Code

remove many unnecessary to_2geom and from_2geom calls
[inkscape.git] / src / pen-context.cpp
index 2a6c84bc7ba02260a285b4573e3b7f77132b5825..30b09013b09f770a37fa83d8d72d61dcd8c8895d 100644 (file)
 #include "message-context.h"
 #include "prefs-utils.h"
 #include "sp-path.h"
-
+#include "display/curve.h"
 #include "pixmaps/cursor-pen.xpm"
 #include "display/canvas-bpath.h"
 #include "display/sp-ctrlline.h"
 #include "display/sodipodi-ctrl.h"
 #include <glibmm/i18n.h>
-#include "libnr/n-art-bpath.h"
 #include "libnr/nr-point-ops.h"
 #include "helper/units.h"
 #include "macros.h"
 #include "context-fns.h"
 
-
 static void sp_pen_context_class_init(SPPenContextClass *klass);
 static void sp_pen_context_init(SPPenContext *pc);
 static void sp_pen_context_dispose(GObject *object);
@@ -55,7 +53,7 @@ static gint sp_pen_context_root_handler(SPEventContext *ec, GdkEvent *event);
 static gint sp_pen_context_item_handler(SPEventContext *event_context, SPItem *item, GdkEvent *event);
 
 static void spdc_pen_set_initial_point(SPPenContext *pc, NR::Point const p);
-static void spdc_pen_set_subsequent_point(SPPenContext *pc, NR::Point const p, bool statusbar);
+static void spdc_pen_set_subsequent_point(SPPenContext *const pc, NR::Point const p, bool statusbar, guint status = 0);
 static void spdc_pen_set_ctrl(SPPenContext *pc, NR::Point const p, guint state);
 static void spdc_pen_finish_segment(SPPenContext *pc, NR::Point p, guint state);
 
@@ -76,6 +74,12 @@ static bool pen_within_tolerance = false;
 
 static SPDrawContextClass *pen_parent_class;
 
+static int pen_next_paraxial_direction(const SPPenContext *const pc, NR::Point const &pt, NR::Point const &origin, guint state);
+static void pen_set_to_nearest_horiz_vert(const SPPenContext *const pc, NR::Point &pt, guint const state);
+static NR::Point pen_get_intermediate_horiz_vert(const SPPenContext *const pc, NR::Point const &pt, guint const state);
+
+static int pen_last_paraxial_dir = 0; // last used direction in horizontal/vertical mode; 0 = horizontal, 1 = vertical
+
 /**
  * Register SPPenContext with Gdk and return its type.
  */
@@ -145,6 +149,9 @@ sp_pen_context_init(SPPenContext *pc)
     pc->cl1 = NULL;
     
     pc->events_disabled = 0;
+
+    pc->num_clicks = 0;
+    pc->waiting_LPE = NULL;
 }
 
 /**
@@ -175,6 +182,18 @@ sp_pen_context_dispose(GObject *object)
     }
 
     G_OBJECT_CLASS(pen_parent_class)->dispose(object);
+
+    if (pc->expecting_clicks_for_LPE > 0) {
+        // we received too few clicks to sanely set the parameter path so we remove the LPE from the item
+        sp_lpe_item_remove_current_path_effect(pc->waiting_item, false);
+    }
+}
+
+void
+sp_pen_context_set_polyline_mode(SPPenContext *const pc) {
+    guint mode = prefs_get_int_attribute("tools.freehand.pen", "freehand-mode", 0);
+    pc->polylines_only = (mode == 2 || mode == 3);
+    pc->polylines_paraxial = (mode == 3);
 }
 
 /**
@@ -210,6 +229,8 @@ sp_pen_context_setup(SPEventContext *ec)
 
     pc->anchor_statusbar = false;
 
+    sp_pen_context_set_polyline_mode(pc);
+
     if (prefs_get_int_attribute("tools.freehand.pen", "selcue", 0) != 0) {
         ec->enableSelectionCue();
     }
@@ -218,6 +239,7 @@ sp_pen_context_setup(SPEventContext *ec)
 static void
 pen_cancel (SPPenContext *const pc) 
 {
+    pc->num_clicks = 0;
     pc->state = SP_PEN_CONTEXT_STOP;
     spdc_reset_colors(pc);
     sp_canvas_item_hide(pc->c0);
@@ -270,11 +292,21 @@ sp_pen_context_set(SPEventContext *ec, gchar const *key, gchar const *val)
 static void
 spdc_endpoint_snap(SPPenContext const *const pc, NR::Point &p, guint const state)
 {
-    if (pc->npoints > 0) {
-        spdc_endpoint_snap_rotation(pc, p, pc->p[0], state);
+    if ((state & GDK_CONTROL_MASK)) { //CTRL enables angular snapping
+        if (pc->npoints > 0) {
+            spdc_endpoint_snap_rotation(pc, p, pc->p[0], state);
+        }
+    } else {
+        if (!(state & GDK_SHIFT_MASK)) { //SHIFT disables all snapping, except the angular snapping above
+                                         //After all, the user explicitely asked for angular snapping by
+                                         //pressing CTRL
+            spdc_endpoint_snap_free(pc, p, state);
+        }
+    }
+    if (pc->polylines_paraxial) {
+        // TODO: must we avoid one of the snaps in the previous case distinction in some situations?
+        pen_set_to_nearest_horiz_vert(pc, p, state);
     }
-
-    spdc_endpoint_snap_free(pc, p, state);
 }
 
 /**
@@ -286,8 +318,13 @@ spdc_endpoint_snap_handle(SPPenContext const *const pc, NR::Point &p, guint cons
     g_return_if_fail(( pc->npoints == 2 ||
                        pc->npoints == 5   ));
 
-    spdc_endpoint_snap_rotation(pc, p, pc->p[pc->npoints - 2], state);
-    spdc_endpoint_snap_free(pc, p, state);
+    if ((state & GDK_CONTROL_MASK)) { //CTRL enables angular snapping
+        spdc_endpoint_snap_rotation(pc, p, pc->p[pc->npoints - 2], state);
+    } else {
+        if (!(state & GDK_SHIFT_MASK)) { //SHIFT disables all snapping, except the angular snapping above
+            spdc_endpoint_snap_free(pc, p, state);
+        }
+    }
 }
 
 static gint 
@@ -301,6 +338,9 @@ sp_pen_context_item_handler(SPEventContext *ec, SPItem *item, GdkEvent *event)
         case GDK_BUTTON_PRESS:
             ret = pen_handle_button_press(pc, event->button);
             break;
+        case GDK_BUTTON_RELEASE:
+            ret = pen_handle_button_release(pc, event->button);
+            break;
         default:
             break;
     }
@@ -376,12 +416,23 @@ static gint pen_handle_button_press(SPPenContext *const pc, GdkEventButton const
     SPEventContext *event_context = SP_EVENT_CONTEXT(pc);
 
     gint ret = FALSE;
-    if (bevent.button == 1 && !event_context->space_panning) {
+    if (bevent.button == 1 && !event_context->space_panning
+        // make sure this is not the last click for a waiting LPE (otherwise we want to finish the path)
+        && pc->expecting_clicks_for_LPE != 1) {
 
         if (Inkscape::have_viable_layer(desktop, dc->_message_context) == false) {
             return TRUE;
         }
 
+        if (!pc->grab ) {
+            /* Grab mouse, so release will not pass unnoticed */
+            pc->grab = SP_CANVAS_ITEM(desktop->acetate);
+            sp_canvas_item_grab(pc->grab, ( GDK_KEY_PRESS_MASK | GDK_BUTTON_PRESS_MASK   |
+                                            GDK_BUTTON_RELEASE_MASK |
+                                            GDK_POINTER_MOTION_MASK  ),
+                                NULL, bevent.time);
+        }
+
         pen_drag_origin_w = event_w;
         pen_within_tolerance = true;
 
@@ -417,34 +468,38 @@ static gint pen_handle_button_press(SPPenContext *const pc, GdkEventButton const
                                 break;
                             }
 
+                            // TODO: Perhaps it would be nicer to rearrange the following case
+                            // distinction so that the case of a waiting LPE is treated separately
+
                             /* Set start anchor */
                             pc->sa = anchor;
                             NR::Point p;
-                            if (anchor) {
-
-                                /* Adjust point to anchor if needed */
+                            if (anchor && !sp_pen_context_has_waiting_LPE(pc)) {
+                                /* Adjust point to anchor if needed; if we have a waiting LPE, we need
+                                   a fresh path to be created so don't continue an existing one */
                                 p = anchor->dp;
                                 desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Continuing selected path"));
-
                             } else {
-
                                 // This is the first click of a new curve; deselect item so that
                                 // this curve is not combined with it (unless it is drawn from its
                                 // anchor, which is handled by the sibling branch above)
                                 Inkscape::Selection * const selection = sp_desktop_selection(desktop);
-                                if (!(bevent.state & GDK_SHIFT_MASK)) {
-
+                                if (!(bevent.state & GDK_SHIFT_MASK) || sp_pen_context_has_waiting_LPE(pc)) {
+                                    /* if we have a waiting LPE, we need a fresh path to be created
+                                       so don't append to an existing one */
                                     selection->clear();
                                     desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Creating new path"));
-
                                 } else if (selection->singleItem() && SP_IS_PATH(selection->singleItem())) {
-
                                     desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Appending to selected path"));
                                 }
 
                                 /* Create green anchor */
                                 p = event_dt;
-                                spdc_endpoint_snap(pc, p, bevent.state);
+                                if (!pc->polylines_paraxial) {
+                                    // only snap the starting point if we're not in horizontal/vertical mode
+                                    // because otherwise it gets shifted; TODO: why do we snap here at all??
+                                    spdc_endpoint_snap(pc, p, bevent.state);
+                                }
                                 pc->green_anchor = sp_draw_anchor_new(pc, pc->green_curve, TRUE, p);
                             }
                             spdc_pen_set_initial_point(pc, p);
@@ -454,7 +509,6 @@ static gint pen_handle_button_press(SPPenContext *const pc, GdkEventButton const
                             pc->ea = anchor;
                             NR::Point p;
                             if (anchor) {
-
                                 p = anchor->dp;
                                 // we hit an anchor, will finish the curve (either with or without closing)
                                 // in release handler
@@ -469,14 +523,16 @@ static gint pen_handle_button_press(SPPenContext *const pc, GdkEventButton const
                                 break;
 
                             } else {
-
                                 p = event_dt;
                                 spdc_endpoint_snap(pc, p, bevent.state); /* Snap node only if not hitting anchor. */
                                 spdc_pen_set_subsequent_point(pc, p, true);
+                                if (pc->polylines_only) {
+                                    spdc_pen_finish_segment(pc, p, bevent.state);
+                                }
                             }
-
                         }
-                        pc->state = SP_PEN_CONTEXT_CONTROL;
+
+                        pc->state = pc->polylines_only ? SP_PEN_CONTEXT_POINT : SP_PEN_CONTEXT_CONTROL;
                         ret = TRUE;
                         break;
                     case SP_PEN_CONTEXT_CONTROL:
@@ -492,7 +548,7 @@ static gint pen_handle_button_press(SPPenContext *const pc, GdkEventButton const
             default:
                 break;
         }
-    } else if (bevent.button == 3) {
+    } else if (bevent.button == 3 || pc->expecting_clicks_for_LPE == 1) { // when the last click for a waiting LPE occurs we want to finish the path
         if (pc->npoints != 0) {
 
             spdc_pen_finish_segment(pc, event_dt, bevent.state);
@@ -508,6 +564,10 @@ static gint pen_handle_button_press(SPPenContext *const pc, GdkEventButton const
         }
     }
 
+    if (pc->expecting_clicks_for_LPE) {
+        --pc->expecting_clicks_for_LPE;
+    }
+
     return ret;
 }
 
@@ -520,12 +580,13 @@ pen_handle_motion_notify(SPPenContext *const pc, GdkEventMotion const &mevent)
     gint ret = FALSE;
 
     SPEventContext *event_context = SP_EVENT_CONTEXT(pc);
+    SPDesktop * const dt = SP_EVENT_CONTEXT_DESKTOP(event_context);
 
     if (event_context->space_panning || mevent.state & GDK_BUTTON2_MASK || mevent.state & GDK_BUTTON3_MASK) {
         // allow scrolling
         return FALSE;
     }
-    
+   
     if (pc->events_disabled) {
         // skip motion events if pen events are disabled
         return FALSE;
@@ -545,16 +606,6 @@ pen_handle_motion_notify(SPPenContext *const pc, GdkEventMotion const &mevent)
     // motion notify coordinates as given (no snapping back to origin)
     pen_within_tolerance = false;
 
-    SPDesktop *const dt = pc->desktop;
-    if ( ( mevent.state & GDK_BUTTON1_MASK ) && !pc->grab ) {
-        /* Grab mouse, so release will not pass unnoticed */
-        pc->grab = SP_CANVAS_ITEM(dt->acetate);
-        sp_canvas_item_grab(pc->grab, ( GDK_KEY_PRESS_MASK | GDK_BUTTON_PRESS_MASK   |
-                                        GDK_BUTTON_RELEASE_MASK |
-                                        GDK_POINTER_MOTION_MASK  ),
-                            NULL, mevent.time);
-    }
-
     /* Find desktop coordinates */
     NR::Point p = dt->w2d(event_w);
 
@@ -596,7 +647,7 @@ pen_handle_motion_notify(SPPenContext *const pc, GdkEventMotion const &mevent)
                             spdc_endpoint_snap(pc, p, mevent.state);
                         }
 
-                        spdc_pen_set_subsequent_point(pc, p, !anchor);
+                        spdc_pen_set_subsequent_point(pc, p, !anchor, mevent.state);
 
                         if (anchor && !pc->anchor_statusbar) {
                             pc->_message_context->set(Inkscape::NORMAL_MESSAGE, _("<b>Click</b> or <b>click and drag</b> to close and finish the path."));
@@ -624,7 +675,11 @@ pen_handle_motion_notify(SPPenContext *const pc, GdkEventMotion const &mevent)
                     // snap the handle
                     spdc_endpoint_snap_handle(pc, p, mevent.state);
 
-                    spdc_pen_set_ctrl(pc, p, mevent.state);
+                    if (!pc->polylines_only) {
+                        spdc_pen_set_ctrl(pc, p, mevent.state);
+                    } else {
+                        spdc_pen_set_ctrl(pc, pc->p[1], mevent.state);
+                    }
                     gobble_motion_events(GDK_BUTTON1_MASK);
                     ret = TRUE;
                     break;
@@ -717,8 +772,10 @@ pen_handle_button_release(SPPenContext *const pc, GdkEventButton const &revent)
                 switch (pc->state) {
                     case SP_PEN_CONTEXT_POINT:
                     case SP_PEN_CONTEXT_CONTROL:
-                        spdc_endpoint_snap(pc, p, revent.state);
-                        spdc_pen_finish_segment(pc, p, revent.state);
+                        if (!pc->polylines_only) {
+                            spdc_endpoint_snap(pc, p, revent.state);
+                            spdc_pen_finish_segment(pc, p, revent.state);
+                        }
                         break;
                     case SP_PEN_CONTEXT_CLOSE:
                         spdc_endpoint_snap(pc, p, revent.state);
@@ -755,6 +812,25 @@ pen_handle_button_release(SPPenContext *const pc, GdkEventButton const &revent)
         dc->green_closed = FALSE;
     }
 
+    // TODO: can we be sure that the path was created correctly?
+    // TODO: should we offer an option to collect the clicks in a list?
+    if (pc->expecting_clicks_for_LPE == 0 && sp_pen_context_has_waiting_LPE(pc)) {
+        sp_pen_context_set_polyline_mode(pc);
+
+        SPEventContext *ec = SP_EVENT_CONTEXT(pc);
+        Inkscape::Selection *selection = sp_desktop_selection (ec->desktop);
+
+        if (pc->waiting_LPE) {
+            // we have an already created LPE waiting for a path
+            pc->waiting_LPE->acceptParamPath(SP_PATH(selection->singleItem()));
+            selection->add(SP_OBJECT(pc->waiting_item));
+            pc->waiting_LPE = NULL;
+        } else {
+            // the case that we need to create a new LPE and apply it to the just-drawn path is
+            // handled in spdc_check_for_and_apply_waiting_LPE() in draw-context.cpp
+        }
+    }
+
     return ret;
 }
 
@@ -790,9 +866,9 @@ pen_redraw_all (SPPenContext *const pc)
     if (pc->green_anchor)
         SP_CTRL(pc->green_anchor->ctrl)->moveto(pc->green_anchor->dp);
 
-    sp_curve_reset(pc->red_curve);
-    sp_curve_moveto(pc->red_curve, pc->p[0]);
-    sp_curve_curveto(pc->red_curve, pc->p[1], pc->p[2], pc->p[3]);
+    pc->red_curve->reset();
+    pc->red_curve->moveto(pc->p[0]);
+    pc->red_curve->curveto(pc->p[1], pc->p[2], pc->p[3]);
     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), pc->red_curve);
 
     // handles
@@ -806,11 +882,15 @@ pen_redraw_all (SPPenContext *const pc)
         sp_canvas_item_hide (pc->cl1);
     }
 
-    NArtBpath *const bpath = sp_curve_last_bpath(pc->green_curve);
-    if (bpath) {
-        if (bpath->code == NR_CURVETO && NR::Point(bpath->x2, bpath->y2) != pc->p[0]) {
-            SP_CTRL(pc->c0)->moveto(NR::Point(bpath->x2, bpath->y2));
-            sp_ctrlline_set_coords(SP_CTRLLINE(pc->cl0), NR::Point(bpath->x2, bpath->y2), pc->p[0]);
+    Geom::Curve const * last_seg = pc->green_curve->last_segment();
+    if (last_seg) {
+        Geom::CubicBezier const * cubic = dynamic_cast<Geom::CubicBezier const *>( last_seg );
+        if ( cubic &&
+             (*cubic)[2] != to_2geom(pc->p[0]) )
+        {
+            NR::Point p2 = (*cubic)[2];
+            SP_CTRL(pc->c0)->moveto(p2);
+            sp_ctrlline_set_coords(SP_CTRLLINE(pc->cl0), p2, pc->p[0]);
             sp_canvas_item_show (pc->c0);
             sp_canvas_item_show (pc->cl0);
         } else {
@@ -827,14 +907,8 @@ pen_lastpoint_move (SPPenContext *const pc, gdouble x, gdouble y)
         return;
 
     // green
-    NArtBpath *const bpath = sp_curve_last_bpath(pc->green_curve);
-    if (bpath) {
-        if (bpath->code == NR_CURVETO) {
-            bpath->x2 += x;
-            bpath->y2 += y;
-        }
-        bpath->x3 += x;
-        bpath->y3 += y;
+    if (!pc->green_curve->is_empty()) {
+        pc->green_curve->last_point_additive_move( Geom::Point(x,y) );
     } else {
         // start anchor too
         if (pc->green_anchor) {
@@ -860,10 +934,9 @@ pen_lastpoint_tocurve (SPPenContext *const pc)
     if (pc->npoints != 5)
         return;
 
-    // red
-    NArtBpath *const bpath = sp_curve_last_bpath(pc->green_curve);
-    if (bpath && bpath->code == NR_CURVETO) {
-        pc->p[1] = pc->p[0] + (NR::Point(bpath->x3, bpath->y3) - NR::Point(bpath->x2, bpath->y2));
+    Geom::CubicBezier const * cubic = dynamic_cast<Geom::CubicBezier const *>( pc->green_curve->last_segment() );
+    if ( cubic ) {
+        pc->p[1] = pc->p[0] + (NR::Point)( (*cubic)[3] - (*cubic)[2] );
     } else {
         pc->p[1] = pc->p[0] + (1./3)*(pc->p[3] - pc->p[0]);
     }
@@ -952,6 +1025,38 @@ pen_handle_key_press(SPPenContext *const pc, GdkEvent *event)
             }
             break;
 
+        case GDK_P:
+        case GDK_p:
+            if (MOD__SHIFT_ONLY) {
+                sp_pen_context_wait_for_LPE_mouse_clicks(pc, Inkscape::LivePathEffect::PARALLEL, 2);
+                ret = TRUE;
+            }
+            break;
+
+        case GDK_C:
+        case GDK_c:
+            if (MOD__SHIFT_ONLY) {
+                sp_pen_context_wait_for_LPE_mouse_clicks(pc, Inkscape::LivePathEffect::CIRCLE_3PTS, 3);
+                ret = TRUE;
+            }
+            break;
+
+        case GDK_B:
+        case GDK_b:
+            if (MOD__SHIFT_ONLY) {
+                sp_pen_context_wait_for_LPE_mouse_clicks(pc, Inkscape::LivePathEffect::PERP_BISECTOR, 2);
+                ret = TRUE;
+            }
+            break;
+
+        case GDK_A:
+        case GDK_a:
+            if (MOD__SHIFT_ONLY) {
+                sp_pen_context_wait_for_LPE_mouse_clicks(pc, Inkscape::LivePathEffect::ANGLE_BISECTOR, 3);
+                ret = TRUE;
+            }
+            break;
+
         case GDK_U:
         case GDK_u:
             if (MOD__SHIFT_ONLY) {
@@ -999,8 +1104,8 @@ pen_handle_key_press(SPPenContext *const pc, GdkEvent *event)
         case GDK_BackSpace:
         case GDK_Delete:
         case GDK_KP_Delete:
-            if (sp_curve_is_empty(pc->green_curve)) {
-                if (!sp_curve_is_empty(pc->red_curve)) {
+            if (pc->green_curve->is_empty()) {
+                if (!pc->red_curve->is_empty()) {
                     pen_cancel (pc);
                     ret = TRUE;
                 } else {
@@ -1008,7 +1113,7 @@ pen_handle_key_press(SPPenContext *const pc, GdkEvent *event)
                 }
             } else {
                 /* Reset red curve */
-                sp_curve_reset(pc->red_curve);
+                pc->red_curve->reset();
                 /* Destroy topmost green bpath */
                 if (pc->green_bpaths) {
                     if (pc->green_bpaths->data)
@@ -1016,23 +1121,24 @@ pen_handle_key_press(SPPenContext *const pc, GdkEvent *event)
                     pc->green_bpaths = g_slist_remove(pc->green_bpaths, pc->green_bpaths->data);
                 }
                 /* Get last segment */
-                NArtBpath const *const p = SP_CURVE_BPATH(pc->green_curve);
-                gint const e = SP_CURVE_LENGTH(pc->green_curve);
-                if ( e < 2 ) {
-                    g_warning("Green curve length is %d", e);
+                if ( pc->green_curve->is_empty() ) {
+                    g_warning("pen_handle_key_press, case GDK_KP_Delete: Green curve is empty");
                     break;
                 }
-                pc->p[0] = p[e - 2].c(3);
-                if (p[e - 1].code == NR_CURVETO) {
-                    pc->p[1] = p[e - 1].c(1);
+                // The code below assumes that pc->green_curve has only ONE path !
+                Geom::Path const & path = pc->green_curve->get_pathvector().back();
+                Geom::Curve const * crv = &path.back_default();
+                pc->p[0] = crv->initialPoint();
+                if ( Geom::CubicBezier const * cubic = dynamic_cast<Geom::CubicBezier const *>(crv)) {
+                    pc->p[1] = (*cubic)[1];
                 } else {
                     pc->p[1] = pc->p[0];
                 }
                 NR::Point const pt(( pc->npoints < 4
-                                     ? p[e - 1].c(3)
+                                     ? (NR::Point)(crv->finalPoint())
                                      : pc->p[3] ));
                 pc->npoints = 2;
-                sp_curve_backspace(pc->green_curve);
+                pc->green_curve->backspace();
                 sp_canvas_item_hide(pc->c0);
                 sp_canvas_item_hide(pc->c1);
                 sp_canvas_item_hide(pc->cl0);
@@ -1052,17 +1158,17 @@ static void
 spdc_reset_colors(SPPenContext *pc)
 {
     /* Red */
-    sp_curve_reset(pc->red_curve);
+    pc->red_curve->reset();
     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), NULL);
     /* Blue */
-    sp_curve_reset(pc->blue_curve);
+    pc->blue_curve->reset();
     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->blue_bpath), NULL);
     /* Green */
     while (pc->green_bpaths) {
         gtk_object_destroy(GTK_OBJECT(pc->green_bpaths->data));
         pc->green_bpaths = g_slist_remove(pc->green_bpaths, pc->green_bpaths->data);
     }
-    sp_curve_reset(pc->green_curve);
+    pc->green_curve->reset();
     if (pc->green_anchor) {
         pc->green_anchor = sp_draw_anchor_destroy(pc->green_anchor);
     }
@@ -1110,7 +1216,7 @@ spdc_pen_set_angle_distance_status_message(SPPenContext *const pc, NR::Point con
 }
 
 static void
-spdc_pen_set_subsequent_point(SPPenContext *const pc, NR::Point const p, bool statusbar)
+spdc_pen_set_subsequent_point(SPPenContext *const pc, NR::Point const p, bool statusbar, guint status)
 {
     g_assert( pc->npoints != 0 );
     /* todo: Check callers to see whether 2 <= npoints is guaranteed. */
@@ -1119,32 +1225,35 @@ spdc_pen_set_subsequent_point(SPPenContext *const pc, NR::Point const p, bool st
     pc->p[3] = p;
     pc->p[4] = p;
     pc->npoints = 5;
-    sp_curve_reset(pc->red_curve);
-    sp_curve_moveto(pc->red_curve, pc->p[0]);
+    pc->red_curve->reset();
     bool is_curve;
-    if ( (pc->onlycurves)
-         || ( pc->p[1] != pc->p[0] ) )
-    {
-        sp_curve_curveto(pc->red_curve, pc->p[1], p, p);
-        is_curve = true;
-    } else {
-        sp_curve_lineto(pc->red_curve, p);
+    pc->red_curve->moveto(pc->p[0]);
+    if (pc->polylines_paraxial && !statusbar) {
+        // we are drawing horizontal/vertical lines and hit an anchor; draw an L-shaped path
+        NR::Point intermed = p;
+        pen_set_to_nearest_horiz_vert(pc, intermed, status);
+        pc->red_curve->lineto(intermed);
+        pc->red_curve->lineto(p);
         is_curve = false;
+    } else {
+        // one of the 'regular' modes
+        if (pc->p[1] != pc->p[0])
+        {
+            pc->red_curve->curveto(pc->p[1], p, p);
+            is_curve = true;
+        } else {
+            pc->red_curve->lineto(p);
+            is_curve = false;
+        }
     }
 
     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), pc->red_curve);
 
     if (statusbar) {
-        gchar *message = g_strconcat(
-                             "<b>",
-                             is_curve ? _("Curve segment") : _("Line segment"),
-                             "</b>: ",
-                             _("angle %3.2f&#176;, distance %s; with <b>Ctrl</b> to snap angle, <b>Enter</b> to finish the path"),
-                             NULL
-                         );
-
+        gchar *message = is_curve ?
+            _("<b>Curve segment</b>: angle %3.2f&#176;, distance %s; with <b>Ctrl</b> to snap angle, <b>Enter</b> to finish the path" ):
+            _("<b>Line segment</b>: angle %3.2f&#176;, distance %s; with <b>Ctrl</b> to snap angle, <b>Enter</b> to finish the path");
         spdc_pen_set_angle_distance_status_message(pc, p, 0, message);
-        g_free(message);
     }
 }
 
@@ -1172,9 +1281,9 @@ spdc_pen_set_ctrl(SPPenContext *const pc, NR::Point const p, guint const state)
             NR::Point delta = p - pc->p[3];
             pc->p[2] = pc->p[3] - delta;
             is_symm = true;
-            sp_curve_reset(pc->red_curve);
-            sp_curve_moveto(pc->red_curve, pc->p[0]);
-            sp_curve_curveto(pc->red_curve, pc->p[1], pc->p[2], pc->p[3]);
+            pc->red_curve->reset();
+            pc->red_curve->moveto(pc->p[0]);
+            pc->red_curve->curveto(pc->p[1], pc->p[2], pc->p[3]);
             sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), pc->red_curve);
         }
         SP_CTRL(pc->c0)->moveto(pc->p[2]);
@@ -1182,30 +1291,29 @@ spdc_pen_set_ctrl(SPPenContext *const pc, NR::Point const p, guint const state)
         SP_CTRL(pc->c1)->moveto(pc->p[4]);
         sp_ctrlline_set_coords(SP_CTRLLINE(pc->cl1), pc->p[3], pc->p[4]);
 
-        gchar *message = g_strconcat(
-                             "<b>",
-                             is_symm ? _("Curve handle, symmetric") : _("Curve handle"),
-                             "</b>: ",
-                             _("angle %3.2f&#176;, length %s; with <b>Ctrl</b> to snap angle, with <b>Shift</b> to move this handle only"),
-                             NULL
-                         );
-
+        gchar *message = is_symm ?
+            _("<b>Curve handle, symmetric</b>: angle %3.2f&#176;, length %s; with <b>Ctrl</b> to snap angle, with <b>Shift</b> to move this handle only") :
+            _("<b>Curve handle</b>: angle %3.2f&#176;, length %s; with <b>Ctrl</b> to snap angle, with <b>Shift</b> to move this handle only");
         spdc_pen_set_angle_distance_status_message(pc, p, 3, message);
-        g_free(message);
     } else {
         g_warning("Something bad happened - npoints is %d", pc->npoints);
     }
 }
 
 static void
-spdc_pen_finish_segment(SPPenContext *const pc, NR::Point const /*p*/, guint const /*state*/)
+spdc_pen_finish_segment(SPPenContext *const pc, NR::Point const p, guint const state)
 {
-    if (!sp_curve_empty(pc->red_curve)) {
-        sp_curve_append_continuous(pc->green_curve, pc->red_curve, 0.0625);
-        SPCurve *curve = sp_curve_copy(pc->red_curve);
+    if (pc->polylines_paraxial) {
+        pen_last_paraxial_dir = pen_next_paraxial_direction(pc, p, pc->p[0], state);
+    }
+    ++pc->num_clicks;
+
+    if (!pc->red_curve->is_empty()) {
+        pc->green_curve->append_continuous(pc->red_curve, 0.0625);
+        SPCurve *curve = pc->red_curve->copy();
         /// \todo fixme:
         SPCanvasItem *cshape = sp_canvas_bpath_new(sp_desktop_sketch(pc->desktop), curve);
-        sp_curve_unref(curve);
+        curve->unref();
         sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(cshape), pc->green_color, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 
         pc->green_bpaths = g_slist_prepend(pc->green_bpaths, cshape);
@@ -1214,20 +1322,27 @@ spdc_pen_finish_segment(SPPenContext *const pc, NR::Point const /*p*/, guint con
         pc->p[1] = pc->p[4];
         pc->npoints = 2;
 
-        sp_curve_reset(pc->red_curve);
+        pc->red_curve->reset();
     }
 }
 
 static void
 spdc_pen_finish(SPPenContext *const pc, gboolean const closed)
 {
+    if (pc->expecting_clicks_for_LPE > 1) {
+        // don't let the path be finished before we have collected the required number of mouse clicks
+        return;
+    }
+
+    pc->num_clicks = 0;
+
     pen_disable_events(pc);
     
     SPDesktop *const desktop = pc->desktop;
     pc->_message_context->clear();
     desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Drawing finished"));
 
-    sp_curve_reset(pc->red_curve);
+    pc->red_curve->reset();
     spdc_concat_colors_and_flush(pc, closed);
     pc->sa = NULL;
     pc->ea = NULL;
@@ -1262,6 +1377,64 @@ pen_enable_events(SPPenContext *const pc) {
   pc->events_disabled--;
 }
 
+void
+sp_pen_context_wait_for_LPE_mouse_clicks(SPPenContext *pc, Inkscape::LivePathEffect::EffectType effect_type,
+                                         unsigned int num_clicks, bool use_polylines)
+{
+    g_print ("Now waiting for %s to be applied\n",
+             Inkscape::LivePathEffect::LPETypeConverter.get_label(effect_type).c_str());
+    pc->expecting_clicks_for_LPE = num_clicks;
+    pc->polylines_only = use_polylines;
+    pc->polylines_paraxial = false; // TODO: think if this is correct for all cases
+    pc->waiting_LPE_type = effect_type;
+}
+
+static int pen_next_paraxial_direction(const SPPenContext *const pc,
+                                       NR::Point const &pt, NR::Point const &origin, guint state) {
+    /*
+     * after the first mouse click we determine whether the mouse pointer is closest to a
+     * horizontal or vertical segment; for all subsequent mouse clicks, we use the direction
+     * orthogonal to the last one; pressing Shift toggles the direction
+     */
+    if (pc->num_clicks == 0) {
+        // first mouse click
+        double dist_h = fabs(pt[NR::X] - origin[NR::X]);
+        double dist_v = fabs(pt[NR::Y] - origin[NR::Y]);
+        int ret = (dist_h < dist_v) ? 1 : 0; // 0 = horizontal, 1 = vertical
+        pen_last_paraxial_dir = (state & GDK_SHIFT_MASK) ? 1 - ret : ret;
+        return pen_last_paraxial_dir;
+    } else {
+        // subsequent mouse click
+        return (state & GDK_SHIFT_MASK) ? pen_last_paraxial_dir : 1 - pen_last_paraxial_dir;
+    }
+}
+
+void pen_set_to_nearest_horiz_vert(const SPPenContext *const pc, NR::Point &pt, guint const state)
+{
+    NR::Point const &origin = pc->p[0];
+
+    int next_dir = pen_next_paraxial_direction(pc, pt, origin, state);
+
+    if (next_dir == 0) {
+        // line is forced to be horizontal
+        pt[NR::Y] = origin[NR::Y];
+    } else {
+        // line is forced to be vertical
+        pt[NR::X] = origin[NR::X];
+    }
+}
+
+NR::Point pen_get_intermediate_horiz_vert(const SPPenContext *const pc, NR::Point const &pt)
+{
+    NR::Point const &origin = pc->p[0];
+
+    if (pen_last_paraxial_dir == 0) {
+        return NR::Point (origin[NR::X], pt[NR::Y]);
+    } else {
+        return NR::Point (pt[NR::X], origin[NR::Y]);
+    }
+}
+
 /*
   Local Variables:
   mode:c++