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  *   Abhishek Sharma
  11  *
  12  * The original dynadraw code:
  13  *   Paul Haeberli <paul@sgi.com>
  14  *
  15  * Copyright (C) 1998 The Free Software Foundation
  16  * Copyright (C) 1999-2005 authors
  17  * Copyright (C) 2001-2002 Ximian, Inc.
  18  * Copyright (C) 2005-2007 bulia byak
  19  * Copyright (C) 2006 MenTaLguY
  20  * Copyright (C) 2008 Jon A. Cruz
  21  *
  22  * Released under GNU GPL, read the file 'COPYING' for more information
  23  */
  24
  25 #define noERASER_VERBOSE
  26
  27 #include "config.h"
  28
  29 #include <gtk/gtk.h>
  30 #include <gdk/gdkkeysyms.h>
  31 #include <glibmm/i18n.h>
  32 #include <string>
  33 #include <cstring>
  34 #include <numeric>
  35
  36 #include "svg/svg.h"
  37 #include "display/sp-canvas.h"
  38 #include "display/canvas-bpath.h"
  39 #include <2geom/bezier-utils.h>
  40
  41 #include <glib/gmem.h>
  42 #include "macros.h"
  43 #include "document.h"
  44 #include "selection.h"
  45 #include "desktop.h"
  46 #include "desktop-events.h"
  47 #include "desktop-handles.h"
  48 #include "desktop-style.h"
  49 #include "message-context.h"
  50 #include "preferences.h"
  51 #include "pixmaps/cursor-eraser.xpm"
  52 #include "xml/repr.h"
  53 #include "context-fns.h"
  54 #include "sp-item.h"
  55 #include "color.h"
  56 #include "rubberband.h"
  57 #include "splivarot.h"
  58 #include "sp-item-group.h"
  59 #include "sp-shape.h"
  60 #include "sp-path.h"
  61 #include "sp-text.h"
  62 #include "display/canvas-bpath.h"
  63 #include "display/canvas-arena.h"
  64 #include "livarot/Shape.h"
  65 #include <2geom/isnan.h>
  66 #include <2geom/pathvector.h>
  67
  68 #include "eraser-context.h"
  69
  70 using Inkscape::DocumentUndo;
  71
  72 #define ERC_RED_RGBA 0xff0000ff
  73
  74 #define TOLERANCE_ERASER 0.1
  75
  76 #define ERASER_EPSILON 0.5e-6
  77 #define ERASER_EPSILON_START 0.5e-2
  78 #define ERASER_VEL_START 1e-5
  79
  80 #define DRAG_MIN 0.0
  81 #define DRAG_DEFAULT 1.0
  82 #define DRAG_MAX 1.0
  83
  84
  85 static void sp_eraser_context_class_init(SPEraserContextClass *klass);
  86 static void sp_eraser_context_init(SPEraserContext *erc);
  87 static void sp_eraser_context_dispose(GObject *object);
  88
  89 static void sp_eraser_context_setup(SPEventContext *ec);
  90 static void sp_eraser_context_set(SPEventContext *ec, Inkscape::Preferences::Entry *val);
  91 static gint sp_eraser_context_root_handler(SPEventContext *ec, GdkEvent *event);
  92
  93 static void clear_current(SPEraserContext *dc);
  94 static void set_to_accumulated(SPEraserContext *dc);
  95 static void add_cap(SPCurve *curve, Geom::Point const &pre, Geom::Point const &from, Geom::Point const &to, Geom::Point const &post, double rounding);
  96 static void accumulate_eraser(SPEraserContext *dc);
  97
  98 static void fit_and_split(SPEraserContext *erc, gboolean release);
  99
 100 static void sp_eraser_reset(SPEraserContext *erc, Geom::Point p);
 101 static Geom::Point sp_eraser_get_npoint(SPEraserContext const *erc, Geom::Point v);
 102 static Geom::Point sp_eraser_get_vpoint(SPEraserContext const *erc, Geom::Point n);
 103 static void draw_temporary_box(SPEraserContext *dc);
 104
 105
 106 static SPEventContextClass *eraser_parent_class = 0;
 107
 108 GType sp_eraser_context_get_type(void)
 109 {
 110     static GType type = 0;
 111     if (!type) {
 112         GTypeInfo info = {
 113             sizeof(SPEraserContextClass),
 114             0, // base_init
 115             0, // base_finalize
 116             (GClassInitFunc)sp_eraser_context_class_init,
 117             0, // class_finalize
 118             0, // class_data
 119             sizeof(SPEraserContext),
 120             0, // n_preallocs
 121             (GInstanceInitFunc)sp_eraser_context_init,
 122             0 // value_table
 123         };
 124         type = g_type_register_static(SP_TYPE_COMMON_CONTEXT, "SPEraserContext", &info, static_cast<GTypeFlags>(0));
 125     }
 126     return type;
 127 }
 128
 129 static void
 130 sp_eraser_context_class_init(SPEraserContextClass *klass)
 131 {
 132     GObjectClass *object_class = (GObjectClass *) klass;
 133     SPEventContextClass *event_context_class = (SPEventContextClass *) klass;
 134
 135     eraser_parent_class = (SPEventContextClass*)g_type_class_peek_parent(klass);
 136
 137     object_class->dispose = sp_eraser_context_dispose;
 138
 139     event_context_class->setup = sp_eraser_context_setup;
 140     event_context_class->set = sp_eraser_context_set;
 141     event_context_class->root_handler = sp_eraser_context_root_handler;
 142 }
 143
 144 static void
 145 sp_eraser_context_init(SPEraserContext *erc)
 146 {
 147     erc->cursor_shape = cursor_eraser_xpm;
 148     erc->hot_x = 4;
 149     erc->hot_y = 4;
 150 }
 151
 152 static void
 153 sp_eraser_context_dispose(GObject *object)
 154 {
 155     //SPEraserContext *erc = SP_ERASER_CONTEXT(object);
 156
 157     G_OBJECT_CLASS(eraser_parent_class)->dispose(object);
 158 }
 159
 160 static void
 161 sp_eraser_context_setup(SPEventContext *ec)
 162 {
 163     SPEraserContext *erc = SP_ERASER_CONTEXT(ec);
 164     SPDesktop *desktop = ec->desktop;
 165
 166     if (((SPEventContextClass *) eraser_parent_class)->setup)
 167         ((SPEventContextClass *) eraser_parent_class)->setup(ec);
 168
 169     erc->accumulated = new SPCurve();
 170     erc->currentcurve = new SPCurve();
 171
 172     erc->cal1 = new SPCurve();
 173     erc->cal2 = new SPCurve();
 174
 175     erc->currentshape = sp_canvas_item_new(sp_desktop_sketch(desktop), SP_TYPE_CANVAS_BPATH, NULL);
 176     sp_canvas_bpath_set_fill(SP_CANVAS_BPATH(erc->currentshape), ERC_RED_RGBA, SP_WIND_RULE_EVENODD);
 177     sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(erc->currentshape), 0x00000000, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 178     /* fixme: Cannot we cascade it to root more clearly? */
 179     g_signal_connect(G_OBJECT(erc->currentshape), "event", G_CALLBACK(sp_desktop_root_handler), desktop);
 180
 181 /*
 182 static ProfileFloatElement f_profile[PROFILE_FLOAT_SIZE] = {
 183     {"mass",0.02, 0.0, 1.0},
 184     {"wiggle",0.0, 0.0, 1.0},
 185     {"angle",30.0, -90.0, 90.0},
 186     {"thinning",0.1, -1.0, 1.0},
 187     {"tremor",0.0, 0.0, 1.0},
 188     {"flatness",0.9, 0.0, 1.0},
 189     {"cap_rounding",0.0, 0.0, 5.0}
 190 };
 191 */
 192
 193     sp_event_context_read(ec, "mass");
 194     sp_event_context_read(ec, "wiggle");
 195     sp_event_context_read(ec, "angle");
 196     sp_event_context_read(ec, "width");
 197     sp_event_context_read(ec, "thinning");
 198     sp_event_context_read(ec, "tremor");
 199     sp_event_context_read(ec, "flatness");
 200     sp_event_context_read(ec, "tracebackground");
 201     sp_event_context_read(ec, "usepressure");
 202     sp_event_context_read(ec, "usetilt");
 203     sp_event_context_read(ec, "abs_width");
 204     sp_event_context_read(ec, "cap_rounding");
 205
 206     erc->is_drawing = false;
 207
 208     erc->_message_context = new Inkscape::MessageContext(desktop->messageStack());
 209
 210     Inkscape::Preferences *prefs = Inkscape::Preferences::get();
 211     if (prefs->getBool("/tools/eraser/selcue", 0) != 0) {
 212         ec->enableSelectionCue();
 213     }
 214 // TODO temp force:
 215     ec->enableSelectionCue();
 216
 217 }
 218
 219 static void
 220 sp_eraser_context_set(SPEventContext *ec, Inkscape::Preferences::Entry *val)
 221 {
 222     //pass on up to parent class to handle common attributes.
 223     if ( eraser_parent_class->set ) {
 224         eraser_parent_class->set(ec, val);
 225     }
 226 }
 227
 228 static double
 229 flerp(double f0, double f1, double p)
 230 {
 231     return f0 + ( f1 - f0 ) * p;
 232 }
 233
 234 /* Get normalized point */
 235 static Geom::Point
 236 sp_eraser_get_npoint(SPEraserContext const *dc, Geom::Point v)
 237 {
 238     Geom::Rect drect = SP_EVENT_CONTEXT(dc)->desktop->get_display_area();
 239     double const max = MAX ( drect.dimensions()[Geom::X], drect.dimensions()[Geom::Y] );
 240     return Geom::Point(( v[Geom::X] - drect.min()[Geom::X] ) / max,  ( v[Geom::Y] - drect.min()[Geom::Y] ) / max);
 241 }
 242
 243 /* Get view point */
 244 static Geom::Point
 245 sp_eraser_get_vpoint(SPEraserContext const *dc, Geom::Point n)
 246 {
 247     Geom::Rect drect = SP_EVENT_CONTEXT(dc)->desktop->get_display_area();
 248     double const max = MAX ( drect.dimensions()[Geom::X], drect.dimensions()[Geom::Y] );
 249     return Geom::Point(n[Geom::X] * max + drect.min()[Geom::X], n[Geom::Y] * max + drect.min()[Geom::Y]);
 250 }
 251
 252 static void
 253 sp_eraser_reset(SPEraserContext *dc, Geom::Point p)
 254 {
 255     dc->last = dc->cur = sp_eraser_get_npoint(dc, p);
 256     dc->vel = Geom::Point(0,0);
 257     dc->vel_max = 0;
 258     dc->acc = Geom::Point(0,0);
 259     dc->ang = Geom::Point(0,0);
 260     dc->del = Geom::Point(0,0);
 261 }
 262
 263 static void
 264 sp_eraser_extinput(SPEraserContext *dc, GdkEvent *event)
 265 {
 266     if (gdk_event_get_axis (event, GDK_AXIS_PRESSURE, &dc->pressure))
 267         dc->pressure = CLAMP (dc->pressure, ERC_MIN_PRESSURE, ERC_MAX_PRESSURE);
 268     else
 269         dc->pressure = ERC_DEFAULT_PRESSURE;
 270
 271     if (gdk_event_get_axis (event, GDK_AXIS_XTILT, &dc->xtilt))
 272         dc->xtilt = CLAMP (dc->xtilt, ERC_MIN_TILT, ERC_MAX_TILT);
 273     else
 274         dc->xtilt = ERC_DEFAULT_TILT;
 275
 276     if (gdk_event_get_axis (event, GDK_AXIS_YTILT, &dc->ytilt))
 277         dc->ytilt = CLAMP (dc->ytilt, ERC_MIN_TILT, ERC_MAX_TILT);
 278     else
 279         dc->ytilt = ERC_DEFAULT_TILT;
 280 }
 281
 282
 283 static gboolean
 284 sp_eraser_apply(SPEraserContext *dc, Geom::Point p)
 285 {
 286     Geom::Point n = sp_eraser_get_npoint(dc, p);
 287
 288     /* Calculate mass and drag */
 289     double const mass = flerp(1.0, 160.0, dc->mass);
 290     double const drag = flerp(0.0, 0.5, dc->drag * dc->drag);
 291
 292     /* Calculate force and acceleration */
 293     Geom::Point force = n - dc->cur;
 294
 295     // If force is below the absolute threshold ERASER_EPSILON,
 296     // or we haven't yet reached ERASER_VEL_START (i.e. at the beginning of stroke)
 297     // _and_ the force is below the (higher) ERASER_EPSILON_START threshold,
 298     // discard this move.
 299     // This prevents flips, blobs, and jerks caused by microscopic tremor of the tablet pen,
 300     // especially bothersome at the start of the stroke where we don't yet have the inertia to
 301     // smooth them out.
 302     if ( Geom::L2(force) < ERASER_EPSILON || (dc->vel_max < ERASER_VEL_START && Geom::L2(force) < ERASER_EPSILON_START)) {
 303         return FALSE;
 304     }
 305
 306     dc->acc = force / mass;
 307
 308     /* Calculate new velocity */
 309     dc->vel += dc->acc;
 310
 311     if (Geom::L2(dc->vel) > dc->vel_max)
 312         dc->vel_max = Geom::L2(dc->vel);
 313
 314     /* Calculate angle of drawing tool */
 315
 316     double a1;
 317     if (dc->usetilt) {
 318         // 1a. calculate nib angle from input device tilt:
 319         gdouble length = std::sqrt(dc->xtilt*dc->xtilt + dc->ytilt*dc->ytilt);;
 320
 321         if (length > 0) {
 322             Geom::Point ang1 = Geom::Point(dc->ytilt/length, dc->xtilt/length);
 323             a1 = atan2(ang1);
 324         }
 325         else
 326             a1 = 0.0;
 327     }
 328     else {
 329         // 1b. fixed dc->angle (absolutely flat nib):
 330         double const radians = ( (dc->angle - 90) / 180.0 ) * M_PI;
 331         Geom::Point ang1 = Geom::Point(-sin(radians),  cos(radians));
 332         a1 = atan2(ang1);
 333     }
 334
 335     // 2. perpendicular to dc->vel (absolutely non-flat nib):
 336     gdouble const mag_vel = Geom::L2(dc->vel);
 337     if ( mag_vel < ERASER_EPSILON ) {
 338         return FALSE;
 339     }
 340     Geom::Point ang2 = Geom::rot90(dc->vel) / mag_vel;
 341
 342     // 3. Average them using flatness parameter:
 343     // calculate angles
 344     double a2 = atan2(ang2);
 345     // flip a2 to force it to be in the same half-circle as a1
 346     bool flipped = false;
 347     if (fabs (a2-a1) > 0.5*M_PI) {
 348         a2 += M_PI;
 349         flipped = true;
 350     }
 351     // normalize a2
 352     if (a2 > M_PI)
 353         a2 -= 2*M_PI;
 354     if (a2 < -M_PI)
 355         a2 += 2*M_PI;
 356     // find the flatness-weighted bisector angle, unflip if a2 was flipped
 357     // FIXME: when dc->vel is oscillating around the fixed angle, the new_ang flips back and forth. How to avoid this?
 358     double new_ang = a1 + (1 - dc->flatness) * (a2 - a1) - (flipped? M_PI : 0);
 359
 360     // Try to detect a sudden flip when the new angle differs too much from the previous for the
 361     // current velocity; in that case discard this move
 362     double angle_delta = Geom::L2(Geom::Point (cos (new_ang), sin (new_ang)) - dc->ang);
 363     if ( angle_delta / Geom::L2(dc->vel) > 4000 ) {
 364         return FALSE;
 365     }
 366
 367     // convert to point
 368     dc->ang = Geom::Point (cos (new_ang), sin (new_ang));
 369
 370 //    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);
 371
 372     /* Apply drag */
 373     dc->vel *= 1.0 - drag;
 374
 375     /* Update position */
 376     dc->last = dc->cur;
 377     dc->cur += dc->vel;
 378
 379     return TRUE;
 380 }
 381
 382 static void
 383 sp_eraser_brush(SPEraserContext *dc)
 384 {
 385     g_assert( dc->npoints >= 0 && dc->npoints < SAMPLING_SIZE );
 386
 387     // How much velocity thins strokestyle
 388     double vel_thin = flerp (0, 160, dc->vel_thin);
 389
 390     // Influence of pressure on thickness
 391     double pressure_thick = (dc->usepressure ? dc->pressure : 1.0);
 392
 393     // get the real brush point, not the same as pointer (affected by hatch tracking and/or mass
 394     // drag)
 395     Geom::Point brush = sp_eraser_get_vpoint(dc, dc->cur);
 396     Geom::Point brush_w = SP_EVENT_CONTEXT(dc)->desktop->d2w(brush);
 397
 398     double trace_thick = 1;
 399
 400     double width = (pressure_thick * trace_thick - vel_thin * Geom::L2(dc->vel)) * dc->width;
 401
 402     double tremble_left = 0, tremble_right = 0;
 403     if (dc->tremor > 0) {
 404         // obtain two normally distributed random variables, using polar Box-Muller transform
 405         double x1, x2, w, y1, y2;
 406         do {
 407             x1 = 2.0 * g_random_double_range(0,1) - 1.0;
 408             x2 = 2.0 * g_random_double_range(0,1) - 1.0;
 409             w = x1 * x1 + x2 * x2;
 410         } while ( w >= 1.0 );
 411         w = sqrt( (-2.0 * log( w ) ) / w );
 412         y1 = x1 * w;
 413         y2 = x2 * w;
 414
 415         // deflect both left and right edges randomly and independently, so that:
 416         // (1) dc->tremor=1 corresponds to sigma=1, decreasing dc->tremor narrows the bell curve;
 417         // (2) deflection depends on width, but is upped for small widths for better visual uniformity across widths;
 418         // (3) deflection somewhat depends on speed, to prevent fast strokes looking
 419         // comparatively smooth and slow ones excessively jittery
 420         tremble_left  = (y1)*dc->tremor * (0.15 + 0.8*width) * (0.35 + 14*Geom::L2(dc->vel));
 421         tremble_right = (y2)*dc->tremor * (0.15 + 0.8*width) * (0.35 + 14*Geom::L2(dc->vel));
 422     }
 423
 424     if ( width < 0.02 * dc->width ) {
 425         width = 0.02 * dc->width;
 426     }
 427
 428     double dezoomify_factor = 0.05 * 1000;
 429     if (!dc->abs_width) {
 430         dezoomify_factor /= SP_EVENT_CONTEXT(dc)->desktop->current_zoom();
 431     }
 432
 433     Geom::Point del_left = dezoomify_factor * (width + tremble_left) * dc->ang;
 434     Geom::Point del_right = dezoomify_factor * (width + tremble_right) * dc->ang;
 435
 436     dc->point1[dc->npoints] = brush + del_left;
 437     dc->point2[dc->npoints] = brush - del_right;
 438
 439     dc->del = 0.5*(del_left + del_right);
 440
 441     dc->npoints++;
 442 }
 443
 444 void
 445 sp_erc_update_toolbox (SPDesktop *desktop, const gchar *id, double value)
 446 {
 447     desktop->setToolboxAdjustmentValue (id, value);
 448 }
 449
 450 static void
 451 eraser_cancel(SPEraserContext *dc)
 452 {
 453     SPDesktop *desktop = SP_EVENT_CONTEXT(dc)->desktop;
 454     dc->dragging = FALSE;
 455     dc->is_drawing = false;
 456     sp_canvas_item_ungrab(SP_CANVAS_ITEM(desktop->acetate), 0);
 457             /* Remove all temporary line segments */
 458             while (dc->segments) {
 459                 gtk_object_destroy(GTK_OBJECT(dc->segments->data));
 460                 dc->segments = g_slist_remove(dc->segments, dc->segments->data);
 461             }
 462             /* reset accumulated curve */
 463             dc->accumulated->reset();
 464             clear_current(dc);
 465             if (dc->repr) {
 466                 dc->repr = NULL;
 467             }
 468 }
 469
 470
 471 gint
 472 sp_eraser_context_root_handler(SPEventContext *event_context,
 473                                   GdkEvent *event)
 474 {
 475     SPEraserContext *dc = SP_ERASER_CONTEXT(event_context);
 476     SPDesktop *desktop = event_context->desktop;
 477
 478     gint ret = FALSE;
 479
 480     switch (event->type) {
 481         case GDK_BUTTON_PRESS:
 482             if (event->button.button == 1 && !event_context->space_panning) {
 483
 484                 if (Inkscape::have_viable_layer(desktop, dc->_message_context) == false) {
 485                     return TRUE;
 486                 }
 487
 488                 Geom::Point const button_w(event->button.x,
 489                                          event->button.y);
 490                 Geom::Point const button_dt(desktop->w2d(button_w));
 491                 sp_eraser_reset(dc, button_dt);
 492                 sp_eraser_extinput(dc, event);
 493                 sp_eraser_apply(dc, button_dt);
 494                 dc->accumulated->reset();
 495                 if (dc->repr) {
 496                     dc->repr = NULL;
 497                 }
 498
 499                 Inkscape::Rubberband::get(desktop)->start(desktop, button_dt);
 500                 Inkscape::Rubberband::get(desktop)->setMode(RUBBERBAND_MODE_TOUCHPATH);
 501
 502                 /* initialize first point */
 503                 dc->npoints = 0;
 504
 505                 sp_canvas_item_grab(SP_CANVAS_ITEM(desktop->acetate),
 506                                     ( GDK_KEY_PRESS_MASK |
 507                                       GDK_BUTTON_RELEASE_MASK |
 508                                       GDK_POINTER_MOTION_MASK |
 509                                       GDK_BUTTON_PRESS_MASK ),
 510                                     NULL,
 511                                     event->button.time);
 512
 513                 ret = TRUE;
 514
 515                 sp_canvas_force_full_redraw_after_interruptions(desktop->canvas, 3);
 516                 dc->is_drawing = true;
 517             }
 518             break;
 519         case GDK_MOTION_NOTIFY:
 520         {
 521             Geom::Point const motion_w(event->motion.x,
 522                                      event->motion.y);
 523             Geom::Point motion_dt(desktop->w2d(motion_w));
 524             sp_eraser_extinput(dc, event);
 525
 526             dc->_message_context->clear();
 527
 528             if ( dc->is_drawing && (event->motion.state & GDK_BUTTON1_MASK) && !event_context->space_panning) {
 529                 dc->dragging = TRUE;
 530
 531                 dc->_message_context->set(Inkscape::NORMAL_MESSAGE, _("<b>Drawing</b> an eraser stroke"));
 532
 533                 if (!sp_eraser_apply(dc, motion_dt)) {
 534                     ret = TRUE;
 535                     break;
 536                 }
 537
 538                 if ( dc->cur != dc->last ) {
 539                     sp_eraser_brush(dc);
 540                     g_assert( dc->npoints > 0 );
 541                     fit_and_split(dc, FALSE);
 542                 }
 543                 ret = TRUE;
 544             }
 545             Inkscape::Rubberband::get(desktop)->move(motion_dt);
 546         }
 547         break;
 548
 549
 550     case GDK_BUTTON_RELEASE:
 551     {
 552         Geom::Point const motion_w(event->button.x, event->button.y);
 553         Geom::Point const motion_dt(desktop->w2d(motion_w));
 554
 555         sp_canvas_item_ungrab(SP_CANVAS_ITEM(desktop->acetate), event->button.time);
 556         sp_canvas_end_forced_full_redraws(desktop->canvas);
 557         dc->is_drawing = false;
 558
 559         if (dc->dragging && event->button.button == 1 && !event_context->space_panning) {
 560             dc->dragging = FALSE;
 561
 562             sp_eraser_apply(dc, motion_dt);
 563
 564             /* Remove all temporary line segments */
 565             while (dc->segments) {
 566                 gtk_object_destroy(GTK_OBJECT(dc->segments->data));
 567                 dc->segments = g_slist_remove(dc->segments, dc->segments->data);
 568             }
 569
 570             /* Create object */
 571             fit_and_split(dc, TRUE);
 572             accumulate_eraser(dc);
 573             set_to_accumulated(dc); // performs document_done
 574
 575             /* reset accumulated curve */
 576             dc->accumulated->reset();
 577
 578             clear_current(dc);
 579             if (dc->repr) {
 580                 dc->repr = NULL;
 581             }
 582
 583             dc->_message_context->clear();
 584             ret = TRUE;
 585         }
 586         if (Inkscape::Rubberband::get(desktop)->is_started()) {
 587             Inkscape::Rubberband::get(desktop)->stop();
 588         }
 589
 590         break;
 591     }
 592
 593     case GDK_KEY_PRESS:
 594         switch (get_group0_keyval (&event->key)) {
 595         case GDK_Up:
 596         case GDK_KP_Up:
 597             if (!MOD__CTRL_ONLY) {
 598                 dc->angle += 5.0;
 599                 if (dc->angle > 90.0)
 600                     dc->angle = 90.0;
 601                 sp_erc_update_toolbox (desktop, "eraser-angle", dc->angle);
 602                 ret = TRUE;
 603             }
 604             break;
 605         case GDK_Down:
 606         case GDK_KP_Down:
 607             if (!MOD__CTRL_ONLY) {
 608                 dc->angle -= 5.0;
 609                 if (dc->angle < -90.0)
 610                     dc->angle = -90.0;
 611                 sp_erc_update_toolbox (desktop, "eraser-angle", dc->angle);
 612                 ret = TRUE;
 613             }
 614             break;
 615         case GDK_Right:
 616         case GDK_KP_Right:
 617             if (!MOD__CTRL_ONLY) {
 618                 dc->width += 0.01;
 619                 if (dc->width > 1.0)
 620                     dc->width = 1.0;
 621                 sp_erc_update_toolbox (desktop, "altx-eraser", dc->width * 100); // the same spinbutton is for alt+x
 622                 ret = TRUE;
 623             }
 624             break;
 625         case GDK_Left:
 626         case GDK_KP_Left:
 627             if (!MOD__CTRL_ONLY) {
 628                 dc->width -= 0.01;
 629                 if (dc->width < 0.01)
 630                     dc->width = 0.01;
 631                 sp_erc_update_toolbox (desktop, "altx-eraser", dc->width * 100);
 632                 ret = TRUE;
 633             }
 634             break;
 635         case GDK_Home:
 636         case GDK_KP_Home:
 637             dc->width = 0.01;
 638             sp_erc_update_toolbox (desktop, "altx-eraser", dc->width * 100);
 639             ret = TRUE;
 640             break;
 641         case GDK_End:
 642         case GDK_KP_End:
 643             dc->width = 1.0;
 644             sp_erc_update_toolbox (desktop, "altx-eraser", dc->width * 100);
 645             ret = TRUE;
 646             break;
 647         case GDK_x:
 648         case GDK_X:
 649             if (MOD__ALT_ONLY) {
 650                 desktop->setToolboxFocusTo ("altx-eraser");
 651                 ret = TRUE;
 652             }
 653             break;
 654         case GDK_Escape:
 655             Inkscape::Rubberband::get(desktop)->stop();
 656             if (dc->is_drawing) {
 657                 // if drawing, cancel, otherwise pass it up for deselecting
 658                 eraser_cancel (dc);
 659                 ret = TRUE;
 660             }
 661             break;
 662         case GDK_z:
 663         case GDK_Z:
 664             if (MOD__CTRL_ONLY && dc->is_drawing) {
 665                 // if drawing, cancel, otherwise pass it up for undo
 666                 eraser_cancel (dc);
 667                 ret = TRUE;
 668             }
 669             break;
 670         default:
 671             break;
 672         }
 673         break;
 674
 675     case GDK_KEY_RELEASE:
 676         switch (get_group0_keyval(&event->key)) {
 677             case GDK_Control_L:
 678             case GDK_Control_R:
 679                 dc->_message_context->clear();
 680                 break;
 681             default:
 682                 break;
 683         }
 684
 685     default:
 686         break;
 687     }
 688
 689     if (!ret) {
 690         if (((SPEventContextClass *) eraser_parent_class)->root_handler) {
 691             ret = ((SPEventContextClass *) eraser_parent_class)->root_handler(event_context, event);
 692         }
 693     }
 694
 695     return ret;
 696 }
 697
 698
 699 static void
 700 clear_current(SPEraserContext *dc)
 701 {
 702     // reset bpath
 703     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(dc->currentshape), NULL);
 704
 705     // reset curve
 706     dc->currentcurve->reset();
 707     dc->cal1->reset();
 708     dc->cal2->reset();
 709
 710     // reset points
 711     dc->npoints = 0;
 712 }
 713
 714 static void
 715 set_to_accumulated(SPEraserContext *dc)
 716 {
 717     SPDesktop *desktop = SP_EVENT_CONTEXT(dc)->desktop;
 718     bool workDone = false;
 719
 720     if (!dc->accumulated->is_empty()) {
 721         if (!dc->repr) {
 722             /* Create object */
 723             Inkscape::XML::Document *xml_doc = desktop->doc()->getReprDoc();
 724             Inkscape::XML::Node *repr = xml_doc->createElement("svg:path");
 725
 726             /* Set style */
 727             sp_desktop_apply_style_tool (desktop, repr, "/tools/eraser", false);
 728
 729             dc->repr = repr;
 730
 731             SPItem *item=SP_ITEM(desktop->currentLayer()->appendChildRepr(dc->repr));
 732             Inkscape::GC::release(dc->repr);
 733             item->transform = SP_ITEM(desktop->currentLayer())->i2doc_affine().inverse();
 734             item->updateRepr();
 735         }
 736         Geom::PathVector pathv = dc->accumulated->get_pathvector() * desktop->dt2doc();
 737         gchar *str = sp_svg_write_path(pathv);
 738         g_assert( str != NULL );
 739         dc->repr->setAttribute("d", str);
 740         g_free(str);
 741
 742         if ( dc->repr ) {
 743             bool wasSelection = false;
 744             Inkscape::Selection *selection = sp_desktop_selection(desktop);
 745             Inkscape::Preferences *prefs = Inkscape::Preferences::get();
 746
 747             gint eraserMode = prefs->getBool("/tools/eraser/mode") ? 1 : 0;
 748             Inkscape::XML::Document *xml_doc = desktop->doc()->getReprDoc();
 749
 750             SPItem* acid = SP_ITEM(desktop->doc()->getObjectByRepr(dc->repr));
 751             Geom::OptRect eraserBbox = acid->getBounds(Geom::identity());
 752             Geom::Rect bounds = (*eraserBbox) * desktop->doc2dt();
 753             std::vector<SPItem*> remainingItems;
 754             GSList* toWorkOn = 0;
 755             if (selection->isEmpty()) {
 756                 if ( eraserMode ) {
 757                     toWorkOn = sp_desktop_document(desktop)->getItemsPartiallyInBox(desktop->dkey, bounds);
 758                 } else {
 759                     Inkscape::Rubberband *r = Inkscape::Rubberband::get(desktop);
 760                     toWorkOn = sp_desktop_document(desktop)->getItemsAtPoints(desktop->dkey, r->getPoints());
 761                 }
 762                 toWorkOn = g_slist_remove( toWorkOn, acid );
 763             } else {
 764                 toWorkOn = g_slist_copy(const_cast<GSList*>(selection->itemList()));
 765                 wasSelection = true;
 766             }
 767
 768             if ( g_slist_length(toWorkOn) > 0 ) {
 769                 if ( eraserMode ) {
 770                     for (GSList *i = toWorkOn ; i ; i = i->next ) {
 771                         SPItem *item = SP_ITEM(i->data);
 772                         if ( eraserMode ) {
 773                             Geom::OptRect bbox = item->getBounds(Geom::identity());
 774                             if (bbox && bbox->intersects(*eraserBbox)) {
 775                                 Inkscape::XML::Node* dup = dc->repr->duplicate(xml_doc);
 776                                 dc->repr->parent()->appendChild(dup);
 777                                 Inkscape::GC::release(dup); // parent takes over
 778
 779                                 selection->set(item);
 780                                 selection->add(dup);
 781                                 sp_selected_path_diff_skip_undo(desktop);
 782                                 workDone = true; // TODO set this only if something was cut.
 783                                 if ( !selection->isEmpty() ) {
 784                                     // If the item was not completely erased, track the new remainder.
 785                                     GSList *nowSel = g_slist_copy(const_cast<GSList *>(selection->itemList()));
 786                                     for (GSList const *i2 = nowSel ; i2 ; i2 = i2->next ) {
 787                                         remainingItems.push_back(SP_ITEM(i2->data));
 788                                     }
 789                                     g_slist_free(nowSel);
 790                                 }
 791                             } else {
 792                                 remainingItems.push_back(item);
 793                             }
 794                         }
 795                     }
 796                 } else {
 797                     for (GSList *i = toWorkOn ; i ; i = i->next ) {
 798                         sp_object_ref( SP_ITEM(i->data), 0 );
 799                     }
 800                     for (GSList *i = toWorkOn ; i ; i = i->next ) {
 801                         SPItem *item = SP_ITEM(i->data);
 802                         item->deleteObject(true);
 803                         sp_object_unref(item);
 804                         workDone = true;
 805                     }
 806                 }
 807
 808                 g_slist_free(toWorkOn);
 809
 810                 if ( !eraserMode ) {
 811                     //sp_selection_delete(desktop);
 812                     remainingItems.clear();
 813                 }
 814
 815                 selection->clear();
 816                 if ( wasSelection ) {
 817                     if ( !remainingItems.empty() ) {
 818                         selection->add(remainingItems.begin(), remainingItems.end());
 819                     }
 820                 }
 821             }
 822
 823             // Remove the eraser stroke itself:
 824             sp_repr_unparent( dc->repr );
 825             dc->repr = 0;
 826         }
 827     } else {
 828         if (dc->repr) {
 829             sp_repr_unparent(dc->repr);
 830             dc->repr = 0;
 831         }
 832     }
 833
 834
 835     if ( workDone ) {
 836         DocumentUndo::done(sp_desktop_document(desktop), SP_VERB_CONTEXT_ERASER,
 837                            _("Draw eraser stroke"));
 838     } else {
 839         DocumentUndo::cancel(sp_desktop_document(desktop));
 840     }
 841 }
 842
 843 static void
 844 add_cap(SPCurve *curve,
 845         Geom::Point const &pre, Geom::Point const &from,
 846         Geom::Point const &to, Geom::Point const &post,
 847         double rounding)
 848 {
 849     Geom::Point vel = rounding * Geom::rot90( to - from ) / sqrt(2.0);
 850     double mag = Geom::L2(vel);
 851
 852     Geom::Point v_in = from - pre;
 853     double mag_in = Geom::L2(v_in);
 854     if ( mag_in > ERASER_EPSILON ) {
 855         v_in = mag * v_in / mag_in;
 856     } else {
 857         v_in = Geom::Point(0, 0);
 858     }
 859
 860     Geom::Point v_out = to - post;
 861     double mag_out = Geom::L2(v_out);
 862     if ( mag_out > ERASER_EPSILON ) {
 863         v_out = mag * v_out / mag_out;
 864     } else {
 865         v_out = Geom::Point(0, 0);
 866     }
 867
 868     if ( Geom::L2(v_in) > ERASER_EPSILON || Geom::L2(v_out) > ERASER_EPSILON ) {
 869         curve->curveto(from + v_in, to + v_out, to);
 870     }
 871 }
 872
 873 static void
 874 accumulate_eraser(SPEraserContext *dc)
 875 {
 876     if ( !dc->cal1->is_empty() && !dc->cal2->is_empty() ) {
 877         dc->accumulated->reset(); /*  Is this required ?? */
 878         SPCurve *rev_cal2 = dc->cal2->create_reverse();
 879
 880         g_assert(dc->cal1->get_segment_count() > 0);
 881         g_assert(rev_cal2->get_segment_count() > 0);
 882         g_assert( ! dc->cal1->first_path()->closed() );
 883         g_assert( ! rev_cal2->first_path()->closed() );
 884
 885         Geom::CubicBezier const * dc_cal1_firstseg  = dynamic_cast<Geom::CubicBezier const *>( dc->cal1->first_segment() );
 886         Geom::CubicBezier const * rev_cal2_firstseg = dynamic_cast<Geom::CubicBezier const *>( rev_cal2->first_segment() );
 887         Geom::CubicBezier const * dc_cal1_lastseg   = dynamic_cast<Geom::CubicBezier const *>( dc->cal1->last_segment() );
 888         Geom::CubicBezier const * rev_cal2_lastseg  = dynamic_cast<Geom::CubicBezier const *>( rev_cal2->last_segment() );
 889         g_assert( dc_cal1_firstseg );
 890         g_assert( rev_cal2_firstseg );
 891         g_assert( dc_cal1_lastseg );
 892         g_assert( rev_cal2_lastseg );
 893
 894         dc->accumulated->append(dc->cal1, FALSE);
 895
 896         add_cap(dc->accumulated, (*dc_cal1_lastseg)[2], (*dc_cal1_lastseg)[3], (*rev_cal2_firstseg)[0], (*rev_cal2_firstseg)[1], dc->cap_rounding);
 897
 898         dc->accumulated->append(rev_cal2, TRUE);
 899
 900         add_cap(dc->accumulated, (*rev_cal2_lastseg)[2], (*rev_cal2_lastseg)[3], (*dc_cal1_firstseg)[0], (*dc_cal1_firstseg)[1], dc->cap_rounding);
 901
 902         dc->accumulated->closepath();
 903
 904         rev_cal2->unref();
 905
 906         dc->cal1->reset();
 907         dc->cal2->reset();
 908     }
 909 }
 910
 911 static double square(double const x)
 912 {
 913     return x * x;
 914 }
 915
 916 static void
 917 fit_and_split(SPEraserContext *dc, gboolean release)
 918 {
 919     SPDesktop *desktop = SP_EVENT_CONTEXT(dc)->desktop;
 920
 921     double const tolerance_sq = square( desktop->w2d().descrim() * TOLERANCE_ERASER );
 922
 923 #ifdef ERASER_VERBOSE
 924     g_print("[F&S:R=%c]", release?'T':'F');
 925 #endif
 926
 927     if (!( dc->npoints > 0 && dc->npoints < SAMPLING_SIZE ))
 928         return; // just clicked
 929
 930     if ( dc->npoints == SAMPLING_SIZE - 1 || release ) {
 931 #define BEZIER_SIZE       4
 932 #define BEZIER_MAX_BEZIERS  8
 933 #define BEZIER_MAX_LENGTH ( BEZIER_SIZE * BEZIER_MAX_BEZIERS )
 934
 935 #ifdef ERASER_VERBOSE
 936         g_print("[F&S:#] dc->npoints:%d, release:%s\n",
 937                 dc->npoints, release ? "TRUE" : "FALSE");
 938 #endif
 939
 940         /* Current eraser */
 941         if ( dc->cal1->is_empty() || dc->cal2->is_empty() ) {
 942             /* dc->npoints > 0 */
 943             /* g_print("erasers(1|2) reset\n"); */
 944             dc->cal1->reset();
 945             dc->cal2->reset();
 946
 947             dc->cal1->moveto(dc->point1[0]);
 948             dc->cal2->moveto(dc->point2[0]);
 949         }
 950
 951         Geom::Point b1[BEZIER_MAX_LENGTH];
 952         gint const nb1 = Geom::bezier_fit_cubic_r(b1, dc->point1, dc->npoints,
 953                                                tolerance_sq, BEZIER_MAX_BEZIERS);
 954         g_assert( nb1 * BEZIER_SIZE <= gint(G_N_ELEMENTS(b1)) );
 955
 956         Geom::Point b2[BEZIER_MAX_LENGTH];
 957         gint const nb2 = Geom::bezier_fit_cubic_r(b2, dc->point2, dc->npoints,
 958                                                tolerance_sq, BEZIER_MAX_BEZIERS);
 959         g_assert( nb2 * BEZIER_SIZE <= gint(G_N_ELEMENTS(b2)) );
 960
 961         if ( nb1 != -1 && nb2 != -1 ) {
 962             /* Fit and draw and reset state */
 963 #ifdef ERASER_VERBOSE
 964             g_print("nb1:%d nb2:%d\n", nb1, nb2);
 965 #endif
 966             /* CanvasShape */
 967             if (! release) {
 968                 dc->currentcurve->reset();
 969                 dc->currentcurve->moveto(b1[0]);
 970                 for (Geom::Point *bp1 = b1; bp1 < b1 + BEZIER_SIZE * nb1; bp1 += BEZIER_SIZE) {
 971                     dc->currentcurve->curveto(bp1[1],
 972                                      bp1[2], bp1[3]);
 973                 }
 974                 dc->currentcurve->lineto(b2[BEZIER_SIZE*(nb2-1) + 3]);
 975                 for (Geom::Point *bp2 = b2 + BEZIER_SIZE * ( nb2 - 1 ); bp2 >= b2; bp2 -= BEZIER_SIZE) {
 976                     dc->currentcurve->curveto(bp2[2], bp2[1], bp2[0]);
 977                 }
 978                 // FIXME: dc->segments is always NULL at this point??
 979                 if (!dc->segments) { // first segment
 980                     add_cap(dc->currentcurve, b2[1], b2[0], b1[0], b1[1], dc->cap_rounding);
 981                 }
 982                 dc->currentcurve->closepath();
 983                 sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(dc->currentshape), dc->currentcurve);
 984             }
 985
 986             /* Current eraser */
 987             for (Geom::Point *bp1 = b1; bp1 < b1 + BEZIER_SIZE * nb1; bp1 += BEZIER_SIZE) {
 988                 dc->cal1->curveto(bp1[1], bp1[2], bp1[3]);
 989             }
 990             for (Geom::Point *bp2 = b2; bp2 < b2 + BEZIER_SIZE * nb2; bp2 += BEZIER_SIZE) {
 991                 dc->cal2->curveto(bp2[1], bp2[2], bp2[3]);
 992             }
 993         } else {
 994             /* fixme: ??? */
 995 #ifdef ERASER_VERBOSE
 996             g_print("[fit_and_split] failed to fit-cubic.\n");
 997 #endif
 998             draw_temporary_box(dc);
 999
1000             for (gint i = 1; i < dc->npoints; i++) {
1001                 dc->cal1->lineto(dc->point1[i]);
1002             }
1003             for (gint i = 1; i < dc->npoints; i++) {
1004                 dc->cal2->lineto(dc->point2[i]);
1005             }
1006         }
1007
1008         /* Fit and draw and copy last point */
1009 #ifdef ERASER_VERBOSE
1010         g_print("[%d]Yup\n", dc->npoints);
1011 #endif
1012         if (!release) {
1013             Inkscape::Preferences *prefs = Inkscape::Preferences::get();
1014             gint eraserMode = prefs->getBool("/tools/eraser/mode") ? 1 : 0;
1015             g_assert(!dc->currentcurve->is_empty());
1016
1017             SPCanvasItem *cbp = sp_canvas_item_new(sp_desktop_sketch(desktop),
1018                                                    SP_TYPE_CANVAS_BPATH,
1019                                                    NULL);
1020             SPCurve *curve = dc->currentcurve->copy();
1021             sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH (cbp), curve);
1022             curve->unref();
1023
1024             guint32 fillColor = sp_desktop_get_color_tool (desktop, "/tools/eraser", true);
1025             //guint32 strokeColor = sp_desktop_get_color_tool (desktop, "/tools/eraser", false);
1026             double opacity = sp_desktop_get_master_opacity_tool (desktop, "/tools/eraser");
1027             double fillOpacity = sp_desktop_get_opacity_tool (desktop, "/tools/eraser", true);
1028             //double strokeOpacity = sp_desktop_get_opacity_tool (desktop, "/tools/eraser", false);
1029             sp_canvas_bpath_set_fill(SP_CANVAS_BPATH(cbp), ((fillColor & 0xffffff00) | SP_COLOR_F_TO_U(opacity*fillOpacity)), SP_WIND_RULE_EVENODD);
1030             //on second thougtht don't do stroke yet because we don't have stoke-width yet and because stoke appears between segments while drawing
1031             //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);
1032             sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(cbp), 0x00000000, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
1033             /* fixme: Cannot we cascade it to root more clearly? */
1034             g_signal_connect(G_OBJECT(cbp), "event", G_CALLBACK(sp_desktop_root_handler), desktop);
1035
1036             dc->segments = g_slist_prepend(dc->segments, cbp);
1037
1038             if ( !eraserMode ) {
1039                 sp_canvas_item_hide(cbp);
1040                 sp_canvas_item_hide(dc->currentshape);
1041             }
1042         }
1043
1044         dc->point1[0] = dc->point1[dc->npoints - 1];
1045         dc->point2[0] = dc->point2[dc->npoints - 1];
1046         dc->npoints = 1;
1047     } else {
1048         draw_temporary_box(dc);
1049     }
1050 }
1051
1052 static void
1053 draw_temporary_box(SPEraserContext *dc)
1054 {
1055     dc->currentcurve->reset();
1056
1057     dc->currentcurve->moveto(dc->point1[dc->npoints-1]);
1058     for (gint i = dc->npoints-2; i >= 0; i--) {
1059         dc->currentcurve->lineto(dc->point1[i]);
1060     }
1061     for (gint i = 0; i < dc->npoints; i++) {
1062         dc->currentcurve->lineto(dc->point2[i]);
1063     }
1064     if (dc->npoints >= 2) {
1065         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);
1066     }
1067
1068     dc->currentcurve->closepath();
1069     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(dc->currentshape), dc->currentcurve);
1070 }
1071
1072 /*
1073   Local Variables:
1074   mode:c++
1075   c-file-style:"stroustrup"
1076   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
1077   indent-tabs-mode:nil
1078   fill-column:99
1079   End:
1080 */
1081 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :