1 files changed, 118 insertions, 0 deletions
diff --git a/src/extension/internal/filter/image.h b/src/extension/internal/filter/image.h
new file mode 100644
index 0000000..8820122
--- /dev/null
+++ b/src/extension/internal/filter/image.h
@@ -0,0 +1,118 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#ifndef SEEN_INKSCAPE_EXTENSION_INTERNAL_FILTER_IMAGE_H__
+#define SEEN_INKSCAPE_EXTENSION_INTERNAL_FILTER_IMAGE_H__
+/* Change the 'IMAGE' above to be your file name */
+
+/*
+ * Copyright (C) 2011 Authors:
+ *   Ivan Louette (filters)
+ *   Nicolas Dufour (UI) <nicoduf@yahoo.fr>
+ *
+ * Image filters
+ *   Edge detect
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+/* ^^^ Change the copyright to be you and your e-mail address ^^^ */
+
+#include "filter.h"
+
+#include "extension/internal/clear-n_.h"
+#include "extension/system.h"
+#include "extension/extension.h"
+
+namespace Inkscape {
+namespace Extension {
+namespace Internal {
+namespace Filter {
+
+/**
+    \brief    Custom predefined Edge detect filter.
+    
+    Detect color edges in object.
+
+    Filter's parameters:
+    * Detection type (enum, default Full) -> convolve (kernelMatrix)
+    * Level (0.01->10., default 1.) -> convolve (divisor)
+    * Inverted (boolean, default false) -> convolve (bias)
+*/
+class EdgeDetect : public Inkscape::Extension::Internal::Filter::Filter {
+protected:
+    gchar const * get_filter_text (Inkscape::Extension::Extension * ext) override;
+
+public:
+    EdgeDetect ( ) : Filter() { };
+    ~EdgeDetect ( ) override { if (_filter != nullptr) g_free((void *)_filter); return; }
+
+    static void init () {
+        // clang-format off
+        Inkscape::Extension::build_from_mem(
+            "<inkscape-extension xmlns=\"" INKSCAPE_EXTENSION_URI "\">\n"
+              "<name>" N_("Edge Detect") "</name>\n"
+              "<id>org.inkscape.effect.filter.EdgeDetect</id>\n"
+              "<param name=\"type\" gui-text=\"" N_("Detect:") "\" type=\"optiongroup\" appearance=\"combo\" >\n"
+                "<option value=\"all\">" N_("All") "</option>\n"
+                "<option value=\"vertical\">" N_("Vertical lines") "</option>\n"
+                "<option value=\"horizontal\">" N_("Horizontal lines") "</option>\n"
+              "</param>\n"
+              "<param name=\"level\" gui-text=\"" N_("Level") "\" type=\"float\" appearance=\"full\" min=\"0.1\" max=\"100.0\">1.0</param>\n"
+              "<param name=\"inverted\" gui-text=\"" N_("Invert colors") "\" type=\"bool\" >false</param>\n"
+              "<effect>\n"
+                "<object-type>all</object-type>\n"
+                "<effects-menu>\n"
+                  "<submenu name=\"" N_("Filters") "\">\n"
+                     "<submenu name=\"" N_("Image Effects") "\"/>\n"
+                  "</submenu>\n"
+                "</effects-menu>\n"
+              "<menu-tip>" N_("Detect color edges in object") "</menu-tip>\n"
+              "</effect>\n"
+            "</inkscape-extension>\n", new EdgeDetect());
+        // clang-format on
+    };
+
+};
+
+gchar const *
+EdgeDetect::get_filter_text (Inkscape::Extension::Extension * ext)
+{
+    if (_filter != nullptr) g_free((void *)_filter);
+
+    std::ostringstream matrix;
+    std::ostringstream inverted;
+    std::ostringstream level;
+    
+    const gchar *type = ext->get_param_optiongroup("type");
+
+    level << 1 / ext->get_param_float("level");
+    
+    if ((g_ascii_strcasecmp("vertical", type) == 0)) {
+        matrix << "0 0 0 1 -2 1 0 0 0";
+    } else if ((g_ascii_strcasecmp("horizontal", type) == 0)) {
+        matrix << "0 1 0 0 -2 0 0 1 0";
+    } else {
+        matrix << "0 1 0 1 -4 1 0 1 0";
+    }
+    
+    if (ext->get_param_bool("inverted")) {
+        inverted << "1";
+    } else {
+        inverted << "0";
+    }
+    
+    // clang-format off
+    _filter = g_strdup_printf(
+        "<filter xmlns:inkscape=\"http://www.inkscape.org/namespaces/inkscape\" style=\"color-interpolation-filters:sRGB;\" inkscape:label=\"Edge Detect\">\n"
+          "<feConvolveMatrix in=\"SourceGraphic\" kernelMatrix=\"%s\" order=\"3 3\" bias=\"%s\" divisor=\"%s\" targetX=\"1\" targetY=\"1\" preserveAlpha=\"true\" result=\"convolve\" />\n"
+        "</filter>\n", matrix.str().c_str(), inverted.str().c_str(), level.str().c_str());
+    // clang-format on
+
+    return _filter;
+};
+
+}; /* namespace Filter */
+}; /* namespace Internal */
+}; /* namespace Extension */
+}; /* namespace Inkscape */
+
+/* Change the 'IMAGE' below to be your file name */
+#endif /* SEEN_INKSCAPE_EXTENSION_INTERNAL_FILTER_IMAGE_H__ */