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-affine.h"
  47 #include "desktop-style.h"
  48 #include "message-context.h"
  49 #include "preferences.h"
  50 #include "pixmaps/cursor-eraser.xpm"
  51 #include "xml/repr.h"
  52 #include "context-fns.h"
  53 #include "sp-item.h"
  54 #include "color.h"
  55 #include "rubberband.h"
  56 #include "splivarot.h"
  57 #include "sp-item-group.h"
  58 #include "sp-shape.h"
  59 #include "sp-path.h"
  60 #include "sp-text.h"
  61 #include "display/canvas-bpath.h"
  62 #include "display/canvas-arena.h"
  63 #include "livarot/Shape.h"
  64 #include <2geom/isnan.h>
  65 #include <2geom/pathvector.h>
  66
  67 #include "eraser-context.h"
  68
  69 #define ERC_RED_RGBA 0xff0000ff
  70
  71 #define TOLERANCE_ERASER 0.1
  72
  73 #define ERASER_EPSILON 0.5e-6
  74 #define ERASER_EPSILON_START 0.5e-2
  75 #define ERASER_VEL_START 1e-5
  76
  77 #define DRAG_MIN 0.0
  78 #define DRAG_DEFAULT 1.0
  79 #define DRAG_MAX 1.0
  80
  81
  82 static void sp_eraser_context_class_init(SPEraserContextClass *klass);
  83 static void sp_eraser_context_init(SPEraserContext *erc);
  84 static void sp_eraser_context_dispose(GObject *object);
  85
  86 static void sp_eraser_context_setup(SPEventContext *ec);
  87 static void sp_eraser_context_set(SPEventContext *ec, Inkscape::Preferences::Entry *val);
  88 static gint sp_eraser_context_root_handler(SPEventContext *ec, GdkEvent *event);
  89
  90 static void clear_current(SPEraserContext *dc);
  91 static void set_to_accumulated(SPEraserContext *dc);
  92 static void add_cap(SPCurve *curve, Geom::Point const &pre, Geom::Point const &from, Geom::Point const &to, Geom::Point const &post, double rounding);
  93 static void accumulate_eraser(SPEraserContext *dc);
  94
  95 static void fit_and_split(SPEraserContext *erc, gboolean release);
  96
  97 static void sp_eraser_reset(SPEraserContext *erc, Geom::Point p);
  98 static Geom::Point sp_eraser_get_npoint(SPEraserContext const *erc, Geom::Point v);
  99 static Geom::Point sp_eraser_get_vpoint(SPEraserContext const *erc, Geom::Point n);
 100 static void draw_temporary_box(SPEraserContext *dc);
 101
 102
 103 static SPEventContextClass *eraser_parent_class = 0;
 104
 105 GType sp_eraser_context_get_type(void)
 106 {
 107     static GType type = 0;
 108     if (!type) {
 109         GTypeInfo info = {
 110             sizeof(SPEraserContextClass),
 111             0, // base_init
 112             0, // base_finalize
 113             (GClassInitFunc)sp_eraser_context_class_init,
 114             0, // class_finalize
 115             0, // class_data
 116             sizeof(SPEraserContext),
 117             0, // n_preallocs
 118             (GInstanceInitFunc)sp_eraser_context_init,
 119             0 // value_table
 120         };
 121         type = g_type_register_static(SP_TYPE_COMMON_CONTEXT, "SPEraserContext", &info, static_cast<GTypeFlags>(0));
 122     }
 123     return type;
 124 }
 125
 126 static void
 127 sp_eraser_context_class_init(SPEraserContextClass *klass)
 128 {
 129     GObjectClass *object_class = (GObjectClass *) klass;
 130     SPEventContextClass *event_context_class = (SPEventContextClass *) klass;
 131
 132     eraser_parent_class = (SPEventContextClass*)g_type_class_peek_parent(klass);
