Write distinguished corners of 3D boxes to the svg representation from which the box can be recomputed.

This is used to fix several bugs related to the editing of boxes resulting from cloning, undo operations or newly opened documents (we had stray pointers to SPPaths before that made Inkscape crash).

(bzr r3239)

1 files changed, 124 insertions, 25 deletions

diff --git a/src/box3d.cpp b/src/box3d.cpp
index 1e4cad8b3..101cce565 100644
--- a/src/box3d.cpp
+++ b/src/box3d.cpp
@@ -16,6 +16,7 @@
  */
 
 #include <glibmm/i18n.h>
+#include "attributes.h"
 #include "box3d.h"
 
 static void sp_3dbox_class_init(SP3DBoxClass *klass);
@@ -32,6 +33,9 @@ static gchar *sp_3dbox_description(SPItem *item);
 //static void sp_3dbox_set_shape(SPShape *shape);
 static void sp_3dbox_set_shape(SP3DBox *box3d);
 
+static gchar * sp_3dbox_get_corner_coords_string (SP3DBox *box, guint id);
+static std::pair<gdouble, gdouble> sp_3dbox_get_coord_pair_from_string (const gchar *);
+
 static SPGroupClass *parent_class;
 
 GType
@@ -78,8 +82,25 @@ sp_3dbox_class_init(SP3DBoxClass *klass)
 static void
 sp_3dbox_init(SP3DBox *box)
 {
-    // We create all faces in the beginning (but only the non-degenerate ones
-    // should be written to the svg representation later in sp_3dbox_write).
+    for (int i = 0; i < 8; ++i) box->corners[i] = NR::Point(0,0);
+    for (int i = 0; i < 6; ++i) box->faces[i] = NULL;
+}
+
+static void
+sp_3dbox_build(SPObject *object, SPDocument *document, Inkscape::XML::Node *repr)
+{
+    if (((SPObjectClass *) (parent_class))->build) {
+        ((SPObjectClass *) (parent_class))->build(object, document, repr);
+    }
+
+    SP3DBox *box = SP_3DBOX (object);
+
+    sp_object_read_attr(object, "inkscape:box3dcornerA");
+    sp_object_read_attr(object, "inkscape:box3dcornerB");
+    sp_object_read_attr(object, "inkscape:box3dcornerC");
+
+    // TODO: We create all faces in the beginning, but only the non-degenerate ones
+    //       should be written to the svg representation later in sp_3dbox_write.
     Box3D::Axis cur_plane, axis, dir1, dir2;
     Box3D::FrontOrRear cur_pos;
     for (int i = 0; i < 3; ++i) {
@@ -98,16 +119,10 @@ sp_3dbox_init(SP3DBox *box)
                                     cur_plane, cur_pos);
         }
     }
-}
 
-static void
-sp_3dbox_build(SPObject *object, SPDocument *document, Inkscape::XML::Node *repr)
-{
-    if (((SPObjectClass *) (parent_class))->build) {
-        ((SPObjectClass *) (parent_class))->build(object, document, repr);
-    }
-
-    //sp_object_read_attr(object, "width");
+    // Check whether the paths of the faces of the box need to be linked to existing paths in the
+    // document (e.g., after a 'redo' operation or after opening a file) and do so if necessary.
+    sp_3dbox_link_to_existing_paths (box, repr);
 }
 
 /*
@@ -127,17 +142,30 @@ sp_3dbox_release (SPObject *object)
 }
 */
 
-static void sp_3dbox_set(SPObject *object, unsigned int key, const gchar *value)
+static void
+sp_3dbox_update_corner_with_value_from_svg (SPObject *object, guint corner_id, const gchar *value)
 {
-    //SP3DBox *box3d = SP_3DBOX(object);
+    if (value == NULL) return;
+    SP3DBox *box = SP_3DBOX(object);
 
+    std::pair<gdouble, gdouble> coord_pair = sp_3dbox_get_coord_pair_from_string (value);
+    box->corners[corner_id] = NR::Point (coord_pair.first, coord_pair.second);
+    sp_3dbox_recompute_corners (box, box->corners[2], box->corners[1], box->corners[5]);
+    object->requestDisplayUpdate(SP_OBJECT_MODIFIED_FLAG);
+}
+
+static void sp_3dbox_set(SPObject *object, unsigned int key, const gchar *value)
+{
     switch (key) {
-        /***
-        case SP_ATTR_WIDTH:
-            rect->width.readOrUnset(value);
-            object->requestDisplayUpdate(SP_OBJECT_MODIFIED_FLAG);
+        case SP_ATTR_INKSCAPE_3DBOX_CORNER_A:
+            sp_3dbox_update_corner_with_value_from_svg (object, 2, value);
+            break;
+        case SP_ATTR_INKSCAPE_3DBOX_CORNER_B:
+            sp_3dbox_update_corner_with_value_from_svg (object, 1, value);
+            break;
+        case SP_ATTR_INKSCAPE_3DBOX_CORNER_C:
+            sp_3dbox_update_corner_with_value_from_svg (object, 5, value);
             break;
-        ***/
 	default:
             if (((SPObjectClass *) (parent_class))->set) {
                 ((SPObjectClass *) (parent_class))->set(object, key, value);
@@ -146,24 +174,19 @@ static void sp_3dbox_set(SPObject *object, unsigned int key, const gchar *value)
     }
 }
 
-
 static void
 sp_3dbox_update(SPObject *object, SPCtx *ctx, guint flags)
 {
-    //SP3DBox *box3d = SP_3DBOX(object);
-
     /* Invoke parent method */
     if (((SPObjectClass *) (parent_class))->update)
         ((SPObjectClass *) (parent_class))->update(object, ctx, flags);
-    
-    //sp_3dbox_set_shape (box3d);
 }
 
 
 
 static Inkscape::XML::Node *sp_3dbox_write(SPObject *object, Inkscape::XML::Node *repr, guint flags)
 {
-    SP3DBox *box3d = SP_3DBOX(object);
+    SP3DBox *box = SP_3DBOX(object);
     // FIXME: How to handle other contexts???
     // FIXME: Is tools_isactive(..) more recommended to check for the current context/tool?
     if (!SP_IS_3DBOX_CONTEXT(inkscape_active_event_context()))
@@ -173,10 +196,28 @@ static Inkscape::XML::Node *sp_3dbox_write(SPObject *object, Inkscape::XML::Node
         Inkscape::XML::Document *xml_doc = sp_document_repr_doc(SP_OBJECT_DOCUMENT(object));
         repr = xml_doc->createElement("svg:g");
         repr->setAttribute("sodipodi:type", "inkscape:3dbox");
+        /* Hook paths to the faces of the box */
+        for (int i = 0; i < 6; ++i) {
+            box->faces[i]->hook_path_to_3dbox();
+        }
     }
 
     for (int i = 0; i < 6; ++i) {
-        box3d->faces[i]->set_path_repr();
+        box->faces[i]->set_path_repr();
+    }
+
+    if (flags & SP_OBJECT_WRITE_EXT) {
+        gchar *coords;
+        coords = sp_3dbox_get_corner_coords_string (box, 2);
+        repr->setAttribute("inkscape:box3dcornerA", coords);
+
+        coords = sp_3dbox_get_corner_coords_string (box, 1);
+        repr->setAttribute("inkscape:box3dcornerB", coords);
+
+        coords = sp_3dbox_get_corner_coords_string (box, 5);
+        repr->setAttribute("inkscape:box3dcornerC", coords);
+
+        g_free ((void *) coords);
     }
 
     if (((SPObjectClass *) (parent_class))->write) {
@@ -259,6 +300,38 @@ sp_3dbox_update_curves (SP3DBox *box) {
 }
 
 void
+sp_3dbox_link_to_existing_paths (SP3DBox *box, Inkscape::XML::Node *repr) {
+    // TODO: We should probably destroy the existing paths and recreate them because we don't know
+    //       precisely which path corresponds to which face. Does this make a difference?
+    //       In sp_3dbox_write we write the correct paths anyway, don't we? But we could get into
+    //       trouble at a later stage when we only write single faces for degenerate boxes.
+
+    SPDocument *document = SP_OBJECT_DOCUMENT(box);
+    guint face_id = 0;
+
+    for (Inkscape::XML::Node *i = sp_repr_children(repr); i != NULL; i = sp_repr_next(i)) {
+        if (face_id > 5) {
+            g_warning ("SVG representation of 3D boxes must contain 6 paths or less.\n");
+            break;
+        }
+
+        SPObject *face_object = document->getObjectByRepr((Inkscape::XML::Node *) i);
+        if (!SP_IS_PATH(face_object)) {
+            g_warning ("SVG representation of 3D boxes should only contain paths.\n");
+            continue;
+        }
+        box->faces[face_id]->hook_path_to_3dbox(SP_PATH(face_object));
+        ++face_id;
+    }
+    if (face_id < 6) {
+        //g_warning ("SVG representation of 3D boxes should contain exactly 6 paths (degenerate boxes are not yet supported).\n");
+        // TODO: Check whether it is safe to add the remaining paths to the box and do so in case it is.
+        //       (But we also land here for newly created boxes where we shouldn't add any paths because
+        //       This is done in sp_3dbox_write later on.
+    }
+}
+
+void
 sp_3dbox_move_corner_in_XY_plane (SP3DBox *box, guint id, NR::Point pt, Box3D::Axis axes)
 {
     NR::Point A (box->corners[id ^ Box3D::XY]);
@@ -346,6 +419,32 @@ sp_3dbox_get_midpoint_between_corners (SP3DBox *box, guint id_corner1, guint id_
     }
 }
 
+static gchar *
+sp_3dbox_get_corner_coords_string (SP3DBox *box, guint id)
+{
+    id = id % 8;
+    return g_strdup_printf ("%f,%f", box->corners[id][NR::X], box->corners[id][NR::Y]);
+}
+
+static std::pair<gdouble, gdouble>
+sp_3dbox_get_coord_pair_from_string (const gchar *coords)
+{
+    gchar **coordlist = g_strsplit( coords, ",", 0);
+    // We might as well rely on g_strtod to convert the NULL pointer to 0.0,
+    // but we include the following test anyway
+    if (coordlist[0] == NULL || coordlist[1] == NULL) {
+        g_strfreev (coordlist);
+        g_warning ("Coordinate conversion failed.\n");
+        return std::make_pair(0.0, 0.0);
+    }
+
+    gdouble coord1 = g_strtod(coordlist[0], NULL);
+    gdouble coord2 = g_strtod(coordlist[1], NULL);
+    g_strfreev (coordlist);
+
+    return std::make_pair(coord1, coord2);
+}
+
 /*
   Local Variables:
   mode:c++