1 files changed, 236 insertions, 0 deletions
diff --git a/src/extension/internal/filter/filter.cpp b/src/extension/internal/filter/filter.cpp
new file mode 100644
index 0000000..c9779c7
--- /dev/null
+++ b/src/extension/internal/filter/filter.cpp
@@ -0,0 +1,236 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Authors:
+ *   Ted Gould <ted@gould.cx>
+ *
+ * Copyright (C) 2008 Authors
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include "desktop.h"
+#include "selection.h"
+#include "extension/extension.h"
+#include "extension/effect.h"
+#include "extension/system.h"
+#include "xml/repr.h"
+#include "xml/simple-node.h"
+#include "xml/attribute-record.h"
+#include "object/sp-defs.h"
+
+#include "filter.h"
+
+namespace Inkscape {
+namespace Extension {
+namespace Internal {
+namespace Filter {
+
+Filter::Filter() :
+    Inkscape::Extension::Implementation::Implementation(),
+    _filter(nullptr) {
+    return;
+}
+
+Filter::Filter(gchar const * filter) :
+    Inkscape::Extension::Implementation::Implementation(),
+    _filter(filter) {
+    return;
+}
+
+Filter::~Filter () {
+    if (_filter != nullptr) {
+        _filter = nullptr;
+    }
+
+    return;
+}
+
+bool Filter::load(Inkscape::Extension::Extension * /*module*/)
+{
+    return true;
+}
+
+Inkscape::Extension::Implementation::ImplementationDocumentCache *Filter::newDocCache(Inkscape::Extension::Extension * /*ext*/,
+										      Inkscape::UI::View::View * /*doc*/)
+{
+    return nullptr;
+}
+
+gchar const *Filter::get_filter_text(Inkscape::Extension::Extension * /*ext*/)
+{
+    return _filter;
+}
+
+Inkscape::XML::Document *
+Filter::get_filter (Inkscape::Extension::Extension * ext) {
+    gchar const * filter = get_filter_text(ext);
+    return sp_repr_read_mem(filter, strlen(filter), nullptr);
+}
+
+void
+Filter::merge_filters( Inkscape::XML::Node * to, Inkscape::XML::Node * from,
+		       Inkscape::XML::Document * doc,
+		       gchar const * srcGraphic, gchar const * srcGraphicAlpha)
+{
+    if (from == nullptr) return;
+
+    // copy attributes
+    for ( const auto & iter : from->attributeList()) {
+        gchar const * attr = g_quark_to_string(iter.key);
+        //printf("Attribute List: %s\n", attr);
+        if (!strcmp(attr, "id")) continue; // nope, don't copy that one!
+        to->setAttribute(attr, from->attribute(attr));
+
+        if (!strcmp(attr, "in") || !strcmp(attr, "in2") || !strcmp(attr, "in3")) {
+            if (srcGraphic != nullptr && !strcmp(from->attribute(attr), "SourceGraphic")) {
+                to->setAttribute(attr, srcGraphic);
+            }
+
+            if (srcGraphicAlpha != nullptr && !strcmp(from->attribute(attr), "SourceAlpha")) {
+                to->setAttribute(attr, srcGraphicAlpha);
+            }
+        }
+    }
+
+    // for each child call recursively
+    for (Inkscape::XML::Node * from_child = from->firstChild();
+         from_child != nullptr ; from_child = from_child->next()) {
+        Glib::ustring name = "svg:";
+        name += from_child->name();
+
+        Inkscape::XML::Node * to_child = doc->createElement(name.c_str());
+        to->appendChild(to_child);
+        merge_filters(to_child, from_child, doc, srcGraphic, srcGraphicAlpha);
+
+        if (from_child == from->firstChild() && !strcmp("filter", from->name()) && srcGraphic != nullptr && to_child->attribute("in") == nullptr) {
+            to_child->setAttribute("in", srcGraphic);
+        }
+        Inkscape::GC::release(to_child);
+    }
+}
+
+#define FILTER_SRC_GRAPHIC       "fbSourceGraphic"
+#define FILTER_SRC_GRAPHIC_ALPHA "fbSourceGraphicAlpha"
+
+void Filter::effect(Inkscape::Extension::Effect *module, Inkscape::UI::View::View *document,
+                    Inkscape::Extension::Implementation::ImplementationDocumentCache * /*docCache*/)
+{
+    Inkscape::XML::Document *filterdoc = get_filter(module);
+    if (filterdoc == nullptr) {
+        return; // could not parse the XML source of the filter; typically parser will stderr a warning
+    }
+
+    //printf("Calling filter effect\n");
+    Inkscape::Selection * selection = ((SPDesktop *)document)->selection;
+
+    // TODO need to properly refcount the items, at least
+    std::vector<SPItem*> items(selection->items().begin(), selection->items().end());
+
+    Inkscape::XML::Document * xmldoc = document->doc()->getReprDoc();
+    Inkscape::XML::Node * defsrepr = document->doc()->getDefs()->getRepr();
+
+    for(auto spitem : items) {
+        Inkscape::XML::Node *node = spitem->getRepr();
+
+        SPCSSAttr * css = sp_repr_css_attr(node, "style");
+        gchar const * filter = sp_repr_css_property(css, "filter", nullptr);
+
+        if (filter == nullptr) {
+
+            Inkscape::XML::Node * newfilterroot = xmldoc->createElement("svg:filter");
+            merge_filters(newfilterroot, filterdoc->root(), xmldoc);
+            defsrepr->appendChild(newfilterroot);
+            document->doc()->resources_changed_signals[g_quark_from_string("filter")].emit();
+
+            Glib::ustring url = "url(#"; url += newfilterroot->attribute("id"); url += ")";
+
+
+            Inkscape::GC::release(newfilterroot);
+
+            sp_repr_css_set_property(css, "filter", url.c_str());
+            sp_repr_css_set(node, css, "style");
+        } else {
+            if (strncmp(filter, "url(#", strlen("url(#")) || filter[strlen(filter) - 1] != ')') {
+                // This is not url(#id) -- we can't handle it
+                continue;
+            }
+
+            gchar * lfilter = g_strndup(filter + 5, strlen(filter) - 6);
+            Inkscape::XML::Node * filternode = nullptr;
+            for (Inkscape::XML::Node * child = defsrepr->firstChild(); child != nullptr; child = child->next()) {
+                if (!strcmp(lfilter, child->attribute("id"))) {
+                    filternode = child;
+                    break;
+                }
+            }
+            g_free(lfilter);
+
+            // no filter
+            if (filternode == nullptr) {
+                g_warning("no assigned filter found!");
+                continue;
+            }
+
+            if (filternode->lastChild() == nullptr) {
+                // empty filter, we insert
+                merge_filters(filternode, filterdoc->root(), xmldoc);
+            } else {
+                // existing filter, we merge
+                filternode->lastChild()->setAttribute("result", FILTER_SRC_GRAPHIC);
+                Inkscape::XML::Node * alpha = xmldoc->createElement("svg:feColorMatrix");
+                alpha->setAttribute("result", FILTER_SRC_GRAPHIC_ALPHA);
+                alpha->setAttribute("in", FILTER_SRC_GRAPHIC); // not required, but we're being explicit
+                alpha->setAttribute("values", "0 0 0 -1 0 0 0 0 -1 0 0 0 0 -1 0 0 0 0 1 0");
+
+                filternode->appendChild(alpha);
+
+                merge_filters(filternode, filterdoc->root(), xmldoc, FILTER_SRC_GRAPHIC, FILTER_SRC_GRAPHIC_ALPHA);
+
+                Inkscape::GC::release(alpha);
+            }
+        }
+    }
+
+    return;
+}
+
+#include "extension/internal/clear-n_.h"
+
+void
+Filter::filter_init (gchar const * id, gchar const * name, gchar const * submenu, gchar const * tip, gchar const * filter)
+{
+    // clang-format off
+    gchar * xml_str = g_strdup_printf(
+        "<inkscape-extension xmlns=\"" INKSCAPE_EXTENSION_URI "\">\n"
+        "<name>%s</name>\n"
+        "<id>org.inkscape.effect.filter.%s</id>\n"
+        "<effect>\n"
+        "<object-type>all</object-type>\n"
+        "<effects-menu>\n"
+        "<submenu name=\"" N_("Filters") "\" />\n"
+        "<submenu name=\"%s\"/>\n"
+        "</effects-menu>\n"
+        "<menu-tip>%s</menu-tip>\n"
+        "</effect>\n"
+        "</inkscape-extension>\n", name, id, submenu, tip);
+    // clang-format on
+    Inkscape::Extension::build_from_mem(xml_str, new Filter(filter));
+    g_free(xml_str);
+    return;
+}
+
+}; /* namespace Filter */
+}; /* namespace Internal */
+}; /* namespace Extension */
+}; /* namespace Inkscape */
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :