Remove all NRRect use.

(bzr r10582.1.5)

22 files changed, 178 insertions, 250 deletions

diff --git a/src/desktop.cpp b/src/desktop.cpp
index f1a63d22c..dc06f773e 100644
--- a/src/desktop.cpp
+++ b/src/desktop.cpp
@@ -144,8 +144,6 @@ SPDesktop::SPDesktop() :
     page_border( 0 ),
     current( 0 ),
     _focusMode(false),
-    zooms_past( 0 ),
-    zooms_future( 0 ),
     dkey( 0 ),
     number( 0 ),
     window_state(0),
@@ -410,9 +408,6 @@ void SPDesktop::destroy()
 
     delete _guides_message_context;
     _guides_message_context = NULL;
-
-    g_list_free (zooms_past);
-    g_list_free (zooms_future);
 }
 
 SPDesktop::~SPDesktop() {}
@@ -771,25 +766,12 @@ SPDesktop::point() const
  * Put current zoom data in history list.
  */
 void
-SPDesktop::push_current_zoom (GList **history)
+SPDesktop::push_current_zoom (std::list<Geom::Rect> &history)
 {
-    Geom::Rect const area = get_display_area();
+    Geom::Rect area = get_display_area();
 
-    NRRect *old_zoom = g_new(NRRect, 1);
-    old_zoom->x0 = area.min()[Geom::X];
-    old_zoom->x1 = area.max()[Geom::X];
-    old_zoom->y0 = area.min()[Geom::Y];
-    old_zoom->y1 = area.max()[Geom::Y];
-    if ( *history == NULL
-         || !( ( ((NRRect *) ((*history)->data))->x0 == old_zoom->x0 ) &&
-               ( ((NRRect *) ((*history)->data))->x1 == old_zoom->x1 ) &&
-               ( ((NRRect *) ((*history)->data))->y0 == old_zoom->y0 ) &&
-               ( ((NRRect *) ((*history)->data))->y1 == old_zoom->y1 ) ) )
-    {
-        *history = g_list_prepend (*history, old_zoom);
-    } else {
-        g_free(old_zoom);
-        old_zoom = 0;
+    if (history.empty() || history.front() == area) {
+        history.push_front(area);
     }
 }
 
@@ -804,10 +786,9 @@ SPDesktop::set_display_area (double x0, double y0, double x1, double y1, double
 
     // save the zoom
     if (log) {
-        push_current_zoom(&zooms_past);
+        push_current_zoom(zooms_past);
         // if we do a logged zoom, our zoom-forward list is invalidated, so delete it
-        g_list_free (zooms_future);
-        zooms_future = NULL;
+        zooms_future.clear();
     }
 
     double const cx = 0.5 * (x0 + x1);
@@ -882,23 +863,20 @@ Geom::Rect SPDesktop::get_display_area() const
 void
 SPDesktop::prev_zoom()
 {
-    if (zooms_past == NULL) {
+    if (zooms_past.empty()) {
         messageStack()->flash(Inkscape::WARNING_MESSAGE, _("No previous zoom."));
         return;
     }
 
     // push current zoom into forward zooms list
-    push_current_zoom (&zooms_future);
+    push_current_zoom (zooms_future);
 
     // restore previous zoom
-    set_display_area (((NRRect *) zooms_past->data)->x0,
-            ((NRRect *) zooms_past->data)->y0,
-            ((NRRect *) zooms_past->data)->x1,
-            ((NRRect *) zooms_past->data)->y1,
-            0, false);
+    Geom::Rect past = zooms_past.front();
+    set_display_area (past.left(), past.top(), past.right(), past.bottom(), 0, false);
 
     // remove the just-added zoom from the past zooms list
-    zooms_past = g_list_remove (zooms_past, ((NRRect *) zooms_past->data));
+    zooms_past.pop_front();
 }
 
 /**
@@ -907,23 +885,20 @@ SPDesktop::prev_zoom()
 void
 SPDesktop::next_zoom()
 {
-    if (zooms_future == NULL) {
+    if (zooms_future.empty()) {
         this->messageStack()->flash(Inkscape::WARNING_MESSAGE, _("No next zoom."));
         return;
     }
 
     // push current zoom into past zooms list
-    push_current_zoom (&zooms_past);
+    push_current_zoom (zooms_past);
 
     // restore next zoom
-    set_display_area (((NRRect *) zooms_future->data)->x0,
-            ((NRRect *) zooms_future->data)->y0,
-            ((NRRect *) zooms_future->data)->x1,
-            ((NRRect *) zooms_future->data)->y1,
-            0, false);
+    Geom::Rect future = zooms_future.front();
+    set_display_area (future.left(), future.top(), future.right(), future.bottom(), 0, false);
 
     // remove the just-used zoom from the zooms_future list
-    zooms_future = g_list_remove (zooms_future, ((NRRect *) zooms_future->data));
+    zooms_future.pop_front();
 }
 
 /** \brief  Performs a quick zoom into what the user is working on
diff --git a/src/desktop.h b/src/desktop.h
index 5dcd014ca..d15fb7d69 100644
--- a/src/desktop.h
+++ b/src/desktop.h
@@ -117,8 +117,9 @@ public:
     SPCSSAttr     *current;     ///< current style
     bool           _focusMode;  ///< Whether we're focused working or general working
 
-    GList *zooms_past;
-    GList *zooms_future;
+    std::list<Geom::Rect> zooms_past;
+    std::list<Geom::Rect> zooms_future;
+
     bool _quick_zoom_enabled; ///< Signifies that currently we're in quick zoom mode
     Geom::Rect _quick_zoom_stored_area;  ///< The area of the screen before quick zoom
     unsigned int dkey;
@@ -359,7 +360,7 @@ private:
     bool grids_visible; /* don't set this variable directly, use the method below */
     void set_grids_visible(bool visible);
 
-    void push_current_zoom (GList**);
+    void push_current_zoom(std::list<Geom::Rect> &);
 
     sigc::signal<void,SPDesktop*,SPDocument*>     _document_replaced_signal;
     sigc::signal<void>                 _activate_signal;
diff --git a/src/document.cpp b/src/document.cpp
index cf2474fe5..d45041296 100644
--- a/src/document.cpp
+++ b/src/document.cpp
@@ -534,7 +534,7 @@ gdouble SPDocument::getWidth() const
 
     gdouble result = root->width.computed;
     if (root->width.unit == SVGLength::PERCENT && root->viewBox_set) {
-        result = root->viewBox.x1 - root->viewBox.x0;
+        result = root->viewBox.width();
     }
     return result;
 }
@@ -542,7 +542,7 @@ gdouble SPDocument::getWidth() const
 void SPDocument::setWidth(gdouble width, const SPUnit *unit)
 {
     if (root->width.unit == SVGLength::PERCENT && root->viewBox_set) { // set to viewBox=
-        root->viewBox.x1 = root->viewBox.x0 + sp_units_get_pixels (width, *unit);
+        root->viewBox.setMax(Geom::Point(root->viewBox.left() + sp_units_get_pixels (width, *unit), root->viewBox.bottom()));
     } else { // set to width=
         gdouble old_computed = root->width.computed;
         root->width.computed = sp_units_get_pixels (width, *unit);
@@ -557,16 +557,28 @@ void SPDocument::setWidth(gdouble width, const SPUnit *unit)
         }
 
         if (root->viewBox_set)
-            root->viewBox.x1 = root->viewBox.x0 + (root->width.computed / old_computed) * (root->viewBox.x1 - root->viewBox.x0);
+            root->viewBox.setMax(Geom::Point(root->viewBox.left() + (root->width.computed / old_computed) * root->viewBox.width(), root->viewBox.bottom()));
     }
 
     root->updateRepr();
 }
 
+gdouble SPDocument::getHeight() const
+{
+    g_return_val_if_fail(this->priv != NULL, 0.0);
+    g_return_val_if_fail(this->root != NULL, 0.0);
+
+    gdouble result = root->height.computed;
+    if (root->height.unit == SVGLength::PERCENT && root->viewBox_set) {
+        result = root->viewBox.height();
+    }
+    return result;
+}
+
 void SPDocument::setHeight(gdouble height, const SPUnit *unit)
 {
     if (root->height.unit == SVGLength::PERCENT && root->viewBox_set) { // set to viewBox=
-        root->viewBox.y1 = root->viewBox.y0 + sp_units_get_pixels (height, *unit);
+        root->viewBox.setMax(Geom::Point(root->viewBox.right(), root->viewBox.top() + sp_units_get_pixels (height, *unit)));
     } else { // set to height=
         gdouble old_computed = root->height.computed;
         root->height.computed = sp_units_get_pixels (height, *unit);
@@ -581,24 +593,12 @@ void SPDocument::setHeight(gdouble height, const SPUnit *unit)
         }
 
         if (root->viewBox_set)
-            root->viewBox.y1 = root->viewBox.y0 + (root->height.computed / old_computed) * (root->viewBox.y1 - root->viewBox.y0);
+            root->viewBox.setMax(Geom::Point(root->viewBox.right(), root->viewBox.top() + (root->height.computed / old_computed) * root->viewBox.height()));
     }
 
     root->updateRepr();
 }
 
-gdouble SPDocument::getHeight() const
-{
-    g_return_val_if_fail(this->priv != NULL, 0.0);
-    g_return_val_if_fail(this->root != NULL, 0.0);
-
-    gdouble result = root->height.computed;
-    if (root->height.unit == SVGLength::PERCENT && root->viewBox_set) {
-        result = root->viewBox.y1 - root->viewBox.y0;
-    }
-    return result;
-}
-
 Geom::Point SPDocument::getDimensions() const
 {
     return Geom::Point(getWidth(), getHeight());
@@ -941,15 +941,9 @@ void SPDocument::setupViewport(SPItemCtx *ctx)
     ctx->i2doc = Geom::identity();
     // Set up viewport in case svg has it defined as percentages
     if (root->viewBox_set) { // if set, take from viewBox
-        ctx->vp.x0 = root->viewBox.x0;
-        ctx->vp.y0 = root->viewBox.y0;
-        ctx->vp.x1 = root->viewBox.x1;
-        ctx->vp.y1 = root->viewBox.y1;
+        ctx->viewport = root->viewBox;
     } else { // as a last resort, set size to A4
-        ctx->vp.x0 = 0.0;
-        ctx->vp.y0 = 0.0;
-        ctx->vp.x1 = 210 * PX_PER_MM;
-        ctx->vp.y1 = 297 * PX_PER_MM;
+        ctx->viewport = Geom::Rect::from_xywh(0, 0, 210 * PX_PER_MM, 297 * PX_PER_MM);
     }
     ctx->i2vp = Geom::identity();
 }
diff --git a/src/document.h b/src/document.h
index c94b66c4d..83cb57eea 100644
--- a/src/document.h
+++ b/src/document.h
@@ -38,7 +38,6 @@ namespace Avoid {
 class Router;
 }
 
-struct NRRect;
 struct SPDesktop;
 struct SPItem;
 struct SPObject;
diff --git a/src/extension/internal/cairo-render-context.cpp b/src/extension/internal/cairo-render-context.cpp
index a0573d9ff..9bafa9432 100644
--- a/src/extension/internal/cairo-render-context.cpp
+++ b/src/extension/internal/cairo-render-context.cpp
@@ -87,19 +87,19 @@
 #define TEST(_args)
 
 // FIXME: expose these from sp-clippath/mask.cpp
-struct SPClipPathView {
+/*struct SPClipPathView {
     SPClipPathView *next;
     unsigned int key;
     Inkscape::DrawingItem *arenaitem;
-    NRRect bbox;
+    Geom::OptRect bbox;
 };
 
 struct SPMaskView {
     SPMaskView *next;
     unsigned int key;
     Inkscape::DrawingItem *arenaitem;
-    NRRect bbox;
-};
+    Geom::OptRect bbox;
+};*/
 
 namespace Inkscape {
 namespace Extension {
@@ -1043,27 +1043,22 @@ CairoRenderContext::_createPatternPainter(SPPaintServer const *const paintserver
 
     // create pattern contents coordinate system
     if (pat->viewBox_set) {
-        NRRect *view_box = pattern_viewBox(pat);
+        Geom::Rect view_box = *pattern_viewBox(pat);
 
         double x, y, w, h;
-        double view_width, view_height;
         x = 0;
         y = 0;
         w = width * bbox_width_scaler;
         h = height * bbox_height_scaler;
 
-        view_width = view_box->x1 - view_box->x0;
-        view_height = view_box->y1 - view_box->y0;
-
         //calculatePreserveAspectRatio(pat->aspect_align, pat->aspect_clip, view_width, view_height, &x, &y, &w, &h);
-        pcs2dev[0] = w / view_width;
-        pcs2dev[3] = h / view_height;
-        pcs2dev[4] = x - view_box->x0 * pcs2dev[0];
-        pcs2dev[5] = y - view_box->y0 * pcs2dev[3];
+        pcs2dev[0] = w / view_box.width();
+        pcs2dev[3] = h / view_box.height();
+        pcs2dev[4] = x - view_box.left() * pcs2dev[0];
+        pcs2dev[5] = y - view_box.top() * pcs2dev[3];
     } else if (pbox && pattern_patternContentUnits(pat) == SP_PATTERN_UNITS_OBJECTBOUNDINGBOX) {
         pcs2dev[0] = pbox->width();
         pcs2dev[3] = pbox->height();
-
     }
 
     // Calculate the size of the surface which has to be created
diff --git a/src/extension/internal/cairo-renderer.cpp b/src/extension/internal/cairo-renderer.cpp
index adfa0421d..3a2cea3c1 100644
--- a/src/extension/internal/cairo-renderer.cpp
+++ b/src/extension/internal/cairo-renderer.cpp
@@ -87,14 +87,14 @@ struct SPClipPathView {
     SPClipPathView *next;
     unsigned int key;
     Inkscape::DrawingItem *arenaitem;
-    NRRect bbox;
+    Geom::OptRect bbox;
 };
 
 struct SPMaskView {
     SPMaskView *next;
     unsigned int key;
     Inkscape::DrawingItem *arenaitem;
-    NRRect bbox;
+    Geom::OptRect bbox;
 };
 
 namespace Inkscape {
@@ -394,8 +394,8 @@ static void sp_symbol_render(SPItem *item, CairoRenderContext *ctx)
         width = 1.0;
         height = 1.0;
 
-        view_width = symbol->viewBox.x1 - symbol->viewBox.x0;
-        view_height = symbol->viewBox.y1 - symbol->viewBox.y0;
+        view_width = symbol->viewBox.width();
+        view_height = symbol->viewBox.height();
 
         calculatePreserveAspectRatio(symbol->aspect_align, symbol->aspect_clip, view_width, view_height,
                                      &x, &y,&width, &height);
@@ -404,8 +404,8 @@ static void sp_symbol_render(SPItem *item, CairoRenderContext *ctx)
         vb2user = Geom::identity();
         vb2user[0] = width / view_width;
         vb2user[3] = height / view_height;
-        vb2user[4] = x - symbol->viewBox.x0 * vb2user[0];
-        vb2user[5] = y - symbol->viewBox.y0 * vb2user[3];
+        vb2user[4] = x - symbol->viewBox.left() * vb2user[0];
+        vb2user[5] = y - symbol->viewBox.top() * vb2user[3];
 
         ctx->transform(vb2user);
     }
@@ -668,13 +668,14 @@ CairoRenderer::applyClipPath(CairoRenderContext *ctx, SPClipPath const *cp)
     CairoRenderContext::CairoRenderMode saved_mode = ctx->getRenderMode();
     ctx->setRenderMode(CairoRenderContext::RENDER_MODE_CLIP);
 
+    // FIXME: the access to the first clippath view to obtain the bbox is completely bogus
     Geom::Affine saved_ctm;
-    if (cp->clipPathUnits == SP_CONTENT_UNITS_OBJECTBOUNDINGBOX) {
+    if (cp->clipPathUnits == SP_CONTENT_UNITS_OBJECTBOUNDINGBOX && cp->display->bbox) {
         //SP_PRINT_DRECT("clipd", cp->display->bbox);
-        NRRect clip_bbox(cp->display->bbox);
-        Geom::Affine t(Geom::Scale(clip_bbox.x1 - clip_bbox.x0, clip_bbox.y1 - clip_bbox.y0));
-        t[4] = clip_bbox.x0;
-        t[5] = clip_bbox.y0;
+        Geom::Rect clip_bbox = *cp->display->bbox;
+        Geom::Affine t(Geom::Scale(clip_bbox.dimensions()));
+        t[4] = clip_bbox.left();
+        t[5] = clip_bbox.top();
         t *= ctx->getCurrentState()->transform;
         saved_ctm = ctx->getTransform();
         ctx->setTransform(t);
@@ -720,13 +721,14 @@ CairoRenderer::applyMask(CairoRenderContext *ctx, SPMask const *mask)
     if (mask == NULL)
         return;
 
-    //SP_PRINT_DRECT("maskd", &mask->display->bbox);
-    NRRect mask_bbox(mask->display->bbox);
+    // FIXME: the access to the first mask view to obtain the bbox is completely bogus
     // TODO: should the bbox be transformed if maskUnits != userSpaceOnUse ?
-    if (mask->maskContentUnits == SP_CONTENT_UNITS_OBJECTBOUNDINGBOX) {
-        Geom::Affine t(Geom::Scale(mask_bbox.x1 - mask_bbox.x0, mask_bbox.y1 - mask_bbox.y0));
-        t[4] = mask_bbox.x0;
-        t[5] = mask_bbox.y0;
+    if (mask->maskContentUnits == SP_CONTENT_UNITS_OBJECTBOUNDINGBOX && mask->display->bbox) {
+        //SP_PRINT_DRECT("maskd", &mask->display->bbox);
+        Geom::Rect mask_bbox = *mask->display->bbox;
+        Geom::Affine t(Geom::Scale(mask_bbox.dimensions()));
+        t[4] = mask_bbox.left();
+        t[5] = mask_bbox.top();
         t *= ctx->getCurrentState()->transform;
         ctx->setTransform(t);
     }
diff --git a/src/marker.cpp b/src/marker.cpp
index 9db5cfdc1..db9779460 100644
--- a/src/marker.cpp
+++ b/src/marker.cpp
@@ -349,10 +349,7 @@ static void sp_marker_update(SPObject *object, SPCtx *ctx, guint flags)
 	rctx.i2doc = Geom::identity();
 	rctx.i2vp = Geom::identity();
 	/* Set up viewport */
-	rctx.vp.x0 = 0.0;
-	rctx.vp.y0 = 0.0;
-	rctx.vp.x1 = marker->markerWidth.computed;
-	rctx.vp.y1 = marker->markerHeight.computed;
+	rctx.viewport = Geom::Rect::from_xywh(0, 0, marker->markerWidth.computed, marker->markerHeight.computed);
 
 	/* Start with identity transform */
 	marker->c2p.setIdentity();
@@ -361,20 +358,20 @@ static void sp_marker_update(SPObject *object, SPCtx *ctx, guint flags)
     if (marker->viewBox) {
         vb = *marker->viewBox;
 	} else {
-        vb = *(rctx.vp.upgrade_2geom());
+        vb = rctx.viewport;
 	}
 	/* Now set up viewbox transformation */
 	/* Determine actual viewbox in viewport coordinates */
 	if (marker->aspect_align == SP_ASPECT_NONE) {
 		x = 0.0;
 		y = 0.0;
-		width = rctx.vp.x1 - rctx.vp.x0;
-		height = rctx.vp.y1 - rctx.vp.y0;
+		width = rctx.viewport.width();
+		height = rctx.viewport.height();
 	} else {
 		double scalex, scaley, scale;
 		/* Things are getting interesting */
-        scalex = (rctx.vp.x1 - rctx.vp.x0) / (vb.width());
-        scaley = (rctx.vp.y1 - rctx.vp.y0) / (vb.height());
+        scalex = rctx.viewport.width() / (vb.width());
+        scaley = rctx.viewport.height() / (vb.height());
 		scale = (marker->aspect_clip == SP_ASPECT_MEET) ? MIN (scalex, scaley) : MAX (scalex, scaley);
         width = (vb.width()) * scale;
         height = (vb.height()) * scale;
@@ -385,36 +382,36 @@ static void sp_marker_update(SPObject *object, SPCtx *ctx, guint flags)
 			y = 0.0;
 			break;
 		case SP_ASPECT_XMID_YMIN:
-			x = 0.5 * ((rctx.vp.x1 - rctx.vp.x0) - width);
+			x = 0.5 * (rctx.viewport.width() - width);
 			y = 0.0;
 			break;
 		case SP_ASPECT_XMAX_YMIN:
-			x = 1.0 * ((rctx.vp.x1 - rctx.vp.x0) - width);
+			x = 1.0 * (rctx.viewport.width() - width);
 			y = 0.0;
 			break;
 		case SP_ASPECT_XMIN_YMID:
 			x = 0.0;
-			y = 0.5 * ((rctx.vp.y1 - rctx.vp.y0) - height);
+			y = 0.5 * (rctx.viewport.height() - height);
 			break;
 		case SP_ASPECT_XMID_YMID:
-			x = 0.5 * ((rctx.vp.x1 - rctx.vp.x0) - width);
-			y = 0.5 * ((rctx.vp.y1 - rctx.vp.y0) - height);
+			x = 0.5 * (rctx.viewport.width() - width);
+			y = 0.5 * (rctx.viewport.height() - height);
 			break;
 		case SP_ASPECT_XMAX_YMID:
-			x = 1.0 * ((rctx.vp.x1 - rctx.vp.x0) - width);
-			y = 0.5 * ((rctx.vp.y1 - rctx.vp.y0) - height);
+			x = 1.0 * (rctx.viewport.width() - width);
+			y = 0.5 * (rctx.viewport.height() - height);
 			break;
 		case SP_ASPECT_XMIN_YMAX:
 			x = 0.0;
-			y = 1.0 * ((rctx.vp.y1 - rctx.vp.y0) - height);
+			y = 1.0 * (rctx.viewport.height() - height);
 			break;
 		case SP_ASPECT_XMID_YMAX:
-			x = 0.5 * ((rctx.vp.x1 - rctx.vp.x0) - width);
-			y = 1.0 * ((rctx.vp.y1 - rctx.vp.y0) - height);
+			x = 0.5 * (rctx.viewport.width() - width);
+			y = 1.0 * (rctx.viewport.height() - height);
 			break;
 		case SP_ASPECT_XMAX_YMAX:
-			x = 1.0 * ((rctx.vp.x1 - rctx.vp.x0) - width);
-			y = 1.0 * ((rctx.vp.y1 - rctx.vp.y0) - height);
+			x = 1.0 * (rctx.viewport.width() - width);
+			y = 1.0 * (rctx.viewport.height() - height);
 			break;
 		default:
 			x = 0.0;
@@ -432,10 +429,7 @@ static void sp_marker_update(SPObject *object, SPCtx *ctx, guint flags)
 	/* If viewBox is set reinitialize child viewport */
 	/* Otherwise it already correct */
 	if (marker->viewBox) {
-            rctx.vp.x0 = marker->viewBox->min()[Geom::X];
-            rctx.vp.y0 = marker->viewBox->min()[Geom::Y];
-            rctx.vp.x1 = marker->viewBox->max()[Geom::X];
-            rctx.vp.y1 = marker->viewBox->max()[Geom::Y];
+	    rctx.viewport = *marker->viewBox;
             rctx.i2vp = Geom::identity();
 	}
 
diff --git a/src/print.h b/src/print.h
index d584245e5..422f18669 100644
--- a/src/print.h
+++ b/src/print.h
@@ -17,7 +17,6 @@
 #include "forward.h"
 #include "extension/extension-forward.h"
 
-struct NRRect;
 struct SPPrintContext {
     Inkscape::Extension::Print *module;
 };
diff --git a/src/sp-ellipse.cpp b/src/sp-ellipse.cpp
index 99189da45..ba100a1d7 100644
--- a/src/sp-ellipse.cpp
+++ b/src/sp-ellipse.cpp
@@ -140,19 +140,18 @@ sp_genericellipse_update(SPObject *object, SPCtx *ctx, guint flags)
     if (flags & (SP_OBJECT_MODIFIED_FLAG | SP_OBJECT_STYLE_MODIFIED_FLAG | SP_OBJECT_VIEWPORT_MODIFIED_FLAG)) {
         SPGenericEllipse *ellipse = (SPGenericEllipse *) object;
         SPStyle const *style = object->style;
-        Geom::OptRect viewbox = ((SPItemCtx const *) ctx)->vp;
-        if (viewbox) {
-            double const dx = viewbox->width();
-            double const dy = viewbox->height();
-            double const dr = sqrt(dx*dx + dy*dy)/sqrt(2);
-            double const em = style->font_size.computed;
-            double const ex = em * 0.5; // fixme: get from pango or libnrtype
-            ellipse->cx.update(em, ex, dx);
-            ellipse->cy.update(em, ex, dy);
-            ellipse->rx.update(em, ex, dr);
-            ellipse->ry.update(em, ex, dr);
-            static_cast<SPShape *>(object)->setShape();
-        }
+        Geom::Rect const &viewbox = ((SPItemCtx const *) ctx)->viewport;
+
+        double const dx = viewbox.width();
+        double const dy = viewbox.height();
+        double const dr = sqrt(dx*dx + dy*dy)/sqrt(2);
+        double const em = style->font_size.computed;
+        double const ex = em * 0.5; // fixme: get from pango or libnrtype
+        ellipse->cx.update(em, ex, dx);
+        ellipse->cy.update(em, ex, dy);
+        ellipse->rx.update(em, ex, dr);
+        ellipse->ry.update(em, ex, dr);
+        static_cast<SPShape *>(object)->setShape();
     }
 
     if (((SPObjectClass *) ge_parent_class)->update)
diff --git a/src/sp-item.h b/src/sp-item.h
index 62336e3c8..21b3d9006 100644
--- a/src/sp-item.h
+++ b/src/sp-item.h
@@ -88,7 +88,7 @@ public:
     /** Item to document transformation */
     Geom::Affine i2doc;
     /** Viewport size */
-    NRRect vp;
+    Geom::Rect viewport;
     /** Item to viewport transformation */
     Geom::Affine i2vp;
 };
diff --git a/src/sp-line.cpp b/src/sp-line.cpp
index d3faf2299..06604a1d6 100644
--- a/src/sp-line.cpp
+++ b/src/sp-line.cpp
@@ -127,8 +127,8 @@ void SPLine::update(SPObject *object, SPCtx *ctx, guint flags)
 
         SPStyle const *style = object->style;
         SPItemCtx const *ictx = (SPItemCtx const *) ctx;
-        double const w = (ictx->vp.x1 - ictx->vp.x0);
-        double const h = (ictx->vp.y1 - ictx->vp.y0);
+        double const w = ictx->viewport.width();
+        double const h = ictx->viewport.height();
         double const em = style->font_size.computed;
         double const ex = em * 0.5;  // fixme: get from pango or libnrtype.
         line->x1.update(em, ex, w);
diff --git a/src/sp-namedview.cpp b/src/sp-namedview.cpp
index 71ee8298b..e94a02265 100644
--- a/src/sp-namedview.cpp
+++ b/src/sp-namedview.cpp
@@ -807,10 +807,7 @@ void sp_namedview_window_from_document(SPDesktop *desktop)
     }
 
     // cancel any history of zooms up to this point
-    if (desktop->zooms_past) {
-        g_list_free(desktop->zooms_past);
-        desktop->zooms_past = NULL;
-    }
+    desktop->zooms_past.clear();
 }
 
 bool SPNamedView::getSnapGlobal() const
diff --git a/src/sp-paint-server.cpp b/src/sp-paint-server.cpp
index be7494908..ceb36740f 100644
--- a/src/sp-paint-server.cpp
+++ b/src/sp-paint-server.cpp
@@ -73,11 +73,8 @@ cairo_pattern_t *sp_paint_server_create_pattern(SPPaintServer *ps,
                                                 Geom::OptRect const &bbox,
                                                 double opacity)
 {
-    // NOTE: the ct argument is used for when rendering patterns
-    // to create a group, instead of explicitly creating a temporary surface
     g_return_val_if_fail(ps != NULL, NULL);
     g_return_val_if_fail(SP_IS_PAINT_SERVER(ps), NULL);
-    g_return_val_if_fail(bbox != NULL, NULL);
 
     cairo_pattern_t *cp = NULL;
     SPPaintServerClass *psc = (SPPaintServerClass *) G_OBJECT_GET_CLASS(ps);
diff --git a/src/sp-paint-server.h b/src/sp-paint-server.h
index 7d6f7a5ef..a266ee5a5 100644
--- a/src/sp-paint-server.h
+++ b/src/sp-paint-server.h
@@ -20,8 +20,6 @@
 #include "sp-object.h"
 #include "uri-references.h"
 
-struct NRRect;
-
 #define SP_TYPE_PAINT_SERVER (SPPaintServer::get_type())
 #define SP_PAINT_SERVER(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), SP_TYPE_PAINT_SERVER, SPPaintServer))
 #define SP_PAINT_SERVER_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST ((klass), SP_TYPE_PAINT_SERVER, SPPaintServerClass))
diff --git a/src/sp-pattern.cpp b/src/sp-pattern.cpp
index b8ccf5648..03afc1bf3 100644
--- a/src/sp-pattern.cpp
+++ b/src/sp-pattern.cpp
@@ -245,11 +245,8 @@ sp_pattern_set (SPObject *object, unsigned int key, const gchar *value)
 			height = g_ascii_strtod (eptr, &eptr);
 			while (*eptr && ((*eptr == ',') || (*eptr == ' '))) eptr++;
 			if ((width > 0) && (height > 0)) {
-				pat->viewBox.x0 = x;
-				pat->viewBox.y0 = y;
-				pat->viewBox.x1 = x + width;
-				pat->viewBox.y1 = y + height;
-				pat->viewBox_set = TRUE;
+			    pat->viewBox = Geom::Rect::from_xywh(x, y, width, height);
+			    pat->viewBox_set = TRUE;
 			} else {
 				pat->viewBox_set = FALSE;
 			}
@@ -581,13 +578,16 @@ gdouble pattern_height (SPPattern *pat)
 	return 0;
 }
 
-NRRect *pattern_viewBox (SPPattern *pat)
+Geom::OptRect pattern_viewBox (SPPattern *pat)
 {
-	for (SPPattern *pat_i = pat; pat_i != NULL; pat_i = pat_i->ref ? pat_i->ref->getObject() : NULL) {
-		if (pat_i->viewBox_set)
-			return &(pat_i->viewBox);
-	}
-	return &(pat->viewBox);
+    Geom::OptRect viewbox;
+    for (SPPattern *pat_i = pat; pat_i != NULL; pat_i = pat_i->ref ? pat_i->ref->getObject() : NULL) {
+        if (pat_i->viewBox_set) {
+            viewbox = pat_i->viewBox;
+            break;
+        }
+    }
+    return viewbox;
 }
 
 bool pattern_hasItemChildren (SPPattern *pat)
@@ -647,11 +647,12 @@ sp_pattern_create_pattern(SPPaintServer *ps,
     }
 
     if (pat->viewBox_set) {
-        gdouble tmp_x = pattern_width (pat) / (pattern_viewBox(pat)->x1 - pattern_viewBox(pat)->x0);
-        gdouble tmp_y = pattern_height (pat) / (pattern_viewBox(pat)->y1 - pattern_viewBox(pat)->y0);
+        Geom::Rect vb = *pattern_viewBox(pat);
+        gdouble tmp_x = pattern_width (pat) / vb.width();
+        gdouble tmp_y = pattern_height (pat) / vb.height();
 
         // FIXME: preserveAspectRatio must be taken into account here too!
-        vb2ps = Geom::Affine(tmp_x, 0.0, 0.0, tmp_y, pattern_x(pat) - pattern_viewBox(pat)->x0 * tmp_x, pattern_y(pat) - pattern_viewBox(pat)->y0 * tmp_y);
+        vb2ps = Geom::Affine(tmp_x, 0.0, 0.0, tmp_y, pattern_x(pat) - vb.left() * tmp_x, pattern_y(pat) - vb.top() * tmp_y);
     }
 
     ps2user = pattern_patternTransform(pat);
diff --git a/src/sp-pattern.h b/src/sp-pattern.h
index 1f545bfc4..ee7ffd477 100644
--- a/src/sp-pattern.h
+++ b/src/sp-pattern.h
@@ -72,7 +72,7 @@ struct SPPattern : public SPPaintServer {
     SVGLength width;
     SVGLength height;
     /* VieBox */
-    NRRect viewBox;
+    Geom::Rect viewBox;
     guint viewBox_set : 1;
 
     sigc::connection modified_connection;
@@ -98,7 +98,7 @@ gdouble pattern_x (SPPattern *pat);
 gdouble pattern_y (SPPattern *pat);
 gdouble pattern_width (SPPattern *pat);
 gdouble pattern_height (SPPattern *pat);
-NRRect *pattern_viewBox (SPPattern *pat);
+Geom::OptRect pattern_viewBox (SPPattern *pat);
 
 #endif // SEEN_SP_PATTERN_H
 
diff --git a/src/sp-rect.cpp b/src/sp-rect.cpp
index 729e2a34c..22a403345 100644
--- a/src/sp-rect.cpp
+++ b/src/sp-rect.cpp
@@ -173,8 +173,8 @@ sp_rect_update(SPObject *object, SPCtx *ctx, guint flags)
         SPRect *rect = (SPRect *) object;
         SPStyle *style = object->style;
         SPItemCtx const *ictx = (SPItemCtx const *) ctx;
-        double const w = (ictx->vp.x1 - ictx->vp.x0);
-        double const h = (ictx->vp.y1 - ictx->vp.y0);
+        double const w = ictx->viewport.width();
+        double const h = ictx->viewport.height();
         double const em = style->font_size.computed;
         double const ex = 0.5 * em;  // fixme: get x height from pango or libnrtype.
         rect->x.update(em, ex, w);
diff --git a/src/sp-root.cpp b/src/sp-root.cpp
index a6df580d3..788d1958a 100644
--- a/src/sp-root.cpp
+++ b/src/sp-root.cpp
@@ -123,7 +123,6 @@ sp_root_init(SPRoot *root)
     root->width.unset(SVGLength::PERCENT, 1.0, 1.0);
     root->height.unset(SVGLength::PERCENT, 1.0, 1.0);
 
-    /* root->viewbox.set_identity(); */
     root->viewBox_set = FALSE;
 
     root->c2p.setIdentity();
@@ -253,10 +252,7 @@ sp_root_set(SPObject *object, unsigned int key, gchar const *value)
                 while (*eptr && ((*eptr == ',') || (*eptr == ' '))) eptr++;
                 if ((width > 0) && (height > 0)) {
                     /* Set viewbox */
-                    root->viewBox.x0 = x;
-                    root->viewBox.y0 = y;
-                    root->viewBox.x1 = x + width;
-                    root->viewBox.y1 = y + height;
+                    root->viewBox = Geom::Rect::from_xywh(x, y, width, height);
                     root->viewBox_set = TRUE;
                 } else {
                     root->viewBox_set = FALSE;
@@ -404,16 +400,16 @@ static void sp_root_update(SPObject *object, SPCtx *ctx, guint flags)
     /* fixme: We should calculate only if parent viewport has changed (Lauris) */
     /* If position is specified as percentage, calculate actual values */
     if (root->x.unit == SVGLength::PERCENT) {
-        root->x.computed = root->x.value * (ictx->vp.x1 - ictx->vp.x0);
+        root->x.computed = root->x.value * ictx->viewport.width();
     }
     if (root->y.unit == SVGLength::PERCENT) {
-        root->y.computed = root->y.value * (ictx->vp.y1 - ictx->vp.y0);
+        root->y.computed = root->y.value * ictx->viewport.height();
     }
     if (root->width.unit == SVGLength::PERCENT) {
-        root->width.computed = root->width.value * (ictx->vp.x1 - ictx->vp.x0);
+        root->width.computed = root->width.value * ictx->viewport.width();
     }
     if (root->height.unit == SVGLength::PERCENT) {
-        root->height.computed = root->height.value * (ictx->vp.y1 - ictx->vp.y0);
+        root->height.computed = root->height.value * ictx->viewport.height();
     }
 
     /* Create copy of item context */
@@ -445,11 +441,11 @@ static void sp_root_update(SPObject *object, SPCtx *ctx, guint flags)
         } else {
             double scalex, scaley, scale;
             /* Things are getting interesting */
-            scalex = root->width.computed / (root->viewBox.x1 - root->viewBox.x0);
-            scaley = root->height.computed / (root->viewBox.y1 - root->viewBox.y0);
+            scalex = root->width.computed / root->viewBox.width();
+            scaley = root->height.computed / root->viewBox.height();
             scale = (root->aspect_clip == SP_ASPECT_MEET) ? MIN(scalex, scaley) : MAX(scalex, scaley);
-            width = (root->viewBox.x1 - root->viewBox.x0) * scale;
-            height = (root->viewBox.y1 - root->viewBox.y0) * scale;
+            width = root->viewBox.width() * scale;
+            height = root->viewBox.height() * scale;
             /* Now place viewbox to requested position */
             /* todo: Use an array lookup to find the 0.0/0.5/1.0 coefficients,
                as is done for dialogs/align.cpp. */
@@ -498,38 +494,27 @@ static void sp_root_update(SPObject *object, SPCtx *ctx, guint flags)
         }
 
         /* Compose additional transformation from scale and position */
-        Geom::Point const viewBox_min(root->viewBox.x0,
-                                    root->viewBox.y0);
-        Geom::Point const viewBox_max(root->viewBox.x1,
-                                    root->viewBox.y1);
-        Geom::Scale const viewBox_length( viewBox_max - viewBox_min );
+        Geom::Scale const viewBox_length( root->viewBox.dimensions() );
         Geom::Scale const new_length(width, height);
 
         /* Append viewbox transformation */
         /* TODO: The below looks suspicious to me (pjrm): I wonder whether the RHS
            expression should have c2p at the beginning rather than at the end.  Test it. */
-        root->c2p = Geom::Translate(-viewBox_min) * ( new_length * viewBox_length.inverse() ) * Geom::Translate(x, y) * root->c2p;
+        root->c2p = Geom::Translate(-root->viewBox.min()) * ( new_length * viewBox_length.inverse() ) * Geom::Translate(x, y) * root->c2p;
     }
 
     rctx.i2doc = root->c2p * rctx.i2doc;
 
     /* Initialize child viewport */
     if (root->viewBox_set) {
-        rctx.vp.x0 = root->viewBox.x0;
-        rctx.vp.y0 = root->viewBox.y0;
-        rctx.vp.x1 = root->viewBox.x1;
-        rctx.vp.y1 = root->viewBox.y1;
+        rctx.viewport = root->viewBox;
     } else {
         /* fixme: I wonder whether this logic is correct (Lauris) */
+        Geom::Point minp(0,0);
         if (object->parent) {
-            rctx.vp.x0 = root->x.computed;
-            rctx.vp.y0 = root->y.computed;
-        } else {
-            rctx.vp.x0 = 0.0;
-            rctx.vp.y0 = 0.0;
+            minp = Geom::Point(root->x.computed, root->y.computed);
         }
-        rctx.vp.x1 = root->width.computed;
-        rctx.vp.y1 = root->height.computed;
+        rctx.viewport = Geom::Rect::from_xywh(minp[Geom::X], minp[Geom::Y], root->width.computed, root->height.computed);
     }
 
     rctx.i2vp = Geom::identity();
@@ -597,7 +582,8 @@ sp_root_write(SPObject *object, Inkscape::XML::Document *xml_doc, Inkscape::XML:
 
     if (root->viewBox_set) {
         Inkscape::SVGOStringStream os;
-        os << root->viewBox.x0 << " " << root->viewBox.y0 << " " << root->viewBox.x1 - root->viewBox.x0 << " " << root->viewBox.y1 - root->viewBox.y0;
+        os << root->viewBox.left() << " " << root->viewBox.top() << " "
+           << root->viewBox.width() << " " << root->viewBox.height();
         repr->setAttribute("viewBox", os.str().c_str());
     }
 
diff --git a/src/sp-root.h b/src/sp-root.h
index 86b92b2b3..e2bad917b 100644
--- a/src/sp-root.h
+++ b/src/sp-root.h
@@ -1,6 +1,3 @@
-#ifndef SP_ROOT_H_SEEN
-#define SP_ROOT_H_SEEN
-
 /** \file
  * SPRoot: SVG \<svg\> implementation.
  */
@@ -14,17 +11,20 @@
  * Released under GNU GPL, read the file 'COPYING' for more information
  */
 
-#define SP_TYPE_ROOT (sp_root_get_type())
-#define SP_ROOT(o) (G_TYPE_CHECK_INSTANCE_CAST((o), SP_TYPE_ROOT, SPRoot))
-#define SP_ROOT_CLASS(k) (G_TYPE_CHECK_CLASS_CAST((k), SP_TYPE_ROOT, SPRootClass))
-#define SP_IS_ROOT(o) (G_TYPE_CHECK_INSTANCE_TYPE((o), SP_TYPE_ROOT))
-#define SP_IS_ROOT_CLASS(k) (G_TYPE_CHECK_CLASS_TYPE((k), SP_TYPE_ROOT))
+#ifndef SP_ROOT_H_SEEN
+#define SP_ROOT_H_SEEN
 
 #include "version.h"
 #include "svg/svg-length.h"
 #include "enums.h"
 #include "sp-item-group.h"
 
+#define SP_TYPE_ROOT (sp_root_get_type())
+#define SP_ROOT(o) (G_TYPE_CHECK_INSTANCE_CAST((o), SP_TYPE_ROOT, SPRoot))
+#define SP_ROOT_CLASS(k) (G_TYPE_CHECK_CLASS_CAST((k), SP_TYPE_ROOT, SPRootClass))
+#define SP_IS_ROOT(o) (G_TYPE_CHECK_INSTANCE_TYPE((o), SP_TYPE_ROOT))
+#define SP_IS_ROOT_CLASS(k) (G_TYPE_CHECK_CLASS_TYPE((k), SP_TYPE_ROOT))
+
 class SPDefs;
 
 /** \<svg\> element */
@@ -41,7 +41,7 @@ struct SPRoot : public SPGroup {
 
     /* viewBox; */
     unsigned int viewBox_set : 1;
-    NRRect viewBox;
+    Geom::Rect viewBox;
 
     /* preserveAspectRatio */
     unsigned int aspect_set : 1;
diff --git a/src/sp-symbol.cpp b/src/sp-symbol.cpp
index 0a1ebdb06..87cd210e4 100644
--- a/src/sp-symbol.cpp
+++ b/src/sp-symbol.cpp
@@ -131,10 +131,7 @@ static void sp_symbol_set(SPObject *object, unsigned int key, const gchar *value
             while (*eptr && ((*eptr == ',') || (*eptr == ' '))) eptr++;
             if ((width > 0) && (height > 0)) {
                 /* Set viewbox */
-                symbol->viewBox.x0 = x;
-                symbol->viewBox.y0 = y;
-                symbol->viewBox.x1 = x + width;
-                symbol->viewBox.y1 = y + height;
+                symbol->viewBox = Geom::Rect::from_xywh(x, y, width, height);
                 symbol->viewBox_set = TRUE;
             } else {
                 symbol->viewBox_set = FALSE;
@@ -234,7 +231,7 @@ static void sp_symbol_update(SPObject *object, SPCtx *ctx, guint flags)
 
         /* Calculate child to parent transformation */
         /* Apply parent <use> translation (set up as vewport) */
-        symbol->c2p = Geom::Affine(Geom::Translate(rctx.vp.x0, rctx.vp.y0));
+        symbol->c2p = Geom::Translate(rctx.viewport.min());
 
         if (symbol->viewBox_set) {
             double x, y, width, height;
@@ -242,16 +239,16 @@ static void sp_symbol_update(SPObject *object, SPCtx *ctx, guint flags)
             if (symbol->aspect_align == SP_ASPECT_NONE) {
                 x = 0.0;
                 y = 0.0;
-                width = rctx.vp.x1 - rctx.vp.x0;
-                height = rctx.vp.y1 - rctx.vp.y0;
+                width = rctx.viewport.width();
+                height = rctx.viewport.height();
             } else {
                 double scalex, scaley, scale;
                 /* Things are getting interesting */
-                scalex = (rctx.vp.x1 - rctx.vp.x0) / (symbol->viewBox.x1 - symbol->viewBox.x0);
-                scaley = (rctx.vp.y1 - rctx.vp.y0) / (symbol->viewBox.y1 - symbol->viewBox.y0);
+                scalex = rctx.viewport.width() / symbol->viewBox.width();
+                scaley = rctx.viewport.height() / symbol->viewBox.height();
                 scale = (symbol->aspect_clip == SP_ASPECT_MEET) ? MIN (scalex, scaley) : MAX (scalex, scaley);
-                width = (symbol->viewBox.x1 - symbol->viewBox.x0) * scale;
-                height = (symbol->viewBox.y1 - symbol->viewBox.y0) * scale;
+                width = symbol->viewBox.width() * scale;
+                height = symbol->viewBox.height() * scale;
                 /* Now place viewbox to requested position */
                 switch (symbol->aspect_align) {
                 case SP_ASPECT_XMIN_YMIN:
@@ -259,36 +256,36 @@ static void sp_symbol_update(SPObject *object, SPCtx *ctx, guint flags)
                     y = 0.0;
                     break;
                 case SP_ASPECT_XMID_YMIN:
-                    x = 0.5 * ((rctx.vp.x1 - rctx.vp.x0) - width);
+                    x = 0.5 * (rctx.viewport.width() - width);
                     y = 0.0;
                     break;
                 case SP_ASPECT_XMAX_YMIN:
-                    x = 1.0 * ((rctx.vp.x1 - rctx.vp.x0) - width);
+                    x = 1.0 * (rctx.viewport.width() - width);
                     y = 0.0;
                     break;
                 case SP_ASPECT_XMIN_YMID:
                     x = 0.0;
-                    y = 0.5 * ((rctx.vp.y1 - rctx.vp.y0) - height);
+                    y = 0.5 * (rctx.viewport.height() - height);
                     break;
                 case SP_ASPECT_XMID_YMID:
-                    x = 0.5 * ((rctx.vp.x1 - rctx.vp.x0) - width);
-                    y = 0.5 * ((rctx.vp.y1 - rctx.vp.y0) - height);
+                    x = 0.5 * (rctx.viewport.width() - width);
+                    y = 0.5 * (rctx.viewport.height() - height);
                     break;
                 case SP_ASPECT_XMAX_YMID:
-                    x = 1.0 * ((rctx.vp.x1 - rctx.vp.x0) - width);
-                    y = 0.5 * ((rctx.vp.y1 - rctx.vp.y0) - height);
+                    x = 1.0 * (rctx.viewport.width() - width);
+                    y = 0.5 * (rctx.viewport.height() - height);
                     break;
                 case SP_ASPECT_XMIN_YMAX:
                     x = 0.0;
-                    y = 1.0 * ((rctx.vp.y1 - rctx.vp.y0) - height);
+                    y = 1.0 * (rctx.viewport.height() - height);
                     break;
                 case SP_ASPECT_XMID_YMAX:
-                    x = 0.5 * ((rctx.vp.x1 - rctx.vp.x0) - width);
-                    y = 1.0 * ((rctx.vp.y1 - rctx.vp.y0) - height);
+                    x = 0.5 * (rctx.viewport.width() - width);
+                    y = 1.0 * (rctx.viewport.height() - height);
                     break;
                 case SP_ASPECT_XMAX_YMAX:
-                    x = 1.0 * ((rctx.vp.x1 - rctx.vp.x0) - width);
-                    y = 1.0 * ((rctx.vp.y1 - rctx.vp.y0) - height);
+                    x = 1.0 * (rctx.viewport.width() - width);
+                    y = 1.0 * (rctx.viewport.height() - height);
                     break;
                 default:
                     x = 0.0;
@@ -298,12 +295,12 @@ static void sp_symbol_update(SPObject *object, SPCtx *ctx, guint flags)
             }
             /* Compose additional transformation from scale and position */
             Geom::Affine q;
-            q[0] = width / (symbol->viewBox.x1 - symbol->viewBox.x0);
+            q[0] = width / symbol->viewBox.width();
             q[1] = 0.0;
             q[2] = 0.0;
-            q[3] = height / (symbol->viewBox.y1 - symbol->viewBox.y0);
-            q[4] = -symbol->viewBox.x0 * q[0] + x;
-            q[5] = -symbol->viewBox.y0 * q[3] + y;
+            q[3] = height / symbol->viewBox.height();
+            q[4] = -symbol->viewBox.left() * q[0] + x;
+            q[5] = -symbol->viewBox.top() * q[3] + y;
             /* Append viewbox transformation */
             symbol->c2p = q * symbol->c2p;
         }
@@ -313,10 +310,7 @@ static void sp_symbol_update(SPObject *object, SPCtx *ctx, guint flags)
         /* If viewBox is set initialize child viewport */
         /* Otherwise <use> has set it up already */
         if (symbol->viewBox_set) {
-            rctx.vp.x0 = symbol->viewBox.x0;
-            rctx.vp.y0 = symbol->viewBox.y0;
-            rctx.vp.x1 = symbol->viewBox.x1;
-            rctx.vp.y1 = symbol->viewBox.y1;
+            rctx.viewport = symbol->viewBox;
             rctx.i2vp = Geom::identity();
         }
 
diff --git a/src/sp-symbol.h b/src/sp-symbol.h
index 120591459..536486bc3 100644
--- a/src/sp-symbol.h
+++ b/src/sp-symbol.h
@@ -33,7 +33,7 @@ class SPSymbolClass;
 struct SPSymbol : public SPGroup {
 	/* viewBox; */
 	unsigned int viewBox_set : 1;
-	NRRect viewBox;
+	Geom::Rect viewBox;
 
 	/* preserveAspectRatio */
 	unsigned int aspect_set : 1;
diff --git a/src/sp-use.cpp b/src/sp-use.cpp
index 057c01ef1..04cf1eb2c 100644
--- a/src/sp-use.cpp
+++ b/src/sp-use.cpp
@@ -594,21 +594,18 @@ sp_use_update(SPObject *object, SPCtx *ctx, unsigned flags)
 
     /* Set up child viewport */
     if (use->x.unit == SVGLength::PERCENT) {
-        use->x.computed = use->x.value * (ictx->vp.x1 - ictx->vp.x0);
+        use->x.computed = use->x.value * ictx->viewport.width();
     }
     if (use->y.unit == SVGLength::PERCENT) {
-        use->y.computed = use->y.value * (ictx->vp.y1 - ictx->vp.y0);
+        use->y.computed = use->y.value * ictx->viewport.height();
     }
     if (use->width.unit == SVGLength::PERCENT) {
-        use->width.computed = use->width.value * (ictx->vp.x1 - ictx->vp.x0);
+        use->width.computed = use->width.value * ictx->viewport.width();
     }
     if (use->height.unit == SVGLength::PERCENT) {
-        use->height.computed = use->height.value * (ictx->vp.y1 - ictx->vp.y0);
+        use->height.computed = use->height.value * ictx->viewport.height();
     }
-    cctx.vp.x0 = 0.0;
-    cctx.vp.y0 = 0.0;
-    cctx.vp.x1 = use->width.computed;
-    cctx.vp.y1 = use->height.computed;
+    cctx.viewport = Geom::Rect::from_xywh(0, 0, use->width.computed, use->height.computed);
     cctx.i2vp = Geom::identity();
     flags&=~SP_OBJECT_USER_MODIFIED_FLAG_B;