL-2.0-or-later
+/** \file
+ * SPGradient, SPStop, SPLinearGradient, SPRadialGradient,
+ * SPMeshGradient, SPMeshRow, SPMeshPatch
+ */
+/*
+ * Authors:
+ * Lauris Kaplinski <lauris@kaplinski.com>
+ * bulia byak <buliabyak@users.sf.net>
+ * Jasper van de Gronde <th.v.d.gronde@hccnet.nl>
+ * Jon A. Cruz <jon@joncruz.org>
+ * Abhishek Sharma
+ * Tavmjong Bah <tavmjong@free.fr>
+ *
+ * Copyright (C) 1999-2002 Lauris Kaplinski
+ * Copyright (C) 2000-2001 Ximian, Inc.
+ * Copyright (C) 2004 David Turner
+ * Copyright (C) 2009 Jasper van de Gronde
+ * Copyright (C) 2011 Tavmjong Bah
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ *
+ */
+
+#define noSP_GRADIENT_VERBOSE
+//#define OBJECT_TRACE
+
+#include "sp-gradient.h"
+
+#include <cstring>
+#include <string>
+
+#include <2geom/transforms.h>
+
+#include <cairo.h>
+
+#include <sigc++/functors/ptr_fun.h>
+#include <sigc++/adaptors/bind.h>
+
+#include "attributes.h"
+#include "bad-uri-exception.h"
+#include "document.h"
+#include "gradient-chemistry.h"
+
+#include "sp-gradient-reference.h"
+#include "sp-linear-gradient.h"
+#include "sp-radial-gradient.h"
+#include "sp-mesh-gradient.h"
+#include "sp-mesh-row.h"
+#include "sp-mesh-patch.h"
+#include "sp-stop.h"
+
+#include "display/cairo-utils.h"
+
+#include "svg/svg.h"
+#include "svg/css-ostringstream.h"
+
+bool SPGradient::hasStops() const
+{
+ return has_stops;
+}
+
+bool SPGradient::hasPatches() const
+{
+ return has_patches;
+}
+
+bool SPGradient::isUnitsSet() const
+{
+ return units_set;
+}
+
+SPGradientUnits SPGradient::getUnits() const
+{
+ return units;
+}
+
+bool SPGradient::isSpreadSet() const
+{
+ return spread_set;
+}
+
+SPGradientSpread SPGradient::getSpread() const
+{
+ return spread;
+}
+
+void SPGradient::setSwatch( bool swatch )
+{
+ if ( swatch != isSwatch() ) {
+ this->swatch = swatch; // to make isSolid() work, this happens first
+ gchar const* paintVal = swatch ? (isSolid() ? "solid" : "gradient") : nullptr;
+ setAttribute( "inkscape:swatch", paintVal);
+
+ requestModified( SP_OBJECT_MODIFIED_FLAG );
+ }
+}
+
+
+/**
+ * return true if this gradient is "equivalent" to that gradient.
+ * Equivalent meaning they have the same stop count, same stop colors and same stop opacity
+ * @param that - A gradient to compare this to
+ */
+bool SPGradient::isEquivalent(SPGradient *that)
+{
+ //TODO Make this work for mesh gradients
+
+ bool status = false;
+
+ while(true){ // not really a loop, used to avoid deep nesting or multiple exit points from function
+ if (this->getStopCount() != that->getStopCount()) { break; }
+ if (this->hasStops() != that->hasStops()) { break; }
+ if (!this->getVector() || !that->getVector()) { break; }
+ if (this->isSwatch() != that->isSwatch()) { break; }
+ if ( this->isSwatch() ){
+ // drop down to check stops.
+ }
+ else if (
+ (SP_IS_LINEARGRADIENT(this) && SP_IS_LINEARGRADIENT(that)) ||
+ (SP_IS_RADIALGRADIENT(this) && SP_IS_RADIALGRADIENT(that)) ||
+ (SP_IS_MESHGRADIENT(this) && SP_IS_MESHGRADIENT(that))) {
+ if(!this->isAligned(that))break;
+ }
+ else { break; } // this should never happen, some unhandled type of gradient
+
+ SPStop *as = this->getVector()->getFirstStop();
+ SPStop *bs = that->getVector()->getFirstStop();
+
+ bool effective = true;
+ while (effective && (as && bs)) {
+ if (!as->getColor().isClose(bs->getColor(), 0.001) ||
+ as->offset != bs->offset || as->getOpacity() != bs->getOpacity() ) {
+ effective = false;
+ break;
+ }
+ else {
+ as = as->getNextStop();
+ bs = bs->getNextStop();
+ }
+ }
+ if (!effective) break;
+
+ status = true;
+ break;
+ }
+ return status;
+}
+
+/**
+ * return true if this gradient is "aligned" to that gradient.
+ * Aligned means that they have exactly the same coordinates and transform.
+ * @param that - A gradient to compare this to
+ */
+bool SPGradient::isAligned(SPGradient *that)
+{
+ bool status = false;
+
+ /* Some gradients have coordinates/other values specified, some don't.
+ yes/yes check the coordinates/other values
+ no/no aligned (because both have all default values)
+ yes/no not aligned
+ no/yes not aligned
+ It is NOT safe to just compare the computed values because if that field has
+ not been set the computed value could be full of garbage.
+
+ In theory the yes/no and no/yes cases could be aligned if the specified value
+ matches the default value.
+ */
+
+ while(true){ // not really a loop, used to avoid deep nesting or multiple exit points from function
+ if(this->gradientTransform_set != that->gradientTransform_set) { break; }
+ if(this->gradientTransform_set &&
+ (this->gradientTransform != that->gradientTransform)) { break; }
+ if (SP_IS_LINEARGRADIENT(this) && SP_IS_LINEARGRADIENT(that)) {
+ SPLinearGradient *sg=SP_LINEARGRADIENT(this);
+ SPLinearGradient *tg=SP_LINEARGRADIENT(that);
+
+ if( sg->x1._set != tg->x1._set) { break; }
+ if( sg->y1._set != tg->y1._set) { break; }
+ if( sg->x2._set != tg->x2._set) { break; }
+ if( sg->y2._set != tg->y2._set) { break; }
+ if( sg->x1._set && sg->y1._set && sg->x2._set && sg->y2._set) {
+ if( (sg->x1.computed != tg->x1.computed) ||
+ (sg->y1.computed != tg->y1.computed) ||
+ (sg->x2.computed != tg->x2.computed) ||
+ (sg->y2.computed != tg->y2.computed) ) { break; }
+ } else if( sg->x1._set || sg->y1._set || sg->x2._set || sg->y2._set) { break; } // some mix of set and not set
+ // none set? assume aligned and fall through
+ } else if (SP_IS_RADIALGRADIENT(this) && SP_IS_LINEARGRADIENT(that)) {
+ SPRadialGradient *sg=SP_RADIALGRADIENT(this);
+ SPRadialGradient *tg=SP_RADIALGRADIENT(that);
+
+ if( sg->cx._set != tg->cx._set) { break; }
+ if( sg->cy._set != tg->cy._set) { break; }
+ if( sg->r._set != tg->r._set) { break; }
+ if( sg->fx._set != tg->fx._set) { break; }
+ if( sg->fy._set != tg->fy._set) { break; }
+ if( sg->cx._set && sg->cy._set && sg->fx._set && sg->fy._set && sg->r._set) {
+ if( (sg->cx.computed != tg->cx.computed) ||
+ (sg->cy.computed != tg->cy.computed) ||
+ (sg->r.computed != tg->r.computed ) ||
+ (sg->fx.computed != tg->fx.computed) ||
+ (sg->fy.computed != tg->fy.computed) ) { break; }
+ } else if( sg->cx._set || sg->cy._set || sg->fx._set || sg->fy._set || sg->r._set ) { break; } // some mix of set and not set
+ // none set? assume aligned and fall through
+ } else if (SP_IS_MESHGRADIENT(this) && SP_IS_MESHGRADIENT(that)) {
+ SPMeshGradient *sg=SP_MESHGRADIENT(this);
+ SPMeshGradient *tg=SP_MESHGRADIENT(that);
+
+ if( sg->x._set != !tg->x._set) { break; }
+ if( sg->y._set != !tg->y._set) { break; }
+ if( sg->x._set && sg->y._set) {
+ if( (sg->x.computed != tg->x.computed) ||
+ (sg->y.computed != tg->y.computed) ) { break; }
+ } else if( sg->x._set || sg->y._set) { break; } // some mix of set and not set
+ // none set? assume aligned and fall through
+ } else {
+ break;
+ }
+ status = true;
+ break;
+ }
+ return status;
+}
+
+/*
+ * Gradient
+ */
+SPGradient::SPGradient() : SPPaintServer(), units(),
+ spread(),
+ ref(nullptr),
+ state(2),
+ vector() {
+
+ this->ref = new SPGradientReference(this);
+ this->ref->changedSignal().connect(sigc::bind(sigc::ptr_fun(SPGradient::gradientRefChanged), this));
+
+ /** \todo
+ * Fixme: reprs being rearranged (e.g. via the XML editor)
+ * may require us to clear the state.
+ */
+ this->state = SP_GRADIENT_STATE_UNKNOWN;
+
+ this->units = SP_GRADIENT_UNITS_OBJECTBOUNDINGBOX;
+ this->units_set = FALSE;
+
+ this->gradientTransform = Geom::identity();
+ this->gradientTransform_set = FALSE;
+
+ this->spread = SP_GRADIENT_SPREAD_PAD;
+ this->spread_set = FALSE;
+
+ this->has_stops = FALSE;
+ this->has_patches = FALSE;
+
+ this->vector.built = false;
+ this->vector.stops.clear();
+}
+
+SPGradient::~SPGradient() = default;
+
+/**
+ * Virtual build: set gradient attributes from its associated repr.
+ */
+void SPGradient::build(SPDocument *document, Inkscape::XML::Node *repr)
+{
+ // Work-around in case a swatch had been marked for immediate collection:
+ if ( repr->attribute("inkscape:swatch") && repr->attribute("inkscape:collect") ) {
+ repr->removeAttribute("inkscape:collect");
+ }
+
+ this->readAttr(SPAttr::STYLE);
+
+ SPPaintServer::build(document, repr);
+
+ for (auto& ochild: children) {
+ if (SP_IS_STOP(&ochild)) {
+ this->has_stops = TRUE;
+ break;
+ }
+ if (SP_IS_MESHROW(&ochild)) {
+ for (auto& ochild2: ochild.children) {
+ if (SP_IS_MESHPATCH(&ochild2)) {
+ this->has_patches = TRUE;
+ break;
+ }
+ }
+ if (this->has_patches == TRUE) {
+ break;
+ }
+ }
+ }
+
+ this->readAttr(SPAttr::GRADIENTUNITS);
+ this->readAttr(SPAttr::GRADIENTTRANSFORM);
+ this->readAttr(SPAttr::SPREADMETHOD);
+ this->readAttr(SPAttr::XLINK_HREF);
+ this->readAttr(SPAttr::INKSCAPE_SWATCH);
+
+ // Register ourselves
+ document->addResource("gradient", this);
+}
+
+/**
+ * Virtual release of SPGradient members before destruction.
+ */
+void SPGradient::release()
+{
+
+#ifdef SP_GRADIENT_VERBOSE
+ g_print("Releasing this %s\n", this->getId());
+#endif
+
+ if (this->document) {
+ // Unregister ourselves
+ this->document->removeResource("gradient", this);
+ }
+
+ if (this->ref) {
+ this->modified_connection.disconnect();
+ this->ref->detach();
+ delete this->ref;
+ this->ref = nullptr;
+ }
+
+ //this->modified_connection.~connection();
+
+ SPPaintServer::release();
+}
+
+/**
+ * Set gradient attribute to value.
+ */
+void SPGradient::set(SPAttr key, gchar const *value)
+{
+#ifdef OBJECT_TRACE
+ std::stringstream temp;
+ temp << "SPGradient::set: " << sp_attribute_name(key) << " " << (value?value:"null");
+ objectTrace( temp.str() );
+#endif
+
+ switch (key) {
+ case SPAttr::GRADIENTUNITS:
+ if (value) {
+ if (!strcmp(value, "userSpaceOnUse")) {
+ this->units = SP_GRADIENT_UNITS_USERSPACEONUSE;
+ } else {
+ this->units = SP_GRADIENT_UNITS_OBJECTBOUNDINGBOX;
+ }
+
+ this->units_set = TRUE;
+ } else {
+ this->units = SP_GRADIENT_UNITS_OBJECTBOUNDINGBOX;
+ this->units_set = FALSE;
+ }
+
+ this->requestModified(SP_OBJECT_MODIFIED_FLAG);
+ break;
+
+ case SPAttr::GRADIENTTRANSFORM: {
+ Geom::Affine t;
+ if (value && sp_svg_transform_read(value, &t)) {
+ this->gradientTransform = t;
+ this->gradientTransform_set = TRUE;
+ } else {
+ this->gradientTransform = Geom::identity();
+ this->gradientTransform_set = FALSE;
+ }
+
+ this->requestModified(SP_OBJECT_MODIFIED_FLAG);
+ break;
+ }
+ case SPAttr::SPREADMETHOD:
+ if (value) {
+ if (!strcmp(value, "reflect")) {
+ this->spread = SP_GRADIENT_SPREAD_REFLECT;
+ } else if (!strcmp(value, "repeat")) {
+ this->spread = SP_GRADIENT_SPREAD_REPEAT;
+ } else {
+ this->spread = SP_GRADIENT_SPREAD_PAD;
+ }
+
+ this->spread_set = TRUE;
+ } else {
+ this->spread_set = FALSE;
+ }
+
+ this->requestModified(SP_OBJECT_MODIFIED_FLAG);
+ break;
+
+ case SPAttr::XLINK_HREF:
+ if (value) {
+ try {
+ this->ref->attach(Inkscape::URI(value));
+ } catch (Inkscape::BadURIException &e) {
+ g_warning("%s", e.what());
+ this->ref->detach();
+ }
+ } else {
+ this->ref->detach();
+ }
+ break;
+
+ case SPAttr::INKSCAPE_SWATCH:
+ {
+ bool newVal = (value != nullptr);
+ bool modified = false;
+
+ if (newVal != this->swatch) {
+ this->swatch = newVal;
+ modified = true;
+ }
+
+ if (newVal) {
+ // Might need to flip solid/gradient
+ Glib::ustring paintVal = ( this->hasStops() && (this->getStopCount() <= 1) ) ? "solid" : "gradient";
+
+ if ( paintVal != value ) {
+ this->setAttribute( "inkscape:swatch", paintVal);
+ modified = true;
+ }
+ }
+
+ if (modified) {
+ this->requestModified(SP_OBJECT_MODIFIED_FLAG);
+ }
+ }
+ break;
+ default:
+ SPPaintServer::set(key, value);
+ break;
+ }
+
+#ifdef OBJECT_TRACE
+ objectTrace( "SPGradient::set", false );
+#endif
+}
+
+/**
+ * Gets called when the gradient is (re)attached to another gradient.
+ */
+void SPGradient::gradientRefChanged(SPObject *old_ref, SPObject *ref, SPGradient *gr)
+{
+ if (old_ref) {
+ gr->modified_connection.disconnect();
+ }
+ if ( SP_IS_GRADIENT(ref)
+ && ref != gr )
+ {
+ gr->modified_connection = ref->connectModified(sigc::bind<2>(sigc::ptr_fun(&SPGradient::gradientRefModified), gr));
+ }
+
+ // Per SVG, all unset attributes must be inherited from linked gradient.
+ // So, as we're now (re)linked, we assign linkee's values to this gradient if they are not yet set -
+ // but without setting the _set flags.
+ // FIXME: do the same for gradientTransform too
+ if (!gr->units_set) {
+ gr->units = gr->fetchUnits();
+ }
+ if (!gr->spread_set) {
+ gr->spread = gr->fetchSpread();
+ }
+
+ /// \todo Fixme: what should the flags (second) argument be? */
+ gradientRefModified(ref, 0, gr);
+}
+
+/**
+ * Callback for child_added event.
+ */
+void SPGradient::child_added(Inkscape::XML::Node *child, Inkscape::XML::Node *ref)
+{
+ this->invalidateVector();
+
+ SPPaintServer::child_added(child, ref);
+
+ SPObject *ochild = this->get_child_by_repr(child);
+ if ( ochild && SP_IS_STOP(ochild) ) {
+ this->has_stops = TRUE;
+ if ( this->getStopCount() > 1 ) {
+ gchar const * attr = this->getAttribute("inkscape:swatch");
+ if ( attr && strcmp(attr, "gradient") ) {
+ this->setAttribute( "inkscape:swatch", "gradient" );
+ }
+ }
+ }
+ if ( ochild && SP_IS_MESHROW(ochild) ) {
+ this->has_patches = TRUE;
+ }
+
+ /// \todo Fixme: should we schedule "modified" here?
+ this->requestModified(SP_OBJECT_MODIFIED_FLAG);
+}
+
+/**
+ * Callback for remove_child event.
+ */
+void SPGradient::remove_child(Inkscape::XML::Node *child)
+{
+ this->invalidateVector();
+
+ SPPaintServer::remove_child(child);
+
+ this->has_stops = FALSE;
+ this->has_patches = FALSE;
+ for (auto& ochild: children) {
+ if (SP_IS_STOP(&ochild)) {
+ this->has_stops = TRUE;
+ break;
+ }
+ if (SP_IS_MESHROW(&ochild)) {
+ for (auto& ochild2: ochild.children) {
+ if (SP_IS_MESHPATCH(&ochild2)) {
+ this->has_patches = TRUE;
+ break;
+ }
+ }
+ if (this->has_patches == TRUE) {
+ break;
+ }
+ }
+ }
+
+ if ( this->getStopCount() <= 1 ) {
+ gchar const * attr = this->getAttribute("inkscape:swatch");
+
+ if ( attr && strcmp(attr, "solid") ) {
+ this->setAttribute( "inkscape:swatch", "solid" );
+ }
+ }
+
+ /* Fixme: should we schedule "modified" here? */
+ this->requestModified(SP_OBJECT_MODIFIED_FLAG);
+}
+
+/**
+ * Callback for modified event.
+ */
+void SPGradient::modified(guint flags)
+{
+#ifdef OBJECT_TRACE
+ objectTrace( "SPGradient::modified" );
+#endif
+ if (flags & SP_OBJECT_CHILD_MODIFIED_FLAG) {
+ if (SP_IS_MESHGRADIENT(this)) {
+ this->invalidateArray();
+ } else {
+ this->invalidateVector();
+ }
+ }
+
+ if (flags & SP_OBJECT_STYLE_MODIFIED_FLAG) {
+ if (SP_IS_MESHGRADIENT(this)) {
+ this->ensureArray();
+ } else {
+ this->ensureVector();
+ }
+ }
+
+ if (flags & SP_OBJECT_MODIFIED_FLAG) flags |= SP_OBJECT_PARENT_MODIFIED_FLAG;
+ flags &= SP_OBJECT_MODIFIED_CASCADE;
+
+ // FIXME: climb up the ladder of hrefs
+ std::vector<SPObject *> l;
+ for (auto& child: children) {
+ sp_object_ref(&child);
+ l.push_back(&child);
+ }
+
+ for (auto child:l) {
+ if (flags || (child->mflags & (SP_OBJECT_MODIFIED_FLAG | SP_OBJECT_CHILD_MODIFIED_FLAG))) {
+ child->emitModified(flags);
+ }
+ sp_object_unref(child);
+ }
+
+#ifdef OBJECT_TRACE
+ objectTrace( "SPGradient::modified", false );
+#endif
+}
+
+SPStop* SPGradient::getFirstStop()
+{
+ SPStop* first = nullptr;
+ for (auto& ochild: children) {
+ if (SP_IS_STOP(&ochild)) {
+ first = SP_STOP(&ochild);
+ break;
+ }
+ }
+ return first;
+}
+
+int SPGradient::getStopCount() const
+{
+ int count = 0;
+ // fixed off-by one count
+ SPStop *stop = const_cast<SPGradient*>(this)->getFirstStop();
+ while (stop) {
+ count++;
+ stop = stop->getNextStop();
+ }
+
+ return count;
+}
+
+/**
+ * Write gradient attributes to repr.
+ */
+Inkscape::XML::Node *SPGradient::write(Inkscape::XML::Document *xml_doc, Inkscape::XML::Node *repr, guint flags)
+{
+#ifdef OBJECT_TRACE
+ objectTrace( "SPGradient::write" );
+#endif
+
+ SPPaintServer::write(xml_doc, repr, flags);
+
+ if (flags & SP_OBJECT_WRITE_BUILD) {
+ std::vector<Inkscape::XML::Node *> l;
+
+ for (auto& child: children) {
+ Inkscape::XML::Node *crepr = child.updateRepr(xml_doc, nullptr, flags);
+
+ if (crepr) {
+ l.push_back(crepr);
+ }
+ }
+
+ for (auto i=l.rbegin();i!=l.rend();++i) {
+ repr->addChild(*i, nullptr);
+ Inkscape::GC::release(*i);
+ }
+ }
+
+ if (this->ref->getURI()) {
+ auto uri_string = this->ref->getURI()->str();
+ repr->setAttributeOrRemoveIfEmpty("xlink:href", uri_string);
+ }
+
+ if ((flags & SP_OBJECT_WRITE_ALL) || this->units_set) {
+ switch (this->units) {
+ case SP_GRADIENT_UNITS_USERSPACEONUSE:
+ repr->setAttribute("gradientUnits", "userSpaceOnUse");
+ break;
+ default:
+ repr->setAttribute("gradientUnits", "objectBoundingBox");
+ break;
+ }
+ }
+
+ if ((flags & SP_OBJECT_WRITE_ALL) || this->gradientTransform_set) {
+ auto c = sp_svg_transform_write(this->gradientTransform);
+ repr->setAttributeOrRemoveIfEmpty("gradientTransform", c);
+ }
+
+ if ((flags & SP_OBJECT_WRITE_ALL) || this->spread_set) {
+ /* FIXME: Ensure that this->spread is the inherited value
+ * if !this->spread_set. Not currently happening: see SPGradient::modified.
+ */
+ switch (this->spread) {
+ case SP_GRADIENT_SPREAD_REFLECT:
+ repr->setAttribute("spreadMethod", "reflect");
+ break;
+ case SP_GRADIENT_SPREAD_REPEAT:
+ repr->setAttribute("spreadMethod", "repeat");
+ break;
+ default:
+ repr->setAttribute("spreadMethod", "pad");
+ break;
+ }
+ }
+
+ if ( (flags & SP_OBJECT_WRITE_EXT) && this->isSwatch() ) {
+ if ( this->isSolid() ) {
+ repr->setAttribute( "inkscape:swatch", "solid" );
+ } else {
+ repr->setAttribute( "inkscape:swatch", "gradient" );
+ }
+ } else {
+ repr->removeAttribute("inkscape:swatch");
+ }
+
+#ifdef OBJECT_TRACE
+ objectTrace( "SPGradient::write", false );
+#endif
+ return repr;
+}
+
+/**
+ * Forces the vector to be built, if not present (i.e., changed).
+ *
+ * \pre SP_IS_GRADIENT(gradient).
+ */
+void SPGradient::ensureVector()
+{
+ if ( !vector.built ) {
+ rebuildVector();
+ }
+}
+
+/**
+ * Forces the array to be built, if not present (i.e., changed).
+ *
+ * \pre SP_IS_GRADIENT(gradient).
+ */
+void SPGradient::ensureArray()
+{
+ //std::cout << "SPGradient::ensureArray()" << std::endl;
+ if ( !array.built ) {
+ rebuildArray();
+ }
+}
+
+/**
+ * Set units property of gradient and emit modified.
+ */
+void SPGradient::setUnits(SPGradientUnits units)
+{
+ if (units != this->units) {
+ this->units = units;
+ units_set = TRUE;
+ requestModified(SP_OBJECT_MODIFIED_FLAG);
+ }
+}
+
+/**
+ * Set spread property of gradient and emit modified.
+ */
+void SPGradient::setSpread(SPGradientSpread spread)
+{
+ if (spread != this->spread) {
+ this->spread = spread;
+ spread_set = TRUE;
+ requestModified(SP_OBJECT_MODIFIED_FLAG);
+ }
+}
+
+/**
+ * Returns the first of {src, src-\>ref-\>getObject(),
+ * src-\>ref-\>getObject()-\>ref-\>getObject(),...}
+ * for which \a match is true, or NULL if none found.
+ *
+ * The raison d'ĂȘtre of this routine is that it correctly handles cycles in the href chain (e.g., if
+ * a gradient gives itself as its href, or if each of two gradients gives the other as its href).
+ *
+ * \pre SP_IS_GRADIENT(src).
+ */
+static SPGradient *
+chase_hrefs(SPGradient *const src, bool (*match)(SPGradient const *))
+{
+ g_return_val_if_fail(SP_IS_GRADIENT(src), NULL);
+
+ /* Use a pair of pointers for detecting loops: p1 advances half as fast as p2. If there is a
+ loop, then once p1 has entered the loop, we'll detect it the next time the distance between
+ p1 and p2 is a multiple of the loop size. */
+ SPGradient *p1 = src, *p2 = src;
+ bool do1 = false;
+ for (;;) {
+ if (match(p2)) {
+ return p2;
+ }
+
+ p2 = p2->ref->getObject();
+ if (!p2) {
+ return p2;
+ }
+ if (do1) {
+ p1 = p1->ref->getObject();
+ }
+ do1 = !do1;
+
+ if ( p2 == p1 ) {
+ /* We've been here before, so return NULL to indicate that no matching gradient found
+ * in the chain. */
+ return nullptr;
+ }
+ }
+}
+
+/**
+ * True if gradient has stops.
+ */
+static bool has_stopsFN(SPGradient const *gr)
+{
+ return gr->hasStops();
+}
+
+/**
+ * True if gradient has patches (i.e. a mesh).
+ */
+static bool has_patchesFN(SPGradient const *gr)
+{
+ return gr->hasPatches();
+}
+
+/**
+ * True if gradient has spread set.
+ */
+static bool has_spread_set(SPGradient const *gr)
+{
+ return gr->isSpreadSet();
+}
+
+/**
+ * True if gradient has units set.
+ */
+static bool
+has_units_set(SPGradient const *gr)
+{
+ return gr->isUnitsSet();
+}
+
+
+SPGradient *SPGradient::getVector(bool force_vector)
+{
+ SPGradient * src = chase_hrefs(this, has_stopsFN);
+ if (src == nullptr) {
+ src = this;
+ }
+
+ if (force_vector) {
+ src = sp_gradient_ensure_vector_normalized(src);
+ }
+ return src;
+}
+
+SPGradient *SPGradient::getArray(bool force_vector)
+{
+ SPGradient * src = chase_hrefs(this, has_patchesFN);
+ if (src == nullptr) {
+ src = this;
+ }
+ return src;
+}
+
+/**
+ * Returns the effective spread of given gradient (climbing up the refs chain if needed).
+ *
+ * \pre SP_IS_GRADIENT(gradient).
+ */
+SPGradientSpread SPGradient::fetchSpread()
+{
+ SPGradient const *src = chase_hrefs(this, has_spread_set);
+ return ( src
+ ? src->spread
+ : SP_GRADIENT_SPREAD_PAD ); // pad is the default
+}
+
+/**
+ * Returns the effective units of given gradient (climbing up the refs chain if needed).
+ *
+ * \pre SP_IS_GRADIENT(gradient).
+ */
+SPGradientUnits SPGradient::fetchUnits()
+{
+ SPGradient const *src = chase_hrefs(this, has_units_set);
+ return ( src
+ ? src->units
+ : SP_GRADIENT_UNITS_OBJECTBOUNDINGBOX ); // bbox is the default
+}
+
+
+/**
+ * Clears the gradient's svg:stop children from its repr.
+ */
+void
+SPGradient::repr_clear_vector()
+{
+ Inkscape::XML::Node *repr = getRepr();
+
+ /* Collect stops from original repr */
+ std::vector<Inkscape::XML::Node *> l;
+ for (Inkscape::XML::Node *child = repr->firstChild() ; child != nullptr; child = child->next() ) {
+ if (!strcmp(child->name(), "svg:stop")) {
+ l.push_back(child);
+ }
+ }
+ /* Remove all stops */
+ for (auto i=l.rbegin();i!=l.rend();++i) {
+ /** \todo
+ * fixme: This should work, unless we make gradient
+ * into generic group.
+ */
+ sp_repr_unparent(*i);
+ }
+}
+
+/**
+ * Writes the gradient's internal vector (whether from its own stops, or
+ * inherited from refs) into the gradient repr as svg:stop elements.
+ */
+void
+SPGradient::repr_write_vector()
+{
+ Inkscape::XML::Document *xml_doc = document->getReprDoc();
+ Inkscape::XML::Node *repr = getRepr();
+
+ /* We have to be careful, as vector may be our own, so construct repr list at first */
+ std::vector<Inkscape::XML::Node *> l;
+
+ for (auto & stop : vector.stops) {
+ Inkscape::CSSOStringStream os;
+ Inkscape::XML::Node *child = xml_doc->createElement("svg:stop");
+ child->setAttributeCssDouble("offset", stop.offset);
+ /* strictly speaking, offset an SVG <number> rather than a CSS one, but exponents make no
+ * sense for offset proportions. */
+ os << "stop-color:" << stop.color.toString() << ";stop-opacity:" << stop.opacity;
+ child->setAttribute("style", os.str());
+ /* Order will be reversed here */
+ l.push_back(child);
+ }
+
+ repr_clear_vector();
+
+ /* And insert new children from list */
+ for (auto i=l.rbegin();i!=l.rend();++i) {
+ Inkscape::XML::Node *child = *i;
+ repr->addChild(child, nullptr);
+ Inkscape::GC::release(child);
+ }
+}
+
+
+void SPGradient::gradientRefModified(SPObject */*href*/, guint /*flags*/, SPGradient *gradient)
+{
+ if ( gradient->invalidateVector() ) {
+ gradient->requestModified(SP_OBJECT_MODIFIED_FLAG);
+ // Conditional to avoid causing infinite loop if there's a cycle in the href chain.
+ }
+}
+
+/** Return true if change made. */
+bool SPGradient::invalidateVector()
+{
+ bool ret = false;
+
+ if (vector.built) {
+ vector.built = false;
+ vector.stops.clear();
+ ret = true;
+ }
+
+ return ret;
+}
+
+/** Return true if change made. */
+bool SPGradient::invalidateArray()
+{
+ bool ret = false;
+
+ if (array.built) {
+ array.built = false;
+ // array.clear();
+ ret = true;
+ }
+
+ return ret;
+}
+
+/** Creates normalized color vector */
+void SPGradient::rebuildVector()
+{
+ gint len = 0;
+ for (auto& child: children) {
+ if (SP_IS_STOP(&child)) {
+ len ++;
+ }
+ }
+
+ has_stops = (len != 0);
+
+ vector.stops.clear();
+
+ SPGradient *reffed = ref ? ref->getObject() : nullptr;
+ if ( !hasStops() && reffed ) {
+ /* Copy vector from referenced gradient */
+ vector.built = true; // Prevent infinite recursion.
+ reffed->ensureVector();
+ if (!reffed->vector.stops.empty()) {
+ vector.built = reffed->vector.built;
+ vector.stops.assign(reffed->vector.stops.begin(), reffed->vector.stops.end());
+ return;
+ }
+ }
+
+ for (auto& child: children) {
+ if (SP_IS_STOP(&child)) {
+ SPStop *stop = SP_STOP(&child);
+
+ SPGradientStop gstop;
+ if (!vector.stops.empty()) {
+ // "Each gradient offset value is required to be equal to or greater than the
+ // previous gradient stop's offset value. If a given gradient stop's offset
+ // value is not equal to or greater than all previous offset values, then the
+ // offset value is adjusted to be equal to the largest of all previous offset
+ // values."
+ gstop.offset = MAX(stop->offset, vector.stops.back().offset);
+ } else {
+ gstop.offset = stop->offset;
+ }
+
+ // "Gradient offset values less than 0 (or less than 0%) are rounded up to
+ // 0%. Gradient offset values greater than 1 (or greater than 100%) are rounded
+ // down to 100%."
+ gstop.offset = CLAMP(gstop.offset, 0, 1);
+
+ gstop.color = stop->getColor();
+ gstop.opacity = stop->getOpacity();
+
+ vector.stops.push_back(gstop);
+ }
+ }
+
+ // Normalize per section 13.2.4 of SVG 1.1.
+ if (vector.stops.empty()) {
+ /* "If no stops are defined, then painting shall occur as if 'none' were specified as the
+ * paint style."
+ */
+ {
+ SPGradientStop gstop;
+ gstop.offset = 0.0;
+ gstop.color.set( 0x00000000 );
+ gstop.opacity = 0.0;
+ vector.stops.push_back(gstop);
+ }
+ {
+ SPGradientStop gstop;
+ gstop.offset = 1.0;
+ gstop.color.set( 0x00000000 );
+ gstop.opacity = 0.0;
+ vector.stops.push_back(gstop);
+ }
+ } else {
+ /* "If one stop is defined, then paint with the solid color fill using the color defined
+ * for that gradient stop."
+ */
+ if (vector.stops.front().offset > 0.0) {
+ // If the first one is not at 0, then insert a copy of the first at 0.
+ SPGradientStop gstop;
+ gstop.offset = 0.0;
+ gstop.color = vector.stops.front().color;
+ gstop.opacity = vector.stops.front().opacity;
+ vector.stops.insert(vector.stops.begin(), gstop);
+ }
+ if (vector.stops.back().offset < 1.0) {
+ // If the last one is not at 1, then insert a copy of the last at 1.
+ SPGradientStop gstop;
+ gstop.offset = 1.0;
+ gstop.color = vector.stops.back().color;
+ gstop.opacity = vector.stops.back().opacity;
+ vector.stops.push_back(gstop);
+ }
+ }
+
+ vector.built = true;
+}
+
+/** Creates normalized color mesh patch array */
+void SPGradient::rebuildArray()
+{
+ // std::cout << "SPGradient::rebuildArray()" << std::endl;
+
+ if( !SP_IS_MESHGRADIENT(this) ) {
+ g_warning( "SPGradient::rebuildArray() called for non-mesh gradient" );
+ return;
+ }
+
+ array.read( SP_MESHGRADIENT( this ) );
+ has_patches = array.patch_columns() > 0;
+}
+
+Geom::Affine
+SPGradient::get_g2d_matrix(Geom::Affine const &ctm, Geom::Rect const &bbox) const
+{
+ if (getUnits() == SP_GRADIENT_UNITS_OBJECTBOUNDINGBOX) {
+ return ( Geom::Scale(bbox.dimensions())
+ * Geom::Translate(bbox.min())
+ * Geom::Affine(ctm) );
+ } else {
+ return ctm;
+ }
+}
+
+Geom::Affine
+SPGradient::get_gs2d_matrix(Geom::Affine const &ctm, Geom::Rect const &bbox) const
+{
+ if (getUnits() == SP_GRADIENT_UNITS_OBJECTBOUNDINGBOX) {
+ return ( gradientTransform
+ * Geom::Scale(bbox.dimensions())
+ * Geom::Translate(bbox.min())
+ * Geom::Affine(ctm) );
+ } else {
+ return gradientTransform * ctm;
+ }
+}
+
+void
+SPGradient::set_gs2d_matrix(Geom::Affine const &ctm,
+ Geom::Rect const &bbox, Geom::Affine const &gs2d)
+{
+ gradientTransform = gs2d * ctm.inverse();
+ if (getUnits() == SP_GRADIENT_UNITS_OBJECTBOUNDINGBOX ) {
+ gradientTransform = ( gradientTransform
+ * Geom::Translate(-bbox.min())
+ * Geom::Scale(bbox.dimensions()).inverse() );
+ }
+ gradientTransform_set = TRUE;
+
+ requestModified(SP_OBJECT_MODIFIED_FLAG);
+}
+
+
+
+
+/* CAIRO RENDERING STUFF */
+
+void
+sp_gradient_pattern_common_setup(cairo_pattern_t *cp,
+ SPGradient *gr,
+ Geom::OptRect const &bbox,
+ double opacity)
+{
+ // set spread type
+ switch (gr->getSpread()) {
+ case SP_GRADIENT_SPREAD_REFLECT:
+ cairo_pattern_set_extend(cp, CAIRO_EXTEND_REFLECT);
+ break;
+ case SP_GRADIENT_SPREAD_REPEAT:
+ cairo_pattern_set_extend(cp, CAIRO_EXTEND_REPEAT);
+ break;
+ case SP_GRADIENT_SPREAD_PAD:
+ default:
+ cairo_pattern_set_extend(cp, CAIRO_EXTEND_PAD);
+ break;
+ }
+
+ // add stops
+ if (!SP_IS_MESHGRADIENT(gr)) {
+ for (auto & stop : gr->vector.stops)
+ {
+ // multiply stop opacity by paint opacity
+ cairo_pattern_add_color_stop_rgba(cp, stop.offset,
+ stop.color.v.c[0], stop.color.v.c[1], stop.color.v.c[2], stop.opacity * opacity);
+ }
+ }
+
+ // set pattern transform matrix
+ Geom::Affine gs2user = gr->gradientTransform;
+ if (gr->getUnits() == SP_GRADIENT_UNITS_OBJECTBOUNDINGBOX && bbox) {
+ Geom::Affine bbox2user(bbox->width(), 0, 0, bbox->height(), bbox->left(), bbox->top());
+ gs2user *= bbox2user;
+ }
+ ink_cairo_pattern_set_matrix(cp, gs2user.inverse());
+}
+
+cairo_pattern_t *
+SPGradient::create_preview_pattern(double width)
+{
+ cairo_pattern_t *pat = nullptr;
+
+ if (!SP_IS_MESHGRADIENT(this)) {
+ ensureVector();
+
+ pat = cairo_pattern_create_linear(0, 0, width, 0);
+
+ for (auto & stop : vector.stops)
+ {
+ cairo_pattern_add_color_stop_rgba(pat, stop.offset,
+ stop.color.v.c[0], stop.color.v.c[1], stop.color.v.c[2], stop.opacity);
+ }
+ } else {
+
+ // For the moment, use the top row of nodes for preview.
+ unsigned columns = array.patch_columns();
+
+ double offset = 1.0/double(columns);
+
+ pat = cairo_pattern_create_linear(0, 0, width, 0);
+
+ for (unsigned i = 0; i < columns+1; ++i) {
+ SPMeshNode* node = array.node( 0, i*3 );
+ cairo_pattern_add_color_stop_rgba(pat, i*offset,
+ node->color.v.c[0], node->color.v.c[1], node->color.v.c[2], node->opacity);
+ }
+ }
+
+ return pat;
+}
+
+bool SPGradient::isSolid() const
+{
+ if (swatch && hasStops() && getStopCount() == 1) {
+ 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 :