reduce usage of desktop coordinates (#341)

- avoid unnecessary internal usage of desktop coordinates, e.g.
  in SpellCheck::compareTextBboxes
- document whether a function argument is in document  or desktop
  coordinates, e.g. for SPDocument::getItemsInBox

2 files changed, 7 insertions, 6 deletions

diff --git a/src/ui/dialog/export.cpp b/src/ui/dialog/export.cpp
index 160f83965..2c1ebb45d 100644
--- a/src/ui/dialog/export.cpp
+++ b/src/ui/dialog/export.cpp
@@ -1050,7 +1050,7 @@ void Export::onExport ()
             }
             pHYs = (pHYs_adj->get_value() > 0.01) ? pHYs_adj->get_value() : dpi;
 
-            Geom::OptRect area = item->desktopVisualBounds();
+            Geom::OptRect area = item->documentVisualBounds();
             if (area) {
                 gint width = (gint) (area->width() * dpi / DPI_BASE + 0.5);
                 gint height = (gint) (area->height() * dpi / DPI_BASE + 0.5);
@@ -1154,11 +1154,13 @@ void Export::onExport ()
         prog_dlg->set_data("current", GINT_TO_POINTER(0));
         prog_dlg->set_data("total", GINT_TO_POINTER(0));
 
+        auto area = Geom::Rect(Geom::Point(x0, y0), Geom::Point(x1, y1)) * desktop->dt2doc();
+
         /* Do export */
         std::vector<SPItem*> x;
         std::vector<SPItem*> selected(desktop->getSelection()->items().begin(), desktop->getSelection()->items().end());
         ExportResult status = sp_export_png_file(desktop->getDocument(), path.c_str(),
-                              Geom::Rect(Geom::Point(x0, y0), Geom::Point(x1, y1)), width, height, pHYs, pHYs, //previously xdpi, ydpi. 
+                              area, width, height, pHYs, pHYs, //previously xdpi, ydpi.
                               nv->pagecolor,
                               onProgressCallback, (void*)prog_dlg,
                               FALSE,
diff --git a/src/ui/dialog/spellcheck.cpp b/src/ui/dialog/spellcheck.cpp
index ab0282298..eb32d2245 100644
--- a/src/ui/dialog/spellcheck.cpp
+++ b/src/ui/dialog/spellcheck.cpp
@@ -252,15 +252,14 @@ bool SpellCheck::compareTextBboxes (gconstpointer a, gconstpointer b)//returns a
     SPItem *i1 = SP_ITEM(a);
     SPItem *i2 = SP_ITEM(b);
 
-    Geom::OptRect bbox1 = i1->desktopVisualBounds();
-    Geom::OptRect bbox2 = i2->desktopVisualBounds();
+    Geom::OptRect bbox1 = i1->documentVisualBounds();
+    Geom::OptRect bbox2 = i2->documentVisualBounds();
     if (!bbox1 || !bbox2) {
         return false;
     }
 
     // vector between top left corners
-    Geom::Point diff = Geom::Point(bbox2->min()[Geom::X], bbox2->max()[Geom::Y]) -
-                       Geom::Point(bbox1->min()[Geom::X], bbox1->max()[Geom::Y]);
+    Geom::Point diff = bbox1->min() - bbox2->min();
 
     return diff[Geom::Y] == 0 ? (diff[Geom::X] < 0) : (diff[Geom::Y] < 0);
 }