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 #include "livarot/Path.h"
  46
  47 static void sp_pencil_context_class_init(SPPencilContextClass *klass);
  48 static void sp_pencil_context_init(SPPencilContext *pc);
  49 static void sp_pencil_context_setup(SPEventContext *ec);
  50 static void sp_pencil_context_dispose(GObject *object);
  51
  52 static gint sp_pencil_context_root_handler(SPEventContext *event_context, GdkEvent *event);
  53 static gint pencil_handle_button_press(SPPencilContext *const pc, GdkEventButton const &bevent);
  54 static gint pencil_handle_motion_notify(SPPencilContext *const pc, GdkEventMotion const &mevent);
  55 static gint pencil_handle_button_release(SPPencilContext *const pc, GdkEventButton const &revent);
  56 static gint pencil_handle_key_press(SPPencilContext *const pc, guint const keyval, guint const state);
  57 static gint pencil_handle_key_release(SPPencilContext *const pc, guint const keyval, guint const state);
  58
  59 static void spdc_set_startpoint(SPPencilContext *pc, Geom::Point const p);
  60 static void spdc_set_endpoint(SPPencilContext *pc, Geom::Point const p);
  61 static void spdc_finish_endpoint(SPPencilContext *pc);
  62 static void spdc_add_freehand_point(SPPencilContext *pc, Geom::Point p, guint state);
  63 static void fit_and_split(SPPencilContext *pc);
  64 static void interpolate(SPPencilContext *pc);
  65 static void sketch_interpolate(SPPencilContext *pc);
  66
  67 static SPDrawContextClass *pencil_parent_class;
  68 static Geom::Point pencil_drag_origin_w(0, 0);
  69 static bool pencil_within_tolerance = false;
  70
  71 /**
  72  * Register SPPencilContext class with Gdk and return its type number.
  73  */
  74 GType
  75 sp_pencil_context_get_type()
  76 {
  77     static GType type = 0;
  78     if (!type) {
  79         GTypeInfo info = {
  80             sizeof(SPPencilContextClass),
  81             NULL, NULL,
  82             (GClassInitFunc) sp_pencil_context_class_init,
  83             NULL, NULL,
  84             sizeof(SPPencilContext),
  85             4,
  86             (GInstanceInitFunc) sp_pencil_context_init,
  87             NULL,   /* value_table */
  88         };
  89         type = g_type_register_static(SP_TYPE_DRAW_CONTEXT, "SPPencilContext", &info, (GTypeFlags)0);
  90     }
  91     return type;
  92 }
  93
  94 /**
  95  * Initialize SPPencilContext vtable.
  96  */
  97 static void
  98 sp_pencil_context_class_init(SPPencilContextClass *klass)
  99 {
 100     GObjectClass *object_class;
 101     SPEventContextClass *event_context_class;
 102
 103     object_class = (GObjectClass *) klass;
 104     event_context_class = (SPEventContextClass *) klass;
 105
 106     pencil_parent_class = (SPDrawContextClass*)g_type_class_peek_parent(klass);
 107
 108     object_class->dispose = sp_pencil_context_dispose;
 109
 110     event_context_class->setup = sp_pencil_context_setup;
 111     event_context_class->root_handler = sp_pencil_context_root_handler;
 112 }
 113
 114 /**
 115  * Callback to initialize SPPencilContext object.
 116  */
 117 static void
 118 sp_pencil_context_init(SPPencilContext *pc)
 119 {
 120     SPEventContext *event_context = SP_EVENT_CONTEXT(pc);
 121
 122     event_context->cursor_shape = cursor_pencil_xpm;
 123     event_context->hot_x = 4;
 124     event_context->hot_y = 4;
 125
 126     pc->npoints = 0;
 127     pc->state = SP_PENCIL_CONTEXT_IDLE;
 128     pc->req_tangent = Geom::Point(0, 0);
 129
 130     // since SPPencilContext is not properly constructed...
 131     pc->sketch_interpolation = Geom::Piecewise<Geom::D2<Geom::SBasis> >();
 132     pc->sketch_n = 0;
 133 }
 134
 135 /**
 136  * Callback to setup SPPencilContext object.
 137  */
 138 static void
 139 sp_pencil_context_setup(SPEventContext *ec)
 140 {
 141     Inkscape::Preferences *prefs = Inkscape::Preferences::get();
 142     if (prefs->getBool("/tools/freehand/pencil/selcue")) {
 143         ec->enableSelectionCue();
 144     }
 145
 146     if (((SPEventContextClass *) pencil_parent_class)->setup) {
 147         ((SPEventContextClass *) pencil_parent_class)->setup(ec);
 148     }
 149
 150     SPPencilContext *const pc = SP_PENCIL_CONTEXT(ec);
 151     pc->is_drawing = false;
 152
 153     pc->anchor_statusbar = false;
 154 }
 155
 156 static void
 157 sp_pencil_context_dispose(GObject *object)
 158 {
 159     G_OBJECT_CLASS(pencil_parent_class)->dispose(object);
 160 }
 161
 162 /** Snaps new node relative to the previous node. */
 163 static void
 164 spdc_endpoint_snap(SPPencilContext const *pc, Geom::Point &p, guint const state)
 165 {
 166     if ((state & GDK_CONTROL_MASK)) { //CTRL enables constrained snapping
 167         spdc_endpoint_snap_rotation(pc, p, pc->p[0], state);
 168     } else {
 169         if (!(state & GDK_SHIFT_MASK)) { //SHIFT disables all snapping, except the angular snapping above
 170                                          //After all, the user explicitely asked for angular snapping by
 171                                          //pressing CTRL
 172             spdc_endpoint_snap_free(pc, p, state);
 173         }
 174     }
 175 }
 176
 177 /**
 178  * Callback for handling all pencil context events.
 179  */
 180 gint
 181 sp_pencil_context_root_handler(SPEventContext *const ec, GdkEvent *event)
 182 {
 183     SPPencilContext *const pc = SP_PENCIL_CONTEXT(ec);
 184
 185     gint ret = FALSE;
 186
 187     switch (event->type) {
 188         case GDK_BUTTON_PRESS:
 189             ret = pencil_handle_button_press(pc, event->button);
 190             break;
 191
 192         case GDK_MOTION_NOTIFY:
 193             ret = pencil_handle_motion_notify(pc, event->motion);
 194             break;
 195
 196         case GDK_BUTTON_RELEASE:
 197             ret = pencil_handle_button_release(pc, event->button);
 198             break;
 199
 200         case GDK_KEY_PRESS:
 201             ret = pencil_handle_key_press(pc, get_group0_keyval (&event->key), event->key.state);
 202             break;
 203
 204         case GDK_KEY_RELEASE:
 205             ret = pencil_handle_key_release(pc, get_group0_keyval (&event->key), event->key.state);
 206             break;
 207
 208         default:
 209             break;
 210     }
 211
 212     if (!ret) {
 213         gint (*const parent_root_handler)(SPEventContext *, GdkEvent *)
 214             = ((SPEventContextClass *) pencil_parent_class)->root_handler;
 215         if (parent_root_handler) {
 216             ret = parent_root_handler(ec, event);
 217         }
 218     }
 219
 220     return ret;
 221 }
 222
 223 static gint
 224 pencil_handle_button_press(SPPencilContext *const pc, GdkEventButton const &bevent)
 225 {
 226     gint ret = FALSE;
 227     SPEventContext *event_context = SP_EVENT_CONTEXT(pc);
 228     if ( bevent.button == 1  && !event_context->space_panning) {
 229
 230         SPDrawContext *dc = SP_DRAW_CONTEXT (pc);
 231         SPDesktop *desktop = SP_EVENT_CONTEXT_DESKTOP(dc);
 232         Inkscape::Selection *selection = sp_desktop_selection(desktop);
 233
 234         if (Inkscape::have_viable_layer(desktop, dc->_message_context) == false) {
 235             return TRUE;
 236         }
 237
 238         Geom::Point const button_w(bevent.x, bevent.y);
 239
 240         /* Find desktop coordinates */
 241         Geom::Point p = pc->desktop->w2d(button_w);
 242
 243         /* Test whether we hit any anchor. */
 244         SPDrawAnchor *anchor = spdc_test_inside(pc, button_w);
 245
 246         pencil_drag_origin_w = Geom::Point(bevent.x,bevent.y);
 247         pencil_within_tolerance = true;
 248
 249         switch (pc->state) {
 250             case SP_PENCIL_CONTEXT_ADDLINE:
 251                 /* Current segment will be finished with release */
 252                 ret = TRUE;
 253                 break;
 254             default:
 255                 /* Set first point of sequence */
 256                 SnapManager &m = desktop->namedview->snap_manager;
 257                 m.setup(desktop);
 258
 259                 if (bevent.state & GDK_CONTROL_MASK) {
 260                     if (!(bevent.state & GDK_SHIFT_MASK)) {
 261                         m.freeSnapReturnByRef(p, Inkscape::SNAPSOURCE_NODE_HANDLE);
 262                       }
 263                     spdc_create_single_dot(event_context, p, "/tools/freehand/pencil", bevent.state);
 264                     ret = true;
 265                     break;
 266                 }
 267                 if (anchor) {
 268                     p = anchor->dp;
 269                     desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Continuing selected path"));
 270                 } else {
 271
 272                     if (!(bevent.state & GDK_SHIFT_MASK)) {
 273                         // This is the first click of a new curve; deselect item so that
 274                         // this curve is not combined with it (unless it is drawn from its
 275                         // anchor, which is handled by the sibling branch above)
 276                         selection->clear();
 277                         desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Creating new path"));
 278                         m.freeSnapReturnByRef(p, Inkscape::SNAPSOURCE_NODE_HANDLE);
 279                     } else if (selection->singleItem() && SP_IS_PATH(selection->singleItem())) {
 280                         desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Appending to selected path"));
 281                         m.freeSnapReturnByRef(p, Inkscape::SNAPSOURCE_NODE_HANDLE);
 282                     }
 283                 }
 284                 pc->sa = anchor;
 285                 spdc_set_startpoint(pc, p);
 286                 ret = TRUE;
 287                 break;
 288         }
 289
 290         pc->is_drawing = true;
 291     }
 292     return ret;
 293 }
 294
 295 static gint
 296 pencil_handle_motion_notify(SPPencilContext *const pc, GdkEventMotion const &mevent)
 297 {
 298        SPDesktop *const dt = pc->desktop;
 299
 300     if ((mevent.state & GDK_CONTROL_MASK) && (mevent.state & GDK_BUTTON1_MASK)) {
 301         // mouse was accidentally moved during Ctrl+click;
 302         // ignore the motion and create a single point
 303         pc->is_drawing = false;
 304         return TRUE;
 305     }
 306     gint ret = FALSE;
 307
 308     SPEventContext *event_context = SP_EVENT_CONTEXT(pc);
 309     if (event_context->space_panning || mevent.state & GDK_BUTTON2_MASK || mevent.state & GDK_BUTTON3_MASK) {
 310         // allow scrolling
 311         return FALSE;
 312     }
 313
 314     if ( ( mevent.state & GDK_BUTTON1_MASK ) && !pc->grab && pc->is_drawing) {
 315         /* Grab mouse, so release will not pass unnoticed */
 316         pc->grab = SP_CANVAS_ITEM(dt->acetate);
 317         sp_canvas_item_grab(pc->grab, ( GDK_KEY_PRESS_MASK | GDK_BUTTON_PRESS_MASK   |
 318                                         GDK_BUTTON_RELEASE_MASK |
 319                                         GDK_POINTER_MOTION_MASK  ),
 320                             NULL, mevent.time);
 321     }
 322
 323     /* Find desktop coordinates */
 324     Geom::Point p = dt->w2d(Geom::Point(mevent.x, mevent.y));
 325
 326     /* Test whether we hit any anchor. */
 327     SPDrawAnchor *anchor = spdc_test_inside(pc, Geom::Point(mevent.x, mevent.y));
 328
 329     if (pencil_within_tolerance) {
 330         Inkscape::Preferences *prefs = Inkscape::Preferences::get();
 331         gint const tolerance = prefs->getIntLimited("/options/dragtolerance/value", 0, 0, 100);
 332         if ( Geom::LInfty( Geom::Point(mevent.x,mevent.y) - pencil_drag_origin_w ) < tolerance ) {
 333             return FALSE;   // Do not drag if we're within tolerance from origin.
 334         }
 335     }
 336
 337     // Once the user has moved farther than tolerance from the original location
 338     // (indicating they intend to move the object, not click), then always process the
 339     // motion notify coordinates as given (no snapping back to origin)
 340     pencil_within_tolerance = false;
 341
 342     switch (pc->state) {
 343         case SP_PENCIL_CONTEXT_ADDLINE:
 344             /* Set red endpoint */
 345             if (anchor) {
 346                 p = anchor->dp;
 347             } else {
 348                 Geom::Point ptnr(p);
 349                 spdc_endpoint_snap(pc, ptnr, mevent.state);
 350                 p = ptnr;
 351             }
 352             spdc_set_endpoint(pc, p);
 353             ret = TRUE;
 354             break;
 355         default:
 356             /* We may be idle or already freehand */
 357             if ( mevent.state & GDK_BUTTON1_MASK && pc->is_drawing ) {
 358                 if (pc->state == SP_PENCIL_CONTEXT_IDLE) {
 359                     sp_event_context_discard_delayed_snap_event(event_context);
 360                 }
 361                 pc->state = SP_PENCIL_CONTEXT_FREEHAND;
 362
 363                 if ( !pc->sa && !pc->green_anchor ) {
 364                     /* Create green anchor */
 365                     pc->green_anchor = sp_draw_anchor_new(pc, pc->green_curve, TRUE, pc->p[0]);
 366                 }
 367                 /** \todo
 368                  * fixme: I am not sure whether we want to snap to anchors
 369                  * in middle of freehand (Lauris)
 370                  */
 371                 if (anchor) {
 372                     p = anchor->dp;
 373                 }
 374
 375                 if ( pc->npoints != 0) { // buttonpress may have happened before we entered draw context!
 376                     spdc_add_freehand_point(pc, p, mevent.state);
 377                     ret = TRUE;
 378                 }
 379
 380                 if (anchor && !pc->anchor_statusbar) {
 381                     pc->_message_context->set(Inkscape::NORMAL_MESSAGE, _("<b>Release</b> here to close and finish the path."));
 382                     pc->anchor_statusbar = true;
 383                 } else if (!anchor && pc->anchor_statusbar) {
 384                     pc->_message_context->clear();
 385                     pc->anchor_statusbar = false;
 386                 } else if (!anchor) {
 387                     pc->_message_context->set(Inkscape::NORMAL_MESSAGE, _("Drawing a freehand path"));
 388                 }
 389
 390             } else {
 391                 if (anchor && !pc->anchor_statusbar) {
 392                     pc->_message_context->set(Inkscape::NORMAL_MESSAGE, _("<b>Drag</b> to continue the path from this point."));
 393                     pc->anchor_statusbar = true;
 394                 } else if (!anchor && pc->anchor_statusbar) {
 395                     pc->_message_context->clear();
 396                     pc->anchor_statusbar = false;
 397                 }
 398             }
 399             break;
 400     }
 401     return ret;
 402 }
 403
 404 static gint
 405 pencil_handle_button_release(SPPencilContext *const pc, GdkEventButton const &revent)
 406 {
 407     gint ret = FALSE;
 408
 409     SPEventContext *event_context = SP_EVENT_CONTEXT(pc);
 410     if ( revent.button == 1 && pc->is_drawing && !event_context->space_panning) {
 411         SPDesktop *const dt = pc->desktop;
 412
 413         pc->is_drawing = false;
 414
 415         /* Find desktop coordinates */
 416         Geom::Point p = dt->w2d(Geom::Point(revent.x, revent.y));
 417
 418         /* Test whether we hit any anchor. */
 419         SPDrawAnchor *anchor = spdc_test_inside(pc, Geom::Point(revent.x,
 420                                                               revent.y));
 421
 422         switch (pc->state) {
 423             case SP_PENCIL_CONTEXT_IDLE:
 424                 /* Releasing button in idle mode means single click */
 425                 /* We have already set up start point/anchor in button_press */
 426                 if (!(revent.state & GDK_CONTROL_MASK)) {
 427                     // Ctrl+click creates a single point so only set context in ADDLINE mode when Ctrl isn't pressed
 428                     pc->state = SP_PENCIL_CONTEXT_ADDLINE;
 429                 }
 430                 ret = TRUE;
 431                 break;
 432             case SP_PENCIL_CONTEXT_ADDLINE:
 433                 /* Finish segment now */
 434                 if (anchor) {
 435                     p = anchor->dp;
 436                 } else {
 437                     spdc_endpoint_snap(pc, p, revent.state);
 438                 }
 439                 pc->ea = anchor;
 440                 spdc_set_endpoint(pc, p);
 441                 spdc_finish_endpoint(pc);
 442                 pc->state = SP_PENCIL_CONTEXT_IDLE;
 443                 sp_event_context_discard_delayed_snap_event(event_context);
 444                 ret = TRUE;
 445                 break;
 446             case SP_PENCIL_CONTEXT_FREEHAND:
 447                 if (revent.state & GDK_MOD1_MASK) {
 448                     /* sketch mode: interpolate the sketched path and improve the current output path with the new interpolation. don't finish sketch */
 449
 450                     sketch_interpolate(pc);
 451
 452                     if (pc->green_anchor) {
 453                         pc->green_anchor = sp_draw_anchor_destroy(pc->green_anchor);
 454                     }
 455
 456                     pc->state = SP_PENCIL_CONTEXT_SKETCH;
 457                 } else {
 458                     /* Finish segment now */
 459                     /// \todo fixme: Clean up what follows (Lauris)
 460                     if (anchor) {
 461                         p = anchor->dp;
 462                     }
 463                     pc->ea = anchor;
 464                     /* Write curves to object */
 465
 466                     dt->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Finishing freehand"));
 467
 468                     interpolate(pc);
 469                     spdc_concat_colors_and_flush(pc, FALSE);
 470                     pc->sa = NULL;
 471                     pc->ea = NULL;
 472                     if (pc->green_anchor) {
 473                         pc->green_anchor = sp_draw_anchor_destroy(pc->green_anchor);
 474                     }
 475                     pc->state = SP_PENCIL_CONTEXT_IDLE;
 476                     // reset sketch mode too
 477                     pc->sketch_n = 0;
 478                 }
 479                 ret = TRUE;
 480                 break;
 481             case SP_PENCIL_CONTEXT_SKETCH:
 482             default:
 483                 break;
 484         }
 485
 486         if (pc->grab) {
 487             /* Release grab now */
 488             sp_canvas_item_ungrab(pc->grab, revent.time);
 489             pc->grab = NULL;
 490         }
 491
 492         ret = TRUE;
 493     }
 494     return ret;
 495 }
 496
 497 static void
 498 pencil_cancel (SPPencilContext *const pc)
 499 {
 500     if (pc->grab) {
 501         /* Release grab now */
 502         sp_canvas_item_ungrab(pc->grab, 0);
 503         pc->grab = NULL;
 504     }
 505
 506     pc->is_drawing = false;
 507     pc->state = SP_PENCIL_CONTEXT_IDLE;
 508     sp_event_context_discard_delayed_snap_event(SP_EVENT_CONTEXT(pc));
 509
 510     pc->red_curve->reset();
 511     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), NULL);
 512     while (pc->green_bpaths) {
 513         gtk_object_destroy(GTK_OBJECT(pc->green_bpaths->data));
 514         pc->green_bpaths = g_slist_remove(pc->green_bpaths, pc->green_bpaths->data);
 515     }
 516     pc->green_curve->reset();
 517     if (pc->green_anchor) {
 518         pc->green_anchor = sp_draw_anchor_destroy(pc->green_anchor);
 519     }
 520
 521     pc->_message_context->clear();
 522     pc->_message_context->flash(Inkscape::NORMAL_MESSAGE, _("Drawing cancelled"));
 523
 524     sp_canvas_end_forced_full_redraws(pc->desktop->canvas);
 525 }
 526
 527 static gint
 528 pencil_handle_key_press(SPPencilContext *const pc, guint const keyval, guint const state)
 529 {
 530     gint ret = FALSE;
 531     switch (keyval) {
 532         case GDK_Up:
 533         case GDK_Down:
 534         case GDK_KP_Up:
 535         case GDK_KP_Down:
 536             // Prevent the zoom field from activation.
 537             if (!mod_ctrl_only(state)) {
 538                 ret = TRUE;
 539             }
 540             break;
 541         case GDK_Escape:
 542             if (pc->npoints != 0) {
 543                 // if drawing, cancel, otherwise pass it up for deselecting
 544                 if (pc->state != SP_PENCIL_CONTEXT_IDLE) {
 545                     pencil_cancel (pc);
 546                     ret = TRUE;
 547                 }
 548             }
 549             break;
 550         case GDK_z:
 551         case GDK_Z:
 552             if (mod_ctrl_only(state) && pc->npoints != 0) {
 553                 // if drawing, cancel, otherwise pass it up for undo
 554                 if (pc->state != SP_PENCIL_CONTEXT_IDLE) {
 555                     pencil_cancel (pc);
 556                     ret = TRUE;
 557                 }
 558             }
 559             break;
 560         case GDK_g:
 561         case GDK_G:
 562             if (mod_shift_only(state)) {
 563                 sp_selection_to_guides(SP_EVENT_CONTEXT(pc)->desktop);
 564                 ret = true;
 565             }
 566             break;
 567         case GDK_Alt_L:
 568         case GDK_Alt_R:
 569         case GDK_Meta_L:
 570         case GDK_Meta_R:
 571             if (pc->state == SP_PENCIL_CONTEXT_IDLE) {
 572                 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."));
 573             }
 574             break;
 575         default:
 576             break;
 577     }
 578     return ret;
 579 }
 580
 581 static gint
 582 pencil_handle_key_release(SPPencilContext *const pc, guint const keyval, guint const /*state*/)
 583 {
 584     gint ret = FALSE;
 585     switch (keyval) {
 586         case GDK_Alt_L:
 587         case GDK_Alt_R:
 588         case GDK_Meta_L:
 589         case GDK_Meta_R:
 590             if (pc->state == SP_PENCIL_CONTEXT_SKETCH) {
 591                 spdc_concat_colors_and_flush(pc, FALSE);
 592                 pc->sketch_n = 0;
 593                 pc->sa = NULL;
 594                 pc->ea = NULL;
 595                 if (pc->green_anchor) {
 596                     pc->green_anchor = sp_draw_anchor_destroy(pc->green_anchor);
 597                 }
 598                 pc->state = SP_PENCIL_CONTEXT_IDLE;
 599                 sp_event_context_discard_delayed_snap_event(SP_EVENT_CONTEXT(pc));
 600                 pc->desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Finishing freehand sketch"));
 601                 ret = TRUE;
 602             }
 603             break;
 604         default:
 605             break;
 606     }
 607     return ret;
 608 }
 609
 610 /**
 611  * Reset points and set new starting point.
 612  */
 613 static void
 614 spdc_set_startpoint(SPPencilContext *const pc, Geom::Point const p)
 615 {
 616     pc->npoints = 0;
 617     pc->red_curve_is_valid = false;
 618     if (in_svg_plane(p)) {
 619         pc->p[pc->npoints++] = p;
 620     }
 621 }
 622
 623 /**
 624  * Change moving endpoint position.
 625  * <ul>
 626  * <li>Ctrl constrains to moving to H/V direction, snapping in given direction.
 627  * <li>Otherwise we snap freely to whatever attractors are available.
 628  * </ul>
 629  *
 630  * Number of points is (re)set to 2 always, 2nd point is modified.
 631  * We change RED curve.
 632  */
 633 static void
 634 spdc_set_endpoint(SPPencilContext *const pc, Geom::Point const p)
 635 {
 636     if (pc->npoints == 0) {
 637         return;
 638         /* May occur if first point wasn't in SVG plane (e.g. weird w2d transform, perhaps from bad
 639          * zoom setting).
 640          */
 641     }
 642     g_return_if_fail( pc->npoints > 0 );
 643
 644     pc->red_curve->reset();
 645     if ( ( p == pc->p[0] )
 646          || !in_svg_plane(p) )
 647     {
 648         pc->npoints = 1;
 649     } else {
 650         pc->p[1] = p;
 651         pc->npoints = 2;
 652
 653         pc->red_curve->moveto(pc->p[0]);
 654         pc->red_curve->lineto(pc->p[1]);
 655         pc->red_curve_is_valid = true;
 656
 657         sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), pc->red_curve);
 658     }
 659 }
 660
 661 /**
 662  * Finalize addline.
 663  *
 664  * \todo
 665  * fixme: I'd like remove red reset from concat colors (lauris).
 666  * Still not sure, how it will make most sense.
 667  */
 668 static void
 669 spdc_finish_endpoint(SPPencilContext *const pc)
 670 {
 671     if ( ( pc->red_curve->is_empty() )
 672          || ( *(pc->red_curve->first_point()) == *(pc->red_curve->second_point())   ) )
 673     {
 674         pc->red_curve->reset();
 675         sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), NULL);
 676     } else {
 677         /* Write curves to object. */
 678         spdc_concat_colors_and_flush(pc, FALSE);
 679         pc->sa = NULL;
 680         pc->ea = NULL;
 681     }
 682 }
 683
 684
 685 static void
 686 spdc_add_freehand_point(SPPencilContext *pc, Geom::Point p, guint /*state*/)
 687 {
 688     g_assert( pc->npoints > 0 );
 689     g_return_if_fail(unsigned(pc->npoints) < G_N_ELEMENTS(pc->p));
 690
 691     if ( ( p != pc->p[ pc->npoints - 1 ] )
 692          && in_svg_plane(p) )
 693     {
 694         pc->ps.push_back(p);
 695         pc->p[pc->npoints++] = p;
 696         fit_and_split(pc);
 697     }
 698 }
 699
 700 static inline double
 701 square(double const x)
 702 {
 703     return x * x;
 704 }
 705
 706 static void
 707 interpolate(SPPencilContext *pc)
 708 {
 709     if ( pc->ps.size() <= 1 ) {
 710         return;
 711     }
 712
 713     Inkscape::Preferences *prefs = Inkscape::Preferences::get();
 714     double const tol = prefs->getDoubleLimited("/tools/freehand/pencil/tolerance", 10.0, 1.0, 100.0) * 0.4;
 715     double const tolerance_sq = 0.02 * square( pc->desktop->w2d().descrim() *
 716                                                tol) * exp(0.2*tol - 2);
 717
 718     g_assert(is_zero(pc->req_tangent)
 719              || is_unit_vector(pc->req_tangent));
 720     Geom::Point const tHatEnd(0, 0);
 721
 722     guint n_points  = pc->ps.size();
 723     pc->green_curve->reset();
 724     pc->red_curve->reset();
 725     pc->red_curve_is_valid = false;
 726
 727     Geom::Point * b = g_new(Geom::Point, 4*n_points);
 728     Geom::Point * points = g_new(Geom::Point, 4*n_points);
 729     for (unsigned int i = 0; i < pc->ps.size(); i++) {
 730         points[i] = pc->ps[i];
 731     }
 732
 733     // worst case gives us a segment per point
 734     int max_segs = 4*n_points;
 735
 736     int const n_segs = Geom::bezier_fit_cubic_r(b, points, n_points,
 737                                              tolerance_sq, max_segs);
 738
 739     if ( n_segs > 0)
 740     {
 741         /* Fit and draw and reset state */
 742         pc->green_curve->moveto(b[0]);
 743         for (int c = 0; c < n_segs; c++) {
 744             pc->green_curve->curveto(b[4*c+1], b[4*c+2], b[4*c+3]);
 745         }
 746         sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), pc->green_curve);
 747
 748         /* Fit and draw and copy last point */
 749         g_assert(!pc->green_curve->is_empty());
 750
 751         /* Set up direction of next curve. */
 752         {
 753             Geom::CubicBezier const * last_seg = dynamic_cast<Geom::CubicBezier const *>(pc->green_curve->last_segment());
 754             g_assert( last_seg );      // Relevance: validity of (*last_seg)[2]
 755             pc->p[0] = last_seg->finalPoint();
 756             pc->npoints = 1;
 757             Geom::Point const req_vec( pc->p[0] - (*last_seg)[2] );
 758             pc->req_tangent = ( ( Geom::is_zero(req_vec) || !in_svg_plane(req_vec) )
 759                                 ? Geom::Point(0, 0)
 760                                 : Geom::unit_vector(req_vec) );
 761         }
 762     }
 763     g_free(b);
 764     g_free(points);
 765     pc->ps.clear();
 766 }
 767
 768
 769 /* interpolates the sketched curve and tweaks the current sketch interpolation*/
 770 static void
 771 sketch_interpolate(SPPencilContext *pc)
 772 {
 773     if ( pc->ps.size() <= 1 ) {
 774         return;
 775     }
 776
 777     Inkscape::Preferences *prefs = Inkscape::Preferences::get();
 778     double const tol = prefs->getDoubleLimited("/tools/freehand/pencil/tolerance", 10.0, 1.0, 100.0) * 0.4;
 779     double const tolerance_sq = 0.02 * square( pc->desktop->w2d().descrim() *
 780                                                tol) * exp(0.2*tol - 2);
 781
 782     bool average_all_sketches = prefs->getBool("/tools/freehand/pencil/average_all_sketches", true);
 783
 784     g_assert(is_zero(pc->req_tangent)
 785              || is_unit_vector(pc->req_tangent));
 786     Geom::Point const tHatEnd(0, 0);
 787
 788     guint n_points  = pc->ps.size();
 789     pc->red_curve->reset();
 790     pc->red_curve_is_valid = false;
 791
 792     Geom::Point * b = g_new(Geom::Point, 4*n_points);
 793     Geom::Point * points = g_new(Geom::Point, 4*n_points);
 794     for (unsigned i = 0; i < pc->ps.size(); i++) {
 795         points[i] = pc->ps[i];
 796     }
 797
 798     // worst case gives us a segment per point
 799     int max_segs = 4*n_points;
 800
 801     int const n_segs = Geom::bezier_fit_cubic_r(b, points, n_points,
 802                                              tolerance_sq, max_segs);
 803
 804     if ( n_segs > 0)
 805     {
 806         Geom::Path fit(b[0]);
 807         for (int c = 0; c < n_segs; c++) {
 808             fit.appendNew<Geom::CubicBezier>(b[4*c+1], b[4*c+2], b[4*c+3]);
 809         }
 810         Geom::Piecewise<Geom::D2<Geom::SBasis> > fit_pwd2 = fit.toPwSb();
 811
 812         double t =0.;
 813         if ( pc->sketch_n > 0 ) {
 814             if (average_all_sketches) {
 815                 // Average = (sum of all) / n
 816                 //         = (sum of all + new one) / n+1
 817                 //         = ((old average)*n + new one) / n+1
 818                 t = pc->sketch_n / (pc->sketch_n + 1.);
 819             } else {
 820                 t = 0.5;
 821             }
 822             pc->sketch_interpolation = Geom::lerp(t, fit_pwd2, pc->sketch_interpolation);
 823             // simplify path, to eliminate small segments
 824             Path *path = new Path;
 825             path->LoadPathVector(Geom::path_from_piecewise(pc->sketch_interpolation, 0.01));
 826             path->Simplify(0.5);
 827             Geom::PathVector *pathv = path->MakePathVector();
 828             pc->sketch_interpolation = (*pathv)[0].toPwSb();
 829             delete path;
 830             delete pathv;
 831         } else {
 832             pc->sketch_interpolation = fit_pwd2;
 833         }
 834         pc->sketch_n++;
 835
 836         pc->green_curve->reset();
 837         pc->green_curve->set_pathvector(Geom::path_from_piecewise(pc->sketch_interpolation, 0.01));
 838         sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), pc->green_curve);
 839
 840         /* Fit and draw and copy last point */
 841         g_assert(!pc->green_curve->is_empty());
 842
 843         /* Set up direction of next curve. */
 844         {
 845             Geom::CubicBezier const * last_seg = dynamic_cast<Geom::CubicBezier const *>(pc->green_curve->last_segment());
 846             g_assert( last_seg );      // Relevance: validity of (*last_seg)[2]
 847             pc->p[0] = last_seg->finalPoint();
 848             pc->npoints = 1;
 849             Geom::Point const req_vec( pc->p[0] - (*last_seg)[2] );
 850             pc->req_tangent = ( ( Geom::is_zero(req_vec) || !in_svg_plane(req_vec) )
 851                                 ? Geom::Point(0, 0)
 852                                 : Geom::unit_vector(req_vec) );
 853         }
 854     }
 855     g_free(b);
 856     g_free(points);
 857     pc->ps.clear();
 858 }
 859
 860 static void
 861 fit_and_split(SPPencilContext *pc)
 862 {
 863     g_assert( pc->npoints > 1 );
 864
 865     double const tolerance_sq = 0;
 866
 867     Geom::Point b[4];
 868     g_assert(is_zero(pc->req_tangent)
 869              || is_unit_vector(pc->req_tangent));
 870     Geom::Point const tHatEnd(0, 0);
 871     int const n_segs = Geom::bezier_fit_cubic_full(b, NULL, pc->p, pc->npoints,
 872                                                 pc->req_tangent, tHatEnd,
 873                                                 tolerance_sq, 1);
 874     if ( n_segs > 0
 875          && unsigned(pc->npoints) < G_N_ELEMENTS(pc->p) )
 876     {
 877         /* Fit and draw and reset state */
 878         pc->red_curve->reset();
 879         pc->red_curve->moveto(b[0]);
 880         pc->red_curve->curveto(b[1], b[2], b[3]);
 881         sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), pc->red_curve);
 882         pc->red_curve_is_valid = true;
 883     } else {
 884         /* Fit and draw and copy last point */
 885
 886         g_assert(!pc->red_curve->is_empty());
 887
 888         /* Set up direction of next curve. */
 889         {
 890             Geom::CubicBezier const * last_seg = dynamic_cast<Geom::CubicBezier const *>(pc->red_curve->last_segment());
 891             g_assert( last_seg );      // Relevance: validity of (*last_seg)[2]
 892             pc->p[0] = last_seg->finalPoint();
 893             pc->npoints = 1;
 894             Geom::Point const req_vec( pc->p[0] - (*last_seg)[2] );
 895             pc->req_tangent = ( ( Geom::is_zero(req_vec) || !in_svg_plane(req_vec) )
 896                                 ? Geom::Point(0, 0)
 897                                 : Geom::unit_vector(req_vec) );
 898         }
 899
 900         pc->green_curve->append_continuous(pc->red_curve, 0.0625);
 901         SPCurve *curve = pc->red_curve->copy();
 902
 903         /// \todo fixme:
 904         SPCanvasItem *cshape = sp_canvas_bpath_new(sp_desktop_sketch(pc->desktop), curve);
 905         curve->unref();
 906         sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(cshape), pc->green_color, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 907
 908         pc->green_bpaths = g_slist_prepend(pc->green_bpaths, cshape);
 909
 910         pc->red_curve_is_valid = false;
 911     }
 912 }
 913
 914
 915 /*
 916   Local Variables:
 917   mode:c++
 918   c-file-style:"stroustrup"
 919   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
 920   indent-tabs-mode:nil
 921   fill-column:99
 922   End:
 923 */
 924 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :