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/bezier-utils.h>
  34 #include "display/canvas-bpath.h"
  35 #include <glibmm/i18n.h>
  36 #include "libnr/in-svg-plane.h"
  37 #include "context-fns.h"
  38 #include "sp-namedview.h"
  39 #include "xml/repr.h"
  40 #include "document.h"
  41 #include "desktop-style.h"
  42 #include "macros.h"
  43 #include "display/curve.h"
  44
  45 static void sp_pencil_context_class_init(SPPencilContextClass *klass);
  46 static void sp_pencil_context_init(SPPencilContext *pc);
  47 static void sp_pencil_context_setup(SPEventContext *ec);
  48 static void sp_pencil_context_dispose(GObject *object);
  49
  50 static gint sp_pencil_context_root_handler(SPEventContext *event_context, GdkEvent *event);
  51 static gint pencil_handle_button_press(SPPencilContext *const pc, GdkEventButton const &bevent);
  52 static gint pencil_handle_motion_notify(SPPencilContext *const pc, GdkEventMotion const &mevent);
  53 static gint pencil_handle_button_release(SPPencilContext *const pc, GdkEventButton const &revent);
  54 static gint pencil_handle_key_press(SPPencilContext *const pc, guint const keyval, guint const state);
  55 static gint pencil_handle_key_release(SPPencilContext *const pc, guint const keyval, guint const state);
  56
  57 static void spdc_set_startpoint(SPPencilContext *pc, Geom::Point const p);
  58 static void spdc_set_endpoint(SPPencilContext *pc, Geom::Point const p);
  59 static void spdc_finish_endpoint(SPPencilContext *pc);
  60 static void spdc_add_freehand_point(SPPencilContext *pc, Geom::Point p, guint state);
  61 static void fit_and_split(SPPencilContext *pc);
  62 static void interpolate(SPPencilContext *pc);
  63 static void sketch_interpolate(SPPencilContext *pc);
  64
  65 static SPDrawContextClass *pencil_parent_class;
  66 static Geom::Point pencil_drag_origin_w(0, 0);
  67 static bool pencil_within_tolerance = false;
  68
  69 /**
  70  * Register SPPencilContext class with Gdk and return its type number.
  71  */
  72 GType
  73 sp_pencil_context_get_type()
  74 {
  75     static GType type = 0;
  76     if (!type) {
  77         GTypeInfo info = {
  78             sizeof(SPPencilContextClass),
  79             NULL, NULL,
  80             (GClassInitFunc) sp_pencil_context_class_init,
  81             NULL, NULL,
  82             sizeof(SPPencilContext),
  83             4,
  84             (GInstanceInitFunc) sp_pencil_context_init,
  85             NULL,   /* value_table */
  86         };
  87         type = g_type_register_static(SP_TYPE_DRAW_CONTEXT, "SPPencilContext", &info, (GTypeFlags)0);
  88     }
  89     return type;
  90 }
  91
  92 /**
  93  * Initialize SPPencilContext vtable.
  94  */
  95 static void
  96 sp_pencil_context_class_init(SPPencilContextClass *klass)
  97 {
  98     GObjectClass *object_class;
  99     SPEventContextClass *event_context_class;
 100
 101     object_class = (GObjectClass *) klass;
 102     event_context_class = (SPEventContextClass *) klass;
 103
 104     pencil_parent_class = (SPDrawContextClass*)g_type_class_peek_parent(klass);
 105
 106     object_class->dispose = sp_pencil_context_dispose;
 107
 108     event_context_class->setup = sp_pencil_context_setup;
 109     event_context_class->root_handler = sp_pencil_context_root_handler;
 110 }
 111
 112 /**
 113  * Callback to initialize SPPencilContext object.
 114  */
 115 static void
 116 sp_pencil_context_init(SPPencilContext *pc)
 117 {
 118     SPEventContext *event_context = SP_EVENT_CONTEXT(pc);
 119
 120     event_context->cursor_shape = cursor_pencil_xpm;
 121     event_context->hot_x = 4;
 122     event_context->hot_y = 4;
 123
 124     pc->npoints = 0;
 125     pc->state = SP_PENCIL_CONTEXT_IDLE;
 126     pc->req_tangent = Geom::Point(0, 0);
 127
 128     // since SPPencilContext is not properly constructed...
 129     pc->sketch_interpolation = Geom::Path();
 130     pc->sketch_n = 0;
 131 }
 132
 133 /**
 134  * Callback to setup SPPencilContext object.
 135  */
 136 static void
 137 sp_pencil_context_setup(SPEventContext *ec)
 138 {
 139     Inkscape::Preferences *prefs = Inkscape::Preferences::get();
 140     if (prefs->getBool("/tools/freehand/pencil/selcue")) {
 141         ec->enableSelectionCue();
 142     }
 143
 144     if (((SPEventContextClass *) pencil_parent_class)->setup) {
 145         ((SPEventContextClass *) pencil_parent_class)->setup(ec);
 146     }
 147
 148     SPPencilContext *const pc = SP_PENCIL_CONTEXT(ec);
 149     pc->is_drawing = false;
 150
 151     pc->anchor_statusbar = false;
 152 }
 153
 154 static void
 155 sp_pencil_context_dispose(GObject *object)
 156 {
 157     G_OBJECT_CLASS(pencil_parent_class)->dispose(object);
 158 }
 159
 160 /** Snaps new node relative to the previous node. */
 161 static void
 162 spdc_endpoint_snap(SPPencilContext const *pc, Geom::Point &p, guint const state)
 163 {
 164     if ((state & GDK_CONTROL_MASK)) { //CTRL enables constrained snapping
 165         spdc_endpoint_snap_rotation(pc, p, pc->p[0], state);
 166     } else {
 167         if (!(state & GDK_SHIFT_MASK)) { //SHIFT disables all snapping, except the angular snapping above
 168                                          //After all, the user explicitely asked for angular snapping by
 169                                          //pressing CTRL
 170             spdc_endpoint_snap_free(pc, p, state);
 171         }
 172     }
 173 }
 174
 175 /**
 176  * Callback for handling all pencil context events.
 177  */
 178 gint
 179 sp_pencil_context_root_handler(SPEventContext *const ec, GdkEvent *event)
 180 {
 181     SPPencilContext *const pc = SP_PENCIL_CONTEXT(ec);
 182
 183     gint ret = FALSE;
 184
 185     switch (event->type) {
 186         case GDK_BUTTON_PRESS:
 187             ret = pencil_handle_button_press(pc, event->button);
 188             break;
 189
 190         case GDK_MOTION_NOTIFY:
 191             ret = pencil_handle_motion_notify(pc, event->motion);
 192             break;
 193
 194         case GDK_BUTTON_RELEASE:
 195             ret = pencil_handle_button_release(pc, event->button);
 196             break;
 197
 198         case GDK_KEY_PRESS:
 199             ret = pencil_handle_key_press(pc, get_group0_keyval (&event->key), event->key.state);
 200             break;
 201
 202         case GDK_KEY_RELEASE:
 203             ret = pencil_handle_key_release(pc, get_group0_keyval (&event->key), event->key.state);
 204             break;
 205
 206         default:
 207             break;
 208     }
 209
 210     if (!ret) {
 211         gint (*const parent_root_handler)(SPEventContext *, GdkEvent *)
 212             = ((SPEventContextClass *) pencil_parent_class)->root_handler;
 213         if (parent_root_handler) {
 214             ret = parent_root_handler(ec, event);
 215         }
 216     }
 217
 218     return ret;
 219 }
 220
 221 static gint
 222 pencil_handle_button_press(SPPencilContext *const pc, GdkEventButton const &bevent)
 223 {
 224     gint ret = FALSE;
 225     SPEventContext *event_context = SP_EVENT_CONTEXT(pc);
 226     if ( bevent.button == 1  && !event_context->space_panning) {
 227
 228         SPDrawContext *dc = SP_DRAW_CONTEXT (pc);
 229         SPDesktop *desktop = SP_EVENT_CONTEXT_DESKTOP(dc);
 230         Inkscape::Selection *selection = sp_desktop_selection(desktop);
 231
 232         if (Inkscape::have_viable_layer(desktop, dc->_message_context) == false) {
 233             return TRUE;
 234         }
 235
 236         Geom::Point const button_w(bevent.x, bevent.y);
 237
 238         /* Find desktop coordinates */
 239         Geom::Point p = pc->desktop->w2d(button_w);
 240
 241         /* Test whether we hit any anchor. */
 242         SPDrawAnchor *anchor = spdc_test_inside(pc, button_w);
 243
 244         pencil_drag_origin_w = Geom::Point(bevent.x,bevent.y);
 245         pencil_within_tolerance = true;
 246
 247         switch (pc->state) {
 248             case SP_PENCIL_CONTEXT_ADDLINE:
 249                 /* Current segment will be finished with release */
 250                 ret = TRUE;
 251                 break;
 252             default:
 253                 /* Set first point of sequence */
 254                 if (bevent.state & GDK_CONTROL_MASK) {
 255                     spdc_create_single_dot(event_context, from_2geom(p), "/tools/freehand/pencil", bevent.state);
 256                     ret = true;
 257                     break;
 258                 }
 259                 if (anchor) {
 260                     p = to_2geom(anchor->dp);
 261                     desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Continuing selected path"));
 262                 } else {
 263
 264                     if (!(bevent.state & GDK_SHIFT_MASK)) {
 265
 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                         SnapManager &m = desktop->namedview->snap_manager;
 272                         m.setup(desktop);
 273                         Inkscape::SnappedPoint const s = m.freeSnap(Inkscape::SnapPreferences::SNAPPOINT_NODE, p);
 274                         if (s.getSnapped()) {
 275                                 s.getPoint(p);
 276                                 pc->prev_snap_was_succesful = true;
 277                         } else {
 278                                 pc->prev_snap_was_succesful = false;
 279                         }
 280                     } else if (selection->singleItem() && SP_IS_PATH(selection->singleItem())) {
 281                         desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Appending to selected path"));
 282                     }
 283                 }
 284                 pc->sa = anchor;
 285                 spdc_set_startpoint(pc, from_2geom(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     if ((mevent.state & GDK_CONTROL_MASK) && (mevent.state & GDK_BUTTON1_MASK)) {
 299         // mouse was accidentally moved during Ctrl+click;
 300         // ignore the motion and create a single point
 301         pc->is_drawing = false;
 302         return TRUE;
 303     }
 304     gint ret = FALSE;
 305     SPDesktop *const dt = pc->desktop;
 306
 307     SPEventContext *event_context = SP_EVENT_CONTEXT(pc);
 308     if (event_context->space_panning || mevent.state & GDK_BUTTON2_MASK || mevent.state & GDK_BUTTON3_MASK) {
 309         // allow scrolling
 310         return FALSE;
 311     }
 312
 313     if ( ( mevent.state & GDK_BUTTON1_MASK ) && !pc->grab && pc->is_drawing) {
 314         /* Grab mouse, so release will not pass unnoticed */
 315         pc->grab = SP_CANVAS_ITEM(dt->acetate);
 316         sp_canvas_item_grab(pc->grab, ( GDK_KEY_PRESS_MASK | GDK_BUTTON_PRESS_MASK   |
 317                                         GDK_BUTTON_RELEASE_MASK |
 318                                         GDK_POINTER_MOTION_MASK  ),
 319                             NULL, mevent.time);
 320     }
 321
 322     /* Find desktop coordinates */
 323     Geom::Point p = to_2geom(dt->w2d(Geom::Point(mevent.x, mevent.y)));
 324
 325     /* Test whether we hit any anchor. */
 326     SPDrawAnchor *anchor = spdc_test_inside(pc, Geom::Point(mevent.x, mevent.y));
 327
 328     if (pencil_within_tolerance) {
 329         Inkscape::Preferences *prefs = Inkscape::Preferences::get();
 330         gint const tolerance = prefs->getIntLimited("/options/dragtolerance/value", 0, 0, 100);
 331         if ( Geom::LInfty( Geom::Point(mevent.x,mevent.y) - pencil_drag_origin_w ) < tolerance ) {
 332             return FALSE;   // Do not drag if we're within tolerance from origin.
 333         }
 334     }
 335
 336     // Once the user has moved farther than tolerance from the original location
 337     // (indicating they intend to move the object, not click), then always process the
 338     // motion notify coordinates as given (no snapping back to origin)
 339     pencil_within_tolerance = false;
 340
 341     switch (pc->state) {
 342         case SP_PENCIL_CONTEXT_ADDLINE:
 343             /* Set red endpoint */
 344             if (anchor) {
 345                 p = to_2geom(anchor->dp);
 346             } else {
 347                 Geom::Point ptnr = from_2geom(p);
 348                 spdc_endpoint_snap(pc, ptnr, mevent.state);
 349                 p = to_2geom(ptnr);
 350             }
 351             spdc_set_endpoint(pc, from_2geom(p));
 352             ret = TRUE;
 353             break;
 354         default:
 355             /* We may be idle or already freehand */
 356             if ( mevent.state & GDK_BUTTON1_MASK && pc->is_drawing ) {
 357                 pc->state = SP_PENCIL_CONTEXT_FREEHAND;
 358                 if ( !pc->sa && !pc->green_anchor ) {
 359                     /* Create green anchor */
 360                     pc->green_anchor = sp_draw_anchor_new(pc, pc->green_curve, TRUE, pc->p[0]);
 361                 }
 362                 /** \todo
 363                  * fixme: I am not sure whether we want to snap to anchors
 364                  * in middle of freehand (Lauris)
 365                  */
 366                 SnapManager &m = dt->namedview->snap_manager;
 367
 368                 if (anchor) {
 369                     p = to_2geom(anchor->dp);
 370                 } else if ((mevent.state & GDK_SHIFT_MASK) == 0) {
 371                     m.setup(dt);
 372                     Inkscape::SnappedPoint const s = m.freeSnap(Inkscape::SnapPreferences::SNAPPOINT_NODE, p);
 373                     if (s.getSnapped()) {
 374                         s.getPoint(p);
 375                         pc->prev_snap_was_succesful = true;
 376                     } else {
 377                         pc->prev_snap_was_succesful = false;
 378                     }
 379                 }
 380                 if ( pc->npoints != 0) { // buttonpress may have happened before we entered draw context!
 381                         if (!(pc->prev_snap_was_succesful && m.snapprefs.getSnapPostponedGlobally())) {
 382                             // When snapping is enabled but temporarily on hold because the mouse is moving
 383                                 // fast, then we don't want to add nodes off-grid
 384                                 spdc_add_freehand_point(pc, from_2geom(p), mevent.state);
 385                             ret = TRUE;
 386                         }
 387                 }
 388
 389                 if (anchor && !pc->anchor_statusbar) {
 390                     pc->_message_context->set(Inkscape::NORMAL_MESSAGE, _("<b>Release</b> here to close and finish the path."));
 391                     pc->anchor_statusbar = true;
 392                 } else if (!anchor && pc->anchor_statusbar) {
 393                     pc->_message_context->clear();
 394                     pc->anchor_statusbar = false;
 395                 } else if (!anchor) {
 396                     pc->_message_context->set(Inkscape::NORMAL_MESSAGE, _("Drawing a freehand path"));
 397                 }
 398
 399             } else {
 400                 if (anchor && !pc->anchor_statusbar) {
 401                     pc->_message_context->set(Inkscape::NORMAL_MESSAGE, _("<b>Drag</b> to continue the path from this point."));
 402                     pc->anchor_statusbar = true;
 403                 } else if (!anchor && pc->anchor_statusbar) {
 404                     pc->_message_context->clear();
 405                     pc->anchor_statusbar = false;
 406                 }
 407             }
 408             break;
 409     }
 410     return ret;
 411 }
 412
 413 static gint
 414 pencil_handle_button_release(SPPencilContext *const pc, GdkEventButton const &revent)
 415 {
 416     gint ret = FALSE;
 417
 418     SPEventContext *event_context = SP_EVENT_CONTEXT(pc);
 419     if ( revent.button == 1 && pc->is_drawing && !event_context->space_panning) {
 420         SPDesktop *const dt = pc->desktop;
 421
 422         pc->is_drawing = false;
 423
 424         /* Find desktop coordinates */
 425         Geom::Point p = dt->w2d(Geom::Point(revent.x, revent.y));
 426
 427         /* Test whether we hit any anchor. */
 428         SPDrawAnchor *anchor = spdc_test_inside(pc, Geom::Point(revent.x,
 429                                                               revent.y));
 430
 431         switch (pc->state) {
 432             case SP_PENCIL_CONTEXT_IDLE:
 433                 /* Releasing button in idle mode means single click */
 434                 /* We have already set up start point/anchor in button_press */
 435                 if (!(revent.state & GDK_CONTROL_MASK)) {
 436                     // Ctrl+click creates a single point so only set context in ADDLINE mode when Ctrl isn't pressed
 437                     pc->state = SP_PENCIL_CONTEXT_ADDLINE;
 438                 }
 439                 ret = TRUE;
 440                 break;
 441             case SP_PENCIL_CONTEXT_ADDLINE:
 442                 /* Finish segment now */
 443                 if (anchor) {
 444                     p = anchor->dp;
 445                 } else {
 446                     spdc_endpoint_snap(pc, p, revent.state);
 447                 }
 448                 pc->ea = anchor;
 449                 spdc_set_endpoint(pc, p);
 450                 spdc_finish_endpoint(pc);
 451                 pc->state = SP_PENCIL_CONTEXT_IDLE;
 452                 ret = TRUE;
 453                 break;
 454             case SP_PENCIL_CONTEXT_FREEHAND:
 455                 if (revent.state & GDK_MOD1_MASK) {
 456                     /* sketch mode: interpolate the sketched path and improve the current output path with the new interpolation. don't finish sketch */
 457                     if (anchor) {
 458                         p = anchor->dp;
 459                     }
 460                     pc->ea = anchor;
 461
 462                     dt->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Sketching: release <b>Alt</b> to finalize current curve"));
 463
 464                     sketch_interpolate(pc);
 465
 466                     pc->state = SP_PENCIL_CONTEXT_SKETCH;
 467                 } else {
 468                     /* Finish segment now */
 469                     /// \todo fixme: Clean up what follows (Lauris)
 470                     if (anchor) {
 471                         p = anchor->dp;
 472                     }
 473                     pc->ea = anchor;
 474                     /* Write curves to object */
 475
 476                     dt->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Finishing freehand"));
 477
 478                     interpolate(pc);
 479                     spdc_concat_colors_and_flush(pc, FALSE);
 480                     pc->sa = NULL;
 481                     pc->ea = NULL;
 482                     if (pc->green_anchor) {
 483                         pc->green_anchor = sp_draw_anchor_destroy(pc->green_anchor);
 484                     }
 485                     pc->state = SP_PENCIL_CONTEXT_IDLE;
 486                 }
 487                 ret = TRUE;
 488                 break;
 489             case SP_PENCIL_CONTEXT_SKETCH:
 490             default:
 491                 break;
 492         }
 493
 494         if (pc->grab) {
 495             /* Release grab now */
 496             sp_canvas_item_ungrab(pc->grab, revent.time);
 497             pc->grab = NULL;
 498         }
 499
 500         ret = TRUE;
 501     }
 502     return ret;
 503 }
 504
 505 static void
 506 pencil_cancel (SPPencilContext *const pc)
 507 {
 508     if (pc->grab) {
 509         /* Release grab now */
 510         sp_canvas_item_ungrab(pc->grab, 0);
 511         pc->grab = NULL;
 512     }
 513
 514     pc->is_drawing = false;
 515
 516     pc->state = SP_PENCIL_CONTEXT_IDLE;
 517
 518     pc->red_curve->reset();
 519     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), NULL);
 520     while (pc->green_bpaths) {
 521         gtk_object_destroy(GTK_OBJECT(pc->green_bpaths->data));
 522         pc->green_bpaths = g_slist_remove(pc->green_bpaths, pc->green_bpaths->data);
 523     }
 524     pc->green_curve->reset();
 525     if (pc->green_anchor) {
 526         pc->green_anchor = sp_draw_anchor_destroy(pc->green_anchor);
 527     }
 528
 529     pc->_message_context->clear();
 530     pc->_message_context->flash(Inkscape::NORMAL_MESSAGE, _("Drawing cancelled"));
 531
 532     sp_canvas_end_forced_full_redraws(pc->desktop->canvas);
 533 }
 534
 535 static gint
 536 pencil_handle_key_press(SPPencilContext *const pc, guint const keyval, guint const state)
 537 {
 538     gint ret = FALSE;
 539     switch (keyval) {
 540         case GDK_Up:
 541         case GDK_Down:
 542         case GDK_KP_Up:
 543         case GDK_KP_Down:
 544             // Prevent the zoom field from activation.
 545             if (!mod_ctrl_only(state)) {
 546                 ret = TRUE;
 547             }
 548             break;
 549         case GDK_Escape:
 550             if (pc->npoints != 0) {
 551                 // if drawing, cancel, otherwise pass it up for deselecting
 552                 if (pc->state != SP_PENCIL_CONTEXT_IDLE) {
 553                     pencil_cancel (pc);
 554                     ret = TRUE;
 555                 }
 556             }
 557             break;
 558         case GDK_z:
 559         case GDK_Z:
 560             if (mod_ctrl_only(state) && pc->npoints != 0) {
 561                 // if drawing, cancel, otherwise pass it up for undo
 562                 if (pc->state != SP_PENCIL_CONTEXT_IDLE) {
 563                     pencil_cancel (pc);
 564                     ret = TRUE;
 565                 }
 566             }
 567             break;
 568         case GDK_g:
 569         case GDK_G:
 570             if (mod_shift_only(state)) {
 571                 sp_selection_to_guides(SP_EVENT_CONTEXT(pc)->desktop);
 572                 ret = true;
 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_interpolation = Geom::Path();
 593                 pc->sketch_n = 0;
 594                 pc->sa = NULL;
 595                 pc->ea = NULL;
 596                 if (pc->green_anchor) {
 597                     pc->green_anchor = sp_draw_anchor_destroy(pc->green_anchor);
 598                 }
 599                 pc->state = SP_PENCIL_CONTEXT_IDLE;
 600                 ret = TRUE;
 601             }
 602             break;
 603         default:
 604             break;
 605     }
 606     return ret;
 607 }
 608
 609 /**
 610  * Reset points and set new starting point.
 611  */
 612 static void
 613 spdc_set_startpoint(SPPencilContext *const pc, Geom::Point const p)
 614 {
 615     pc->npoints = 0;
 616     pc->red_curve_is_valid = false;
 617     if (in_svg_plane(p)) {
 618         pc->p[pc->npoints++] = p;
 619     }
 620 }
 621
 622 /**
 623  * Change moving endpoint position.
 624  * <ul>
 625  * <li>Ctrl constrains to moving to H/V direction, snapping in given direction.
 626  * <li>Otherwise we snap freely to whatever attractors are available.
 627  * </ul>
 628  *
 629  * Number of points is (re)set to 2 always, 2nd point is modified.
 630  * We change RED curve.
 631  */
 632 static void
 633 spdc_set_endpoint(SPPencilContext *const pc, Geom::Point const p)
 634 {
 635     if (pc->npoints == 0) {
 636         return;
 637         /* May occur if first point wasn't in SVG plane (e.g. weird w2d transform, perhaps from bad
 638          * zoom setting).
 639          */
 640     }
 641     g_return_if_fail( pc->npoints > 0 );
 642
 643     pc->red_curve->reset();
 644     if ( ( p == pc->p[0] )
 645          || !in_svg_plane(p) )
 646     {
 647         pc->npoints = 1;
 648     } else {
 649         pc->p[1] = p;
 650         pc->npoints = 2;
 651
 652         pc->red_curve->moveto(pc->p[0]);
 653         pc->red_curve->lineto(pc->p[1]);
 654         pc->red_curve_is_valid = true;
 655
 656         sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), pc->red_curve);
 657     }
 658 }
 659
 660 /**
 661  * Finalize addline.
 662  *
 663  * \todo
 664  * fixme: I'd like remove red reset from concat colors (lauris).
 665  * Still not sure, how it will make most sense.
 666  */
 667 static void
 668 spdc_finish_endpoint(SPPencilContext *const pc)
 669 {
 670     if ( ( pc->red_curve->is_empty() )
 671          || ( *(pc->red_curve->first_point()) == *(pc->red_curve->second_point())   ) )
 672     {
 673         pc->red_curve->reset();
 674         sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), NULL);
 675     } else {
 676         /* Write curves to object. */
 677         spdc_concat_colors_and_flush(pc, FALSE);
 678         pc->sa = NULL;
 679         pc->ea = NULL;
 680     }
 681 }
 682
 683
 684 static void
 685 spdc_add_freehand_point(SPPencilContext *pc, Geom::Point p, guint /*state*/)
 686 {
 687     g_assert( pc->npoints > 0 );
 688     g_return_if_fail(unsigned(pc->npoints) < G_N_ELEMENTS(pc->p));
 689
 690     if ( ( p != pc->p[ pc->npoints - 1 ] )
 691          && in_svg_plane(p) )
 692     {
 693         pc->ps.push_back(p);
 694         pc->p[pc->npoints++] = p;
 695         fit_and_split(pc);
 696     }
 697 }
 698
 699 static inline double
 700 square(double const x)
 701 {
 702     return x * x;
 703 }
 704
 705 static void
 706 interpolate(SPPencilContext *pc)
 707 {
 708
 709     g_assert( pc->ps.size() > 1 );
 710
 711     Inkscape::Preferences *prefs = Inkscape::Preferences::get();
 712     double const tol = prefs->getDoubleLimited("/tools/freehand/pencil/tolerance", 10.0, 1.0, 100.0) * 0.4;
 713     double const tolerance_sq = 0.02 * square( pc->desktop->w2d().descrim() *
 714                                                tol) * exp(0.2*tol - 2);
 715
 716     g_assert(is_zero(pc->req_tangent)
 717              || is_unit_vector(pc->req_tangent));
 718     Geom::Point const tHatEnd(0, 0);
 719
 720     guint n_points  = pc->ps.size();
 721     pc->green_curve->reset();
 722     pc->red_curve->reset();
 723     pc->red_curve_is_valid = false;
 724
 725     Geom::Point * b = g_new(Geom::Point, 4*n_points);
 726     Geom::Point * points = g_new(Geom::Point, 4*n_points);
 727     for (int i = 0; i < pc->ps.size(); i++) {
 728         points[i] = pc->ps[i];
 729     }
 730
 731     // worst case gives us a segment per point
 732     int max_segs = 4*n_points;
 733
 734     int const n_segs = Geom::bezier_fit_cubic_r(b, points, n_points,
 735                                              tolerance_sq, max_segs);
 736
 737     if ( n_segs > 0)
 738     {
 739         /* Fit and draw and reset state */
 740         pc->green_curve->moveto(b[0]);
 741         for (int c = 0; c < n_segs; c++) {
 742             pc->green_curve->curveto(b[4*c+1], b[4*c+2], b[4*c+3]);
 743         }
 744         sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), pc->green_curve);
 745
 746         /* Fit and draw and copy last point */
 747         g_assert(!pc->green_curve->is_empty());
 748
 749         /* Set up direction of next curve. */
 750         {
 751             Geom::CubicBezier const * last_seg = dynamic_cast<Geom::CubicBezier const *>(pc->green_curve->last_segment());
 752             g_assert( last_seg );      // Relevance: validity of (*last_seg)[2]
 753             pc->p[0] = last_seg->finalPoint();
 754             pc->npoints = 1;
 755             Geom::Point const req_vec( pc->p[0] - (*last_seg)[2] );
 756             pc->req_tangent = ( ( Geom::is_zero(req_vec) || !in_svg_plane(req_vec) )
 757                                 ? Geom::Point(0, 0)
 758                                 : Geom::unit_vector(req_vec) );
 759         }
 760     }
 761     g_free(b);
 762     g_free(points);
 763     pc->ps.clear();
 764 }
 765
 766
 767 /* interpolates the sketched curve and tweaks the current sketch interpolation*/
 768 static void
 769 sketch_interpolate(SPPencilContext *pc)
 770 {
 771     g_assert( pc->ps.size() > 1 );
 772
 773     Inkscape::Preferences *prefs = Inkscape::Preferences::get();
 774     double const tol = 100.0 * 0.4; //prefs->getDoubleLimited("/tools/freehand/pencil/tolerance", 10.0, 1.0, 100.0) * 0.4;
 775     double const tolerance_sq = 0.02 * square( pc->desktop->w2d().descrim() *
 776                                                tol) * exp(0.2*tol - 2);
 777
 778     bool average_all_sketches = prefs->getBool("/tools/freehand/pencil/average_all_sketches", true);
 779
 780     g_assert(is_zero(pc->req_tangent)
 781              || is_unit_vector(pc->req_tangent));
 782     Geom::Point const tHatEnd(0, 0);
 783
 784     guint n_points  = pc->ps.size();
 785     pc->red_curve->reset();
 786     pc->red_curve_is_valid = false;
 787
 788     Geom::Point * b = g_new(Geom::Point, 4*n_points);
 789     Geom::Point * points = g_new(Geom::Point, 4*n_points);
 790     for (unsigned i = 0; i < pc->ps.size(); i++) {
 791         points[i] = pc->ps[i];
 792     }
 793
 794     // worst case gives us a segment per point
 795     int max_segs = 4*n_points;
 796
 797     int const n_segs = Geom::bezier_fit_cubic_r(b, points, n_points,
 798                                              tolerance_sq, max_segs);
 799
 800     if ( n_segs > 0)
 801     {
 802         // only take first cubic and average its coefficients with the old ones
 803
 804         Geom::Point coeffs[4];
 805         if ( pc->sketch_n > 0 ) {
 806             Geom::CubicBezier const * oldcubic = dynamic_cast<Geom::CubicBezier const *>( &pc->sketch_interpolation.front() );
 807             g_assert(oldcubic);
 808             for (unsigned i = 0; i < 4; i++){
 809                 if (average_all_sketches) {
 810                     // Average = (sum of all) / n
 811                     //         = (sum of all + new one) / n+1
 812                     //         = ((old average)*n + new one) / n+1
 813                     coeffs[i] = ((*oldcubic)[i] * pc->sketch_n  +  b[i]) / (pc->sketch_n + 1);
 814                 } else {
 815                     coeffs[i] = 0.5 * (b[i] + (*oldcubic)[i]);
 816                 }
 817             }
 818         } else {
 819             for (unsigned i = 0; i < 4; i++){
 820                 coeffs[i] = b[i];
 821             }
 822         }
 823         pc->sketch_n++;
 824
 825         pc->sketch_interpolation.start(coeffs[0]);
 826         pc->sketch_interpolation.appendNew<Geom::CubicBezier>(coeffs[1], coeffs[2], coeffs[3]);
 827
 828         Geom::PathVector temp;
 829         temp.push_back(pc->sketch_interpolation);
 830
 831         pc->green_curve->reset();
 832         pc->green_curve->set_pathvector(temp);
 833         sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), pc->green_curve);
 834
 835         /* Fit and draw and copy last point */
 836         g_assert(!pc->green_curve->is_empty());
 837
 838         /* Set up direction of next curve. */
 839         {
 840             Geom::CubicBezier const * last_seg = dynamic_cast<Geom::CubicBezier const *>(pc->green_curve->last_segment());
 841             g_assert( last_seg );      // Relevance: validity of (*last_seg)[2]
 842             pc->p[0] = last_seg->finalPoint();
 843             pc->npoints = 1;
 844             Geom::Point const req_vec( pc->p[0] - (*last_seg)[2] );
 845             pc->req_tangent = ( ( Geom::is_zero(req_vec) || !in_svg_plane(req_vec) )
 846                                 ? Geom::Point(0, 0)
 847                                 : Geom::unit_vector(req_vec) );
 848         }
 849     }
 850     g_free(b);
 851     g_free(points);
 852     pc->ps.clear();
 853 }
 854
 855 static void
 856 fit_and_split(SPPencilContext *pc)
 857 {
 858     g_assert( pc->npoints > 1 );
 859
 860     double const tolerance_sq = 0;
 861
 862     Geom::Point b[4];
 863     g_assert(is_zero(pc->req_tangent)
 864              || is_unit_vector(pc->req_tangent));
 865     Geom::Point const tHatEnd(0, 0);
 866     int const n_segs = Geom::bezier_fit_cubic_full(b, NULL, pc->p, pc->npoints,
 867                                                 pc->req_tangent, tHatEnd,
 868                                                 tolerance_sq, 1);
 869     if ( n_segs > 0
 870          && unsigned(pc->npoints) < G_N_ELEMENTS(pc->p) )
 871     {
 872         /* Fit and draw and reset state */
 873         pc->red_curve->reset();
 874         pc->red_curve->moveto(b[0]);
 875         pc->red_curve->curveto(b[1], b[2], b[3]);
 876         sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), pc->red_curve);
 877         pc->red_curve_is_valid = true;
 878     } else {
 879         /* Fit and draw and copy last point */
 880
 881         g_assert(!pc->red_curve->is_empty());
 882
 883         /* Set up direction of next curve. */
 884         {
 885             Geom::CubicBezier const * last_seg = dynamic_cast<Geom::CubicBezier const *>(pc->red_curve->last_segment());
 886             g_assert( last_seg );      // Relevance: validity of (*last_seg)[2]
 887             pc->p[0] = last_seg->finalPoint();
 888             pc->npoints = 1;
 889             Geom::Point const req_vec( pc->p[0] - (*last_seg)[2] );
 890             pc->req_tangent = ( ( Geom::is_zero(req_vec) || !in_svg_plane(req_vec) )
 891                                 ? Geom::Point(0, 0)
 892                                 : Geom::unit_vector(req_vec) );
 893         }
 894
 895         pc->green_curve->append_continuous(pc->red_curve, 0.0625);
 896         SPCurve *curve = pc->red_curve->copy();
 897
 898         /// \todo fixme:
 899         SPCanvasItem *cshape = sp_canvas_bpath_new(sp_desktop_sketch(pc->desktop), curve);
 900         curve->unref();
 901         sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(cshape), pc->green_color, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 902
 903         pc->green_bpaths = g_slist_prepend(pc->green_bpaths, cshape);
 904
 905         pc->red_curve_is_valid = false;
 906     }
 907 }
 908
 909
 910 /*
 911   Local Variables:
 912   mode:c++
 913   c-file-style:"stroustrup"
 914   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
 915   indent-tabs-mode:nil
 916   fill-column:99
 917   End:
 918 */
 919 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :