moving trunk for module inkscape

(bzr r1)

1 files changed, 1133 insertions, 0 deletions

diff --git a/src/gradient-chemistry.cpp b/src/gradient-chemistry.cpp
new file mode 100644
index 000000000..aa77ea0ad
--- /dev/null
+++ b/src/gradient-chemistry.cpp
@@ -0,0 +1,1133 @@
+#define __SP_GRADIENT_CHEMISTRY_C__
+
+/*
+ * Various utility methods for gradients
+ *
+ * Authors:
+ *   Lauris Kaplinski <lauris@kaplinski.com>
+ *   bulia byak
+ *
+ * Copyright (C) 2001-2005 authors
+ * Copyright (C) 2001 Ximian, Inc.
+ *
+ * Released under GNU GPL, read the file 'COPYING' for more information
+ */
+
+
+#include "style.h"
+#include "document-private.h"
+#include "desktop-style.h"
+
+#include "sp-gradient-reference.h"
+#include "sp-linear-gradient.h"
+#include "sp-radial-gradient.h"
+#include "sp-stop.h"
+#include "widgets/gradient-vector.h"
+
+#include "sp-text.h"
+#include "sp-tspan.h"
+#include <libnr/nr-matrix-fns.h>
+#include "xml/repr.h"
+#include "svg/svg.h"
+
+
+// Terminology:
+//
+// "vector" is a gradient that has stops but not position coords. It can be referenced by one or
+// more privates. Objects should not refer to it directly. It has no radial/linear distinction.
+//
+// "private" is a gradient that has no stops but has position coords (e.g. center, radius etc for a
+// radial). It references a vector for the actual colors. Each private is only used by one
+// object. It is either linear or radial.
+
+static void sp_gradient_repr_set_link(Inkscape::XML::Node *repr, SPGradient *gr);
+static void sp_item_repr_set_style_gradient(Inkscape::XML::Node *repr, gchar const *property,
+                                            SPGradient *gr, bool recursive);
+
+SPGradient *
+sp_gradient_ensure_vector_normalized(SPGradient *gr)
+{
+    g_return_val_if_fail(gr != NULL, NULL);
+    g_return_val_if_fail(SP_IS_GRADIENT(gr), NULL);
+
+    /* If we are already normalized vector, just return */
+    if (gr->state == SP_GRADIENT_STATE_VECTOR) return gr;
+    /* Fail, if we have wrong state set */
+    if (gr->state != SP_GRADIENT_STATE_UNKNOWN) {
+        g_warning("file %s: line %d: Cannot normalize private gradient to vector (%s)", __FILE__, __LINE__, SP_OBJECT_ID(gr));
+        return NULL;
+    }
+
+    /* First make sure we have vector directly defined (i.e. gr has its own stops) */
+    if (!gr->has_stops) {
+        /* We do not have stops ourselves, so flatten stops as well */
+        sp_gradient_ensure_vector(gr);
+        g_assert(gr->vector.built);
+        // this adds stops from gr->vector as children to gr
+        sp_gradient_repr_write_vector (gr);
+    }
+
+    /* If gr hrefs some other gradient, remove the href */
+    if (gr->ref->getObject()) {
+        /* We are hrefing someone, so require flattening */
+        SP_OBJECT(gr)->updateRepr(((SPObject *) gr)->repr, SP_OBJECT_WRITE_EXT | SP_OBJECT_WRITE_ALL);
+        sp_gradient_repr_set_link(SP_OBJECT_REPR(gr), NULL);
+    }
+
+    /* Everything is OK, set state flag */
+    gr->state = SP_GRADIENT_STATE_VECTOR;
+    return gr;
+}
+
+/**
+ * Creates new private gradient for the given vector
+ */
+
+static SPGradient *
+sp_gradient_get_private_normalized(SPDocument *document, SPGradient *vector, SPGradientType type)
+{
+    g_return_val_if_fail(document != NULL, NULL);
+    g_return_val_if_fail(vector != NULL, NULL);
+    g_return_val_if_fail(SP_IS_GRADIENT(vector), NULL);
+    g_return_val_if_fail(SP_GRADIENT_HAS_STOPS(vector), NULL);
+
+    SPDefs *defs = (SPDefs *) SP_DOCUMENT_DEFS(document);
+
+    // create a new private gradient of the requested type
+    Inkscape::XML::Node *repr;
+    if (type == SP_GRADIENT_TYPE_LINEAR) {
+        repr = sp_repr_new("svg:linearGradient");
+    } else {
+        repr = sp_repr_new("svg:radialGradient");
+    }
+
+    // privates are garbage-collectable
+    repr->setAttribute("inkscape:collect", "always");
+
+    // link to vector
+    sp_gradient_repr_set_link(repr, vector);
+
+    /* Append the new private gradient to defs */
+    SP_OBJECT_REPR(defs)->appendChild(repr);
+    Inkscape::GC::release(repr);
+
+    // get corresponding object
+    SPGradient *gr = (SPGradient *) document->getObjectByRepr(repr);
+    g_assert(gr != NULL);
+    g_assert(SP_IS_GRADIENT(gr));
+
+    return gr;
+}
+
+/**
+Count how many times gr is used by the styles of o and its descendants
+*/
+guint
+count_gradient_hrefs(SPObject *o, SPGradient *gr)
+{
+    if (!o)
+        return 1;
+
+    guint i = 0;
+
+    SPStyle *style = SP_OBJECT_STYLE(o);
+    if (style
+        && style->fill.type == SP_PAINT_TYPE_PAINTSERVER
+        && SP_IS_GRADIENT(SP_STYLE_FILL_SERVER(style))
+        && SP_GRADIENT(SP_STYLE_FILL_SERVER(style)) == gr)
+    {
+        i ++;
+    }
+    if (style
+        && style->stroke.type == SP_PAINT_TYPE_PAINTSERVER
+        && SP_IS_GRADIENT(SP_STYLE_STROKE_SERVER(style))
+        && SP_GRADIENT(SP_STYLE_STROKE_SERVER(style)) == gr)
+    {
+        i ++;
+    }
+
+    for (SPObject *child = sp_object_first_child(o);
+         child != NULL; child = SP_OBJECT_NEXT(child)) {
+        i += count_gradient_hrefs(child, gr);
+    }
+
+    return i;
+}
+
+
+/**
+ * If gr has other users, create a new private; also check if gr links to vector, relink if not
+ */
+SPGradient *
+sp_gradient_fork_private_if_necessary(SPGradient *gr, SPGradient *vector,
+                                      SPGradientType type, SPObject *o)
+{
+    g_return_val_if_fail(gr != NULL, NULL);
+    g_return_val_if_fail(SP_IS_GRADIENT(gr), NULL);
+
+    // Orphaned gradient, no vector with stops at the end of the line; this used to be an assert
+    // but i think we should not abort on this - maybe just write a validity warning into some sort
+    // of log
+    if (!vector || !SP_GRADIENT_HAS_STOPS(vector))
+        return (gr);
+
+    // user is the object that uses this gradient; normally it's item but for tspans, we
+    // check its ancestor text so that tspans don't get different gradients from their
+    // texts.
+    SPObject *user = o;
+    while (SP_IS_TSPAN(user)) {
+        user = SP_OBJECT_PARENT(user);
+    }
+
+    // Check the number of uses of the gradient within this object;
+    // if we are private and there are no other users,
+    if (SP_OBJECT_HREFCOUNT(gr) <= count_gradient_hrefs(user, gr)) {
+        // check vector
+        if ( gr != vector && gr->ref->getObject() != vector ) {
+            /* our href is not the vector, and vector is different from gr; relink */
+            sp_gradient_repr_set_link(SP_OBJECT_REPR(gr), vector);
+        }
+        return gr;
+    }
+
+    SPDocument *doc = SP_OBJECT_DOCUMENT(gr);
+    SPObject *defs = SP_DOCUMENT_DEFS(doc);
+
+    if ((gr->has_stops) ||
+        (gr->state != SP_GRADIENT_STATE_UNKNOWN) ||
+        (SP_OBJECT_PARENT(gr) != SP_OBJECT(defs)) ||
+        (SP_OBJECT_HREFCOUNT(gr) > 1)) {
+        // we have to clone a fresh new private gradient for the given vector
+
+        // create an empty one
+        SPGradient *gr_new = sp_gradient_get_private_normalized(doc, vector, type);
+
+        // copy all the attributes to it
+        Inkscape::XML::Node *repr_new = SP_OBJECT_REPR(gr_new);
+        Inkscape::XML::Node *repr = SP_OBJECT_REPR(gr);
+        repr_new->setAttribute("gradientUnits", repr->attribute("gradientUnits"));
+        repr_new->setAttribute("gradientTransform", repr->attribute("gradientTransform"));
+        repr_new->setAttribute("spreadMethod", repr->attribute("spreadMethod"));
+        if (SP_IS_RADIALGRADIENT(gr)) {
+            repr_new->setAttribute("cx", repr->attribute("cx"));
+            repr_new->setAttribute("cy", repr->attribute("cy"));
+            repr_new->setAttribute("fx", repr->attribute("fx"));
+            repr_new->setAttribute("fy", repr->attribute("fy"));
+            repr_new->setAttribute("r", repr->attribute("r"));
+        } else {
+            repr_new->setAttribute("x1", repr->attribute("x1"));
+            repr_new->setAttribute("y1", repr->attribute("y1"));
+            repr_new->setAttribute("x2", repr->attribute("x2"));
+            repr_new->setAttribute("y2", repr->attribute("y2"));
+        }
+
+        return gr_new;
+    } else {
+        return gr;
+    }
+}
+
+SPGradient *
+sp_gradient_fork_vector_if_necessary (SPGradient *gr)
+{
+    if (SP_OBJECT_HREFCOUNT(gr) > 1) {
+        SPDocument *document = SP_OBJECT_DOCUMENT(gr);
+
+        Inkscape::XML::Node *repr = SP_OBJECT_REPR (gr)->duplicate();
+        SP_OBJECT_REPR (SP_DOCUMENT_DEFS (document))->addChild(repr, NULL);
+        SPGradient *gr_new = (SPGradient *) document->getObjectByRepr(repr);
+        gr_new = sp_gradient_ensure_vector_normalized (gr_new);
+        Inkscape::GC::release(repr);
+        return gr_new;
+    }
+    return gr;
+}
+
+/**
+ * Convert an item's gradient to userspace _without_ preserving coords, setting them to defaults
+ * instead. No forking or reapplying is done because this is only called for newly created privates.  
+ * @return The new gradient.
+ */
+SPGradient *
+sp_gradient_reset_to_userspace (SPGradient *gr, SPItem *item)
+{
+    Inkscape::XML::Node *repr = SP_OBJECT_REPR(gr);
+
+    // calculate the bbox of the item
+    sp_document_ensure_up_to_date(SP_OBJECT_DOCUMENT(item));
+    NR::Rect const bbox = item->invokeBbox(NR::identity()); // we need "true" bbox without item_i2d_affine
+
+    NR::Coord const width = bbox.dimensions()[NR::X];
+    NR::Coord const height = bbox.dimensions()[NR::Y];
+    g_assert(width > 0 && height > 0);
+
+    NR::Point const center = bbox.midpoint();
+
+    if (SP_IS_RADIALGRADIENT(gr)) {
+        sp_repr_set_svg_double(repr, "cx", center[NR::X]);
+        sp_repr_set_svg_double(repr, "cy", center[NR::Y]);
+        sp_repr_set_svg_double(repr, "fx", center[NR::X]);
+        sp_repr_set_svg_double(repr, "fy", center[NR::Y]);
+        sp_repr_set_svg_double(repr, "r", width/2);
+
+        // we want it to be elliptic, not circular
+        NR::Matrix squeeze = NR::Matrix (NR::translate (-center)) * 
+            NR::Matrix (NR::scale(1, height/width)) * 
+            NR::Matrix (NR::translate (center));
+
+        gr->gradientTransform = squeeze;
+        {
+            gchar c[256];
+            if (sp_svg_transform_write(c, 256, gr->gradientTransform)) {
+                SP_OBJECT_REPR(gr)->setAttribute("gradientTransform", c);
+            } else {
+                SP_OBJECT_REPR(gr)->setAttribute("gradientTransform", NULL);
+            }
+        }
+    } else {
+        sp_repr_set_svg_double(repr, "x1", (center - NR::Point(width/2, 0))[NR::X]);
+        sp_repr_set_svg_double(repr, "y1", (center - NR::Point(width/2, 0))[NR::Y]);
+        sp_repr_set_svg_double(repr, "x2", (center + NR::Point(width/2, 0))[NR::X]);
+        sp_repr_set_svg_double(repr, "y2", (center + NR::Point(width/2, 0))[NR::Y]);
+    }
+
+    // set the gradientUnits
+    repr->setAttribute("gradientUnits", "userSpaceOnUse");
+
+    return gr;
+}
+
+/**
+ * Convert an item's gradient to userspace if necessary, also fork it if necessary.
+ * @return The new gradient.
+ */
+SPGradient *
+sp_gradient_convert_to_userspace(SPGradient *gr, SPItem *item, gchar const *property)
+{
+    g_return_val_if_fail(SP_IS_GRADIENT(gr), NULL);
+
+    // First, fork it if it is shared
+    gr = sp_gradient_fork_private_if_necessary(gr, sp_gradient_get_vector(gr, FALSE),
+                                               SP_IS_RADIALGRADIENT(gr) ? SP_GRADIENT_TYPE_RADIAL : SP_GRADIENT_TYPE_LINEAR, SP_OBJECT(item));
+
+    if (gr->units == SP_GRADIENT_UNITS_OBJECTBOUNDINGBOX) {
+
+        Inkscape::XML::Node *repr = SP_OBJECT_REPR(gr);
+
+        // calculate the bbox of the item
+        sp_document_ensure_up_to_date(SP_OBJECT_DOCUMENT(item));
+        NR::Rect const bbox = item->invokeBbox(NR::identity()); // we need "true" bbox without item_i2d_affine
+        NR::Matrix bbox2user(bbox.dimensions()[NR::X], 0,
+                             0, bbox.dimensions()[NR::Y],
+                             bbox.min()[NR::X], bbox.min()[NR::Y]);
+
+        /* skew is the additional transform, defined by the proportions of the item, that we need
+         * to apply to the gradient in order to work around this weird bit from SVG 1.1
+         * (http://www.w3.org/TR/SVG11/pservers.html#LinearGradients):
+         *
+         *   When gradientUnits="objectBoundingBox" and gradientTransform is the identity
+         *   matrix, the stripes of the linear gradient are perpendicular to the gradient
+         *   vector in object bounding box space (i.e., the abstract coordinate system where
+         *   (0,0) is at the top/left of the object bounding box and (1,1) is at the
+         *   bottom/right of the object bounding box). When the object's bounding box is not
+         *   square, the stripes that are conceptually perpendicular to the gradient vector
+         *   within object bounding box space will render non-perpendicular relative to the
+         *   gradient vector in user space due to application of the non-uniform scaling
+         *   transformation from bounding box space to user space.
+         */
+        NR::Matrix skew = bbox2user;
+        double exp = skew.expansion();
+        skew[0] /= exp;
+        skew[1] /= exp;
+        skew[2] /= exp;
+        skew[3] /= exp;
+        skew[4] = 0;
+        skew[5] = 0;
+
+        // apply skew to the gradient
+        gr->gradientTransform = skew;
+        {
+            gchar c[256];
+            if (sp_svg_transform_write(c, 256, gr->gradientTransform)) {
+                SP_OBJECT_REPR(gr)->setAttribute("gradientTransform", c);
+            } else {
+                SP_OBJECT_REPR(gr)->setAttribute("gradientTransform", NULL);
+            }
+        }
+
+        // Matrix to convert points to userspace coords; postmultiply by inverse of skew so
+        // as to cancel it out when it's applied to the gradient during rendering
+        NR::Matrix point_convert = bbox2user * skew.inverse();
+
+        if (SP_IS_RADIALGRADIENT(gr)) {
+            SPRadialGradient *rg = SP_RADIALGRADIENT(gr);
+
+            // original points in the bbox coords
+            NR::Point c_b = NR::Point(rg->cx.computed, rg->cy.computed);
+            NR::Point f_b = NR::Point(rg->fx.computed, rg->fy.computed);
+            double r_b = rg->r.computed;
+
+            // converted points in userspace coords
+            NR::Point c_u = c_b * point_convert;
+            NR::Point f_u = f_b * point_convert;
+            double r_u = r_b * point_convert.expansion();
+
+            sp_repr_set_svg_double(repr, "cx", c_u[NR::X]);
+            sp_repr_set_svg_double(repr, "cy", c_u[NR::Y]);
+            sp_repr_set_svg_double(repr, "fx", f_u[NR::X]);
+            sp_repr_set_svg_double(repr, "fy", f_u[NR::Y]);
+            sp_repr_set_svg_double(repr, "r", r_u);
+
+        } else {
+            SPLinearGradient *lg = SP_LINEARGRADIENT(gr);
+
+            NR::Point p1_b = NR::Point(lg->x1.computed, lg->y1.computed);
+            NR::Point p2_b = NR::Point(lg->x2.computed, lg->y2.computed);
+
+            NR::Point p1_u = p1_b * point_convert;
+            NR::Point p2_u = p2_b * point_convert;
+
+            sp_repr_set_svg_double(repr, "x1", p1_u[NR::X]);
+            sp_repr_set_svg_double(repr, "y1", p1_u[NR::Y]);
+            sp_repr_set_svg_double(repr, "x2", p2_u[NR::X]);
+            sp_repr_set_svg_double(repr, "y2", p2_u[NR::Y]);
+        }
+
+        // set the gradientUnits
+        repr->setAttribute("gradientUnits", "userSpaceOnUse");
+    }
+
+    // apply the gradient to the item (may be necessary if we forked it); not recursive
+    // generally because grouped items will be taken care of later (we're being called
+    // from sp_item_adjust_paint_recursive); however text and all its children should all
+    // refer to one gradient, hence the recursive call for text (because we can't/don't
+    // want to access tspans and set gradients on them separately)
+    if (SP_IS_TEXT(item))
+        sp_item_repr_set_style_gradient(SP_OBJECT_REPR(item), property, gr, true);
+    else
+        sp_item_repr_set_style_gradient(SP_OBJECT_REPR(item), property, gr, false);
+
+    return gr;
+}
+
+void
+sp_gradient_transform_multiply(SPGradient *gradient, NR::Matrix postmul, bool set)
+{
+    if (set) {
+        gradient->gradientTransform = postmul;
+    } else {
+        gradient->gradientTransform *= postmul; // fixme: get gradient transform by climbing to hrefs?
+    }
+    gradient->gradientTransform_set = TRUE;
+
+    gchar c[256];
+    if (sp_svg_transform_write(c, 256, gradient->gradientTransform)) {
+        SP_OBJECT_REPR(gradient)->setAttribute("gradientTransform", c);
+    } else {
+        SP_OBJECT_REPR(gradient)->setAttribute("gradientTransform", NULL);
+    }
+}
+
+SPGradient *
+sp_item_gradient (SPItem *item, bool fill_or_stroke)
+{
+    SPStyle *style = SP_OBJECT_STYLE (item);
+    SPGradient *gradient = NULL;
+
+    if (fill_or_stroke) {
+        if (style && (style->fill.type == SP_PAINT_TYPE_PAINTSERVER)) {
+            SPObject *server = SP_OBJECT_STYLE_FILL_SERVER(item);
+            if (SP_IS_GRADIENT (server)) {
+                gradient = SP_GRADIENT (server);
+            }
+        }
+    } else {
+        if (style && (style->stroke.type == SP_PAINT_TYPE_PAINTSERVER)) {
+            SPObject *server = SP_OBJECT_STYLE_STROKE_SERVER(item);
+            if (SP_IS_GRADIENT (server)) {
+                gradient = SP_GRADIENT (server);
+            }
+        }
+    }
+ 
+   return gradient;
+}
+
+
+SPStop*
+sp_first_stop(SPGradient *gradient)
+{
+  for (SPObject *ochild = sp_object_first_child(gradient); ochild != NULL; ochild = SP_OBJECT_NEXT(ochild)) {
+	if (SP_IS_STOP (ochild))
+		return SP_STOP(ochild);
+  }
+  return NULL;
+}
+
+SPStop*
+sp_prev_stop(SPStop *stop, SPGradient *gradient)
+{
+	if (sp_object_first_child(SP_OBJECT(gradient)) == SP_OBJECT(stop)) 
+		return NULL;
+	SPObject *found = NULL;
+	for ( SPObject *ochild = sp_object_first_child(SP_OBJECT(gradient)) ; ochild != NULL ; ochild = SP_OBJECT_NEXT(ochild) ) {
+		if (SP_IS_STOP (ochild)) {
+			found = ochild;
+		}
+		if (SP_OBJECT_NEXT(ochild) == SP_OBJECT(stop) || SP_OBJECT(ochild) == SP_OBJECT(stop)) {
+			break;
+		}
+	}
+	return SP_STOP(found);
+}
+
+SPStop*
+sp_next_stop(SPStop *stop)
+{
+  for (SPObject *ochild = SP_OBJECT_NEXT(stop); ochild != NULL; ochild = SP_OBJECT_NEXT(ochild)) {
+	if (SP_IS_STOP (ochild))
+		return SP_STOP(ochild);
+  }
+  return NULL;
+}
+
+SPStop*
+sp_last_stop(SPGradient *gradient)
+{
+    for (SPStop *stop = sp_first_stop (gradient); stop != NULL; stop = sp_next_stop (stop)) {
+        if (sp_next_stop (stop) == NULL)
+		return stop;
+  }
+  return NULL;
+}
+
+
+void
+sp_item_gradient_edit_stop (SPItem *item, guint point_num, bool fill_or_stroke)
+{
+    SPGradient *gradient = sp_item_gradient (item, fill_or_stroke);
+
+    if (!gradient || !SP_IS_GRADIENT(gradient))
+        return;
+
+    SPGradient *vector = sp_gradient_get_vector (gradient, false);
+    switch (point_num) {
+        case POINT_LG_P1:
+        case POINT_RG_CENTER:
+        case POINT_RG_FOCUS:
+        {
+            GtkWidget *dialog = sp_gradient_vector_editor_new (vector, sp_first_stop (vector));
+            gtk_widget_show (dialog);
+        }
+        break;
+
+        case POINT_LG_P2:
+        case POINT_RG_R1:
+        case POINT_RG_R2:
+        {
+            GtkWidget *dialog = sp_gradient_vector_editor_new (vector, sp_last_stop (vector));
+            gtk_widget_show (dialog);
+        }
+        break;
+        default:
+            break;
+    }
+}
+
+guint32
+sp_item_gradient_stop_query_style (SPItem *item, guint point_num, bool fill_or_stroke)
+{
+    SPGradient *gradient = sp_item_gradient (item, fill_or_stroke);
+
+    if (!gradient || !SP_IS_GRADIENT(gradient))
+        return 0;
+
+    SPGradient *vector = sp_gradient_get_vector (gradient, false);
+
+    if (!vector) // orphan!
+        return 0; // what else to do?
+
+    switch (point_num) {
+        case POINT_LG_P1:
+        case POINT_RG_CENTER:
+        case POINT_RG_FOCUS:
+        {
+            SPStop *first = sp_first_stop (vector);
+            if (first) {
+                return sp_stop_get_rgba32(first);
+            }
+        }
+        break;
+
+        case POINT_LG_P2:
+        case POINT_RG_R1:
+        case POINT_RG_R2:
+        {
+            SPStop *last = sp_last_stop (vector);
+            if (last) {
+                return sp_stop_get_rgba32(last);
+            }
+        }
+        break;
+        default:
+            break;
+    }
+    return 0;
+}
+
+void
+sp_item_gradient_stop_set_style (SPItem *item, guint point_num, bool fill_or_stroke, SPCSSAttr *stop)
+{
+    SPGradient *gradient = sp_item_gradient (item, fill_or_stroke);
+
+    if (!gradient || !SP_IS_GRADIENT(gradient))
+        return;
+
+    SPGradient *vector = sp_gradient_get_vector (gradient, false);
+
+    if (!vector) // orphan!
+        return;
+
+    vector = sp_gradient_fork_vector_if_necessary (vector);
+    if ( gradient != vector && gradient->ref->getObject() != vector ) {
+        sp_gradient_repr_set_link(SP_OBJECT_REPR(gradient), vector);
+    }
+
+    switch (point_num) {
+        case POINT_LG_P1:
+        case POINT_RG_CENTER:
+        case POINT_RG_FOCUS:
+        {
+            SPStop *first = sp_first_stop (vector);
+            if (first) {
+                sp_repr_css_change (SP_OBJECT_REPR (first), stop, "style");
+            }
+        }
+        break;
+
+        case POINT_LG_P2:
+        case POINT_RG_R1:
+        case POINT_RG_R2:
+        {
+            SPStop *last = sp_last_stop (vector);
+            if (last) {
+                sp_repr_css_change (SP_OBJECT_REPR (last), stop, "style");
+            }
+        }
+        break;
+        default:
+            break;
+    }
+}
+
+void
+sp_item_gradient_reverse_vector (SPItem *item, bool fill_or_stroke)
+{
+    SPGradient *gradient = sp_item_gradient (item, fill_or_stroke);
+    if (!gradient || !SP_IS_GRADIENT(gradient))
+        return;
+
+    SPGradient *vector = sp_gradient_get_vector (gradient, false);
+    if (!vector) // orphan!
+        return;
+
+    vector = sp_gradient_fork_vector_if_necessary (vector);
+    if ( gradient != vector && gradient->ref->getObject() != vector ) {
+        sp_gradient_repr_set_link(SP_OBJECT_REPR(gradient), vector);
+    }
+
+    GSList *child_reprs = NULL;
+    GSList *child_objects = NULL;
+    std::vector<double> offsets;
+    for (SPObject *child = sp_object_first_child(vector);
+         child != NULL; child = SP_OBJECT_NEXT(child)) {
+        child_reprs = g_slist_prepend (child_reprs, SP_OBJECT_REPR(child));
+        child_objects = g_slist_prepend (child_objects, child);
+        offsets.push_back(sp_repr_get_double_attribute(SP_OBJECT_REPR(child), "offset", 0));
+    }
+
+    GSList *child_copies = NULL;
+    for (GSList *i = child_reprs; i != NULL; i = i->next) {
+        Inkscape::XML::Node *repr = (Inkscape::XML::Node *) i->data;
+        child_copies = g_slist_append (child_copies, repr->duplicate());
+    }
+
+
+    for (GSList *i = child_objects; i != NULL; i = i->next) {
+        SPObject *child = SP_OBJECT (i->data);
+        child->deleteObject();
+    }
+
+    std::vector<double>::iterator iter = offsets.end() - 1;
+    for (GSList *i = child_copies; i != NULL; i = i->next) {
+        Inkscape::XML::Node *copy = (Inkscape::XML::Node *) i->data;
+        vector->appendChildRepr(copy);
+        sp_repr_set_svg_double (copy, "offset", 1 - *iter);
+        iter --;
+        Inkscape::GC::release(copy);
+    }
+
+    g_slist_free (child_reprs);
+    g_slist_free (child_copies);
+    g_slist_free (child_objects);
+}
+
+
+
+/**
+Set the position of point point_num of the gradient applied to item (either fill_or_stroke) to
+p_w (in desktop coordinates). Write_repr if you want the change to become permanent.
+*/
+void
+sp_item_gradient_set_coords (SPItem *item, guint point_num, NR::Point p_w, bool fill_or_stroke, bool write_repr, bool scale)
+{
+    SPGradient *gradient = sp_item_gradient (item, fill_or_stroke);
+
+    if (!gradient || !SP_IS_GRADIENT(gradient))
+        return;
+
+    gradient = sp_gradient_convert_to_userspace (gradient, item, fill_or_stroke? "fill" : "stroke");
+
+    NR::Matrix i2d = sp_item_i2d_affine (item);
+    NR::Point p = p_w * i2d.inverse();
+    p *= (gradient->gradientTransform).inverse();
+    // now p is in gradient's original coordinates
+
+    Inkscape::XML::Node *repr = SP_OBJECT_REPR(gradient);
+
+    if (SP_IS_LINEARGRADIENT(gradient)) {
+        SPLinearGradient *lg = SP_LINEARGRADIENT(gradient);
+        switch (point_num) {
+            case POINT_LG_P1:
+                if (scale) {
+                    lg->x2.computed += (lg->x1.computed - p[NR::X]);
+                    lg->y2.computed += (lg->y1.computed - p[NR::Y]);
+                } 
+                lg->x1.computed = p[NR::X];
+                lg->y1.computed = p[NR::Y];
+                if (write_repr) {
+                    if (scale) {
+                        sp_repr_set_svg_double(repr, "x2", lg->x2.computed);
+                        sp_repr_set_svg_double(repr, "y2", lg->y2.computed);
+                    }
+                    sp_repr_set_svg_double(repr, "x1", lg->x1.computed);
+                    sp_repr_set_svg_double(repr, "y1", lg->y1.computed);
+                } else {
+                    SP_OBJECT (gradient)->requestModified(SP_OBJECT_MODIFIED_FLAG);
+                }
+                break;
+            case POINT_LG_P2:
+                if (scale) {
+                    lg->x1.computed += (lg->x2.computed - p[NR::X]);
+                    lg->y1.computed += (lg->y2.computed - p[NR::Y]);
+                } 
+                lg->x2.computed = p[NR::X];
+                lg->y2.computed = p[NR::Y];
+                if (write_repr) {
+                    if (scale) {
+                        sp_repr_set_svg_double(repr, "x1", lg->x1.computed);
+                        sp_repr_set_svg_double(repr, "y1", lg->y1.computed);
+                    }
+                    sp_repr_set_svg_double(repr, "x2", lg->x2.computed);
+                    sp_repr_set_svg_double(repr, "y2", lg->y2.computed);
+                } else {
+                    SP_OBJECT (gradient)->requestModified(SP_OBJECT_MODIFIED_FLAG);
+                }
+			break;
+		default:
+			break;
+		}
+	} else if (SP_IS_RADIALGRADIENT(gradient)) {
+
+		SPRadialGradient *rg = SP_RADIALGRADIENT(gradient);
+		NR::Point c (rg->cx.computed, rg->cy.computed);
+		NR::Point c_w = c * gradient->gradientTransform * i2d; // now in desktop coords
+           if ((point_num == POINT_RG_R1 || point_num == POINT_RG_R2) && NR::L2 (p_w - c_w) < 1e-3) {
+               // prevent setting a radius too close to the center
+               return;
+           }
+		NR::Matrix new_transform;
+		bool transform_set = false;
+
+		switch (point_num) {
+		case POINT_RG_CENTER:
+			rg->fx.computed = p[NR::X] + (rg->fx.computed - rg->cx.computed);
+			rg->fy.computed = p[NR::Y] + (rg->fy.computed - rg->cy.computed);
+			rg->cx.computed = p[NR::X];
+			rg->cy.computed = p[NR::Y];
+			if (write_repr) {
+				sp_repr_set_svg_double(repr, "fx", rg->fx.computed);
+				sp_repr_set_svg_double(repr, "fy", rg->fy.computed);
+				sp_repr_set_svg_double(repr, "cx", rg->cx.computed);
+				sp_repr_set_svg_double(repr, "cy", rg->cy.computed);
+			} else {
+				SP_OBJECT (gradient)->requestModified(SP_OBJECT_MODIFIED_FLAG);
+			}
+			break;
+		case POINT_RG_FOCUS:
+			rg->fx.computed = p[NR::X];
+			rg->fy.computed = p[NR::Y];
+			if (write_repr) {
+				sp_repr_set_svg_double(repr, "fx", rg->fx.computed);
+				sp_repr_set_svg_double(repr, "fy", rg->fy.computed);
+			} else {
+				SP_OBJECT (gradient)->requestModified(SP_OBJECT_MODIFIED_FLAG);
+			}
+			break;
+		case POINT_RG_R1:
+			{
+				NR::Point r1_w = (c + NR::Point(rg->r.computed, 0)) * gradient->gradientTransform * i2d;
+				double r1_angle = NR::atan2(r1_w - c_w);
+				double move_angle = NR::atan2(p_w - c_w) - r1_angle;
+				double move_stretch = NR::L2(p_w - c_w) / NR::L2(r1_w - c_w);
+
+				NR::Matrix move = NR::Matrix (NR::translate (-c_w)) *
+												 NR::Matrix (NR::rotate(-r1_angle)) * 
+												 NR::Matrix (NR::scale(move_stretch, scale? move_stretch : 1)) *
+												 NR::Matrix (NR::rotate(r1_angle)) * 
+												 NR::Matrix (NR::rotate(move_angle)) * 
+												 NR::Matrix (NR::translate (c_w));
+
+				new_transform = gradient->gradientTransform * i2d * move * i2d.inverse(); 
+				transform_set = true;
+
+				break;
+			}
+		case POINT_RG_R2:
+			{
+				NR::Point r2_w = (c + NR::Point(0, -rg->r.computed)) * gradient->gradientTransform * i2d;
+				double r2_angle = NR::atan2(r2_w - c_w);
+				double move_angle = NR::atan2(p_w - c_w) - r2_angle;
+				double move_stretch = NR::L2(p_w - c_w) / NR::L2(r2_w - c_w);
+
+				NR::Matrix move = NR::Matrix (NR::translate (-c_w)) *
+												 NR::Matrix (NR::rotate(-r2_angle)) * 
+												 NR::Matrix (NR::scale(move_stretch, scale? move_stretch : 1)) *
+												 NR::Matrix (NR::rotate(r2_angle)) * 
+												 NR::Matrix (NR::rotate(move_angle)) * 
+												 NR::Matrix (NR::translate (c_w));
+
+				new_transform = gradient->gradientTransform * i2d * move * i2d.inverse(); 
+				transform_set = true;
+
+				break;
+			}
+		}
+
+		if (transform_set) {
+				gradient->gradientTransform = new_transform; 
+				gradient->gradientTransform_set = TRUE;
+				if (write_repr) {
+					gchar s[256];
+					if (sp_svg_transform_write(s, 256, gradient->gradientTransform)) {
+						SP_OBJECT_REPR(gradient)->setAttribute("gradientTransform", s);
+					} else {
+						SP_OBJECT_REPR(gradient)->setAttribute("gradientTransform", NULL);
+					}
+				} else {
+					SP_OBJECT (gradient)->requestModified(SP_OBJECT_MODIFIED_FLAG);
+				}
+		}
+	}
+}
+
+SPGradient *
+sp_item_gradient_get_vector (SPItem *item, bool fill_or_stroke)
+{
+    SPGradient *gradient = sp_item_gradient (item, fill_or_stroke);
+
+    if (gradient)
+        return sp_gradient_get_vector (gradient, false);
+    return NULL;
+}
+
+SPGradientSpread 
+sp_item_gradient_get_spread (SPItem *item, bool fill_or_stroke)
+{
+    SPGradient *gradient = sp_item_gradient (item, fill_or_stroke);
+
+    if (gradient)
+        return sp_gradient_get_spread (gradient);
+    return SP_GRADIENT_SPREAD_PAD;
+}
+
+
+/**
+Returns the position of point point_num of the gradient applied to item (either fill_or_stroke), 
+in desktop coordinates.
+*/
+
+NR::Point
+sp_item_gradient_get_coords (SPItem *item, guint point_num, bool fill_or_stroke)
+{
+    SPGradient *gradient = sp_item_gradient (item, fill_or_stroke);
+
+    NR::Point p (0, 0);
+
+    if (!gradient)
+        return p;
+
+    if (SP_IS_LINEARGRADIENT(gradient)) {
+        SPLinearGradient *lg = SP_LINEARGRADIENT(gradient);
+        switch (point_num) {
+            case POINT_LG_P1:
+                p = NR::Point (lg->x1.computed, lg->y1.computed);
+                break;
+            case POINT_LG_P2:
+                p = NR::Point (lg->x2.computed, lg->y2.computed);
+                break;
+        }
+    } else     if (SP_IS_RADIALGRADIENT(gradient)) {
+        SPRadialGradient *rg = SP_RADIALGRADIENT(gradient);
+        switch (point_num) {
+            case POINT_RG_CENTER:
+                p = NR::Point (rg->cx.computed, rg->cy.computed);
+                break;
+            case POINT_RG_FOCUS:
+                p = NR::Point (rg->fx.computed, rg->fy.computed);
+                break;
+            case POINT_RG_R1:
+                p = NR::Point (rg->cx.computed + rg->r.computed, rg->cy.computed);
+                break;
+            case POINT_RG_R2:
+                p = NR::Point (rg->cx.computed, rg->cy.computed - rg->r.computed);
+                break;
+        }
+    }
+
+    if (SP_GRADIENT(gradient)->units == SP_GRADIENT_UNITS_OBJECTBOUNDINGBOX) {
+        sp_document_ensure_up_to_date(SP_OBJECT_DOCUMENT(item));
+        NR::Rect const bbox = item->invokeBbox(NR::identity()); // we need "true" bbox without item_i2d_affine
+        p *= NR::Matrix(bbox.dimensions()[NR::X], 0,
+                        0, bbox.dimensions()[NR::Y],
+                        bbox.min()[NR::X], bbox.min()[NR::Y]);
+    }
+    p *= NR::Matrix(gradient->gradientTransform) * sp_item_i2d_affine(item);
+    return p;
+}
+
+
+/**
+ * Sets item fill or stroke to the gradient of the specified type with given vector, creating
+ * new private gradient, if needed.
+ * gr has to be a normalized vector.
+ */
+
+SPGradient *
+sp_item_set_gradient(SPItem *item, SPGradient *gr, SPGradientType type, bool is_fill)
+{
+    g_return_val_if_fail(item != NULL, NULL);
+    g_return_val_if_fail(SP_IS_ITEM(item), NULL);
+    g_return_val_if_fail(gr != NULL, NULL);
+    g_return_val_if_fail(SP_IS_GRADIENT(gr), NULL);
+    g_return_val_if_fail(gr->state == SP_GRADIENT_STATE_VECTOR, NULL);
+
+    SPStyle *style = SP_OBJECT_STYLE(item);
+    g_assert(style != NULL);
+
+    guint style_type = is_fill? style->fill.type : style->stroke.type;
+    SPPaintServer *ps = NULL;
+    if (style_type == SP_PAINT_TYPE_PAINTSERVER)
+        ps = is_fill? SP_STYLE_FILL_SERVER(style) : SP_STYLE_STROKE_SERVER(style);
+
+    if (ps
+        && ( (type == SP_GRADIENT_TYPE_LINEAR && SP_IS_LINEARGRADIENT(ps)) ||
+             (type == SP_GRADIENT_TYPE_RADIAL && SP_IS_RADIALGRADIENT(ps))   ) )
+    {
+
+        /* Current fill style is the gradient of the required type */
+        SPGradient *current = SP_GRADIENT(ps);
+
+        //g_print("hrefcount %d   count %d\n", SP_OBJECT_HREFCOUNT(ig), count_gradient_hrefs(SP_OBJECT(item), ig));
+
+        if (SP_OBJECT_HREFCOUNT(current) == 1 || 
+            SP_OBJECT_HREFCOUNT(current) == count_gradient_hrefs(SP_OBJECT(item), current)) {
+
+            // current is private and it's either used once, or all its uses are by children of item;
+            // so just change its href to vector
+
+            if ( current != gr && sp_gradient_get_vector(current, false) != gr ) {
+                /* href is not the vector */
+                sp_gradient_repr_set_link(SP_OBJECT_REPR(current), gr);
+            }
+            SP_OBJECT(item)->requestDisplayUpdate(SP_OBJECT_MODIFIED_FLAG | SP_OBJECT_STYLE_MODIFIED_FLAG);
+            return current;
+
+        } else {
+
+            // the gradient is not private, or it is shared with someone else;
+            // normalize it (this includes creating new private if necessary)
+            SPGradient *normalized = sp_gradient_fork_private_if_necessary(current, gr, type, item);
+
+            g_return_val_if_fail(normalized != NULL, NULL);
+
+            if (normalized != current) {
+
+                /* We have to change object style here; recursive because this is used from
+                 * fill&stroke and must work for groups etc. */
+                sp_item_repr_set_style_gradient(SP_OBJECT_REPR(item), is_fill? "fill" : "stroke", normalized, true);
+            }
+            SP_OBJECT(item)->requestDisplayUpdate(SP_OBJECT_MODIFIED_FLAG | SP_OBJECT_STYLE_MODIFIED_FLAG);
+            return normalized;
+        }
+
+    } else {
+        /* Current fill style is not a gradient or wrong type, so construct everything */
+        SPGradient *constructed = sp_gradient_get_private_normalized(SP_OBJECT_DOCUMENT(item), gr, type);
+        constructed = sp_gradient_reset_to_userspace(constructed, item);
+        sp_item_repr_set_style_gradient(SP_OBJECT_REPR(item),
+                                        ( is_fill ? "fill" : "stroke" ),
+                                        constructed, true);
+        SP_OBJECT(item)->requestDisplayUpdate(( SP_OBJECT_MODIFIED_FLAG |
+                                                SP_OBJECT_STYLE_MODIFIED_FLAG ));
+        return constructed;
+    }
+}
+
+static void
+sp_gradient_repr_set_link(Inkscape::XML::Node *repr, SPGradient *link)
+{
+    g_return_if_fail(repr != NULL);
+    g_return_if_fail(link != NULL);
+    g_return_if_fail(SP_IS_GRADIENT(link));
+
+    gchar *ref;
+    if (link) {
+        gchar const *id = SP_OBJECT_ID(link);
+        size_t const len = strlen(id);
+        ref = (gchar*) alloca(len + 2);
+        *ref = '#';
+        memcpy(ref + 1, id, len + 1);
+    } else {
+        ref = NULL;
+    }
+
+    repr->setAttribute("xlink:href", ref);
+}
+
+static void
+sp_item_repr_set_style_gradient(Inkscape::XML::Node *repr, gchar const *property,
+                                SPGradient *gr, bool recursive)
+{
+    g_return_if_fail(repr != NULL);
+    g_return_if_fail(gr != NULL);
+    g_return_if_fail(SP_IS_GRADIENT(gr));
+
+    gchar *val = g_strdup_printf("url(#%s)", SP_OBJECT_ID(gr));
+
+    SPCSSAttr *css = sp_repr_css_attr_new();
+    sp_repr_css_set_property(css, property, val);
+    g_free(val);
+    if (recursive) {
+        sp_repr_css_change_recursive(repr, css, "style");
+    } else {
+        sp_repr_css_change(repr, css, "style");
+    }
+    sp_repr_css_attr_unref(css);
+}
+
+/*
+ * Get default normalized gradient vector of document, create if there is none
+ */
+
+SPGradient *
+sp_document_default_gradient_vector(SPDocument *document, guint32 color)
+{
+    SPDefs *defs = (SPDefs *) SP_DOCUMENT_DEFS(document);
+
+    Inkscape::XML::Node *repr = sp_repr_new("svg:linearGradient");
+
+    repr->setAttribute("inkscape:collect", "always");
+    // set here, but removed when it's edited in the gradient editor
+    // to further reduce clutter, we could
+    // (1) here, search gradients by color and return what is found without duplication
+    // (2) in fill & stroke, show only one copy of each gradient in list
+
+    Inkscape::XML::Node *stop = sp_repr_new("svg:stop");
+
+    gchar b[64];
+    sp_svg_write_color(b, 64, color);
+
+    {
+        gchar *t = g_strdup_printf("stop-color:%s;stop-opacity:1;", b);
+        stop->setAttribute("style", t);
+        g_free(t);
+    }
+
+    stop->setAttribute("offset", "0");
+
+    repr->appendChild(stop);
+    Inkscape::GC::release(stop);
+
+    stop = sp_repr_new("svg:stop");
+
+    {
+        gchar *t = g_strdup_printf("stop-color:%s;stop-opacity:0;", b);
+        stop->setAttribute("style", t);
+        g_free(t);
+    }
+
+    stop->setAttribute("offset", "1");
+
+    repr->appendChild(stop);
+    Inkscape::GC::release(stop);
+
+    SP_OBJECT_REPR(defs)->addChild(repr, NULL);
+    Inkscape::GC::release(repr);
+
+    /* fixme: This does not look like nice */
+    SPGradient *gr;
+    gr = (SPGradient *) document->getObjectByRepr(repr);
+    g_assert(gr != NULL);
+    g_assert(SP_IS_GRADIENT(gr));
+    /* fixme: Maybe add extra sanity check here */
+    gr->state = SP_GRADIENT_STATE_VECTOR;
+
+    return gr;
+}
+
+/**
+Return the preferred vector for \a o, made from (in order of preference) its current vector,
+current fill or stroke color, or from desktop style if \a o is NULL or doesn't have style.
+*/
+SPGradient *
+sp_gradient_vector_for_object(SPDocument *const doc, SPDesktop *const desktop,
+                              SPObject *const o, bool const is_fill)
+{
+    guint32 rgba = 0;
+    if (o == NULL || SP_OBJECT_STYLE(o) == NULL) {
+        rgba = sp_desktop_get_color(desktop, is_fill);
+    } else {
+        // take the color of the object
+        SPStyle const &style = *SP_OBJECT_STYLE(o);
+        SPIPaint const &paint = ( is_fill
+                                  ? style.fill
+                                  : style.stroke );
+        if (paint.type == SP_PAINT_TYPE_COLOR) {
+            rgba = sp_color_get_rgba32_ualpha(&paint.value.color, 0xff);
+        } else if (paint.type == SP_PAINT_TYPE_PAINTSERVER) {
+            SPObject *server = is_fill? SP_OBJECT_STYLE_FILL_SERVER(o) : SP_OBJECT_STYLE_STROKE_SERVER(o);
+            if (SP_IS_GRADIENT (server)) {
+                return sp_gradient_get_vector(SP_GRADIENT (server), TRUE);
+            } else {
+                rgba = sp_desktop_get_color(desktop, is_fill);
+            }
+        } else {
+            // if o doesn't use flat color, then take current color of the desktop.
+            rgba = sp_desktop_get_color(desktop, is_fill);
+        }
+    }
+
+    return sp_document_default_gradient_vector(doc, rgba);
+}
+
+/*
+  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:encoding=utf-8:textwidth=99 :