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/sp-canvas.h"
  45 #include "display/curve.h"
  46 #include "livarot/Path.h"
  47
  48 static void sp_pencil_context_class_init(SPPencilContextClass *klass);
  49 static void sp_pencil_context_init(SPPencilContext *pc);
  50 static void sp_pencil_context_setup(SPEventContext *ec);
  51 static void sp_pencil_context_dispose(GObject *object);
  52
  53 static gint sp_pencil_context_root_handler(SPEventContext *event_context, GdkEvent *event);
  54 static gint pencil_handle_button_press(SPPencilContext *const pc, GdkEventButton const &bevent);
  55 static gint pencil_handle_motion_notify(SPPencilContext *const pc, GdkEventMotion const &mevent);
  56 static gint pencil_handle_button_release(SPPencilContext *const pc, GdkEventButton const &revent);
  57 static gint pencil_handle_key_press(SPPencilContext *const pc, guint const keyval, guint const state);
  58 static gint pencil_handle_key_release(SPPencilContext *const pc, guint const keyval, guint const state);
  59
  60 static void spdc_set_startpoint(SPPencilContext *pc, Geom::Point const p);
  61 static void spdc_set_endpoint(SPPencilContext *pc, Geom::Point const p);
  62 static void spdc_finish_endpoint(SPPencilContext *pc);
  63 static void spdc_add_freehand_point(SPPencilContext *pc, Geom::Point p, guint state);
  64 static void fit_and_split(SPPencilContext *pc);
  65 static void interpolate(SPPencilContext *pc);
  66 static void sketch_interpolate(SPPencilContext *pc);
  67
  68 static SPDrawContextClass *pencil_parent_class;
  69 static Geom::Point pencil_drag_origin_w(0, 0);
  70 static bool pencil_within_tolerance = false;
  71
  72 /**
  73  * Register SPPencilContext class with Gdk and return its type number.
  74  */
  75 GType
  76 sp_pencil_context_get_type()
  77 {
  78     static GType type = 0;
  79     if (!type) {
  80         GTypeInfo info = {
  81             sizeof(SPPencilContextClass),
  82             NULL, NULL,
  83             (GClassInitFunc) sp_pencil_context_class_init,
  84             NULL, NULL,
  85             sizeof(SPPencilContext),
  86             4,
  87             (GInstanceInitFunc) sp_pencil_context_init,
  88             NULL,   /* value_table */
  89         };
  90         type = g_type_register_static(SP_TYPE_DRAW_CONTEXT, "SPPencilContext", &info, (GTypeFlags)0);
  91     }
  92     return type;
  93 }
  94
  95 /**
  96  * Initialize SPPencilContext vtable.
  97  */
  98 static void
  99 sp_pencil_context_class_init(SPPencilContextClass *klass)
 100 {
 101     GObjectClass *object_class;
 102     SPEventContextClass *event_context_class;
 103
 104     object_class = (GObjectClass *) klass;
 105     event_context_class = (SPEventContextClass *) klass;
 106
 107     pencil_parent_class = (SPDrawContextClass*)g_type_class_peek_parent(klass);
 108
 109     object_class->dispose = sp_pencil_context_dispose;
 110
 111     event_context_class->setup = sp_pencil_context_setup;
 112     event_context_class->root_handler = sp_pencil_context_root_handler;
 113 }
 114
 115 /**
 116  * Callback to initialize SPPencilContext object.
 117  */
 118 static void
 119 sp_pencil_context_init(SPPencilContext *pc)
 120 {
 121     SPEventContext *event_context = SP_EVENT_CONTEXT(pc);
 122
 123     event_context->cursor_shape = cursor_pencil_xpm;
 124     event_context->hot_x = 4;
 125     event_context->hot_y = 4;
 126
 127     pc->npoints = 0;
 128     pc->state = SP_PENCIL_CONTEXT_IDLE;
 129     pc->req_tangent = Geom::Point(0, 0);
 130
 131     // since SPPencilContext is not properly constructed...
 132     pc->sketch_interpolation = Geom::Piecewise<Geom::D2<Geom::SBasis> >();
 133     pc->sketch_n = 0;
 134 }
 135
 136 /**
 137  * Callback to setup SPPencilContext object.
 138  */
 139 static void
 140 sp_pencil_context_setup(SPEventContext *ec)
 141 {
 142     Inkscape::Preferences *prefs = Inkscape::Preferences::get();
 143     if (prefs->getBool("/tools/freehand/pencil/selcue")) {
 144         ec->enableSelectionCue();
 145     }
 146
 147     if (((SPEventContextClass *) pencil_parent_class)->setup) {
 148         ((SPEventContextClass *) pencil_parent_class)->setup(ec);
 149     }
 150
 151     SPPencilContext *const pc = SP_PENCIL_CONTEXT(ec);
 152     pc->is_drawing = false;
 153
 154     pc->anchor_statusbar = false;
 155 }
 156
 157 static void
 158 sp_pencil_context_dispose(GObject *object)
 159 {
 160     G_OBJECT_CLASS(pencil_parent_class)->dispose(object);
 161 }
 162
 163 /** Snaps new node relative to the previous node. */
 164 static void
 165 spdc_endpoint_snap(SPPencilContext const *pc, Geom::Point &p, guint const state)
 166 {
 167     if ((state & GDK_CONTROL_MASK)) { //CTRL enables constrained snapping
 168         spdc_endpoint_snap_rotation(pc, p, pc->p[0], state);
 169     } else {
 170         if (!(state & GDK_SHIFT_MASK)) { //SHIFT disables all snapping, except the angular snapping above
 171                                          //After all, the user explicitely asked for angular snapping by
 172                                          //pressing CTRL
 173             spdc_endpoint_snap_free(pc, p, state);
 174         }
 175     }
 176 }
 177
 178 /**
 179  * Callback for handling all pencil context events.
 180  */
 181 gint
 182 sp_pencil_context_root_handler(SPEventContext *const ec, GdkEvent *event)
 183 {
 184     SPPencilContext *const pc = SP_PENCIL_CONTEXT(ec);
 185
 186     gint ret = FALSE;
 187
 188     switch (event->type) {
 189         case GDK_BUTTON_PRESS:
 190             ret = pencil_handle_button_press(pc, event->button);
 191             break;
 192
 193         case GDK_MOTION_NOTIFY:
 194             ret = pencil_handle_motion_notify(pc, event->motion);
 195             break;
 196
 197         case GDK_BUTTON_RELEASE:
 198             ret = pencil_handle_button_release(pc, event->button);
 199             break;
 200
 201         case GDK_KEY_PRESS:
 202             ret = pencil_handle_key_press(pc, get_group0_keyval (&event->key), event->key.state);
 203             break;
 204
 205         case GDK_KEY_RELEASE:
 206             ret = pencil_handle_key_release(pc, get_group0_keyval (&event->key), event->key.state);
 207             break;
 208
 209         default:
 210             break;
 211     }
 212
 213     if (!ret) {
 214         gint (*const parent_root_handler)(SPEventContext *, GdkEvent *)
 215             = ((SPEventContextClass *) pencil_parent_class)->root_handler;
 216         if (parent_root_handler) {
 217             ret = parent_root_handler(ec, event);
 218         }
 219     }
 220
 221     return ret;
 222 }
 223
 224 static gint
 225 pencil_handle_button_press(SPPencilContext *const pc, GdkEventButton const &bevent)
 226 {
 227     gint ret = FALSE;
 228     SPEventContext *event_context = SP_EVENT_CONTEXT(pc);
 229     if ( bevent.button == 1  && !event_context->space_panning) {
 230
 231         SPDrawContext *dc = SP_DRAW_CONTEXT (pc);
 232         SPDesktop *desktop = SP_EVENT_CONTEXT_DESKTOP(dc);
 233         Inkscape::Selection *selection = sp_desktop_selection(desktop);
 234
 235         if (Inkscape::have_viable_layer(desktop, dc->_message_context) == false) {
 236             return TRUE;
 237         }
 238
 239         if (!pc->grab) {
 240             /* Grab mouse, so release will not pass unnoticed */
 241             pc->grab = SP_CANVAS_ITEM(desktop->acetate);
 242             sp_canvas_item_grab(pc->grab, ( GDK_KEY_PRESS_MASK | GDK_BUTTON_PRESS_MASK   |
 243                                             GDK_BUTTON_RELEASE_MASK |
 244                                             GDK_POINTER_MOTION_MASK  ),
 245                                 NULL, bevent.time);
 246         }
 247
 248         Geom::Point const button_w(bevent.x, bevent.y);
 249
 250         /* Find desktop coordinates */
 251         Geom::Point p = pc->desktop->w2d(button_w);
 252
 253         /* Test whether we hit any anchor. */
 254         SPDrawAnchor *anchor = spdc_test_inside(pc, button_w);
 255
 256         pencil_drag_origin_w = Geom::Point(bevent.x,bevent.y);
 257         pencil_within_tolerance = true;
 258
 259         switch (pc->state) {
 260             case SP_PENCIL_CONTEXT_ADDLINE:
 261                 /* Current segment will be finished with release */
 262                 ret = TRUE;
 263                 break;
 264             default:
 265                 /* Set first point of sequence */
 266                 SnapManager &m = desktop->namedview->snap_manager;
 267
 268                 if (bevent.state & GDK_CONTROL_MASK) {
 269                     m.setup(desktop);
 270                     if (!(bevent.state & GDK_SHIFT_MASK)) {
 271                         m.freeSnapReturnByRef(p, Inkscape::SNAPSOURCE_NODE_HANDLE);
 272                       }
 273                     spdc_create_single_dot(event_context, p, "/tools/freehand/pencil", bevent.state);
 274                     m.unSetup();
 275                     ret = true;
 276                     break;
 277                 }
 278                 if (anchor) {
 279                     p = anchor->dp;
 280                     desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Continuing selected path"));
 281                 } else {
 282                     m.setup(desktop);
 283                     if (!(bevent.state & GDK_SHIFT_MASK)) {
 284                         // This is the first click of a new curve; deselect item so that
 285                         // this curve is not combined with it (unless it is drawn from its
 286                         // anchor, which is handled by the sibling branch above)
 287                         selection->clear();
 288                         desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Creating new path"));
 289                         m.freeSnapReturnByRef(p, Inkscape::SNAPSOURCE_NODE_HANDLE);
 290                     } else if (selection->singleItem() && SP_IS_PATH(selection->singleItem())) {
 291                         desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Appending to selected path"));
 292                         m.freeSnapReturnByRef(p, Inkscape::SNAPSOURCE_NODE_HANDLE);
 293                     }
 294                     m.unSetup();
 295                 }
 296                 pc->sa = anchor;
 297                 spdc_set_startpoint(pc, p);
 298                 ret = TRUE;
 299                 break;
 300         }
 301
 302         pc->is_drawing = true;
 303     }
 304     return ret;
 305 }
 306
 307 static gint
 308 pencil_handle_motion_notify(SPPencilContext *const pc, GdkEventMotion const &mevent)
 309 {
 310     SPDesktop *const dt = pc->desktop;
 311
 312     if ((mevent.state & GDK_CONTROL_MASK) && (mevent.state & GDK_BUTTON1_MASK)) {
 313         // mouse was accidentally moved during Ctrl+click;
 314         // ignore the motion and create a single point
 315         pc->is_drawing = false;
 316         return TRUE;
 317     }
 318     gint ret = FALSE;
 319
 320     SPEventContext *event_context = SP_EVENT_CONTEXT(pc);
 321     if (event_context->space_panning || mevent.state & GDK_BUTTON2_MASK || mevent.state & GDK_BUTTON3_MASK) {
 322         // allow scrolling
 323         return FALSE;
 324     }
 325
 326     if ( ( mevent.state & GDK_BUTTON1_MASK ) && !pc->grab && pc->is_drawing) {
 327         /* Grab mouse, so release will not pass unnoticed */
 328         pc->grab = SP_CANVAS_ITEM(dt->acetate);
 329         sp_canvas_item_grab(pc->grab, ( GDK_KEY_PRESS_MASK | GDK_BUTTON_PRESS_MASK   |
 330                                         GDK_BUTTON_RELEASE_MASK |
 331                                         GDK_POINTER_MOTION_MASK  ),
 332                             NULL, mevent.time);
 333     }
 334
 335     /* Find desktop coordinates */
 336     Geom::Point p = dt->w2d(Geom::Point(mevent.x, mevent.y));
 337
 338     /* Test whether we hit any anchor. */
 339     SPDrawAnchor *anchor = spdc_test_inside(pc, Geom::Point(mevent.x, mevent.y));
 340
 341     if (pencil_within_tolerance) {
 342         Inkscape::Preferences *prefs = Inkscape::Preferences::get();
 343         gint const tolerance = prefs->getIntLimited("/options/dragtolerance/value", 0, 0, 100);
 344         if ( Geom::LInfty( Geom::Point(mevent.x,mevent.y) - pencil_drag_origin_w ) < tolerance ) {
 345             return FALSE;   // Do not drag if we're within tolerance from origin.
 346         }
 347     }
 348
 349     // Once the user has moved farther than tolerance from the original location
 350     // (indicating they intend to move the object, not click), then always process the
 351     // motion notify coordinates as given (no snapping back to origin)
 352     pencil_within_tolerance = false;
 353
 354     switch (pc->state) {
 355         case SP_PENCIL_CONTEXT_ADDLINE:
 356             /* Set red endpoint */
 357             if (anchor) {
 358                 p = anchor->dp;
 359             } else {
 360                 Geom::Point ptnr(p);
 361                 spdc_endpoint_snap(pc, ptnr, mevent.state);
 362                 p = ptnr;
 363             }
 364             spdc_set_endpoint(pc, p);
 365             ret = TRUE;
 366             break;
 367         default:
 368             /* We may be idle or already freehand */
 369             if ( mevent.state & GDK_BUTTON1_MASK && pc->is_drawing ) {
 370                 if (pc->state == SP_PENCIL_CONTEXT_IDLE) {
 371                     sp_event_context_discard_delayed_snap_event(event_context);
 372                 }
 373                 pc->state = SP_PENCIL_CONTEXT_FREEHAND;
 374
 375                 if ( !pc->sa && !pc->green_anchor ) {
 376                     /* Create green anchor */
 377                     pc->green_anchor = sp_draw_anchor_new(pc, pc->green_curve, TRUE, pc->p[0]);
 378                 }
 379                 if (anchor) {
 380                     p = anchor->dp;
 381                 }
 382
 383                 if ( pc->npoints != 0) { // buttonpress may have happened before we entered draw context!
 384                     if (pc->ps.size() == 0) {
 385                         // Only in freehand mode we have to add the first point also to pc->ps (apparently)
 386                         // - We cannot add this point in spdc_set_startpoint, because we only need it for freehand
 387                         // - We cannot do this in the button press handler because at that point we don't know yet
 388                         //   wheter we're going into freehand mode or not
 389                         pc->ps.push_back(pc->p[0]);
 390                     }
 391                     spdc_add_freehand_point(pc, p, mevent.state);
 392                     ret = TRUE;
 393                 }
 394
 395                 if (anchor && !pc->anchor_statusbar) {
 396                     pc->_message_context->set(Inkscape::NORMAL_MESSAGE, _("<b>Release</b> here to close and finish the path."));
 397                     pc->anchor_statusbar = true;
 398                 } else if (!anchor && pc->anchor_statusbar) {
 399                     pc->_message_context->clear();
 400                     pc->anchor_statusbar = false;
 401                 } else if (!anchor) {
 402                     pc->_message_context->set(Inkscape::NORMAL_MESSAGE, _("Drawing a freehand path"));
 403                 }
 404
 405             } else {
 406                 if (anchor && !pc->anchor_statusbar) {
 407                     pc->_message_context->set(Inkscape::NORMAL_MESSAGE, _("<b>Drag</b> to continue the path from this point."));
 408                     pc->anchor_statusbar = true;
 409                 } else if (!anchor && pc->anchor_statusbar) {
 410                     pc->_message_context->clear();
 411                     pc->anchor_statusbar = false;
 412                 }
 413             }
 414
 415             // Show the pre-snap indicator to communicate to the user where we would snap to if he/she were to
 416             // a) press the mousebutton to start a freehand drawing, or
 417             // b) release the mousebutton to finish a freehand drawing
 418             if (!sp_event_context_knot_mouseover(pc)) {
 419                 SnapManager &m = dt->namedview->snap_manager;
 420                 m.setup(dt);
 421                 m.preSnap(Inkscape::SnapCandidatePoint(p, Inkscape::SNAPSOURCE_NODE_HANDLE));
 422                 m.unSetup();
 423             }
 424             break;
 425     }
 426     return ret;
 427 }
 428
 429 static gint
 430 pencil_handle_button_release(SPPencilContext *const pc, GdkEventButton const &revent)
 431 {
 432     gint ret = FALSE;
 433
 434     SPEventContext *event_context = SP_EVENT_CONTEXT(pc);
 435     if ( revent.button == 1 && pc->is_drawing && !event_context->space_panning) {
 436         SPDesktop *const dt = pc->desktop;
 437
 438         pc->is_drawing = false;
 439
 440         /* Find desktop coordinates */
 441         Geom::Point p = dt->w2d(Geom::Point(revent.x, revent.y));
 442
 443         /* Test whether we hit any anchor. */
 444         SPDrawAnchor *anchor = spdc_test_inside(pc, Geom::Point(revent.x,
 445                                                               revent.y));
 446
 447         switch (pc->state) {
 448             case SP_PENCIL_CONTEXT_IDLE:
 449                 /* Releasing button in idle mode means single click */
 450                 /* We have already set up start point/anchor in button_press */
 451                 if (!(revent.state & GDK_CONTROL_MASK)) {
 452                     // Ctrl+click creates a single point so only set context in ADDLINE mode when Ctrl isn't pressed
 453                     pc->state = SP_PENCIL_CONTEXT_ADDLINE;
 454                 }
 455                 ret = TRUE;
 456                 break;
 457             case SP_PENCIL_CONTEXT_ADDLINE:
 458                 /* Finish segment now */
 459                 if (anchor) {
 460                     p = anchor->dp;
 461                 } else {
 462                     spdc_endpoint_snap(pc, p, revent.state);
 463                 }
 464                 pc->ea = anchor;
 465                 spdc_set_endpoint(pc, p);
 466                 spdc_finish_endpoint(pc);
 467                 pc->state = SP_PENCIL_CONTEXT_IDLE;
 468                 sp_event_context_discard_delayed_snap_event(event_context);
 469                 ret = TRUE;
 470                 break;
 471             case SP_PENCIL_CONTEXT_FREEHAND:
 472                 if (revent.state & GDK_MOD1_MASK) {
 473                     /* sketch mode: interpolate the sketched path and improve the current output path with the new interpolation. don't finish sketch */
 474
 475                     sketch_interpolate(pc);
 476
 477                     if (pc->green_anchor) {
 478                         pc->green_anchor = sp_draw_anchor_destroy(pc->green_anchor);
 479                     }
 480
 481                     pc->state = SP_PENCIL_CONTEXT_SKETCH;
 482                 } else {
 483                     /* Finish segment now */
 484                     /// \todo fixme: Clean up what follows (Lauris)
 485                     if (anchor) {
 486                         p = anchor->dp;
 487                     } else {
 488                         Geom::Point p_end = p;
 489                         spdc_endpoint_snap(pc, p_end, revent.state);
 490                         if (p_end != p) {
 491                             // then we must have snapped!
 492                             spdc_add_freehand_point(pc, p_end, revent.state);
 493                         }
 494                     }
 495
 496                     pc->ea = anchor;
 497                     /* Write curves to object */
 498
 499                     dt->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Finishing freehand"));
 500
 501                     interpolate(pc);
 502                     spdc_concat_colors_and_flush(pc, FALSE);
 503                     pc->sa = NULL;
 504                     pc->ea = NULL;
 505                     if (pc->green_anchor) {
 506                         pc->green_anchor = sp_draw_anchor_destroy(pc->green_anchor);
 507                     }
 508                     pc->state = SP_PENCIL_CONTEXT_IDLE;
 509                     // reset sketch mode too
 510                     pc->sketch_n = 0;
 511                 }
 512                 ret = TRUE;
 513                 break;
 514             case SP_PENCIL_CONTEXT_SKETCH:
 515             default:
 516                 break;
 517         }
 518
 519         if (pc->grab) {
 520             /* Release grab now */
 521             sp_canvas_item_ungrab(pc->grab, revent.time);
 522             pc->grab = NULL;
 523         }
 524
 525         ret = TRUE;
 526     }
 527     return ret;
 528 }
 529
 530 static void
 531 pencil_cancel (SPPencilContext *const pc)
 532 {
 533     if (pc->grab) {
 534         /* Release grab now */
 535         sp_canvas_item_ungrab(pc->grab, 0);
 536         pc->grab = NULL;
 537     }
 538
 539     pc->is_drawing = false;
 540     pc->state = SP_PENCIL_CONTEXT_IDLE;
 541     sp_event_context_discard_delayed_snap_event(SP_EVENT_CONTEXT(pc));
 542
 543     pc->red_curve->reset();
 544     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), NULL);
 545     while (pc->green_bpaths) {
 546         gtk_object_destroy(GTK_OBJECT(pc->green_bpaths->data));
 547         pc->green_bpaths = g_slist_remove(pc->green_bpaths, pc->green_bpaths->data);
 548     }
 549     pc->green_curve->reset();
 550     if (pc->green_anchor) {
 551         pc->green_anchor = sp_draw_anchor_destroy(pc->green_anchor);
 552     }
 553
 554     pc->_message_context->clear();
 555     pc->_message_context->flash(Inkscape::NORMAL_MESSAGE, _("Drawing cancelled"));
 556
 557     sp_canvas_end_forced_full_redraws(pc->desktop->canvas);
 558 }
 559
 560 static gint
 561 pencil_handle_key_press(SPPencilContext *const pc, guint const keyval, guint const state)
 562 {
 563     gint ret = FALSE;
 564     switch (keyval) {
 565         case GDK_Up:
 566         case GDK_Down:
 567         case GDK_KP_Up:
 568         case GDK_KP_Down:
 569             // Prevent the zoom field from activation.
 570             if (!mod_ctrl_only(state)) {
 571                 ret = TRUE;
 572             }
 573             break;
 574         case GDK_Escape:
 575             if (pc->npoints != 0) {
 576                 // if drawing, cancel, otherwise pass it up for deselecting
 577                 if (pc->state != SP_PENCIL_CONTEXT_IDLE) {
 578                     pencil_cancel (pc);
 579                     ret = TRUE;
 580                 }
 581             }
 582             break;
 583         case GDK_z:
 584         case GDK_Z:
 585             if (mod_ctrl_only(state) && pc->npoints != 0) {
 586                 // if drawing, cancel, otherwise pass it up for undo
 587                 if (pc->state != SP_PENCIL_CONTEXT_IDLE) {
 588                     pencil_cancel (pc);
 589                     ret = TRUE;
 590                 }
 591             }
 592             break;
 593         case GDK_g:
 594         case GDK_G:
 595             if (mod_shift_only(state)) {
 596                 sp_selection_to_guides(SP_EVENT_CONTEXT(pc)->desktop);
 597                 ret = true;
 598             }
 599             break;
 600         case GDK_Alt_L:
 601         case GDK_Alt_R:
 602         case GDK_Meta_L:
 603         case GDK_Meta_R:
 604             if (pc->state == SP_PENCIL_CONTEXT_IDLE) {
 605                 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."));
 606             }
 607             break;
 608         default:
 609             break;
 610     }
 611     return ret;
 612 }
 613
 614 static gint
 615 pencil_handle_key_release(SPPencilContext *const pc, guint const keyval, guint const /*state*/)
 616 {
 617     gint ret = FALSE;
 618     switch (keyval) {
 619         case GDK_Alt_L:
 620         case GDK_Alt_R:
 621         case GDK_Meta_L:
 622         case GDK_Meta_R:
 623             if (pc->state == SP_PENCIL_CONTEXT_SKETCH) {
 624                 spdc_concat_colors_and_flush(pc, FALSE);
 625                 pc->sketch_n = 0;
 626                 pc->sa = NULL;
 627                 pc->ea = NULL;
 628                 if (pc->green_anchor) {
 629                     pc->green_anchor = sp_draw_anchor_destroy(pc->green_anchor);
 630                 }
 631                 pc->state = SP_PENCIL_CONTEXT_IDLE;
 632                 sp_event_context_discard_delayed_snap_event(SP_EVENT_CONTEXT(pc));
 633                 pc->desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Finishing freehand sketch"));
 634                 ret = TRUE;
 635             }
 636             break;
 637         default:
 638             break;
 639     }
 640     return ret;
 641 }
 642
 643 /**
 644  * Reset points and set new starting point.
 645  */
 646 static void
 647 spdc_set_startpoint(SPPencilContext *const pc, Geom::Point const p)
 648 {
 649     pc->npoints = 0;
 650     pc->red_curve_is_valid = false;
 651     if (in_svg_plane(p)) {
 652         pc->p[pc->npoints++] = p;
 653     }
 654 }
 655
 656 /**
 657  * Change moving endpoint position.
 658  * <ul>
 659  * <li>Ctrl constrains to moving to H/V direction, snapping in given direction.
 660  * <li>Otherwise we snap freely to whatever attractors are available.
 661  * </ul>
 662  *
 663  * Number of points is (re)set to 2 always, 2nd point is modified.
 664  * We change RED curve.
 665  */
 666 static void
 667 spdc_set_endpoint(SPPencilContext *const pc, Geom::Point const p)
 668 {
 669     if (pc->npoints == 0) {
 670         return;
 671         /* May occur if first point wasn't in SVG plane (e.g. weird w2d transform, perhaps from bad
 672          * zoom setting).
 673          */
 674     }
 675     g_return_if_fail( pc->npoints > 0 );
 676
 677     pc->red_curve->reset();
 678     if ( ( p == pc->p[0] )
 679          || !in_svg_plane(p) )
 680     {
 681         pc->npoints = 1;
 682     } else {
 683         pc->p[1] = p;
 684         pc->npoints = 2;
 685
 686         pc->red_curve->moveto(pc->p[0]);
 687         pc->red_curve->lineto(pc->p[1]);
 688         pc->red_curve_is_valid = true;
 689
 690         sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), pc->red_curve);
 691     }
 692 }
 693
 694 /**
 695  * Finalize addline.
 696  *
 697  * \todo
 698  * fixme: I'd like remove red reset from concat colors (lauris).
 699  * Still not sure, how it will make most sense.
 700  */
 701 static void
 702 spdc_finish_endpoint(SPPencilContext *const pc)
 703 {
 704     if ( ( pc->red_curve->is_empty() )
 705          || ( *(pc->red_curve->first_point()) == *(pc->red_curve->second_point())   ) )
 706     {
 707         pc->red_curve->reset();
 708         sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), NULL);
 709     } else {
 710         /* Write curves to object. */
 711         spdc_concat_colors_and_flush(pc, FALSE);
 712         pc->sa = NULL;
 713         pc->ea = NULL;
 714     }
 715 }
 716
 717
 718 static void
 719 spdc_add_freehand_point(SPPencilContext *pc, Geom::Point p, guint /*state*/)
 720 {
 721     g_assert( pc->npoints > 0 );
 722     g_return_if_fail(unsigned(pc->npoints) < G_N_ELEMENTS(pc->p));
 723
 724     if ( ( p != pc->p[ pc->npoints - 1 ] )
 725          && in_svg_plane(p) )
 726     {
 727         pc->ps.push_back(p);
 728         pc->p[pc->npoints++] = p;
 729         fit_and_split(pc);
 730     }
 731 }
 732
 733 static inline double
 734 square(double const x)
 735 {
 736     return x * x;
 737 }
 738
 739 static void
 740 interpolate(SPPencilContext *pc)
 741 {
 742     if ( pc->ps.size() <= 1 ) {
 743         return;
 744     }
 745
 746     Inkscape::Preferences *prefs = Inkscape::Preferences::get();
 747     double const tol = prefs->getDoubleLimited("/tools/freehand/pencil/tolerance", 10.0, 1.0, 100.0) * 0.4;
 748     double const tolerance_sq = 0.02 * square( pc->desktop->w2d().descrim() *
 749                                                tol) * exp(0.2*tol - 2);
 750
 751     g_assert(is_zero(pc->req_tangent)
 752              || is_unit_vector(pc->req_tangent));
 753     Geom::Point const tHatEnd(0, 0);
 754
 755     guint n_points  = pc->ps.size();
 756     pc->green_curve->reset();
 757     pc->red_curve->reset();
 758     pc->red_curve_is_valid = false;
 759
 760     Geom::Point * b = g_new(Geom::Point, 4*n_points);
 761     Geom::Point * points = g_new(Geom::Point, 4*n_points);
 762     for (unsigned int i = 0; i < pc->ps.size(); i++) {
 763         points[i] = pc->ps[i];
 764     }
 765
 766     // worst case gives us a segment per point
 767     int max_segs = 4*n_points;
 768
 769     int const n_segs = Geom::bezier_fit_cubic_r(b, points, n_points,
 770                                              tolerance_sq, max_segs);
 771
 772     if ( n_segs > 0)
 773     {
 774         /* Fit and draw and reset state */
 775         pc->green_curve->moveto(b[0]);
 776         for (int c = 0; c < n_segs; c++) {
 777             pc->green_curve->curveto(b[4*c+1], b[4*c+2], b[4*c+3]);
 778         }
 779         sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), pc->green_curve);
 780
 781         /* Fit and draw and copy last point */
 782         g_assert(!pc->green_curve->is_empty());
 783
 784         /* Set up direction of next curve. */
 785         {
 786             Geom::CubicBezier const * last_seg = dynamic_cast<Geom::CubicBezier const *>(pc->green_curve->last_segment());
 787             g_assert( last_seg );      // Relevance: validity of (*last_seg)[2]
 788             pc->p[0] = last_seg->finalPoint();
 789             pc->npoints = 1;
 790             Geom::Point const req_vec( pc->p[0] - (*last_seg)[2] );
 791             pc->req_tangent = ( ( Geom::is_zero(req_vec) || !in_svg_plane(req_vec) )
 792                                 ? Geom::Point(0, 0)
 793                                 : Geom::unit_vector(req_vec) );
 794         }
 795     }
 796     g_free(b);
 797     g_free(points);
 798     pc->ps.clear();
 799 }
 800
 801
 802 /* interpolates the sketched curve and tweaks the current sketch interpolation*/
 803 static void
 804 sketch_interpolate(SPPencilContext *pc)
 805 {
 806     if ( pc->ps.size() <= 1 ) {
 807         return;
 808     }
 809
 810     Inkscape::Preferences *prefs = Inkscape::Preferences::get();
 811     double const tol = prefs->getDoubleLimited("/tools/freehand/pencil/tolerance", 10.0, 1.0, 100.0) * 0.4;
 812     double const tolerance_sq = 0.02 * square( pc->desktop->w2d().descrim() *
 813                                                tol) * exp(0.2*tol - 2);
 814
 815     bool average_all_sketches = prefs->getBool("/tools/freehand/pencil/average_all_sketches", true);
 816
 817     g_assert(is_zero(pc->req_tangent)
 818              || is_unit_vector(pc->req_tangent));
 819     Geom::Point const tHatEnd(0, 0);
 820
 821     guint n_points  = pc->ps.size();
 822     pc->red_curve->reset();
 823     pc->red_curve_is_valid = false;
 824
 825     Geom::Point * b = g_new(Geom::Point, 4*n_points);
 826     Geom::Point * points = g_new(Geom::Point, 4*n_points);
 827     for (unsigned i = 0; i < pc->ps.size(); i++) {
 828         points[i] = pc->ps[i];
 829     }
 830
 831     // worst case gives us a segment per point
 832     int max_segs = 4*n_points;
 833
 834     int const n_segs = Geom::bezier_fit_cubic_r(b, points, n_points,
 835                                              tolerance_sq, max_segs);
 836
 837     if ( n_segs > 0)
 838     {
 839         Geom::Path fit(b[0]);
 840         for (int c = 0; c < n_segs; c++) {
 841             fit.appendNew<Geom::CubicBezier>(b[4*c+1], b[4*c+2], b[4*c+3]);
 842         }
 843         Geom::Piecewise<Geom::D2<Geom::SBasis> > fit_pwd2 = fit.toPwSb();
 844
 845         double t =0.;
 846         if ( pc->sketch_n > 0 ) {
 847             if (average_all_sketches) {
 848                 // Average = (sum of all) / n
 849                 //         = (sum of all + new one) / n+1
 850                 //         = ((old average)*n + new one) / n+1
 851                 t = pc->sketch_n / (pc->sketch_n + 1.);
 852             } else {
 853                 t = 0.5;
 854             }
 855             pc->sketch_interpolation = Geom::lerp(t, fit_pwd2, pc->sketch_interpolation);
 856             // simplify path, to eliminate small segments
 857             Path *path = new Path;
 858             path->LoadPathVector(Geom::path_from_piecewise(pc->sketch_interpolation, 0.01));
 859             path->Simplify(0.5);
 860             Geom::PathVector *pathv = path->MakePathVector();
 861             pc->sketch_interpolation = (*pathv)[0].toPwSb();
 862             delete path;
 863             delete pathv;
 864         } else {
 865             pc->sketch_interpolation = fit_pwd2;
 866         }
 867         pc->sketch_n++;
 868
 869         pc->green_curve->reset();
 870         pc->green_curve->set_pathvector(Geom::path_from_piecewise(pc->sketch_interpolation, 0.01));
 871         sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), pc->green_curve);
 872
 873         /* Fit and draw and copy last point */
 874         g_assert(!pc->green_curve->is_empty());
 875
 876         /* Set up direction of next curve. */
 877         {
 878             Geom::CubicBezier const * last_seg = dynamic_cast<Geom::CubicBezier const *>(pc->green_curve->last_segment());
 879             g_assert( last_seg );      // Relevance: validity of (*last_seg)[2]
 880             pc->p[0] = last_seg->finalPoint();
 881             pc->npoints = 1;
 882             Geom::Point const req_vec( pc->p[0] - (*last_seg)[2] );
 883             pc->req_tangent = ( ( Geom::is_zero(req_vec) || !in_svg_plane(req_vec) )
 884                                 ? Geom::Point(0, 0)
 885                                 : Geom::unit_vector(req_vec) );
 886         }
 887     }
 888     g_free(b);
 889     g_free(points);
 890     pc->ps.clear();
 891 }
 892
 893 static void
 894 fit_and_split(SPPencilContext *pc)
 895 {
 896     g_assert( pc->npoints > 1 );
 897
 898     double const tolerance_sq = 0;
 899
 900     Geom::Point b[4];
 901     g_assert(is_zero(pc->req_tangent)
 902              || is_unit_vector(pc->req_tangent));
 903     Geom::Point const tHatEnd(0, 0);
 904     int const n_segs = Geom::bezier_fit_cubic_full(b, NULL, pc->p, pc->npoints,
 905                                                 pc->req_tangent, tHatEnd,
 906                                                 tolerance_sq, 1);
 907     if ( n_segs > 0
 908          && unsigned(pc->npoints) < G_N_ELEMENTS(pc->p) )
 909     {
 910         /* Fit and draw and reset state */
 911         pc->red_curve->reset();
 912         pc->red_curve->moveto(b[0]);
 913         pc->red_curve->curveto(b[1], b[2], b[3]);
 914         sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), pc->red_curve);
 915         pc->red_curve_is_valid = true;
 916     } else {
 917         /* Fit and draw and copy last point */
 918
 919         g_assert(!pc->red_curve->is_empty());
 920
 921         /* Set up direction of next curve. */
 922         {
 923             Geom::CubicBezier const * last_seg = dynamic_cast<Geom::CubicBezier const *>(pc->red_curve->last_segment());
 924             g_assert( last_seg );      // Relevance: validity of (*last_seg)[2]
 925             pc->p[0] = last_seg->finalPoint();
 926             pc->npoints = 1;
 927             Geom::Point const req_vec( pc->p[0] - (*last_seg)[2] );
 928             pc->req_tangent = ( ( Geom::is_zero(req_vec) || !in_svg_plane(req_vec) )
 929                                 ? Geom::Point(0, 0)
 930                                 : Geom::unit_vector(req_vec) );
 931         }
 932
 933         pc->green_curve->append_continuous(pc->red_curve, 0.0625);
 934         SPCurve *curve = pc->red_curve->copy();
 935
 936         /// \todo fixme:
 937         SPCanvasItem *cshape = sp_canvas_bpath_new(sp_desktop_sketch(pc->desktop), curve);
 938         curve->unref();
 939         sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(cshape), pc->green_color, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 940
 941         pc->green_bpaths = g_slist_prepend(pc->green_bpaths, cshape);
 942
 943         pc->red_curve_is_valid = false;
 944     }
 945 }
 946
 947
 948 /*
 949   Local Variables:
 950   mode:c++
 951   c-file-style:"stroustrup"
 952   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
 953   indent-tabs-mode:nil
 954   fill-column:99
 955   End:
 956 */
 957 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :