1 files changed, 157 insertions, 0 deletions
diff --git a/src/helper/pixbuf-ops.cpp b/src/helper/pixbuf-ops.cpp
new file mode 100644
index 0000000..dbe9ff6
--- /dev/null
+++ b/src/helper/pixbuf-ops.cpp
@@ -0,0 +1,157 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Helpers for SPItem -> gdk_pixbuf related stuff
+ *
+ * Authors:
+ *   John Cliff <simarilius@yahoo.com>
+ *   Jon A. Cruz <jon@joncruz.org>
+ *   Abhishek Sharma
+ *
+ * Copyright (C) 2008 John Cliff
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include <2geom/transforms.h>
+
+#include "helper/png-write.h"
+#include "display/cairo-utils.h"
+#include "display/drawing.h"
+#include "display/drawing-context.h"
+#include "document.h"
+#include "object/sp-root.h"
+#include "object/sp-defs.h"
+#include "object/sp-use.h"
+#include "util/units.h"
+#include "inkscape.h"
+
+#include "helper/pixbuf-ops.h"
+
+#include <gdk/gdk.h>
+
+// TODO look for copy-n-paste duplication of this function:
+/**
+ * Hide all items that are not in list, recursively, skipping groups and defs.
+ */
+static void hide_other_items_recursively(SPObject *object, const std::vector<SPItem*> &items, unsigned dkey)
+{
+    SPItem *item = dynamic_cast<SPItem *>(object);
+    if (!item) {
+        // <defs>, <metadata>, etc.
+        return;
+    }
+
+    if (std::find (items.begin(), items.end(), item) != items.end()) {
+        // It's in our list, don't hide!
+        return;
+    }
+
+    if ( !dynamic_cast<SPRoot  *>(item) &&
+         !dynamic_cast<SPGroup *>(item) &&
+         !dynamic_cast<SPUse   *>(item) ) {
+        // Hide if not container or def.
+        item->invoke_hide(dkey);
+    }
+
+    for (auto& child: object->children) {
+        hide_other_items_recursively(&child, items, dkey);
+    }
+}
+
+
+/**
+    generates a bitmap from given items
+    the bitmap is stored in RAM and not written to file
+    @param document Inkscape document.
+    @param area     Export area in document units.
+    @param dpi      Resolution.
+    @param items    Vector of pointers to SPItems to export. Export all items if empty.
+    @param opaque   Set items opacity to 1 (used by Cairo renderer for filtered objects rendered as bitmaps).
+    @return The created GdkPixbuf structure or nullptr if rendering failed.
+*/
+Inkscape::Pixbuf *sp_generate_internal_bitmap(SPDocument *document,
+                                              Geom::Rect const &area,
+                                              double dpi,
+                                              std::vector<SPItem *> items,
+                                              bool opaque)
+{
+    // Geometry
+    if (area.hasZeroArea()) {
+        return nullptr;
+    }
+
+    Geom::Point origin = area.min();
+    double scale_factor = Inkscape::Util::Quantity::convert(dpi, "px", "in");
+    Geom::Affine affine = Geom::Translate(-origin) * Geom::Scale (scale_factor, scale_factor);
+
+    int width  = std::ceil(scale_factor * area.width());
+    int height = std::ceil(scale_factor * area.height());
+
+    // Document
+    document->ensureUpToDate();
+    unsigned dkey = SPItem::display_key_new(1);
+
+    // Drawing
+    Inkscape::Drawing drawing; // New drawing for offscreen rendering.
+    drawing.setExact(true); // Maximum quality for blurs.
+
+    /* Create ArenaItems and set transform */
+    Inkscape::DrawingItem *root = document->getRoot()->invoke_show( drawing, dkey, SP_ITEM_SHOW_DISPLAY);
+    root->setTransform(affine);
+    drawing.setRoot(root);
+
+    // Hide all items we don't want, instead of showing only requested items,
+    // because that would not work if the shown item references something in defs.
+    if (!items.empty()) {
+        hide_other_items_recursively(document->getRoot(), items, dkey);
+    }
+
+    Geom::IntRect final_area = Geom::IntRect::from_xywh(0, 0, width, height);
+    drawing.update(final_area);
+
+    if (opaque) {
+        // Required by sp_asbitmap_render().
+        for (auto item : items) {
+            if (item->get_arenaitem(dkey)) {
+                item->get_arenaitem(dkey)->setOpacity(1.0);
+            }
+        }
+    }
+
+    // Rendering
+    cairo_surface_t *surface = cairo_image_surface_create(CAIRO_FORMAT_ARGB32, width, height);
+    Inkscape::Pixbuf* pixbuf = nullptr;
+
+    if (cairo_surface_status(surface) == CAIRO_STATUS_SUCCESS) {
+        Inkscape::DrawingContext dc(surface, Geom::Point(0,0));
+
+        // render items
+        drawing.render(dc, final_area, Inkscape::DrawingItem::RENDER_BYPASS_CACHE);
+
+        pixbuf = new Inkscape::Pixbuf(surface);
+
+    } else {
+
+        long long size =
+            (long long) height *
+            (long long) cairo_format_stride_for_width(CAIRO_FORMAT_ARGB32, width);
+        g_warning("sp_generate_internal_bitmap: not enough memory to create pixel buffer. Need %lld.", size);
+        cairo_surface_destroy(surface);
+    }
+
+    // Return to previous state.
+    document->getRoot()->invoke_hide(dkey);
+
+    return pixbuf;
+}
+
+/*
+  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 :