src/pencil-context.cpp

   1 /** \file
   2  * Pencil event context implementation.
   3  */
   4
   5 /*
   6  * Authors:
   7  *   Lauris Kaplinski <lauris@kaplinski.com>
   8  *   bulia byak <buliabyak@users.sf.net>
   9  *
  10  * Copyright (C) 2000 Lauris Kaplinski
  11  * Copyright (C) 2000-2001 Ximian, Inc.
  12  * Copyright (C) 2002 Lauris Kaplinski
  13  * Copyright (C) 2004 Monash University
  14  *
  15  * Released under GNU GPL, read the file 'COPYING' for more information
  16  */
  17
  18 #include <gdk/gdkkeysyms.h>
  19
  20 #include "pencil-context.h"
  21 #include "desktop.h"
  22 #include "desktop-handles.h"
  23 #include "selection.h"
  24 #include "selection-chemistry.h"
  25 #include "draw-anchor.h"
  26 #include "message-stack.h"
  27 #include "message-context.h"
  28 #include "modifier-fns.h"
  29 #include "sp-path.h"
  30 #include "preferences.h"
  31 #include "snap.h"
  32 #include "pixmaps/cursor-pencil.xpm"
  33 #include <2geom/sbasis-to-bezier.h>
  34 #include <2geom/bezier-utils.h>
  35 #include "display/canvas-bpath.h"
  36 #include <glibmm/i18n.h>
  37 #include "libnr/in-svg-plane.h"
  38 #include "context-fns.h"
  39 #include "sp-namedview.h"
  40 #include "xml/repr.h"
  41 #include "document.h"
  42 #include "desktop-style.h"
  43 #include "macros.h"
  44 #include "display/curve.h"
  45
  46 static void sp_pencil_context_class_init(SPPencilContextClass *klass);
  47 static void sp_pencil_context_init(SPPencilContext *pc);
  48 static void sp_pencil_context_setup(SPEventContext *ec);
  49 static void sp_pencil_context_dispose(GObject *object);
  50
  51 static gint sp_pencil_context_root_handler(SPEventContext *event_context, GdkEvent *event);
  52 static gint pencil_handle_button_press(SPPencilContext *const pc, GdkEventButton const &bevent);
  53 static gint pencil_handle_motion_notify(SPPencilContext *const pc, GdkEventMotion const &mevent);
  54 static gint pencil_handle_button_release(SPPencilContext *const pc, GdkEventButton const &revent);
  55 static gint pencil_handle_key_press(SPPencilContext *const pc, guint const keyval, guint const state);
  56 static gint pencil_handle_key_release(SPPencilContext *const pc, guint const keyval, guint const state);
  57
  58 static void spdc_set_startpoint(SPPencilContext *pc, Geom::Point const p);
  59 static void spdc_set_endpoint(SPPencilContext *pc, Geom::Point const p);
  60 static void spdc_finish_endpoint(SPPencilContext *pc);
  61 static void spdc_add_freehand_point(SPPencilContext *pc, Geom::Point p, guint state);
  62 static void fit_and_split(SPPencilContext *pc);
  63 static void interpolate(SPPencilContext *pc);
  64 static void sketch_interpolate(SPPencilContext *pc);
  65
  66 static SPDrawContextClass *pencil_parent_class;
  67 static Geom::Point pencil_drag_origin_w(0, 0);
  68 static bool pencil_within_tolerance = false;
  69
  70 /**
  71  * Register SPPencilContext class with Gdk and return its type number.
  72  */
  73 GType
  74 sp_pencil_context_get_type()
  75 {
  76     static GType type = 0;
  77     if (!type) {
  78         GTypeInfo info = {
  79             sizeof(SPPencilContextClass),
  80             NULL, NULL,
  81             (GClassInitFunc) sp_pencil_context_class_init,
  82             NULL, NULL,
  83             sizeof(SPPencilContext),
  84             4,
  85             (GInstanceInitFunc) sp_pencil_context_init,
  86             NULL,   /* value_table */
  87         };
  88         type = g_type_register_static(SP_TYPE_DRAW_CONTEXT, "SPPencilContext", &info, (GTypeFlags)0);
  89     }
  90     return type;
  91 }
  92
  93 /**
  94  * Initialize SPPencilContext vtable.
  95  */
  96 static void
  97 sp_pencil_context_class_init(SPPencilContextClass *klass)
  98 {
  99     GObjectClass *object_class;
 100     SPEventContextClass *event_context_class;
 101
 102     object_class = (GObjectClass *) klass;
 103     event_context_class = (SPEventContextClass *) klass;
 104
 105     pencil_parent_class = (SPDrawContextClass*)g_type_class_peek_parent(klass);
 106
 107     object_class->dispose = sp_pencil_context_dispose;
 108
 109     event_context_class->setup = sp_pencil_context_setup;
 110     event_context_class->root_handler = sp_pencil_context_root_handler;
 111 }
 112
 113 /**
 114  * Callback to initialize SPPencilContext object.
 115  */
 116 static void
 117 sp_pencil_context_init(SPPencilContext *pc)
 118 {
 119     SPEventContext *event_context = SP_EVENT_CONTEXT(pc);
 120
 121     event_context->cursor_shape = cursor_pencil_xpm;
 122     event_context->hot_x = 4;
 123     event_context->hot_y = 4;
 124
 125     pc->npoints = 0;
 126     pc->state = SP_PENCIL_CONTEXT_IDLE;
 127     pc->req_tangent = Geom::Point(0, 0);
 128
 129     // since SPPencilContext is not properly constructed...
 130     pc->sketch_interpolation = Geom::Piecewise<Geom::D2<Geom::SBasis> >();
 131     pc->sketch_n = 0;
 132 }
 133
 134 /**
 135  * Callback to setup SPPencilContext object.
 136  */
 137 static void
 138 sp_pencil_context_setup(SPEventContext *ec)
 139 {
 140     Inkscape::Preferences *prefs = Inkscape::Preferences::get();
 141     if (prefs->getBool("/tools/freehand/pencil/selcue")) {
 142         ec->enableSelectionCue();
 143     }
 144
 145     if (((SPEventContextClass *) pencil_parent_class)->setup) {
 146         ((SPEventContextClass *) pencil_parent_class)->setup(ec);
 147     }
 148
 149     SPPencilContext *const pc = SP_PENCIL_CONTEXT(ec);
 150     pc->is_drawing = false;
 151
 152     pc->anchor_statusbar = false;
 153 }
 154
 155 static void
 156 sp_pencil_context_dispose(GObject *object)
 157 {
 158     G_OBJECT_CLASS(pencil_parent_class)->dispose(object);
 159 }
 160
 161 /** Snaps new node relative to the previous node. */
 162 static void
 163 spdc_endpoint_snap(SPPencilContext const *pc, Geom::Point &p, guint const state)
 164 {
 165     if ((state & GDK_CONTROL_MASK)) { //CTRL enables constrained snapping
 166         spdc_endpoint_snap_rotation(pc, p, pc->p[0], state);
 167     } else {
 168         if (!(state & GDK_SHIFT_MASK)) { //SHIFT disables all snapping, except the angular snapping above
 169                                          //After all, the user explicitely asked for angular snapping by
 170                                          //pressing CTRL
 171             spdc_endpoint_snap_free(pc, p, state);
 172         }
 173     }
 174 }
 175
 176 /**
 177  * Callback for handling all pencil context events.
 178  */
 179 gint
 180 sp_pencil_context_root_handler(SPEventContext *const ec, GdkEvent *event)
 181 {
 182     SPPencilContext *const pc = SP_PENCIL_CONTEXT(ec);
 183
 184     gint ret = FALSE;
 185
 186     switch (event->type) {
 187         case GDK_BUTTON_PRESS:
 188             ret = pencil_handle_button_press(pc, event->button);
 189             break;
 190
 191         case GDK_MOTION_NOTIFY:
 192             ret = pencil_handle_motion_notify(pc, event->motion);
 193             break;
 194
 195         case GDK_BUTTON_RELEASE:
 196             ret = pencil_handle_button_release(pc, event->button);
 197             break;
 198
 199         case GDK_KEY_PRESS:
 200             ret = pencil_handle_key_press(pc, get_group0_keyval (&event->key), event->key.state);
 201             break;
 202
 203         case GDK_KEY_RELEASE:
 204             ret = pencil_handle_key_release(pc, get_group0_keyval (&event->key), event->key.state);
 205             break;
 206
 207         default:
 208             break;
 209     }
 210
 211     if (!ret) {
 212         gint (*const parent_root_handler)(SPEventContext *, GdkEvent *)
 213             = ((SPEventContextClass *) pencil_parent_class)->root_handler;
 214         if (parent_root_handler) {
 215             ret = parent_root_handler(ec, event);
 216         }
 217     }
 218
 219     return ret;
 220 }
 221
 222 static gint
 223 pencil_handle_button_press(SPPencilContext *const pc, GdkEventButton const &bevent)
 224 {
 225     gint ret = FALSE;
 226     SPEventContext *event_context = SP_EVENT_CONTEXT(pc);
 227     if ( bevent.button == 1  && !event_context->space_panning) {
 228
 229         SPDrawContext *dc = SP_DRAW_CONTEXT (pc);
 230         SPDesktop *desktop = SP_EVENT_CONTEXT_DESKTOP(dc);
 231         Inkscape::Selection *selection = sp_desktop_selection(desktop);
 232
 233         if (Inkscape::have_viable_layer(desktop, dc->_message_context) == false) {
 234             return TRUE;
 235         }
 236
 237         Geom::Point const button_w(bevent.x, bevent.y);
 238
 239         /* Find desktop coordinates */
 240         Geom::Point p = pc->desktop->w2d(button_w);
 241
 242         /* Test whether we hit any anchor. */
 243         SPDrawAnchor *anchor = spdc_test_inside(pc, button_w);
 244
 245         pencil_drag_origin_w = Geom::Point(bevent.x,bevent.y);
 246         pencil_within_tolerance = true;
 247
 248         switch (pc->state) {
 249             case SP_PENCIL_CONTEXT_ADDLINE:
 250                 /* Current segment will be finished with release */
 251                 ret = TRUE;
 252                 break;
 253             default:
 254                 /* Set first point of sequence */
 255                 SnapManager &m = desktop->namedview->snap_manager;
 256                                 m.setup(desktop);
 257                                 sp_canvas_set_snap_delay_active(desktop->canvas, true);
 258
 259                 if (bevent.state & GDK_CONTROL_MASK) {
 260                         if (!(bevent.state & GDK_SHIFT_MASK)) {
 261                                 m.freeSnapReturnByRef(Inkscape::SnapPreferences::SNAPPOINT_NODE, p);
 262                         }
 263                                         spdc_create_single_dot(event_context, p, "/tools/freehand/pencil", bevent.state);
 264                                         sp_canvas_set_snap_delay_active(desktop->canvas, false);
 265                                         ret = true;
 266                     break;
 267                 }
 268                 if (anchor) {
 269                     p = anchor->dp;
 270                     desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Continuing selected path"));
 271                 } else {
 272
 273                     if (!(bevent.state & GDK_SHIFT_MASK)) {
 274                                                 // This is the first click of a new curve; deselect item so that
 275                         // this curve is not combined with it (unless it is drawn from its
 276                         // anchor, which is handled by the sibling branch above)
 277                         selection->clear();
 278                         desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Creating new path"));
 279                         m.freeSnapReturnByRef(Inkscape::SnapPreferences::SNAPPOINT_NODE, p);
 280                     } else if (selection->singleItem() && SP_IS_PATH(selection->singleItem())) {
 281                         desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Appending to selected path"));
 282                         m.freeSnapReturnByRef(Inkscape::SnapPreferences::SNAPPOINT_NODE, p);
 283                     }
 284                 }
 285                 pc->sa = anchor;
 286                 spdc_set_startpoint(pc, p);
 287                 ret = TRUE;
 288                 break;
 289         }
 290
 291         pc->is_drawing = true;
 292     }
 293     return ret;
 294 }
 295
 296 static gint
 297 pencil_handle_motion_notify(SPPencilContext *const pc, GdkEventMotion const &mevent)
 298 {
 299         SPDesktop *const dt = pc->desktop;
 300
 301         if ((mevent.state & GDK_CONTROL_MASK) && (mevent.state & GDK_BUTTON1_MASK)) {
 302         // mouse was accidentally moved during Ctrl+click;
 303         // ignore the motion and create a single point
 304         pc->is_drawing = false;
 305         return TRUE;
 306     }
 307     gint ret = FALSE;
 308
 309     SPEventContext *event_context = SP_EVENT_CONTEXT(pc);
 310     if (event_context->space_panning || mevent.state & GDK_BUTTON2_MASK || mevent.state & GDK_BUTTON3_MASK) {
 311         // allow scrolling
 312         return FALSE;
 313     }
 314
 315     if ( ( mevent.state & GDK_BUTTON1_MASK ) && !pc->grab && pc->is_drawing) {
 316         /* Grab mouse, so release will not pass unnoticed */
 317         pc->grab = SP_CANVAS_ITEM(dt->acetate);
 318         sp_canvas_item_grab(pc->grab, ( GDK_KEY_PRESS_MASK | GDK_BUTTON_PRESS_MASK   |
 319                                         GDK_BUTTON_RELEASE_MASK |
 320                                         GDK_POINTER_MOTION_MASK  ),
 321                             NULL, mevent.time);
 322     }
 323
 324     /* Find desktop coordinates */
 325     Geom::Point p = dt->w2d(Geom::Point(mevent.x, mevent.y));
 326
 327     /* Test whether we hit any anchor. */
 328     SPDrawAnchor *anchor = spdc_test_inside(pc, Geom::Point(mevent.x, mevent.y));
 329
 330     if (pencil_within_tolerance) {
 331         Inkscape::Preferences *prefs = Inkscape::Preferences::get();
 332         gint const tolerance = prefs->getIntLimited("/options/dragtolerance/value", 0, 0, 100);
 333         if ( Geom::LInfty( Geom::Point(mevent.x,mevent.y) - pencil_drag_origin_w ) < tolerance ) {
 334             return FALSE;   // Do not drag if we're within tolerance from origin.
 335         }
 336     }
 337
 338     // Once the user has moved farther than tolerance from the original location
 339     // (indicating they intend to move the object, not click), then always process the
 340     // motion notify coordinates as given (no snapping back to origin)
 341     pencil_within_tolerance = false;
 342
 343     switch (pc->state) {
 344         case SP_PENCIL_CONTEXT_ADDLINE:
 345             /* Set red endpoint */
 346             if (anchor) {
 347                 p = anchor->dp;
 348             } else {
 349                 Geom::Point ptnr(p);
 350                 spdc_endpoint_snap(pc, ptnr, mevent.state);
 351                 p = ptnr;
 352             }
 353             spdc_set_endpoint(pc, p);
 354             ret = TRUE;
 355             break;
 356         default:
 357             /* We may be idle or already freehand */
 358             if ( mevent.state & GDK_BUTTON1_MASK && pc->is_drawing ) {
 359                 if (pc->state == SP_PENCIL_CONTEXT_IDLE) {
 360                         sp_canvas_set_snap_delay_active(dt->canvas, false);
 361                 }
 362                 pc->state = SP_PENCIL_CONTEXT_FREEHAND;
 363
 364                 if ( !pc->sa && !pc->green_anchor ) {
 365                     /* Create green anchor */
 366                     pc->green_anchor = sp_draw_anchor_new(pc, pc->green_curve, TRUE, pc->p[0]);
 367                 }
 368                 /** \todo
 369                  * fixme: I am not sure whether we want to snap to anchors
 370                  * in middle of freehand (Lauris)
 371                  */
 372                 if (anchor) {
 373                     p = anchor->dp;
 374                 }
 375
 376                 if ( pc->npoints != 0) { // buttonpress may have happened before we entered draw context!
 377                                         spdc_add_freehand_point(pc, p, mevent.state);
 378                                         ret = TRUE;
 379                 }
 380
 381                 if (anchor && !pc->anchor_statusbar) {
 382                     pc->_message_context->set(Inkscape::NORMAL_MESSAGE, _("<b>Release</b> here to close and finish the path."));
 383                     pc->anchor_statusbar = true;
 384                 } else if (!anchor && pc->anchor_statusbar) {
 385                     pc->_message_context->clear();
 386                     pc->anchor_statusbar = false;
 387                 } else if (!anchor) {
 388                     pc->_message_context->set(Inkscape::NORMAL_MESSAGE, _("Drawing a freehand path"));
 389                 }
 390
 391             } else {
 392                 if (anchor && !pc->anchor_statusbar) {
 393                     pc->_message_context->set(Inkscape::NORMAL_MESSAGE, _("<b>Drag</b> to continue the path from this point."));
 394                     pc->anchor_statusbar = true;
 395                 } else if (!anchor && pc->anchor_statusbar) {
 396                     pc->_message_context->clear();
 397                     pc->anchor_statusbar = false;
 398                 }
 399             }
 400             break;
 401     }
 402     return ret;
 403 }
 404
 405 static gint
 406 pencil_handle_button_release(SPPencilContext *const pc, GdkEventButton const &revent)
 407 {
 408     gint ret = FALSE;
 409
 410     SPEventContext *event_context = SP_EVENT_CONTEXT(pc);
 411     if ( revent.button == 1 && pc->is_drawing && !event_context->space_panning) {
 412         SPDesktop *const dt = pc->desktop;
 413
 414         pc->is_drawing = false;
 415
 416         /* Find desktop coordinates */
 417         Geom::Point p = dt->w2d(Geom::Point(revent.x, revent.y));
 418
 419         /* Test whether we hit any anchor. */
 420         SPDrawAnchor *anchor = spdc_test_inside(pc, Geom::Point(revent.x,
 421                                                               revent.y));
 422
 423         switch (pc->state) {
 424             case SP_PENCIL_CONTEXT_IDLE:
 425                 /* Releasing button in idle mode means single click */
 426                 /* We have already set up start point/anchor in button_press */
 427                 if (!(revent.state & GDK_CONTROL_MASK)) {
 428                     // Ctrl+click creates a single point so only set context in ADDLINE mode when Ctrl isn't pressed
 429                     pc->state = SP_PENCIL_CONTEXT_ADDLINE;
 430                     //sp_canvas_set_snap_delay_active(dt->canvas, true);
 431                 }
 432                 ret = TRUE;
 433                 break;
 434             case SP_PENCIL_CONTEXT_ADDLINE:
 435                 /* Finish segment now */
 436                 if (anchor) {
 437                     p = anchor->dp;
 438                 } else {
 439                     spdc_endpoint_snap(pc, p, revent.state);
 440                 }
 441                 pc->ea = anchor;
 442                 spdc_set_endpoint(pc, p);
 443                 spdc_finish_endpoint(pc);
 444                 pc->state = SP_PENCIL_CONTEXT_IDLE;
 445                 sp_canvas_set_snap_delay_active(dt->canvas, false);
 446                 ret = TRUE;
 447                 break;
 448             case SP_PENCIL_CONTEXT_FREEHAND:
 449                 if (revent.state & GDK_MOD1_MASK) {
 450                     /* sketch mode: interpolate the sketched path and improve the current output path with the new interpolation. don't finish sketch */
 451
 452                     sketch_interpolate(pc);
 453
 454                     if (pc->green_anchor) {
 455                         pc->green_anchor = sp_draw_anchor_destroy(pc->green_anchor);
 456                     }
 457
 458                     pc->state = SP_PENCIL_CONTEXT_SKETCH;
 459                     //sp_canvas_set_snap_delay_active(dt->canvas, true);
 460                 } else {
 461                     /* Finish segment now */
 462                     /// \todo fixme: Clean up what follows (Lauris)
 463                     if (anchor) {
 464                         p = anchor->dp;
 465                     }
 466                     pc->ea = anchor;
 467                     /* Write curves to object */
 468
 469                     dt->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Finishing freehand"));
 470
 471                     interpolate(pc);
 472                     spdc_concat_colors_and_flush(pc, FALSE);
 473                     pc->sa = NULL;
 474                     pc->ea = NULL;
 475                     if (pc->green_anchor) {
 476                         pc->green_anchor = sp_draw_anchor_destroy(pc->green_anchor);
 477                     }
 478                     pc->state = SP_PENCIL_CONTEXT_IDLE;
 479                     // sp_canvas_set_snap_delay_active(dt->canvas, false);
 480                     // reset sketch mode too
 481                     pc->sketch_n = 0;
 482                 }
 483                 ret = TRUE;
 484                 break;
 485             case SP_PENCIL_CONTEXT_SKETCH:
 486             default:
 487                 break;
 488         }
 489
 490         if (pc->grab) {
 491             /* Release grab now */
 492             sp_canvas_item_ungrab(pc->grab, revent.time);
 493             pc->grab = NULL;
 494         }
 495
 496         ret = TRUE;
 497     }
 498     return ret;
 499 }
 500
 501 static void
 502 pencil_cancel (SPPencilContext *const pc)
 503 {
 504     if (pc->grab) {
 505         /* Release grab now */
 506         sp_canvas_item_ungrab(pc->grab, 0);
 507         pc->grab = NULL;
 508     }
 509
 510     pc->is_drawing = false;
 511     pc->state = SP_PENCIL_CONTEXT_IDLE;
 512     sp_canvas_set_snap_delay_active(pc->desktop->canvas, false);
 513
 514     pc->red_curve->reset();
 515     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), NULL);
 516     while (pc->green_bpaths) {
 517         gtk_object_destroy(GTK_OBJECT(pc->green_bpaths->data));
 518         pc->green_bpaths = g_slist_remove(pc->green_bpaths, pc->green_bpaths->data);
 519     }
 520     pc->green_curve->reset();
 521     if (pc->green_anchor) {
 522         pc->green_anchor = sp_draw_anchor_destroy(pc->green_anchor);
 523     }
 524
 525     pc->_message_context->clear();
 526     pc->_message_context->flash(Inkscape::NORMAL_MESSAGE, _("Drawing cancelled"));
 527
 528     sp_canvas_end_forced_full_redraws(pc->desktop->canvas);
 529 }
 530
 531 static gint
 532 pencil_handle_key_press(SPPencilContext *const pc, guint const keyval, guint const state)
 533 {
 534     gint ret = FALSE;
 535     switch (keyval) {
 536         case GDK_Up:
 537         case GDK_Down:
 538         case GDK_KP_Up:
 539         case GDK_KP_Down:
 540             // Prevent the zoom field from activation.
 541             if (!mod_ctrl_only(state)) {
 542                 ret = TRUE;
 543             }
 544             break;
 545         case GDK_Escape:
 546             if (pc->npoints != 0) {
 547                 // if drawing, cancel, otherwise pass it up for deselecting
 548                 if (pc->state != SP_PENCIL_CONTEXT_IDLE) {
 549                     pencil_cancel (pc);
 550                     ret = TRUE;
 551                 }
 552             }
 553             break;
 554         case GDK_z:
 555         case GDK_Z:
 556             if (mod_ctrl_only(state) && pc->npoints != 0) {
 557                 // if drawing, cancel, otherwise pass it up for undo
 558                 if (pc->state != SP_PENCIL_CONTEXT_IDLE) {
 559                     pencil_cancel (pc);
 560                     ret = TRUE;
 561                 }
 562             }
 563             break;
 564         case GDK_g:
 565         case GDK_G:
 566             if (mod_shift_only(state)) {
 567                 sp_selection_to_guides(SP_EVENT_CONTEXT(pc)->desktop);
 568                 ret = true;
 569             }
 570             break;
 571         case GDK_Alt_L:
 572         case GDK_Alt_R:
 573         case GDK_Meta_L:
 574         case GDK_Meta_R:
 575             if (pc->state == SP_PENCIL_CONTEXT_IDLE) {
 576                 pc->desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("<b>Sketch mode</b>: holding <b>Alt</b> interpolates between sketched paths. Release <b>Alt</b> to finalize."));
 577             }
 578             break;
 579         default:
 580             break;
 581     }
 582     return ret;
 583 }
 584
 585 static gint
 586 pencil_handle_key_release(SPPencilContext *const pc, guint const keyval, guint const /*state*/)
 587 {
 588     gint ret = FALSE;
 589     switch (keyval) {
 590         case GDK_Alt_L:
 591         case GDK_Alt_R:
 592         case GDK_Meta_L:
 593         case GDK_Meta_R:
 594             if (pc->state == SP_PENCIL_CONTEXT_SKETCH) {
 595                 spdc_concat_colors_and_flush(pc, FALSE);
 596                 pc->sketch_n = 0;
 597                 pc->sa = NULL;
 598                 pc->ea = NULL;
 599                 if (pc->green_anchor) {
 600                     pc->green_anchor = sp_draw_anchor_destroy(pc->green_anchor);
 601                 }
 602                 pc->state = SP_PENCIL_CONTEXT_IDLE;
 603                 sp_canvas_set_snap_delay_active(pc->desktop->canvas, false);
 604                 pc->desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Finishing freehand sketch"));
 605                 ret = TRUE;
 606             }
 607             break;
 608         default:
 609             break;
 610     }
 611     return ret;
 612 }
 613
 614 /**
 615  * Reset points and set new starting point.
 616  */
 617 static void
 618 spdc_set_startpoint(SPPencilContext *const pc, Geom::Point const p)
 619 {
 620     pc->npoints = 0;
 621     pc->red_curve_is_valid = false;
 622     if (in_svg_plane(p)) {
 623         pc->p[pc->npoints++] = p;
 624     }
 625 }
 626
 627 /**
 628  * Change moving endpoint position.
 629  * <ul>
 630  * <li>Ctrl constrains to moving to H/V direction, snapping in given direction.
 631  * <li>Otherwise we snap freely to whatever attractors are available.
 632  * </ul>
 633  *
 634  * Number of points is (re)set to 2 always, 2nd point is modified.
 635  * We change RED curve.
 636  */
 637 static void
 638 spdc_set_endpoint(SPPencilContext *const pc, Geom::Point const p)
 639 {
 640     if (pc->npoints == 0) {
 641         return;
 642         /* May occur if first point wasn't in SVG plane (e.g. weird w2d transform, perhaps from bad
 643          * zoom setting).
 644          */
 645     }
 646     g_return_if_fail( pc->npoints > 0 );
 647
 648     pc->red_curve->reset();
 649     if ( ( p == pc->p[0] )
 650          || !in_svg_plane(p) )
 651     {
 652         pc->npoints = 1;
 653     } else {
 654         pc->p[1] = p;
 655         pc->npoints = 2;
 656
 657         pc->red_curve->moveto(pc->p[0]);
 658         pc->red_curve->lineto(pc->p[1]);
 659         pc->red_curve_is_valid = true;
 660
 661         sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), pc->red_curve);
 662     }
 663 }
 664
 665 /**
 666  * Finalize addline.
 667  *
 668  * \todo
 669  * fixme: I'd like remove red reset from concat colors (lauris).
 670  * Still not sure, how it will make most sense.
 671  */
 672 static void
 673 spdc_finish_endpoint(SPPencilContext *const pc)
 674 {
 675     if ( ( pc->red_curve->is_empty() )
 676          || ( *(pc->red_curve->first_point()) == *(pc->red_curve->second_point())   ) )
 677     {
 678         pc->red_curve->reset();
 679         sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), NULL);
 680     } else {
 681         /* Write curves to object. */
 682         spdc_concat_colors_and_flush(pc, FALSE);
 683         pc->sa = NULL;
 684         pc->ea = NULL;
 685     }
 686 }
 687
 688
 689 static void
 690 spdc_add_freehand_point(SPPencilContext *pc, Geom::Point p, guint /*state*/)
 691 {
 692     g_assert( pc->npoints > 0 );
 693     g_return_if_fail(unsigned(pc->npoints) < G_N_ELEMENTS(pc->p));
 694
 695     if ( ( p != pc->p[ pc->npoints - 1 ] )
 696          && in_svg_plane(p) )
 697     {
 698         pc->ps.push_back(p);
 699         pc->p[pc->npoints++] = p;
 700         fit_and_split(pc);
 701     }
 702 }
 703
 704 static inline double
 705 square(double const x)
 706 {
 707     return x * x;
 708 }
 709
 710 static void
 711 interpolate(SPPencilContext *pc)
 712 {
 713
 714     if ( pc->ps.size() <= 1 ) {
 715         return;
 716     }
 717
 718     Inkscape::Preferences *prefs = Inkscape::Preferences::get();
 719     double const tol = prefs->getDoubleLimited("/tools/freehand/pencil/tolerance", 10.0, 1.0, 100.0) * 0.4;
 720     double const tolerance_sq = 0.02 * square( pc->desktop->w2d().descrim() *
 721                                                tol) * exp(0.2*tol - 2);
 722
 723     g_assert(is_zero(pc->req_tangent)
 724              || is_unit_vector(pc->req_tangent));
 725     Geom::Point const tHatEnd(0, 0);
 726
 727     guint n_points  = pc->ps.size();
 728     pc->green_curve->reset();
 729     pc->red_curve->reset();
 730     pc->red_curve_is_valid = false;
 731
 732     Geom::Point * b = g_new(Geom::Point, 4*n_points);
 733     Geom::Point * points = g_new(Geom::Point, 4*n_points);
 734     for (unsigned int i = 0; i < pc->ps.size(); i++) {
 735         points[i] = pc->ps[i];
 736     }
 737
 738     // worst case gives us a segment per point
 739     int max_segs = 4*n_points;
 740
 741     int const n_segs = Geom::bezier_fit_cubic_r(b, points, n_points,
 742                                              tolerance_sq, max_segs);
 743
 744     if ( n_segs > 0)
 745     {
 746         /* Fit and draw and reset state */
 747         pc->green_curve->moveto(b[0]);
 748         for (int c = 0; c < n_segs; c++) {
 749             pc->green_curve->curveto(b[4*c+1], b[4*c+2], b[4*c+3]);
 750         }
 751         sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), pc->green_curve);
 752
 753         /* Fit and draw and copy last point */
 754         g_assert(!pc->green_curve->is_empty());
 755
 756         /* Set up direction of next curve. */
 757         {
 758             Geom::CubicBezier const * last_seg = dynamic_cast<Geom::CubicBezier const *>(pc->green_curve->last_segment());
 759             g_assert( last_seg );      // Relevance: validity of (*last_seg)[2]
 760             pc->p[0] = last_seg->finalPoint();
 761             pc->npoints = 1;
 762             Geom::Point const req_vec( pc->p[0] - (*last_seg)[2] );
 763             pc->req_tangent = ( ( Geom::is_zero(req_vec) || !in_svg_plane(req_vec) )
 764                                 ? Geom::Point(0, 0)
 765                                 : Geom::unit_vector(req_vec) );
 766         }
 767     }
 768     g_free(b);
 769     g_free(points);
 770     pc->ps.clear();
 771 }
 772
 773
 774 /* interpolates the sketched curve and tweaks the current sketch interpolation*/
 775 static void
 776 sketch_interpolate(SPPencilContext *pc)
 777 {
 778     g_assert( pc->ps.size() > 1 );
 779
 780     Inkscape::Preferences *prefs = Inkscape::Preferences::get();
 781     double const tol = prefs->getDoubleLimited("/tools/freehand/pencil/tolerance", 10.0, 1.0, 100.0) * 0.4;
 782     double const tolerance_sq = 0.02 * square( pc->desktop->w2d().descrim() *
 783                                                tol) * exp(0.2*tol - 2);
 784
 785     bool average_all_sketches = prefs->getBool("/tools/freehand/pencil/average_all_sketches", true);
 786
 787     g_assert(is_zero(pc->req_tangent)
 788              || is_unit_vector(pc->req_tangent));
 789     Geom::Point const tHatEnd(0, 0);
 790
 791     guint n_points  = pc->ps.size();
 792     pc->red_curve->reset();
 793     pc->red_curve_is_valid = false;
 794
 795     Geom::Point * b = g_new(Geom::Point, 4*n_points);
 796     Geom::Point * points = g_new(Geom::Point, 4*n_points);
 797     for (unsigned i = 0; i < pc->ps.size(); i++) {
 798         points[i] = pc->ps[i];
 799     }
 800
 801     // worst case gives us a segment per point
 802     int max_segs = 4*n_points;
 803
 804     int const n_segs = Geom::bezier_fit_cubic_r(b, points, n_points,
 805                                              tolerance_sq, max_segs);
 806
 807     if ( n_segs > 0)
 808     {
 809         Geom::Path fit(b[0]);
 810         for (int c = 0; c < n_segs; c++) {
 811             fit.appendNew<Geom::CubicBezier>(b[4*c+1], b[4*c+2], b[4*c+3]);
 812         }
 813         Geom::Piecewise<Geom::D2<Geom::SBasis> > fit_pwd2 = fit.toPwSb();
 814
 815         double t =0.;
 816         if ( pc->sketch_n > 0 ) {
 817             if (average_all_sketches) {
 818                 // Average = (sum of all) / n
 819                 //         = (sum of all + new one) / n+1
 820                 //         = ((old average)*n + new one) / n+1
 821                 t = pc->sketch_n / (pc->sketch_n + 1.);
 822             } else {
 823                 t = 0.5;
 824             }
 825             pc->sketch_interpolation = Geom::lerp(t, fit_pwd2, pc->sketch_interpolation);
 826         } else {
 827             pc->sketch_interpolation = fit_pwd2;
 828         }
 829         pc->sketch_n++;
 830
 831         pc->green_curve->reset();
 832         pc->green_curve->set_pathvector(Geom::path_from_piecewise(pc->sketch_interpolation, 0.01));
 833         sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), pc->green_curve);
 834
 835         /* Fit and draw and copy last point */
 836         g_assert(!pc->green_curve->is_empty());
 837
 838         /* Set up direction of next curve. */
 839         {
 840             Geom::CubicBezier const * last_seg = dynamic_cast<Geom::CubicBezier const *>(pc->green_curve->last_segment());
 841             g_assert( last_seg );      // Relevance: validity of (*last_seg)[2]
 842             pc->p[0] = last_seg->finalPoint();
 843             pc->npoints = 1;
 844             Geom::Point const req_vec( pc->p[0] - (*last_seg)[2] );
 845             pc->req_tangent = ( ( Geom::is_zero(req_vec) || !in_svg_plane(req_vec) )
 846                                 ? Geom::Point(0, 0)
 847                                 : Geom::unit_vector(req_vec) );
 848         }
 849     }
 850     g_free(b);
 851     g_free(points);
 852     pc->ps.clear();
 853 }
 854
 855 static void
 856 fit_and_split(SPPencilContext *pc)
 857 {
 858     g_assert( pc->npoints > 1 );
 859
 860     double const tolerance_sq = 0;
 861
 862     Geom::Point b[4];
 863     g_assert(is_zero(pc->req_tangent)
 864              || is_unit_vector(pc->req_tangent));
 865     Geom::Point const tHatEnd(0, 0);
 866     int const n_segs = Geom::bezier_fit_cubic_full(b, NULL, pc->p, pc->npoints,
 867                                                 pc->req_tangent, tHatEnd,
 868                                                 tolerance_sq, 1);
 869     if ( n_segs > 0
 870          && unsigned(pc->npoints) < G_N_ELEMENTS(pc->p) )
 871     {
 872         /* Fit and draw and reset state */
 873         pc->red_curve->reset();
 874         pc->red_curve->moveto(b[0]);
 875         pc->red_curve->curveto(b[1], b[2], b[3]);
 876         sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), pc->red_curve);
 877         pc->red_curve_is_valid = true;
 878     } else {
 879         /* Fit and draw and copy last point */
 880
 881         g_assert(!pc->red_curve->is_empty());
 882
 883         /* Set up direction of next curve. */
 884         {
 885             Geom::CubicBezier const * last_seg = dynamic_cast<Geom::CubicBezier const *>(pc->red_curve->last_segment());
 886             g_assert( last_seg );      // Relevance: validity of (*last_seg)[2]
 887             pc->p[0] = last_seg->finalPoint();
 888             pc->npoints = 1;
 889             Geom::Point const req_vec( pc->p[0] - (*last_seg)[2] );
 890             pc->req_tangent = ( ( Geom::is_zero(req_vec) || !in_svg_plane(req_vec) )
 891                                 ? Geom::Point(0, 0)
 892                                 : Geom::unit_vector(req_vec) );
 893         }
 894
 895         pc->green_curve->append_continuous(pc->red_curve, 0.0625);
 896         SPCurve *curve = pc->red_curve->copy();
 897
 898         /// \todo fixme:
 899         SPCanvasItem *cshape = sp_canvas_bpath_new(sp_desktop_sketch(pc->desktop), curve);
 900         curve->unref();
 901         sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(cshape), pc->green_color, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 902
 903         pc->green_bpaths = g_slist_prepend(pc->green_bpaths, cshape);
 904
 905         pc->red_curve_is_valid = false;
 906     }
 907 }
 908
 909
 910 /*
 911   Local Variables:
 912   mode:c++
 913   c-file-style:"stroustrup"
 914   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
 915   indent-tabs-mode:nil
 916   fill-column:99
 917   End:
 918 */
 919 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :