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                                 sp_event_context_snap_window_open(event_context);
 259
 260                 if (anchor) {
 261                     p = anchor->dp;
 262                     desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Continuing selected path"));
 263                 } else {
 264
 265                     if (!(bevent.state & GDK_SHIFT_MASK)) {
 266                                                 // This is the first click of a new curve; deselect item so that
 267                         // this curve is not combined with it (unless it is drawn from its
 268                         // anchor, which is handled by the sibling branch above)
 269                         selection->clear();
 270                         desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Creating new path"));
 271                         m.freeSnapReturnByRef(Inkscape::SnapPreferences::SNAPPOINT_NODE, p, Inkscape::SNAPSOURCE_HANDLE);
 272                     } else if (selection->singleItem() && SP_IS_PATH(selection->singleItem())) {
 273                         desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Appending to selected path"));
 274                         m.freeSnapReturnByRef(Inkscape::SnapPreferences::SNAPPOINT_NODE, p, Inkscape::SNAPSOURCE_HANDLE);
 275                     }
 276                 }
 277                 pc->sa = anchor;
 278                 spdc_set_startpoint(pc, p);
 279                 ret = TRUE;
 280                 break;
 281         }
 282
 283         pc->is_drawing = true;
 284     }
 285     return ret;
 286 }
 287
 288 static gint
 289 pencil_handle_motion_notify(SPPencilContext *const pc, GdkEventMotion const &mevent)
 290 {
 291         SPDesktop *const dt = pc->desktop;
 292
 293         if ((mevent.state & GDK_CONTROL_MASK) && (mevent.state & GDK_BUTTON1_MASK)) {
 294         // mouse was accidentally moved during Ctrl+click;
 295         // ignore the motion and create a single point
 296         pc->is_drawing = false;
 297         return TRUE;
 298     }
 299     gint ret = FALSE;
 300
 301     SPEventContext *event_context = SP_EVENT_CONTEXT(pc);
 302     if (event_context->space_panning || mevent.state & GDK_BUTTON2_MASK || mevent.state & GDK_BUTTON3_MASK) {
 303         // allow scrolling
 304         return FALSE;
 305     }
 306
 307     if ( ( mevent.state & GDK_BUTTON1_MASK ) && !pc->grab && pc->is_drawing) {
 308         /* Grab mouse, so release will not pass unnoticed */
 309         pc->grab = SP_CANVAS_ITEM(dt->acetate);
 310         sp_canvas_item_grab(pc->grab, ( GDK_KEY_PRESS_MASK | GDK_BUTTON_PRESS_MASK   |
 311                                         GDK_BUTTON_RELEASE_MASK |
 312                                         GDK_POINTER_MOTION_MASK  ),
 313                             NULL, mevent.time);
 314     }
 315
 316     /* Find desktop coordinates */
 317     Geom::Point p = dt->w2d(Geom::Point(mevent.x, mevent.y));
 318
 319     /* Test whether we hit any anchor. */
 320     SPDrawAnchor *anchor = spdc_test_inside(pc, Geom::Point(mevent.x, mevent.y));
 321
 322     if (pencil_within_tolerance) {
 323         Inkscape::Preferences *prefs = Inkscape::Preferences::get();
 324         gint const tolerance = prefs->getIntLimited("/options/dragtolerance/value", 0, 0, 100);
 325         if ( Geom::LInfty( Geom::Point(mevent.x,mevent.y) - pencil_drag_origin_w ) < tolerance ) {
 326             return FALSE;   // Do not drag if we're within tolerance from origin.
 327         }
 328     }
 329
 330     // Once the user has moved farther than tolerance from the original location
 331     // (indicating they intend to move the object, not click), then always process the
 332     // motion notify coordinates as given (no snapping back to origin)
 333     pencil_within_tolerance = false;
 334
 335     switch (pc->state) {
 336         case SP_PENCIL_CONTEXT_ADDLINE:
 337             /* Set red endpoint */
 338             if (anchor) {
 339                 p = anchor->dp;
 340             } else {
 341                 Geom::Point ptnr(p);
 342                 spdc_endpoint_snap(pc, ptnr, mevent.state);
 343                 p = ptnr;
 344             }
 345             spdc_set_endpoint(pc, p);
 346             ret = TRUE;
 347             break;
 348         default:
 349             /* We may be idle or already freehand */
 350             if ( mevent.state & GDK_BUTTON1_MASK && pc->is_drawing ) {
 351                 if (pc->state == SP_PENCIL_CONTEXT_IDLE) {
 352                         sp_event_context_snap_window_closed(event_context);
 353                 }
 354                 pc->state = SP_PENCIL_CONTEXT_FREEHAND;
 355
 356                 if ( !pc->sa && !pc->green_anchor ) {
 357                     /* Create green anchor */
 358                     pc->green_anchor = sp_draw_anchor_new(pc, pc->green_curve, TRUE, pc->p[0]);
 359                 }
 360                 /** \todo
 361                  * fixme: I am not sure whether we want to snap to anchors
 362                  * in middle of freehand (Lauris)
 363                  */
 364                 if (anchor) {
 365                     p = anchor->dp;
 366                 }
 367
 368                 if ( pc->npoints != 0) { // buttonpress may have happened before we entered draw context!
 369                                         spdc_add_freehand_point(pc, p, mevent.state);
 370                                         ret = TRUE;
 371                 }
 372
 373                 if (anchor && !pc->anchor_statusbar) {
 374                     pc->_message_context->set(Inkscape::NORMAL_MESSAGE, _("<b>Release</b> here to close and finish the path."));
 375                     pc->anchor_statusbar = true;
 376                 } else if (!anchor && pc->anchor_statusbar) {
 377                     pc->_message_context->clear();
 378                     pc->anchor_statusbar = false;
 379                 } else if (!anchor) {
 380                     pc->_message_context->set(Inkscape::NORMAL_MESSAGE, _("Drawing a freehand path"));
 381                 }
 382
 383             } else {
 384                 if (anchor && !pc->anchor_statusbar) {
 385                     pc->_message_context->set(Inkscape::NORMAL_MESSAGE, _("<b>Drag</b> to continue the path from this point."));
 386                     pc->anchor_statusbar = true;
 387                 } else if (!anchor && pc->anchor_statusbar) {
 388                     pc->_message_context->clear();
 389                     pc->anchor_statusbar = false;
 390                 }
 391             }
 392             break;
 393     }
 394     return ret;
 395 }
 396
 397 static gint
 398 pencil_handle_button_release(SPPencilContext *const pc, GdkEventButton const &revent)
 399 {
 400     gint ret = FALSE;
 401
 402     SPEventContext *event_context = SP_EVENT_CONTEXT(pc);
 403     if ( revent.button == 1 && pc->is_drawing && !event_context->space_panning) {
 404         SPDesktop *const dt = pc->desktop;
 405
 406         pc->is_drawing = false;
 407
 408         /* Find desktop coordinates */
 409         Geom::Point p = dt->w2d(Geom::Point(revent.x, revent.y));
 410
 411         /* Test whether we hit any anchor. */
 412         SPDrawAnchor *anchor = spdc_test_inside(pc, Geom::Point(revent.x,
 413                                                               revent.y));
 414
 415         switch (pc->state) {
 416             case SP_PENCIL_CONTEXT_IDLE:
 417                 /* Releasing button in idle mode means single click */
 418                 /* We have already set up start point/anchor in button_press */
 419                 pc->state = SP_PENCIL_CONTEXT_ADDLINE;
 420                 //sp_event_context_snap_window_open(dt->canvas);
 421                 ret = TRUE;
 422                 break;
 423             case SP_PENCIL_CONTEXT_ADDLINE:
 424                 /* Finish segment now */
 425                 if (anchor) {
 426                     p = anchor->dp;
 427                 } else {
 428                     spdc_endpoint_snap(pc, p, revent.state);
 429                 }
 430                 pc->ea = anchor;
 431                 spdc_set_endpoint(pc, p);
 432                 spdc_finish_endpoint(pc);
 433                 pc->state = SP_PENCIL_CONTEXT_IDLE;
 434                 sp_event_context_snap_window_closed(event_context);
 435                 ret = TRUE;
 436                 break;
 437             case SP_PENCIL_CONTEXT_FREEHAND:
 438                 if (revent.state & GDK_MOD1_MASK) {
 439                     /* sketch mode: interpolate the sketched path and improve the current output path with the new interpolation. don't finish sketch */
 440
 441                     sketch_interpolate(pc);
 442
 443                     if (pc->green_anchor) {
 444                         pc->green_anchor = sp_draw_anchor_destroy(pc->green_anchor);
 445                     }
 446
 447                     pc->state = SP_PENCIL_CONTEXT_SKETCH;
 448                     //sp_event_context_snap_window_open(dt->canvas);
 449                 } else {
 450                     /* Finish segment now */
 451                     /// \todo fixme: Clean up what follows (Lauris)
 452                     if (anchor) {
 453                         p = anchor->dp;
 454                     }
 455                     pc->ea = anchor;
 456                     /* Write curves to object */
 457
 458                     dt->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Finishing freehand"));
 459
 460                     interpolate(pc);
 461                     spdc_concat_colors_and_flush(pc, FALSE);
 462                     pc->sa = NULL;
 463                     pc->ea = NULL;
 464                     if (pc->green_anchor) {
 465                         pc->green_anchor = sp_draw_anchor_destroy(pc->green_anchor);
 466                     }
 467                     pc->state = SP_PENCIL_CONTEXT_IDLE;
 468                     // sp_event_context_snap_window_closed(dt->canvas);
 469                     // reset sketch mode too
 470                     pc->sketch_n = 0;
 471                 }
 472                 ret = TRUE;
 473                 break;
 474             case SP_PENCIL_CONTEXT_SKETCH:
 475             default:
 476                 break;
 477         }
 478
 479         if (pc->grab) {
 480             /* Release grab now */
 481             sp_canvas_item_ungrab(pc->grab, revent.time);
 482             pc->grab = NULL;
 483         }
 484
 485         ret = TRUE;
 486     }
 487     return ret;
 488 }
 489
 490 static void
 491 pencil_cancel (SPPencilContext *const pc)
 492 {
 493     if (pc->grab) {
 494         /* Release grab now */
 495         sp_canvas_item_ungrab(pc->grab, 0);
 496         pc->grab = NULL;
 497     }
 498
 499     pc->is_drawing = false;
 500     pc->state = SP_PENCIL_CONTEXT_IDLE;
 501     sp_event_context_snap_window_closed(SP_EVENT_CONTEXT(pc));
 502
 503     pc->red_curve->reset();
 504     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), NULL);
 505     while (pc->green_bpaths) {
 506         gtk_object_destroy(GTK_OBJECT(pc->green_bpaths->data));
 507         pc->green_bpaths = g_slist_remove(pc->green_bpaths, pc->green_bpaths->data);
 508     }
 509     pc->green_curve->reset();
 510     if (pc->green_anchor) {
 511         pc->green_anchor = sp_draw_anchor_destroy(pc->green_anchor);
 512     }
 513
 514     pc->_message_context->clear();
 515     pc->_message_context->flash(Inkscape::NORMAL_MESSAGE, _("Drawing cancelled"));
 516
 517     sp_canvas_end_forced_full_redraws(pc->desktop->canvas);
 518 }
 519
 520 static gint
 521 pencil_handle_key_press(SPPencilContext *const pc, guint const keyval, guint const state)
 522 {
 523     gint ret = FALSE;
 524     switch (keyval) {
 525         case GDK_Up:
 526         case GDK_Down:
 527         case GDK_KP_Up:
 528         case GDK_KP_Down:
 529             // Prevent the zoom field from activation.
 530             if (!mod_ctrl_only(state)) {
 531                 ret = TRUE;
 532             }
 533             break;
 534         case GDK_Escape:
 535             if (pc->npoints != 0) {
 536                 // if drawing, cancel, otherwise pass it up for deselecting
 537                 if (pc->state != SP_PENCIL_CONTEXT_IDLE) {
 538                     pencil_cancel (pc);
 539                     ret = TRUE;
 540                 }
 541             }
 542             break;
 543         case GDK_z:
 544         case GDK_Z:
 545             if (mod_ctrl_only(state) && pc->npoints != 0) {
 546                 // if drawing, cancel, otherwise pass it up for undo
 547                 if (pc->state != SP_PENCIL_CONTEXT_IDLE) {
 548                     pencil_cancel (pc);
 549                     ret = TRUE;
 550                 }
 551             }
 552             break;
 553         case GDK_g:
 554         case GDK_G:
 555             if (mod_shift_only(state)) {
 556                 sp_selection_to_guides(SP_EVENT_CONTEXT(pc)->desktop);
 557                 ret = true;
 558             }
 559             break;
 560         case GDK_Alt_L:
 561         case GDK_Alt_R:
 562         case GDK_Meta_L:
 563         case GDK_Meta_R:
 564             if (pc->state == SP_PENCIL_CONTEXT_IDLE) {
 565                 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."));
 566             }
 567             break;
 568         default:
 569             break;
 570     }
 571     return ret;
 572 }
 573
 574 static gint
 575 pencil_handle_key_release(SPPencilContext *const pc, guint const keyval, guint const /*state*/)
 576 {
 577     gint ret = FALSE;
 578     switch (keyval) {
 579         case GDK_Alt_L:
 580         case GDK_Alt_R:
 581         case GDK_Meta_L:
 582         case GDK_Meta_R:
 583             if (pc->state == SP_PENCIL_CONTEXT_SKETCH) {
 584                 spdc_concat_colors_and_flush(pc, FALSE);
 585                 pc->sketch_n = 0;
 586                 pc->sa = NULL;
 587                 pc->ea = NULL;
 588                 if (pc->green_anchor) {
 589                     pc->green_anchor = sp_draw_anchor_destroy(pc->green_anchor);
 590                 }
 591                 pc->state = SP_PENCIL_CONTEXT_IDLE;
 592                 sp_event_context_snap_window_closed(SP_EVENT_CONTEXT(pc));
 593                 pc->desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Finishing freehand sketch"));
 594                 ret = TRUE;
 595             }
 596             break;
 597         default:
 598             break;
 599     }
 600     return ret;
 601 }
 602
 603 /**
 604  * Reset points and set new starting point.
 605  */
 606 static void
 607 spdc_set_startpoint(SPPencilContext *const pc, Geom::Point const p)
 608 {
 609     pc->npoints = 0;
 610     pc->red_curve_is_valid = false;
 611     if (in_svg_plane(p)) {
 612         pc->p[pc->npoints++] = p;
 613     }
 614 }
 615
 616 /**
 617  * Change moving endpoint position.
 618  * <ul>
 619  * <li>Ctrl constrains to moving to H/V direction, snapping in given direction.
 620  * <li>Otherwise we snap freely to whatever attractors are available.
 621  * </ul>
 622  *
 623  * Number of points is (re)set to 2 always, 2nd point is modified.
 624  * We change RED curve.
 625  */
 626 static void
 627 spdc_set_endpoint(SPPencilContext *const pc, Geom::Point const p)
 628 {
 629     if (pc->npoints == 0) {
 630         return;
 631         /* May occur if first point wasn't in SVG plane (e.g. weird w2d transform, perhaps from bad
 632          * zoom setting).
 633          */
 634     }
 635     g_return_if_fail( pc->npoints > 0 );
 636
 637     pc->red_curve->reset();
 638     if ( ( p == pc->p[0] )
 639          || !in_svg_plane(p) )
 640     {
 641         pc->npoints = 1;
 642     } else {
 643         pc->p[1] = p;
 644         pc->npoints = 2;
 645
 646         pc->red_curve->moveto(pc->p[0]);
 647         pc->red_curve->lineto(pc->p[1]);
 648         pc->red_curve_is_valid = true;
 649
 650         sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), pc->red_curve);
 651     }
 652 }
 653
 654 /**
 655  * Finalize addline.
 656  *
 657  * \todo
 658  * fixme: I'd like remove red reset from concat colors (lauris).
 659  * Still not sure, how it will make most sense.
 660  */
 661 static void
 662 spdc_finish_endpoint(SPPencilContext *const pc)
 663 {
 664     if ( ( pc->red_curve->is_empty() )
 665          || ( *(pc->red_curve->first_point()) == *(pc->red_curve->second_point())   ) )
 666     {
 667         pc->red_curve->reset();
 668         sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), NULL);
 669     } else {
 670         /* Write curves to object. */
 671         spdc_concat_colors_and_flush(pc, FALSE);
 672         pc->sa = NULL;
 673         pc->ea = NULL;
 674     }
 675 }
 676
 677
 678 static void
 679 spdc_add_freehand_point(SPPencilContext *pc, Geom::Point p, guint /*state*/)
 680 {
 681     g_assert( pc->npoints > 0 );
 682     g_return_if_fail(unsigned(pc->npoints) < G_N_ELEMENTS(pc->p));
 683
 684     if ( ( p != pc->p[ pc->npoints - 1 ] )
 685          && in_svg_plane(p) )
 686     {
 687         pc->ps.push_back(p);
 688         pc->p[pc->npoints++] = p;
 689         fit_and_split(pc);
 690     }
 691 }
 692
 693 static inline double
 694 square(double const x)
 695 {
 696     return x * x;
 697 }
 698
 699 static void
 700 interpolate(SPPencilContext *pc)
 701 {
 702     if ( pc->ps.size() <= 1 ) {
 703         return;
 704     }
 705
 706     Inkscape::Preferences *prefs = Inkscape::Preferences::get();
 707     double const tol = prefs->getDoubleLimited("/tools/freehand/pencil/tolerance", 10.0, 1.0, 100.0) * 0.4;
 708     double const tolerance_sq = 0.02 * square( pc->desktop->w2d().descrim() *
 709                                                tol) * exp(0.2*tol - 2);
 710
 711     g_assert(is_zero(pc->req_tangent)
 712              || is_unit_vector(pc->req_tangent));
 713     Geom::Point const tHatEnd(0, 0);
 714
 715     guint n_points  = pc->ps.size();
 716     pc->green_curve->reset();
 717     pc->red_curve->reset();
 718     pc->red_curve_is_valid = false;
 719
 720     Geom::Point * b = g_new(Geom::Point, 4*n_points);
 721     Geom::Point * points = g_new(Geom::Point, 4*n_points);
 722     for (unsigned int i = 0; i < pc->ps.size(); i++) {
 723         points[i] = pc->ps[i];
 724     }
 725
 726     // worst case gives us a segment per point
 727     int max_segs = 4*n_points;
 728
 729     int const n_segs = Geom::bezier_fit_cubic_r(b, points, n_points,
 730                                              tolerance_sq, max_segs);
 731
 732     if ( n_segs > 0)
 733     {
 734         /* Fit and draw and reset state */
 735         pc->green_curve->moveto(b[0]);
 736         for (int c = 0; c < n_segs; c++) {
 737             pc->green_curve->curveto(b[4*c+1], b[4*c+2], b[4*c+3]);
 738         }
 739         sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), pc->green_curve);
 740
 741         /* Fit and draw and copy last point */
 742         g_assert(!pc->green_curve->is_empty());
 743
 744         /* Set up direction of next curve. */
 745         {
 746             Geom::CubicBezier const * last_seg = dynamic_cast<Geom::CubicBezier const *>(pc->green_curve->last_segment());
 747             g_assert( last_seg );      // Relevance: validity of (*last_seg)[2]
 748             pc->p[0] = last_seg->finalPoint();
 749             pc->npoints = 1;
 750             Geom::Point const req_vec( pc->p[0] - (*last_seg)[2] );
 751             pc->req_tangent = ( ( Geom::is_zero(req_vec) || !in_svg_plane(req_vec) )
 752                                 ? Geom::Point(0, 0)
 753                                 : Geom::unit_vector(req_vec) );
 754         }
 755     }
 756     g_free(b);
 757     g_free(points);
 758     pc->ps.clear();
 759 }
 760
 761
 762 /* interpolates the sketched curve and tweaks the current sketch interpolation*/
 763 static void
 764 sketch_interpolate(SPPencilContext *pc)
 765 {
 766     if ( pc->ps.size() <= 1 ) {
 767         return;
 768     }
 769
 770     Inkscape::Preferences *prefs = Inkscape::Preferences::get();
 771     double const tol = prefs->getDoubleLimited("/tools/freehand/pencil/tolerance", 10.0, 1.0, 100.0) * 0.4;
 772     double const tolerance_sq = 0.02 * square( pc->desktop->w2d().descrim() *
 773                                                tol) * exp(0.2*tol - 2);
 774
 775     bool average_all_sketches = prefs->getBool("/tools/freehand/pencil/average_all_sketches", true);
 776
 777     g_assert(is_zero(pc->req_tangent)
 778              || is_unit_vector(pc->req_tangent));
 779     Geom::Point const tHatEnd(0, 0);
 780
 781     guint n_points  = pc->ps.size();
 782     pc->red_curve->reset();
 783     pc->red_curve_is_valid = false;
 784
 785     Geom::Point * b = g_new(Geom::Point, 4*n_points);
 786     Geom::Point * points = g_new(Geom::Point, 4*n_points);
 787     for (unsigned i = 0; i < pc->ps.size(); i++) {
 788         points[i] = pc->ps[i];
 789     }
 790
 791     // worst case gives us a segment per point
 792     int max_segs = 4*n_points;
 793
 794     int const n_segs = Geom::bezier_fit_cubic_r(b, points, n_points,
 795                                              tolerance_sq, max_segs);
 796
 797     if ( n_segs > 0)
 798     {
 799         Geom::Path fit(b[0]);
 800         for (int c = 0; c < n_segs; c++) {
 801             fit.appendNew<Geom::CubicBezier>(b[4*c+1], b[4*c+2], b[4*c+3]);
 802         }
 803         Geom::Piecewise<Geom::D2<Geom::SBasis> > fit_pwd2 = fit.toPwSb();
 804
 805         double t =0.;
 806         if ( pc->sketch_n > 0 ) {
 807             if (average_all_sketches) {
 808                 // Average = (sum of all) / n
 809                 //         = (sum of all + new one) / n+1
 810                 //         = ((old average)*n + new one) / n+1
 811                 t = pc->sketch_n / (pc->sketch_n + 1.);
 812             } else {
 813                 t = 0.5;
 814             }
 815             pc->sketch_interpolation = Geom::lerp(t, fit_pwd2, pc->sketch_interpolation);
 816             // simplify path, to eliminate small segments
 817             Path *path = new Path;
 818             path->LoadPathVector(Geom::path_from_piecewise(pc->sketch_interpolation, 0.01));
 819             path->Simplify(0.5);
 820             Geom::PathVector *pathv = path->MakePathVector();
 821             pc->sketch_interpolation = (*pathv)[0].toPwSb();
 822             delete path;
 823             delete pathv;
 824         } else {
 825             pc->sketch_interpolation = fit_pwd2;
 826         }
 827         pc->sketch_n++;
 828
 829         pc->green_curve->reset();
 830         pc->green_curve->set_pathvector(Geom::path_from_piecewise(pc->sketch_interpolation, 0.01));
 831         sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), pc->green_curve);
 832
 833         /* Fit and draw and copy last point */
 834         g_assert(!pc->green_curve->is_empty());
 835
 836         /* Set up direction of next curve. */
 837         {
 838             Geom::CubicBezier const * last_seg = dynamic_cast<Geom::CubicBezier const *>(pc->green_curve->last_segment());
 839             g_assert( last_seg );      // Relevance: validity of (*last_seg)[2]
 840             pc->p[0] = last_seg->finalPoint();
 841             pc->npoints = 1;
 842             Geom::Point const req_vec( pc->p[0] - (*last_seg)[2] );
 843             pc->req_tangent = ( ( Geom::is_zero(req_vec) || !in_svg_plane(req_vec) )
 844                                 ? Geom::Point(0, 0)
 845                                 : Geom::unit_vector(req_vec) );
 846         }
 847     }
 848     g_free(b);
 849     g_free(points);
 850     pc->ps.clear();
 851 }
 852
 853 static void
 854 fit_and_split(SPPencilContext *pc)
 855 {
 856     g_assert( pc->npoints > 1 );
 857
 858     double const tolerance_sq = 0;
 859
 860     Geom::Point b[4];
 861     g_assert(is_zero(pc->req_tangent)
 862              || is_unit_vector(pc->req_tangent));
 863     Geom::Point const tHatEnd(0, 0);
 864     int const n_segs = Geom::bezier_fit_cubic_full(b, NULL, pc->p, pc->npoints,
 865                                                 pc->req_tangent, tHatEnd,
 866                                                 tolerance_sq, 1);
 867     if ( n_segs > 0
 868          && unsigned(pc->npoints) < G_N_ELEMENTS(pc->p) )
 869     {
 870         /* Fit and draw and reset state */
 871         pc->red_curve->reset();
 872         pc->red_curve->moveto(b[0]);
 873         pc->red_curve->curveto(b[1], b[2], b[3]);
 874         sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), pc->red_curve);
 875         pc->red_curve_is_valid = true;
 876     } else {
 877         /* Fit and draw and copy last point */
 878
 879         g_assert(!pc->red_curve->is_empty());
 880
 881         /* Set up direction of next curve. */
 882         {
 883             Geom::CubicBezier const * last_seg = dynamic_cast<Geom::CubicBezier const *>(pc->red_curve->last_segment());
 884             g_assert( last_seg );      // Relevance: validity of (*last_seg)[2]
 885             pc->p[0] = last_seg->finalPoint();
 886             pc->npoints = 1;
 887             Geom::Point const req_vec( pc->p[0] - (*last_seg)[2] );
 888             pc->req_tangent = ( ( Geom::is_zero(req_vec) || !in_svg_plane(req_vec) )
 889                                 ? Geom::Point(0, 0)
 890                                 : Geom::unit_vector(req_vec) );
 891         }
 892
 893         pc->green_curve->append_continuous(pc->red_curve, 0.0625);
 894         SPCurve *curve = pc->red_curve->copy();
 895
 896         /// \todo fixme:
 897         SPCanvasItem *cshape = sp_canvas_bpath_new(sp_desktop_sketch(pc->desktop), curve);
 898         curve->unref();
 899         sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(cshape), pc->green_color, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 900
 901         pc->green_bpaths = g_slist_prepend(pc->green_bpaths, cshape);
 902
 903         pc->red_curve_is_valid = false;
 904     }
 905 }
 906
 907
 908 /*
 909   Local Variables:
 910   mode:c++
 911   c-file-style:"stroustrup"
 912   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
 913   indent-tabs-mode:nil
 914   fill-column:99
 915   End:
 916 */
 917 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :