src/eraser-context.cpp

   1 /*
   2  * Eraser drawing mode
   3  *
   4  * Authors:
   5  *   Mitsuru Oka <oka326@parkcity.ne.jp>
   6  *   Lauris Kaplinski <lauris@kaplinski.com>
   7  *   bulia byak <buliabyak@users.sf.net>
   8  *   MenTaLguY <mental@rydia.net>
   9  *   Jon A. Cruz <jon@joncruz.org>
  10  *
  11  * The original dynadraw code:
  12  *   Paul Haeberli <paul@sgi.com>
  13  *
  14  * Copyright (C) 1998 The Free Software Foundation
  15  * Copyright (C) 1999-2005 authors
  16  * Copyright (C) 2001-2002 Ximian, Inc.
  17  * Copyright (C) 2005-2007 bulia byak
  18  * Copyright (C) 2006 MenTaLguY
  19  * Copyright (C) 2008 Jon A. Cruz
  20  *
  21  * Released under GNU GPL, read the file 'COPYING' for more information
  22  */
  23
  24 #define noERASER_VERBOSE
  25
  26 #include "config.h"
  27
  28 #include <gtk/gtk.h>
  29 #include <gdk/gdkkeysyms.h>
  30 #include <glibmm/i18n.h>
  31 #include <string>
  32 #include <cstring>
  33 #include <numeric>
  34
  35 #include "svg/svg.h"
  36 #include "display/canvas-bpath.h"
  37 #include <2geom/bezier-utils.h>
  38
  39 #include <glib/gmem.h>
  40 #include "macros.h"
  41 #include "document.h"
  42 #include "selection.h"
  43 #include "desktop.h"
  44 #include "desktop-events.h"
  45 #include "desktop-handles.h"
  46 #include "desktop-style.h"
  47 #include "message-context.h"
  48 #include "preferences.h"
  49 #include "pixmaps/cursor-eraser.xpm"
  50 #include "xml/repr.h"
  51 #include "context-fns.h"
  52 #include "sp-item.h"
  53 #include "color.h"
  54 #include "rubberband.h"
  55 #include "splivarot.h"
  56 #include "sp-item-group.h"
  57 #include "sp-shape.h"
  58 #include "sp-path.h"
  59 #include "sp-text.h"
  60 #include "display/canvas-bpath.h"
  61 #include "display/canvas-arena.h"
  62 #include "livarot/Shape.h"
  63 #include <2geom/isnan.h>
  64 #include <2geom/pathvector.h>
  65
  66 #include "eraser-context.h"
  67
  68 #define ERC_RED_RGBA 0xff0000ff
  69
  70 #define TOLERANCE_ERASER 0.1
  71
  72 #define ERASER_EPSILON 0.5e-6
  73 #define ERASER_EPSILON_START 0.5e-2
  74 #define ERASER_VEL_START 1e-5
  75
  76 #define DRAG_MIN 0.0
  77 #define DRAG_DEFAULT 1.0
  78 #define DRAG_MAX 1.0
  79
  80
  81 static void sp_eraser_context_class_init(SPEraserContextClass *klass);
  82 static void sp_eraser_context_init(SPEraserContext *erc);
  83 static void sp_eraser_context_dispose(GObject *object);
  84
  85 static void sp_eraser_context_setup(SPEventContext *ec);
  86 static void sp_eraser_context_set(SPEventContext *ec, Inkscape::Preferences::Entry *val);
  87 static gint sp_eraser_context_root_handler(SPEventContext *ec, GdkEvent *event);
  88
  89 static void clear_current(SPEraserContext *dc);
  90 static void set_to_accumulated(SPEraserContext *dc);
  91 static void add_cap(SPCurve *curve, Geom::Point const &pre, Geom::Point const &from, Geom::Point const &to, Geom::Point const &post, double rounding);
  92 static void accumulate_eraser(SPEraserContext *dc);
  93
  94 static void fit_and_split(SPEraserContext *erc, gboolean release);
  95
  96 static void sp_eraser_reset(SPEraserContext *erc, Geom::Point p);
  97 static Geom::Point sp_eraser_get_npoint(SPEraserContext const *erc, Geom::Point v);
  98 static Geom::Point sp_eraser_get_vpoint(SPEraserContext const *erc, Geom::Point n);
  99 static void draw_temporary_box(SPEraserContext *dc);
 100
 101
 102 static SPEventContextClass *eraser_parent_class = 0;
 103
 104 GType sp_eraser_context_get_type(void)
 105 {
 106     static GType type = 0;
 107     if (!type) {
 108         GTypeInfo info = {
 109             sizeof(SPEraserContextClass),
 110             0, // base_init
 111             0, // base_finalize
 112             (GClassInitFunc)sp_eraser_context_class_init,
 113             0, // class_finalize
 114             0, // class_data
 115             sizeof(SPEraserContext),
 116             0, // n_preallocs
 117             (GInstanceInitFunc)sp_eraser_context_init,
 118             0 // value_table
 119         };
 120         type = g_type_register_static(SP_TYPE_COMMON_CONTEXT, "SPEraserContext", &info, static_cast<GTypeFlags>(0));
 121     }
 122     return type;
 123 }
 124
 125 static void
 126 sp_eraser_context_class_init(SPEraserContextClass *klass)
 127 {
 128     GObjectClass *object_class = (GObjectClass *) klass;
 129     SPEventContextClass *event_context_class = (SPEventContextClass *) klass;
 130
 131     eraser_parent_class = (SPEventContextClass*)g_type_class_peek_parent(klass);
 132
 133     object_class->dispose = sp_eraser_context_dispose;
 134
 135     event_context_class->setup = sp_eraser_context_setup;
 136     event_context_class->set = sp_eraser_context_set;
 137     event_context_class->root_handler = sp_eraser_context_root_handler;
 138 }
 139
 140 static void
 141 sp_eraser_context_init(SPEraserContext *erc)
 142 {
 143     erc->cursor_shape = cursor_eraser_xpm;
 144     erc->hot_x = 4;
 145     erc->hot_y = 4;
 146 }
 147
 148 static void
 149 sp_eraser_context_dispose(GObject *object)
 150 {
 151     //SPEraserContext *erc = SP_ERASER_CONTEXT(object);
 152
 153     G_OBJECT_CLASS(eraser_parent_class)->dispose(object);
 154 }
 155
 156 static void
 157 sp_eraser_context_setup(SPEventContext *ec)
 158 {
 159     SPEraserContext *erc = SP_ERASER_CONTEXT(ec);
 160     SPDesktop *desktop = ec->desktop;
 161
 162     if (((SPEventContextClass *) eraser_parent_class)->setup)
 163         ((SPEventContextClass *) eraser_parent_class)->setup(ec);
 164
 165     erc->accumulated = new SPCurve();
 166     erc->currentcurve = new SPCurve();
 167
 168     erc->cal1 = new SPCurve();
 169     erc->cal2 = new SPCurve();
 170
 171     erc->currentshape = sp_canvas_item_new(sp_desktop_sketch(desktop), SP_TYPE_CANVAS_BPATH, NULL);
 172     sp_canvas_bpath_set_fill(SP_CANVAS_BPATH(erc->currentshape), ERC_RED_RGBA, SP_WIND_RULE_EVENODD);
 173     sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(erc->currentshape), 0x00000000, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 174     /* fixme: Cannot we cascade it to root more clearly? */
 175     g_signal_connect(G_OBJECT(erc->currentshape), "event", G_CALLBACK(sp_desktop_root_handler), desktop);
 176
 177 /*
 178 static ProfileFloatElement f_profile[PROFILE_FLOAT_SIZE] = {
 179     {"mass",0.02, 0.0, 1.0},
 180     {"wiggle",0.0, 0.0, 1.0},
 181     {"angle",30.0, -90.0, 90.0},
 182     {"thinning",0.1, -1.0, 1.0},
 183     {"tremor",0.0, 0.0, 1.0},
 184     {"flatness",0.9, 0.0, 1.0},
 185     {"cap_rounding",0.0, 0.0, 5.0}
 186 };
 187 */
 188
 189     sp_event_context_read(ec, "mass");
 190     sp_event_context_read(ec, "wiggle");
 191     sp_event_context_read(ec, "angle");
 192     sp_event_context_read(ec, "width");
 193     sp_event_context_read(ec, "thinning");
 194     sp_event_context_read(ec, "tremor");
 195     sp_event_context_read(ec, "flatness");
 196     sp_event_context_read(ec, "tracebackground");
 197     sp_event_context_read(ec, "usepressure");
 198     sp_event_context_read(ec, "usetilt");
 199     sp_event_context_read(ec, "abs_width");
 200     sp_event_context_read(ec, "cap_rounding");
 201
 202     erc->is_drawing = false;
 203
 204     erc->_message_context = new Inkscape::MessageContext(desktop->messageStack());
 205
 206     Inkscape::Preferences *prefs = Inkscape::Preferences::get();
 207     if (prefs->getBool("/tools/eraser/selcue", 0) != 0) {
 208         ec->enableSelectionCue();
 209     }
 210 // TODO temp force:
 211     ec->enableSelectionCue();
 212
 213 }
 214
 215 static void
 216 sp_eraser_context_set(SPEventContext *ec, Inkscape::Preferences::Entry *val)
 217 {
 218     //pass on up to parent class to handle common attributes.
 219     if ( eraser_parent_class->set ) {
 220         eraser_parent_class->set(ec, val);
 221     }
 222 }
 223
 224 static double
 225 flerp(double f0, double f1, double p)
 226 {
 227     return f0 + ( f1 - f0 ) * p;
 228 }
 229
 230 /* Get normalized point */
 231 static Geom::Point
 232 sp_eraser_get_npoint(SPEraserContext const *dc, Geom::Point v)
 233 {
 234     Geom::Rect drect = SP_EVENT_CONTEXT(dc)->desktop->get_display_area();
 235     double const max = MAX ( drect.dimensions()[Geom::X], drect.dimensions()[Geom::Y] );
 236     return Geom::Point(( v[Geom::X] - drect.min()[Geom::X] ) / max,  ( v[Geom::Y] - drect.min()[Geom::Y] ) / max);
 237 }
 238
 239 /* Get view point */
 240 static Geom::Point
 241 sp_eraser_get_vpoint(SPEraserContext const *dc, Geom::Point n)
 242 {
 243     Geom::Rect drect = SP_EVENT_CONTEXT(dc)->desktop->get_display_area();
 244     double const max = MAX ( drect.dimensions()[Geom::X], drect.dimensions()[Geom::Y] );
 245     return Geom::Point(n[Geom::X] * max + drect.min()[Geom::X], n[Geom::Y] * max + drect.min()[Geom::Y]);
 246 }
 247
 248 static void
 249 sp_eraser_reset(SPEraserContext *dc, Geom::Point p)
 250 {
 251     dc->last = dc->cur = sp_eraser_get_npoint(dc, p);
 252     dc->vel = Geom::Point(0,0);
 253     dc->vel_max = 0;
 254     dc->acc = Geom::Point(0,0);
 255     dc->ang = Geom::Point(0,0);
 256     dc->del = Geom::Point(0,0);
 257 }
 258
 259 static void
 260 sp_eraser_extinput(SPEraserContext *dc, GdkEvent *event)
 261 {
 262     if (gdk_event_get_axis (event, GDK_AXIS_PRESSURE, &dc->pressure))
 263         dc->pressure = CLAMP (dc->pressure, ERC_MIN_PRESSURE, ERC_MAX_PRESSURE);
 264     else
 265         dc->pressure = ERC_DEFAULT_PRESSURE;
 266
 267     if (gdk_event_get_axis (event, GDK_AXIS_XTILT, &dc->xtilt))
 268         dc->xtilt = CLAMP (dc->xtilt, ERC_MIN_TILT, ERC_MAX_TILT);
 269     else
 270         dc->xtilt = ERC_DEFAULT_TILT;
 271
 272     if (gdk_event_get_axis (event, GDK_AXIS_YTILT, &dc->ytilt))
 273         dc->ytilt = CLAMP (dc->ytilt, ERC_MIN_TILT, ERC_MAX_TILT);
 274     else
 275         dc->ytilt = ERC_DEFAULT_TILT;
 276 }
 277
 278
 279 static gboolean
 280 sp_eraser_apply(SPEraserContext *dc, Geom::Point p)
 281 {
 282     Geom::Point n = sp_eraser_get_npoint(dc, p);
 283
 284     /* Calculate mass and drag */
 285     double const mass = flerp(1.0, 160.0, dc->mass);
 286     double const drag = flerp(0.0, 0.5, dc->drag * dc->drag);
 287
 288     /* Calculate force and acceleration */
 289     Geom::Point force = n - dc->cur;
 290
 291     // If force is below the absolute threshold ERASER_EPSILON,
 292     // or we haven't yet reached ERASER_VEL_START (i.e. at the beginning of stroke)
 293     // _and_ the force is below the (higher) ERASER_EPSILON_START threshold,
 294     // discard this move.
 295     // This prevents flips, blobs, and jerks caused by microscopic tremor of the tablet pen,
 296     // especially bothersome at the start of the stroke where we don't yet have the inertia to
 297     // smooth them out.
 298     if ( Geom::L2(force) < ERASER_EPSILON || (dc->vel_max < ERASER_VEL_START && Geom::L2(force) < ERASER_EPSILON_START)) {
 299         return FALSE;
 300     }
 301
 302     dc->acc = force / mass;
 303
 304     /* Calculate new velocity */
 305     dc->vel += dc->acc;
 306
 307     if (Geom::L2(dc->vel) > dc->vel_max)
 308         dc->vel_max = Geom::L2(dc->vel);
 309
 310     /* Calculate angle of drawing tool */
 311
 312     double a1;
 313     if (dc->usetilt) {
 314         // 1a. calculate nib angle from input device tilt:
 315         gdouble length = std::sqrt(dc->xtilt*dc->xtilt + dc->ytilt*dc->ytilt);;
 316
 317         if (length > 0) {
 318             Geom::Point ang1 = Geom::Point(dc->ytilt/length, dc->xtilt/length);
 319             a1 = atan2(ang1);
 320         }
 321         else
 322             a1 = 0.0;
 323     }
 324     else {
 325         // 1b. fixed dc->angle (absolutely flat nib):
 326         double const radians = ( (dc->angle - 90) / 180.0 ) * M_PI;
 327         Geom::Point ang1 = Geom::Point(-sin(radians),  cos(radians));
 328         a1 = atan2(ang1);
 329     }
 330
 331     // 2. perpendicular to dc->vel (absolutely non-flat nib):
 332     gdouble const mag_vel = Geom::L2(dc->vel);
 333     if ( mag_vel < ERASER_EPSILON ) {
 334         return FALSE;
 335     }
 336     Geom::Point ang2 = Geom::rot90(dc->vel) / mag_vel;
 337
 338     // 3. Average them using flatness parameter:
 339     // calculate angles
 340     double a2 = atan2(ang2);
 341     // flip a2 to force it to be in the same half-circle as a1
 342     bool flipped = false;
 343     if (fabs (a2-a1) > 0.5*M_PI) {
 344         a2 += M_PI;
 345         flipped = true;
 346     }
 347     // normalize a2
 348     if (a2 > M_PI)
 349         a2 -= 2*M_PI;
 350     if (a2 < -M_PI)
 351         a2 += 2*M_PI;
 352     // find the flatness-weighted bisector angle, unflip if a2 was flipped
 353     // FIXME: when dc->vel is oscillating around the fixed angle, the new_ang flips back and forth. How to avoid this?
 354     double new_ang = a1 + (1 - dc->flatness) * (a2 - a1) - (flipped? M_PI : 0);
 355
 356     // Try to detect a sudden flip when the new angle differs too much from the previous for the
 357     // current velocity; in that case discard this move
 358     double angle_delta = Geom::L2(Geom::Point (cos (new_ang), sin (new_ang)) - dc->ang);
 359     if ( angle_delta / Geom::L2(dc->vel) > 4000 ) {
 360         return FALSE;
 361     }
 362
 363     // convert to point
 364     dc->ang = Geom::Point (cos (new_ang), sin (new_ang));
 365
 366 //    g_print ("force %g  acc %g  vel_max %g  vel %g  a1 %g  a2 %g  new_ang %g\n", Geom::L2(force), Geom::L2(dc->acc), dc->vel_max, Geom::L2(dc->vel), a1, a2, new_ang);
 367
 368     /* Apply drag */
 369     dc->vel *= 1.0 - drag;
 370
 371     /* Update position */
 372     dc->last = dc->cur;
 373     dc->cur += dc->vel;
 374
 375     return TRUE;
 376 }
 377
 378 static void
 379 sp_eraser_brush(SPEraserContext *dc)
 380 {
 381     g_assert( dc->npoints >= 0 && dc->npoints < SAMPLING_SIZE );
 382
 383     // How much velocity thins strokestyle
 384     double vel_thin = flerp (0, 160, dc->vel_thin);
 385
 386     // Influence of pressure on thickness
 387     double pressure_thick = (dc->usepressure ? dc->pressure : 1.0);
 388
 389     // get the real brush point, not the same as pointer (affected by hatch tracking and/or mass
 390     // drag)
 391     Geom::Point brush = sp_eraser_get_vpoint(dc, dc->cur);
 392     Geom::Point brush_w = SP_EVENT_CONTEXT(dc)->desktop->d2w(brush);
 393
 394     double trace_thick = 1;
 395
 396     double width = (pressure_thick * trace_thick - vel_thin * Geom::L2(dc->vel)) * dc->width;
 397
 398     double tremble_left = 0, tremble_right = 0;
 399     if (dc->tremor > 0) {
 400         // obtain two normally distributed random variables, using polar Box-Muller transform
 401         double x1, x2, w, y1, y2;
 402         do {
 403             x1 = 2.0 * g_random_double_range(0,1) - 1.0;
 404             x2 = 2.0 * g_random_double_range(0,1) - 1.0;
 405             w = x1 * x1 + x2 * x2;
 406         } while ( w >= 1.0 );
 407         w = sqrt( (-2.0 * log( w ) ) / w );
 408         y1 = x1 * w;
 409         y2 = x2 * w;
 410
 411         // deflect both left and right edges randomly and independently, so that:
 412         // (1) dc->tremor=1 corresponds to sigma=1, decreasing dc->tremor narrows the bell curve;
 413         // (2) deflection depends on width, but is upped for small widths for better visual uniformity across widths;
 414         // (3) deflection somewhat depends on speed, to prevent fast strokes looking
 415         // comparatively smooth and slow ones excessively jittery
 416         tremble_left  = (y1)*dc->tremor * (0.15 + 0.8*width) * (0.35 + 14*Geom::L2(dc->vel));
 417         tremble_right = (y2)*dc->tremor * (0.15 + 0.8*width) * (0.35 + 14*Geom::L2(dc->vel));
 418     }
 419
 420     if ( width < 0.02 * dc->width ) {
 421         width = 0.02 * dc->width;
 422     }
 423
 424     double dezoomify_factor = 0.05 * 1000;
 425     if (!dc->abs_width) {
 426         dezoomify_factor /= SP_EVENT_CONTEXT(dc)->desktop->current_zoom();
 427     }
 428
 429     Geom::Point del_left = dezoomify_factor * (width + tremble_left) * dc->ang;
 430     Geom::Point del_right = dezoomify_factor * (width + tremble_right) * dc->ang;
 431
 432     dc->point1[dc->npoints] = brush + del_left;
 433     dc->point2[dc->npoints] = brush - del_right;
 434
 435     dc->del = 0.5*(del_left + del_right);
 436
 437     dc->npoints++;
 438 }
 439
 440 void
 441 sp_erc_update_toolbox (SPDesktop *desktop, const gchar *id, double value)
 442 {
 443     desktop->setToolboxAdjustmentValue (id, value);
 444 }
 445
 446 static void
 447 eraser_cancel(SPEraserContext *dc)
 448 {
 449     SPDesktop *desktop = SP_EVENT_CONTEXT(dc)->desktop;
 450     dc->dragging = FALSE;
 451     dc->is_drawing = false;
 452     sp_canvas_item_ungrab(SP_CANVAS_ITEM(desktop->acetate), 0);
 453             /* Remove all temporary line segments */
 454             while (dc->segments) {
 455                 gtk_object_destroy(GTK_OBJECT(dc->segments->data));
 456                 dc->segments = g_slist_remove(dc->segments, dc->segments->data);
 457             }
 458             /* reset accumulated curve */
 459             dc->accumulated->reset();
 460             clear_current(dc);
 461             if (dc->repr) {
 462                 dc->repr = NULL;
 463             }
 464 }
 465
 466
 467 gint
 468 sp_eraser_context_root_handler(SPEventContext *event_context,
 469                                   GdkEvent *event)
 470 {
 471     SPEraserContext *dc = SP_ERASER_CONTEXT(event_context);
 472     SPDesktop *desktop = event_context->desktop;
 473
 474     gint ret = FALSE;
 475
 476     switch (event->type) {
 477         case GDK_BUTTON_PRESS:
 478             if (event->button.button == 1 && !event_context->space_panning) {
 479
 480                 if (Inkscape::have_viable_layer(desktop, dc->_message_context) == false) {
 481                     return TRUE;
 482                 }
 483
 484                 Geom::Point const button_w(event->button.x,
 485                                          event->button.y);
 486                 Geom::Point const button_dt(desktop->w2d(button_w));
 487                 sp_eraser_reset(dc, button_dt);
 488                 sp_eraser_extinput(dc, event);
 489                 sp_eraser_apply(dc, button_dt);
 490                 dc->accumulated->reset();
 491                 if (dc->repr) {
 492                     dc->repr = NULL;
 493                 }
 494
 495                 Inkscape::Rubberband::get(desktop)->start(desktop, button_dt);
 496                 Inkscape::Rubberband::get(desktop)->setMode(RUBBERBAND_MODE_TOUCHPATH);
 497
 498                 /* initialize first point */
 499                 dc->npoints = 0;
 500
 501                 sp_canvas_item_grab(SP_CANVAS_ITEM(desktop->acetate),
 502                                     ( GDK_KEY_PRESS_MASK |
 503                                       GDK_BUTTON_RELEASE_MASK |
 504                                       GDK_POINTER_MOTION_MASK |
 505                                       GDK_BUTTON_PRESS_MASK ),
 506                                     NULL,
 507                                     event->button.time);
 508
 509                 ret = TRUE;
 510
 511                 sp_canvas_force_full_redraw_after_interruptions(desktop->canvas, 3);
 512                 dc->is_drawing = true;
 513             }
 514             break;
 515         case GDK_MOTION_NOTIFY:
 516         {
 517             Geom::Point const motion_w(event->motion.x,
 518                                      event->motion.y);
 519             Geom::Point motion_dt(desktop->w2d(motion_w));
 520             sp_eraser_extinput(dc, event);
 521
 522             dc->_message_context->clear();
 523
 524             if ( dc->is_drawing && (event->motion.state & GDK_BUTTON1_MASK) && !event_context->space_panning) {
 525                 dc->dragging = TRUE;
 526
 527                 dc->_message_context->set(Inkscape::NORMAL_MESSAGE, _("<b>Drawing</b> an eraser stroke"));
 528
 529                 if (!sp_eraser_apply(dc, motion_dt)) {
 530                     ret = TRUE;
 531                     break;
 532                 }
 533
 534                 if ( dc->cur != dc->last ) {
 535                     sp_eraser_brush(dc);
 536                     g_assert( dc->npoints > 0 );
 537                     fit_and_split(dc, FALSE);
 538                 }
 539                 ret = TRUE;
 540             }
 541             Inkscape::Rubberband::get(desktop)->move(motion_dt);
 542         }
 543         break;
 544
 545
 546     case GDK_BUTTON_RELEASE:
 547     {
 548         Geom::Point const motion_w(event->button.x, event->button.y);
 549         Geom::Point const motion_dt(desktop->w2d(motion_w));
 550
 551         sp_canvas_item_ungrab(SP_CANVAS_ITEM(desktop->acetate), event->button.time);
 552         sp_canvas_end_forced_full_redraws(desktop->canvas);
 553         dc->is_drawing = false;
 554
 555         if (dc->dragging && event->button.button == 1 && !event_context->space_panning) {
 556             dc->dragging = FALSE;
 557
 558             sp_eraser_apply(dc, motion_dt);
 559
 560             /* Remove all temporary line segments */
 561             while (dc->segments) {
 562                 gtk_object_destroy(GTK_OBJECT(dc->segments->data));
 563                 dc->segments = g_slist_remove(dc->segments, dc->segments->data);
 564             }
 565
 566             /* Create object */
 567             fit_and_split(dc, TRUE);
 568             accumulate_eraser(dc);
 569             set_to_accumulated(dc); // performs document_done
 570
 571             /* reset accumulated curve */
 572             dc->accumulated->reset();
 573
 574             clear_current(dc);
 575             if (dc->repr) {
 576                 dc->repr = NULL;
 577             }
 578
 579             Inkscape::Rubberband::get(desktop)->stop();
 580             dc->_message_context->clear();
 581             ret = TRUE;
 582         }
 583         break;
 584     }
 585
 586     case GDK_KEY_PRESS:
 587         switch (get_group0_keyval (&event->key)) {
 588         case GDK_Up:
 589         case GDK_KP_Up:
 590             if (!MOD__CTRL_ONLY) {
 591                 dc->angle += 5.0;
 592                 if (dc->angle > 90.0)
 593                     dc->angle = 90.0;
 594                 sp_erc_update_toolbox (desktop, "eraser-angle", dc->angle);
 595                 ret = TRUE;
 596             }
 597             break;
 598         case GDK_Down:
 599         case GDK_KP_Down:
 600             if (!MOD__CTRL_ONLY) {
 601                 dc->angle -= 5.0;
 602                 if (dc->angle < -90.0)
 603                     dc->angle = -90.0;
 604                 sp_erc_update_toolbox (desktop, "eraser-angle", dc->angle);
 605                 ret = TRUE;
 606             }
 607             break;
 608         case GDK_Right:
 609         case GDK_KP_Right:
 610             if (!MOD__CTRL_ONLY) {
 611                 dc->width += 0.01;
 612                 if (dc->width > 1.0)
 613                     dc->width = 1.0;
 614                 sp_erc_update_toolbox (desktop, "altx-eraser", dc->width * 100); // the same spinbutton is for alt+x
 615                 ret = TRUE;
 616             }
 617             break;
 618         case GDK_Left:
 619         case GDK_KP_Left:
 620             if (!MOD__CTRL_ONLY) {
 621                 dc->width -= 0.01;
 622                 if (dc->width < 0.01)
 623                     dc->width = 0.01;
 624                 sp_erc_update_toolbox (desktop, "altx-eraser", dc->width * 100);
 625                 ret = TRUE;
 626             }
 627             break;
 628         case GDK_Home:
 629         case GDK_KP_Home:
 630             dc->width = 0.01;
 631             sp_erc_update_toolbox (desktop, "altx-eraser", dc->width * 100);
 632             ret = TRUE;
 633             break;
 634         case GDK_End:
 635         case GDK_KP_End:
 636             dc->width = 1.0;
 637             sp_erc_update_toolbox (desktop, "altx-eraser", dc->width * 100);
 638             ret = TRUE;
 639             break;
 640         case GDK_x:
 641         case GDK_X:
 642             if (MOD__ALT_ONLY) {
 643                 desktop->setToolboxFocusTo ("altx-eraser");
 644                 ret = TRUE;
 645             }
 646             break;
 647         case GDK_Escape:
 648             Inkscape::Rubberband::get(desktop)->stop();
 649             if (dc->is_drawing) {
 650                 // if drawing, cancel, otherwise pass it up for deselecting
 651                 eraser_cancel (dc);
 652                 ret = TRUE;
 653             }
 654             break;
 655         case GDK_z:
 656         case GDK_Z:
 657             if (MOD__CTRL_ONLY && dc->is_drawing) {
 658                 // if drawing, cancel, otherwise pass it up for undo
 659                 eraser_cancel (dc);
 660                 ret = TRUE;
 661             }
 662             break;
 663         default:
 664             break;
 665         }
 666         break;
 667
 668     case GDK_KEY_RELEASE:
 669         switch (get_group0_keyval(&event->key)) {
 670             case GDK_Control_L:
 671             case GDK_Control_R:
 672                 dc->_message_context->clear();
 673                 break;
 674             default:
 675                 break;
 676         }
 677
 678     default:
 679         break;
 680     }
 681
 682     if (!ret) {
 683         if (((SPEventContextClass *) eraser_parent_class)->root_handler) {
 684             ret = ((SPEventContextClass *) eraser_parent_class)->root_handler(event_context, event);
 685         }
 686     }
 687
 688     return ret;
 689 }
 690
 691
 692 static void
 693 clear_current(SPEraserContext *dc)
 694 {
 695     // reset bpath
 696     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(dc->currentshape), NULL);
 697
 698     // reset curve
 699     dc->currentcurve->reset();
 700     dc->cal1->reset();
 701     dc->cal2->reset();
 702
 703     // reset points
 704     dc->npoints = 0;
 705 }
 706
 707 static void
 708 set_to_accumulated(SPEraserContext *dc)
 709 {
 710     SPDesktop *desktop = SP_EVENT_CONTEXT(dc)->desktop;
 711     bool workDone = false;
 712
 713     if (!dc->accumulated->is_empty()) {
 714         if (!dc->repr) {
 715             /* Create object */
 716             Inkscape::XML::Document *xml_doc = sp_document_repr_doc(desktop->doc());
 717             Inkscape::XML::Node *repr = xml_doc->createElement("svg:path");
 718
 719             /* Set style */
 720             sp_desktop_apply_style_tool (desktop, repr, "/tools/eraser", false);
 721
 722             dc->repr = repr;
 723
 724             SPItem *item=SP_ITEM(desktop->currentLayer()->appendChildRepr(dc->repr));
 725             Inkscape::GC::release(dc->repr);
 726             item->transform = sp_item_i2doc_affine(SP_ITEM(desktop->currentLayer())).inverse();
 727             item->updateRepr();
 728         }
 729         Geom::PathVector pathv = dc->accumulated->get_pathvector() * desktop->dt2doc();
 730         gchar *str = sp_svg_write_path(pathv);
 731         g_assert( str != NULL );
 732         dc->repr->setAttribute("d", str);
 733         g_free(str);
 734
 735         if ( dc->repr ) {
 736             bool wasSelection = false;
 737             Inkscape::Selection *selection = sp_desktop_selection(desktop);
 738             Inkscape::Preferences *prefs = Inkscape::Preferences::get();
 739
 740             gint eraserMode = prefs->getBool("/tools/eraser/mode") ? 1 : 0;
 741             Inkscape::XML::Document *xml_doc = sp_document_repr_doc(desktop->doc());
 742
 743             SPItem* acid = SP_ITEM(desktop->doc()->getObjectByRepr(dc->repr));
 744             Geom::OptRect eraserBbox = acid->getBounds(Geom::identity());
 745             Geom::Rect bounds = (*eraserBbox) * desktop->doc2dt();
 746             std::vector<SPItem*> remainingItems;
 747             GSList* toWorkOn = 0;
 748             if (selection->isEmpty()) {
 749                 if ( eraserMode ) {
 750                     toWorkOn = sp_document_partial_items_in_box(sp_desktop_document(desktop), desktop->dkey, bounds);
 751                 } else {
 752                     Inkscape::Rubberband::Rubberband *r = Inkscape::Rubberband::get(desktop);
 753                     toWorkOn = sp_document_items_at_points(sp_desktop_document(desktop), desktop->dkey, r->getPoints());
 754                 }
 755                 toWorkOn = g_slist_remove( toWorkOn, acid );
 756             } else {
 757                 toWorkOn = g_slist_copy(const_cast<GSList*>(selection->itemList()));
 758                 wasSelection = true;
 759             }
 760
 761             if ( g_slist_length(toWorkOn) > 0 ) {
 762                 if ( eraserMode ) {
 763                     for (GSList *i = toWorkOn ; i ; i = i->next ) {
 764                         SPItem *item = SP_ITEM(i->data);
 765                         if ( eraserMode ) {
 766                             Geom::OptRect bbox = item->getBounds(Geom::identity());
 767                             if (bbox && bbox->intersects(*eraserBbox)) {
 768                                 Inkscape::XML::Node* dup = dc->repr->duplicate(xml_doc);
 769                                 dc->repr->parent()->appendChild(dup);
 770                                 Inkscape::GC::release(dup); // parent takes over
 771
 772                                 selection->set(item);
 773                                 selection->add(dup);
 774                                 sp_selected_path_diff_skip_undo(desktop);
 775                                 workDone = true; // TODO set this only if something was cut.
 776                                 if ( !selection->isEmpty() ) {
 777                                     // If the item was not completely erased, track the new remainder.
 778                                     GSList *nowSel = g_slist_copy(const_cast<GSList *>(selection->itemList()));
 779                                     for (GSList const *i2 = nowSel ; i2 ; i2 = i2->next ) {
 780                                         remainingItems.push_back(SP_ITEM(i2->data));
 781                                     }
 782                                     g_slist_free(nowSel);
 783                                 }
 784                             } else {
 785                                 remainingItems.push_back(item);
 786                             }
 787                         }
 788                     }
 789                 } else {
 790                     for (GSList *i = toWorkOn ; i ; i = i->next ) {
 791                         sp_object_ref( SP_ITEM(i->data), 0 );
 792                     }
 793                     for (GSList *i = toWorkOn ; i ; i = i->next ) {
 794                         SPItem *item = SP_ITEM(i->data);
 795                         item->deleteObject(true);
 796                         sp_object_unref(item);
 797                         workDone = true;
 798                     }
 799                 }
 800
 801                 g_slist_free(toWorkOn);
 802
 803                 if ( !eraserMode ) {
 804                     //sp_selection_delete(desktop);
 805                     remainingItems.clear();
 806                 }
 807
 808                 selection->clear();
 809                 if ( wasSelection ) {
 810                     if ( !remainingItems.empty() ) {
 811                         selection->add(remainingItems.begin(), remainingItems.end());
 812                     }
 813                 }
 814             }
 815
 816             // Remove the eraser stroke itself:
 817             sp_repr_unparent( dc->repr );
 818             dc->repr = 0;
 819         }
 820     } else {
 821         if (dc->repr) {
 822             sp_repr_unparent(dc->repr);
 823             dc->repr = 0;
 824         }
 825     }
 826
 827
 828     if ( workDone ) {
 829         sp_document_done(sp_desktop_document(desktop), SP_VERB_CONTEXT_ERASER,
 830                          _("Draw eraser stroke"));
 831     } else {
 832         sp_document_cancel(sp_desktop_document(desktop));
 833     }
 834 }
 835
 836 static void
 837 add_cap(SPCurve *curve,
 838         Geom::Point const &pre, Geom::Point const &from,
 839         Geom::Point const &to, Geom::Point const &post,
 840         double rounding)
 841 {
 842     Geom::Point vel = rounding * Geom::rot90( to - from ) / sqrt(2.0);
 843     double mag = Geom::L2(vel);
 844
 845     Geom::Point v_in = from - pre;
 846     double mag_in = Geom::L2(v_in);
 847     if ( mag_in > ERASER_EPSILON ) {
 848         v_in = mag * v_in / mag_in;
 849     } else {
 850         v_in = Geom::Point(0, 0);
 851     }
 852
 853     Geom::Point v_out = to - post;
 854     double mag_out = Geom::L2(v_out);
 855     if ( mag_out > ERASER_EPSILON ) {
 856         v_out = mag * v_out / mag_out;
 857     } else {
 858         v_out = Geom::Point(0, 0);
 859     }
 860
 861     if ( Geom::L2(v_in) > ERASER_EPSILON || Geom::L2(v_out) > ERASER_EPSILON ) {
 862         curve->curveto(from + v_in, to + v_out, to);
 863     }
 864 }
 865
 866 static void
 867 accumulate_eraser(SPEraserContext *dc)
 868 {
 869     if ( !dc->cal1->is_empty() && !dc->cal2->is_empty() ) {
 870         dc->accumulated->reset(); /*  Is this required ?? */
 871         SPCurve *rev_cal2 = dc->cal2->create_reverse();
 872
 873         g_assert(dc->cal1->get_segment_count() > 0);
 874         g_assert(rev_cal2->get_segment_count() > 0);
 875         g_assert( ! dc->cal1->first_path()->closed() );
 876         g_assert( ! rev_cal2->first_path()->closed() );
 877
 878         Geom::CubicBezier const * dc_cal1_firstseg  = dynamic_cast<Geom::CubicBezier const *>( dc->cal1->first_segment() );
 879         Geom::CubicBezier const * rev_cal2_firstseg = dynamic_cast<Geom::CubicBezier const *>( rev_cal2->first_segment() );
 880         Geom::CubicBezier const * dc_cal1_lastseg   = dynamic_cast<Geom::CubicBezier const *>( dc->cal1->last_segment() );
 881         Geom::CubicBezier const * rev_cal2_lastseg  = dynamic_cast<Geom::CubicBezier const *>( rev_cal2->last_segment() );
 882         g_assert( dc_cal1_firstseg );
 883         g_assert( rev_cal2_firstseg );
 884         g_assert( dc_cal1_lastseg );
 885         g_assert( rev_cal2_lastseg );
 886
 887         dc->accumulated->append(dc->cal1, FALSE);
 888
 889         add_cap(dc->accumulated, (*dc_cal1_lastseg)[2], (*dc_cal1_lastseg)[3], (*rev_cal2_firstseg)[0], (*rev_cal2_firstseg)[1], dc->cap_rounding);
 890
 891         dc->accumulated->append(rev_cal2, TRUE);
 892
 893         add_cap(dc->accumulated, (*rev_cal2_lastseg)[2], (*rev_cal2_lastseg)[3], (*dc_cal1_firstseg)[0], (*dc_cal1_firstseg)[1], dc->cap_rounding);
 894
 895         dc->accumulated->closepath();
 896
 897         rev_cal2->unref();
 898
 899         dc->cal1->reset();
 900         dc->cal2->reset();
 901     }
 902 }
 903
 904 static double square(double const x)
 905 {
 906     return x * x;
 907 }
 908
 909 static void
 910 fit_and_split(SPEraserContext *dc, gboolean release)
 911 {
 912     SPDesktop *desktop = SP_EVENT_CONTEXT(dc)->desktop;
 913
 914     double const tolerance_sq = square( desktop->w2d().descrim() * TOLERANCE_ERASER );
 915
 916 #ifdef ERASER_VERBOSE
 917     g_print("[F&S:R=%c]", release?'T':'F');
 918 #endif
 919
 920     if (!( dc->npoints > 0 && dc->npoints < SAMPLING_SIZE ))
 921         return; // just clicked
 922
 923     if ( dc->npoints == SAMPLING_SIZE - 1 || release ) {
 924 #define BEZIER_SIZE       4
 925 #define BEZIER_MAX_BEZIERS  8
 926 #define BEZIER_MAX_LENGTH ( BEZIER_SIZE * BEZIER_MAX_BEZIERS )
 927
 928 #ifdef ERASER_VERBOSE
 929         g_print("[F&S:#] dc->npoints:%d, release:%s\n",
 930                 dc->npoints, release ? "TRUE" : "FALSE");
 931 #endif
 932
 933         /* Current eraser */
 934         if ( dc->cal1->is_empty() || dc->cal2->is_empty() ) {
 935             /* dc->npoints > 0 */
 936             /* g_print("erasers(1|2) reset\n"); */
 937             dc->cal1->reset();
 938             dc->cal2->reset();
 939
 940             dc->cal1->moveto(dc->point1[0]);
 941             dc->cal2->moveto(dc->point2[0]);
 942         }
 943
 944         Geom::Point b1[BEZIER_MAX_LENGTH];
 945         gint const nb1 = Geom::bezier_fit_cubic_r(b1, dc->point1, dc->npoints,
 946                                                tolerance_sq, BEZIER_MAX_BEZIERS);
 947         g_assert( nb1 * BEZIER_SIZE <= gint(G_N_ELEMENTS(b1)) );
 948
 949         Geom::Point b2[BEZIER_MAX_LENGTH];
 950         gint const nb2 = Geom::bezier_fit_cubic_r(b2, dc->point2, dc->npoints,
 951                                                tolerance_sq, BEZIER_MAX_BEZIERS);
 952         g_assert( nb2 * BEZIER_SIZE <= gint(G_N_ELEMENTS(b2)) );
 953
 954         if ( nb1 != -1 && nb2 != -1 ) {
 955             /* Fit and draw and reset state */
 956 #ifdef ERASER_VERBOSE
 957             g_print("nb1:%d nb2:%d\n", nb1, nb2);
 958 #endif
 959             /* CanvasShape */
 960             if (! release) {
 961                 dc->currentcurve->reset();
 962                 dc->currentcurve->moveto(b1[0]);
 963                 for (Geom::Point *bp1 = b1; bp1 < b1 + BEZIER_SIZE * nb1; bp1 += BEZIER_SIZE) {
 964                     dc->currentcurve->curveto(bp1[1],
 965                                      bp1[2], bp1[3]);
 966                 }
 967                 dc->currentcurve->lineto(b2[BEZIER_SIZE*(nb2-1) + 3]);
 968                 for (Geom::Point *bp2 = b2 + BEZIER_SIZE * ( nb2 - 1 ); bp2 >= b2; bp2 -= BEZIER_SIZE) {
 969                     dc->currentcurve->curveto(bp2[2], bp2[1], bp2[0]);
 970                 }
 971                 // FIXME: dc->segments is always NULL at this point??
 972                 if (!dc->segments) { // first segment
 973                     add_cap(dc->currentcurve, b2[1], b2[0], b1[0], b1[1], dc->cap_rounding);
 974                 }
 975                 dc->currentcurve->closepath();
 976                 sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(dc->currentshape), dc->currentcurve);
 977             }
 978
 979             /* Current eraser */
 980             for (Geom::Point *bp1 = b1; bp1 < b1 + BEZIER_SIZE * nb1; bp1 += BEZIER_SIZE) {
 981                 dc->cal1->curveto(bp1[1], bp1[2], bp1[3]);
 982             }
 983             for (Geom::Point *bp2 = b2; bp2 < b2 + BEZIER_SIZE * nb2; bp2 += BEZIER_SIZE) {
 984                 dc->cal2->curveto(bp2[1], bp2[2], bp2[3]);
 985             }
 986         } else {
 987             /* fixme: ??? */
 988 #ifdef ERASER_VERBOSE
 989             g_print("[fit_and_split] failed to fit-cubic.\n");
 990 #endif
 991             draw_temporary_box(dc);
 992
 993             for (gint i = 1; i < dc->npoints; i++) {
 994                 dc->cal1->lineto(dc->point1[i]);
 995             }
 996             for (gint i = 1; i < dc->npoints; i++) {
 997                 dc->cal2->lineto(dc->point2[i]);
 998             }
 999         }
1000
1001         /* Fit and draw and copy last point */
1002 #ifdef ERASER_VERBOSE
1003         g_print("[%d]Yup\n", dc->npoints);
1004 #endif
1005         if (!release) {
1006             Inkscape::Preferences *prefs = Inkscape::Preferences::get();
1007             gint eraserMode = prefs->getBool("/tools/eraser/mode") ? 1 : 0;
1008             g_assert(!dc->currentcurve->is_empty());
1009
1010             SPCanvasItem *cbp = sp_canvas_item_new(sp_desktop_sketch(desktop),
1011                                                    SP_TYPE_CANVAS_BPATH,
1012                                                    NULL);
1013             SPCurve *curve = dc->currentcurve->copy();
1014             sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH (cbp), curve);
1015             curve->unref();
1016
1017             guint32 fillColor = sp_desktop_get_color_tool (desktop, "/tools/eraser", true);
1018             //guint32 strokeColor = sp_desktop_get_color_tool (desktop, "/tools/eraser", false);
1019             double opacity = sp_desktop_get_master_opacity_tool (desktop, "/tools/eraser");
1020             double fillOpacity = sp_desktop_get_opacity_tool (desktop, "/tools/eraser", true);
1021             //double strokeOpacity = sp_desktop_get_opacity_tool (desktop, "/tools/eraser", false);
1022             sp_canvas_bpath_set_fill(SP_CANVAS_BPATH(cbp), ((fillColor & 0xffffff00) | SP_COLOR_F_TO_U(opacity*fillOpacity)), SP_WIND_RULE_EVENODD);
1023             //on second thougtht don't do stroke yet because we don't have stoke-width yet and because stoke appears between segments while drawing
1024             //sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(cbp), ((strokeColor & 0xffffff00) | SP_COLOR_F_TO_U(opacity*strokeOpacity)), 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
1025             sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(cbp), 0x00000000, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
1026             /* fixme: Cannot we cascade it to root more clearly? */
1027             g_signal_connect(G_OBJECT(cbp), "event", G_CALLBACK(sp_desktop_root_handler), desktop);
1028
1029             dc->segments = g_slist_prepend(dc->segments, cbp);
1030
1031             if ( !eraserMode ) {
1032                 sp_canvas_item_hide(cbp);
1033                 sp_canvas_item_hide(dc->currentshape);
1034             }
1035         }
1036
1037         dc->point1[0] = dc->point1[dc->npoints - 1];
1038         dc->point2[0] = dc->point2[dc->npoints - 1];
1039         dc->npoints = 1;
1040     } else {
1041         draw_temporary_box(dc);
1042     }
1043 }
1044
1045 static void
1046 draw_temporary_box(SPEraserContext *dc)
1047 {
1048     dc->currentcurve->reset();
1049
1050     dc->currentcurve->moveto(dc->point1[dc->npoints-1]);
1051     for (gint i = dc->npoints-2; i >= 0; i--) {
1052         dc->currentcurve->lineto(dc->point1[i]);
1053     }
1054     for (gint i = 0; i < dc->npoints; i++) {
1055         dc->currentcurve->lineto(dc->point2[i]);
1056     }
1057     if (dc->npoints >= 2) {
1058         add_cap(dc->currentcurve, dc->point2[dc->npoints-2], dc->point2[dc->npoints-1], dc->point1[dc->npoints-1], dc->point1[dc->npoints-2], dc->cap_rounding);
1059     }
1060
1061     dc->currentcurve->closepath();
1062     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(dc->currentshape), dc->currentcurve);
1063 }
1064
1065 /*
1066   Local Variables:
1067   mode:c++
1068   c-file-style:"stroustrup"
1069   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
1070   indent-tabs-mode:nil
1071   fill-column:99
1072   End:
1073 */
1074 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :