1 files changed, 155 insertions, 0 deletions
diff --git a/src/object/filters/offset.cpp b/src/object/filters/offset.cpp
new file mode 100644
index 0000000..b859598
--- /dev/null
+++ b/src/object/filters/offset.cpp
@@ -0,0 +1,155 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/** \file
+ * SVG <feOffset> implementation.
+ *
+ */
+/*
+ * Authors:
+ *   hugo Rodrigues <haa.rodrigues@gmail.com>
+ *   Niko Kiirala <niko@kiirala.com>
+ *   Abhishek Sharma
+ *
+ * Copyright (C) 2006,2007 authors
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include <2geom/transforms.h>
+
+#include "offset.h"
+
+#include "attributes.h"
+#include "helper-fns.h"
+
+#include "display/nr-filter.h"
+#include "display/nr-filter-offset.h"
+
+#include "svg/svg.h"
+
+#include "xml/repr.h"
+
+SPFeOffset::SPFeOffset() : SPFilterPrimitive() {
+    this->dx = 0;
+    this->dy = 0;
+}
+
+SPFeOffset::~SPFeOffset() = default;
+
+/**
+ * Reads the Inkscape::XML::Node, and initializes SPFeOffset variables.  For this to get called,
+ * our name must be associated with a repr via "sp_object_type_register".  Best done through
+ * sp-object-repr.cpp's repr_name_entries array.
+ */
+void SPFeOffset::build(SPDocument *document, Inkscape::XML::Node *repr) {
+	SPFilterPrimitive::build(document, repr);
+
+	this->readAttr(SPAttr::DX);
+	this->readAttr(SPAttr::DY);
+}
+
+/**
+ * Drops any allocated memory.
+ */
+void SPFeOffset::release() {
+	SPFilterPrimitive::release();
+}
+
+/**
+ * Sets a specific value in the SPFeOffset.
+ */
+void SPFeOffset::set(SPAttr key, gchar const *value) {
+    double read_num;
+
+    switch(key) {
+        case SPAttr::DX:
+            read_num = value ? helperfns_read_number(value) : 0;
+
+            if (read_num != this->dx) {
+                this->dx = read_num;
+                this->parent->requestModified(SP_OBJECT_MODIFIED_FLAG);
+            }
+            break;
+        case SPAttr::DY:
+            read_num = value ? helperfns_read_number(value) : 0;
+
+            if (read_num != this->dy) {
+                this->dy = read_num;
+                this->parent->requestModified(SP_OBJECT_MODIFIED_FLAG);
+            }
+            break;
+            
+	/*DEAL WITH SETTING ATTRIBUTES HERE*/
+        default:
+        	SPFilterPrimitive::set(key, value);
+            break;
+    }
+}
+
+/**
+ * Receives update notifications.
+ */
+void SPFeOffset::update(SPCtx *ctx, guint flags) {
+    if (flags & SP_OBJECT_MODIFIED_FLAG) {
+        this->readAttr(SPAttr::DX);
+        this->readAttr(SPAttr::DY);
+    }
+
+    SPFilterPrimitive::update(ctx, flags);
+}
+
+/**
+ * Writes its settings to an incoming repr object, if any.
+ */
+Inkscape::XML::Node* SPFeOffset::write(Inkscape::XML::Document *doc, Inkscape::XML::Node *repr, guint flags) {
+    /* TODO: Don't just clone, but create a new repr node and write all
+     * relevant values into it */
+    if (!repr) {
+        repr = this->getRepr()->duplicate(doc);
+    }
+
+    SPFilterPrimitive::write(doc, repr, flags);
+
+    return repr;
+}
+
+void SPFeOffset::build_renderer(Inkscape::Filters::Filter* filter) {
+    g_assert(filter != nullptr);
+
+    int primitive_n = filter->add_primitive(Inkscape::Filters::NR_FILTER_OFFSET);
+    Inkscape::Filters::FilterPrimitive *nr_primitive = filter->get_primitive(primitive_n);
+    Inkscape::Filters::FilterOffset *nr_offset = dynamic_cast<Inkscape::Filters::FilterOffset*>(nr_primitive);
+    g_assert(nr_offset != nullptr);
+
+    this->renderer_common(nr_primitive);
+
+    nr_offset->set_dx(this->dx);
+    nr_offset->set_dy(this->dy);
+}
+
+/**
+ * Calculate the region taken up by an offset
+ *
+ * @param region The original shape's region or previous primitive's region output.
+ */
+Geom::Rect SPFeOffset::calculate_region(Geom::Rect region)
+{
+    // Because blur calculates its drawing space based on the resulting region
+    // An offset will actually harm blur's ability to draw, even though it shouldn't
+    // A future fix would require the blur to figure out its region minus any downstream
+    // offset (this effects drop-shadows)
+    // TODO: region *= Geom::Translate(this->dx, this->dy);
+    region.unionWith(region * Geom::Translate(this->dx, this->dy));
+    return region;
+}
+
+
+/*
+  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 :