 133
 134     object_class->dispose = sp_eraser_context_dispose;
 135
 136     event_context_class->setup = sp_eraser_context_setup;
 137     event_context_class->set = sp_eraser_context_set;
 138     event_context_class->root_handler = sp_eraser_context_root_handler;
 139 }
 140
 141 static void
 142 sp_eraser_context_init(SPEraserContext *erc)
 143 {
 144     erc->cursor_shape = cursor_eraser_xpm;
 145     erc->hot_x = 4;
 146     erc->hot_y = 4;
 147 }
 148
 149 static void
 150 sp_eraser_context_dispose(GObject *object)
 151 {
 152     //SPEraserContext *erc = SP_ERASER_CONTEXT(object);
 153
 154     G_OBJECT_CLASS(eraser_parent_class)->dispose(object);
 155 }
 156
 157 static void
 158 sp_eraser_context_setup(SPEventContext *ec)
 159 {
 160     SPEraserContext *erc = SP_ERASER_CONTEXT(ec);
 161     SPDesktop *desktop = ec->desktop;
 162
 163     if (((SPEventContextClass *) eraser_parent_class)->setup)
 164         ((SPEventContextClass *) eraser_parent_class)->setup(ec);
 165
 166     erc->accumulated = new SPCurve();
 167     erc->currentcurve = new SPCurve();
 168
 169     erc->cal1 = new SPCurve();
 170     erc->cal2 = new SPCurve();
 171
 172     erc->currentshape = sp_canvas_item_new(sp_desktop_sketch(desktop), SP_TYPE_CANVAS_BPATH, NULL);
 173     sp_canvas_bpath_set_fill(SP_CANVAS_BPATH(erc->currentshape), ERC_RED_RGBA, SP_WIND_RULE_EVENODD);
 174     sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(erc->currentshape), 0x00000000, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 175     /* fixme: Cannot we cascade it to root more clearly? */
 176     g_signal_connect(G_OBJECT(erc->currentshape), "event", G_CALLBACK(sp_desktop_root_handler), desktop);
 177
 178 /*
 179 static ProfileFloatElement f_profile[PROFILE_FLOAT_SIZE] = {
 180     {"mass",0.02, 0.0, 1.0},
 181     {"wiggle",0.0, 0.0, 1.0},
 182     {"angle",30.0, -90.0, 90.0},
 183     {"thinning",0.1, -1.0, 1.0},
 184     {"tremor",0.0, 0.0, 1.0},
 185     {"flatness",0.9, 0.0, 1.0},
 186     {"cap_rounding",0.0, 0.0, 5.0}
 187 };
 188 */
 189
 190     sp_event_context_read(ec, "mass");
 191     sp_event_context_read(ec, "wiggle");
 192     sp_event_context_read(ec, "angle");
 193     sp_event_context_read(ec, "width");
 194     sp_event_context_read(ec, "thinning");
 195     sp_event_context_read(ec, "tremor");
 196     sp_event_context_read(ec, "flatness");
 197     sp_event_context_read(ec, "tracebackground");
 198     sp_event_context_read(ec, "usepressure");
 199     sp_event_context_read(ec, "usetilt");
 200     sp_event_context_read(ec, "abs_width");
 201     sp_event_context_read(ec, "cap_rounding");
 202
 203     erc->is_drawing = false;
 204
 205     erc->_message_context = new Inkscape::MessageContext(desktop->messageStack());
 206
 207     Inkscape::Preferences *prefs = Inkscape::Preferences::get();
 208     if (prefs->getBool("/tools/eraser/selcue", 0) != 0) {
 209         ec->enableSelectionCue();
 210     }
 211 // TODO temp force:
 212     ec->enableSelectionCue();
 213
 214 }
 215
 216 static void
 217 sp_eraser_context_set(SPEventContext *ec, Inkscape::Preferences::Entry *val)
 218 {
 219     //pass on up to parent class to handle common attributes.
 220     if ( eraser_parent_class->set ) {
 221         eraser_parent_class->set(ec, val);
 222     }
 223 }
 224
 225 static double
 226 flerp(double f0, double f1, double p)
 227 {
 228     return f0 + ( f1 - f0 ) * p;
 229 }
 230
 231 /* Get normalized point */
 232 static Geom::Point
 233 sp_eraser_get_npoint(SPEraserContext const *dc, Geom::Point v)
 234 {
 235     Geom::Rect drect = SP_EVENT_CONTEXT(dc)->desktop->get_display_area();
 236     double const max = MAX ( drect.dimensions()[Geom::X], drect.dimensions()[Geom::Y] );
 237     return Geom::Point(( v[Geom::X] - drect.min()[Geom::X] ) / max,  ( v[Geom::Y] - drect.min()[Geom::Y] ) / max);
 238 }
 239
 240 /* Get view point */
 241 static Geom::Point
 242 sp_eraser_get_vpoint(SPEraserContext const *dc, Geom::Point n)
 243 {
 244     Geom::Rect drect = SP_EVENT_CONTEXT(dc)->desktop->get_display_area();
 245     double const max = MAX ( drect.dimensions()[Geom::X], drect.dimensions()[Geom::Y] );
 246     return Geom::Point(n[Geom::X] * max + drect.min()[Geom::X], n[Geom::Y] * max + drect.min()[Geom::Y]);
 247 }
 248
 249 static void
 250 sp_eraser_reset(SPEraserContext *dc, Geom::Point p)
 251 {
 252     dc->last = dc->cur = sp_eraser_get_npoint(dc, p);
 253     dc->vel = Geom::Point(0,0);
 254     dc->vel_max = 0;
 255     dc->acc = Geom::Point(0,0);
 256     dc->ang = Geom::Point(0,0);
 257     dc->del = Geom::Point(0,0);
 258 }
 259
 260 static void
 261 sp_eraser_extinput(SPEraserContext *dc, GdkEvent *event)
 262 {
 263     if (gdk_event_get_axis (event, GDK_AXIS_PRESSURE, &dc->pressure))
 264         dc->pressure = CLAMP (dc->pressure, ERC_MIN_PRESSURE, ERC_MAX_PRESSURE);
 265     else
 266         dc->pressure = ERC_DEFAULT_PRESSURE;
 267
 268     if (gdk_event_get_axis (event, GDK_AXIS_XTILT, &dc->xtilt))
 269         dc->xtilt = CLAMP (dc->xtilt, ERC_MIN_TILT, ERC_MAX_TILT);
 270     else
 271         dc->xtilt = ERC_DEFAULT_TILT;
 272
 273     if (gdk_event_get_axis (event, GDK_AXIS_YTILT, &dc->ytilt))
 274         dc->ytilt = CLAMP (dc->ytilt, ERC_MIN_TILT, ERC_MAX_TILT);
 275     else
 276         dc->ytilt = ERC_DEFAULT_TILT;
 277 }
 278
 279
 280 static gboolean
 281 sp_eraser_apply(SPEraserContext *dc, Geom::Point p)
 282 {
 283     Geom::Point n = sp_eraser_get_npoint(dc, p);
 284
 285     /* Calculate mass and drag */
 286     double const mass = flerp(1.0, 160.0, dc->mass);
 287     double const drag = flerp(0.0, 0.5, dc->drag * dc->drag);
 288
 289     /* Calculate force and acceleration */
 290     Geom::Point force = n - dc->cur;
 291
 292     // If force is below the absolute threshold ERASER_EPSILON,
 293     // or we haven't yet reached ERASER_VEL_START (i.e. at the beginning of stroke)
 294     // _and_ the force is below the (higher) ERASER_EPSILON_START threshold,
 295     // discard this move.
 296     // This prevents flips, blobs, and jerks caused by microscopic tremor of the tablet pen,
 297     // especially bothersome at the start of the stroke where we don't yet have the inertia to
 298     // smooth them out.
 299     if ( Geom::L2(force) < ERASER_EPSILON || (dc->vel_max < ERASER_VEL_START && Geom::L2(force) < ERASER_EPSILON_START)) {
 300         return FALSE;
 301     }
 302
 303     dc->acc = force / mass;
 304
 305     /* Calculate new velocity */
 306     dc->vel += dc->acc;
 307
 308     if (Geom::L2(dc->vel) > dc->vel_max)
 309         dc->vel_max = Geom::L2(dc->vel);
 310
 311     /* Calculate angle of drawing tool */
 312
 313     double a1;
 314     if (dc->usetilt) {
 315         // 1a. calculate nib angle from input device tilt:
 316         gdouble length = std::sqrt(dc->xtilt*dc->xtilt + dc->ytilt*dc->ytilt);;
 317
 318         if (length > 0) {
 319             Geom::Point ang1 = Geom::Point(dc->ytilt/length, dc->xtilt/length);
 320             a1 = atan2(ang1);
 321         }
 322         else
 323             a1 = 0.0;
 324     }
 325     else {
 326         // 1b. fixed dc->angle (absolutely flat nib):
 327         double const radians = ( (dc->angle - 90) / 180.0 ) * M_PI;
 328         Geom::Point ang1 = Geom::Point(-sin(radians),  cos(radians));
 329         a1 = atan2(ang1);
 330     }
 331
 332     // 2. perpendicular to dc->vel (absolutely non-flat nib):
 333     gdouble const mag_vel = Geom::L2(dc->vel);
 334     if ( mag_vel < ERASER_EPSILON ) {
 335         return FALSE;
 336     }
 337     Geom::Point ang2 = Geom::rot90(dc->vel) / mag_vel;
 338
 339     // 3. Average them using flatness parameter:
 340     // calculate angles
 341     double a2 = atan2(ang2);
 342     // flip a2 to force it to be in the same half-circle as a1
 343     bool flipped = false;
 344     if (fabs (a2-a1) > 0.5*M_PI) {
 345         a2 += M_PI;
 346         flipped = true;
 347     }
 348     // normalize a2
 349     if (a2 > M_PI)
 350         a2 -= 2*M_PI;
 351     if (a2 < -M_PI)
 352         a2 += 2*M_PI;
 353     // find the flatness-weighted bisector angle, unflip if a2 was flipped
 354     // FIXME: when dc->vel is oscillating around the fixed angle, the new_ang flips back and forth. How to avoid this?
 355     double new_ang = a1 + (1 - dc->flatness) * (a2 - a1) - (flipped? M_PI : 0);
 356
 357     // Try to detect a sudden flip when the new angle differs too much from the previous for the
 358     // current velocity; in that case discard this move
 359     double angle_delta = Geom::L2(Geom::Point (cos (new_ang), sin (new_ang)) - dc->ang);
 360     if ( angle_delta / Geom::L2(dc->vel) > 4000 ) {
 361         return FALSE;
 362     }
 363
 364     // convert to point
 365     dc->ang = Geom::Point (cos (new_ang), sin (new_ang));
 366
 367 //    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);
 368
 369     /* Apply drag */
 370     dc->vel *= 1.0 - drag;
 371
 372     /* Update position */
 373     dc->last = dc->cur;
 374     dc->cur += dc->vel;
 375
 376     return TRUE;
 377 }
 378
 379 static void
 380 sp_eraser_brush(SPEraserContext *dc)
 381 {
 382     g_assert( dc->npoints >= 0 && dc->npoints < SAMPLING_SIZE );
 383
 384     // How much velocity thins strokestyle
 385     double vel_thin = flerp (0, 160, dc->vel_thin);
 386
 387     // Influence of pressure on thickness
 388     double pressure_thick = (dc->usepressure ? dc->pressure : 1.0);
 389
 390     // get the real brush point, not the same as pointer (affected by hatch tracking and/or mass
 391     // drag)
 392     Geom::Point brush = sp_eraser_get_vpoint(dc, dc->cur);
 393     Geom::Point brush_w = SP_EVENT_CONTEXT(dc)->desktop->d2w(brush);
 394
 395     double trace_thick = 1;
 396
 397     double width = (pressure_thick * trace_thick - vel_thin * Geom::L2(dc->vel)) * dc->width;
 398
 399     double tremble_left = 0, tremble_right = 0;
 400     if (dc->tremor > 0) {
 401         // obtain two normally distributed random variables, using polar Box-Muller transform
 402         double x1, x2, w, y1, y2;
 403         do {
 404             x1 = 2.0 * g_random_double_range(0,1) - 1.0;
 405             x2 = 2.0 * g_random_double_range(0,1) - 1.0;
 406             w = x1 * x1 + x2 * x2;
 407         } while ( w >= 1.0 );
 408         w = sqrt( (-2.0 * log( w ) ) / w );
 409         y1 = x1 * w;
 410         y2 = x2 * w;
 411
 412         // deflect both left and right edges randomly and independently, so that:
 413         // (1) dc->tremor=1 corresponds to sigma=1, decreasing dc->tremor narrows the bell curve;
 414         // (2) deflection depends on width, but is upped for small widths for better visual uniformity across widths;
 415         // (3) deflection somewhat depends on speed, to prevent fast strokes looking
 416         // comparatively smooth and slow ones excessively jittery
 417         tremble_left  = (y1)*dc->tremor * (0.15 + 0.8*width) * (0.35 + 14*Geom::L2(dc->vel));
 418         tremble_right = (y2)*dc->tremor * (0.15 + 0.8*width) * (0.35 + 14*Geom::L2(dc->vel));
 419     }
 420
 421     if ( width < 0.02 * dc->width ) {
 422         width = 0.02 * dc->width;
 423     }
 424
 425     double dezoomify_factor = 0.05 * 1000;
 426     if (!dc->abs_width) {
 427         dezoomify_factor /= SP_EVENT_CONTEXT(dc)->desktop->current_zoom();
 428     }
 429
 430     Geom::Point del_left = dezoomify_factor * (width + tremble_left) * dc->ang;
 431     Geom::Point del_right = dezoomify_factor * (width + tremble_right) * dc->ang;
 432
 433     dc->point1[dc->npoints] = brush + del_left;
 434     dc->point2[dc->npoints] = brush - del_right;
 435
 436     dc->del = 0.5*(del_left + del_right);
 437
 438     dc->npoints++;
 439 }
 440
 441 void
 442 sp_erc_update_toolbox (SPDesktop *desktop, const gchar *id, double value)
 443 {
 444     desktop->setToolboxAdjustmentValue (id, value);
 445 }
 446
 447 static void
 448 eraser_cancel(SPEraserContext *dc)
 449 {
 450     SPDesktop *desktop = SP_EVENT_CONTEXT(dc)->desktop;
 451     dc->dragging = FALSE;
 452     dc->is_drawing = false;
 453     sp_canvas_item_ungrab(SP_CANVAS_ITEM(desktop->acetate), 0);
 454             /* Remove all temporary line segments */
 455             while (dc->segments) {
 456                 gtk_object_destroy(GTK_OBJECT(dc->segments->data));
 457                 dc->segments = g_slist_remove(dc->segments, dc->segments->data);
 458             }
 459             /* reset accumulated curve */
 460             dc->accumulated->reset();
 461             clear_current(dc);
 462             if (dc->repr) {
 463                 dc->repr = NULL;
 464             }
 465 }
 466
 467
 468 gint
 469 sp_eraser_context_root_handler(SPEventContext *event_context,
 470                                   GdkEvent *event)
 471 {
 472     SPEraserContext *dc = SP_ERASER_CONTEXT(event_context);
 473     SPDesktop *desktop = event_context->desktop;
 474
 475     gint ret = FALSE;
 476
 477     switch (event->type) {
 478         case GDK_BUTTON_PRESS:
 479             if (event->button.button == 1 && !event_context->space_panning) {
 480
 481                 if (Inkscape::have_viable_layer(desktop, dc->_message_context) == false) {
 482                     return TRUE;
 483                 }
 484
 485                 Geom::Point const button_w(event->button.x,
 486                                          event->button.y);
 487                 Geom::Point const button_dt(desktop->w2d(button_w));
 488                 sp_eraser_reset(dc, button_dt);
 489                 sp_eraser_extinput(dc, event);
 490                 sp_eraser_apply(dc, button_dt);
 491                 dc->accumulated->reset();
 492                 if (dc->repr) {
 493                     dc->repr = NULL;
 494                 }
 495
 496                 Inkscape::Rubberband::get(desktop)->start(desktop, button_dt);
 497                 Inkscape::Rubberband::get(desktop)->setMode(RUBBERBAND_MODE_TOUCHPATH);
 498
 499                 /* initialize first point */
 500                 dc->npoints = 0;
 501
 502                 sp_canvas_item_grab(SP_CANVAS_ITEM(desktop->acetate),
 503                                     ( GDK_KEY_PRESS_MASK |
 504                                       GDK_BUTTON_RELEASE_MASK |
 505                                       GDK_POINTER_MOTION_MASK |
 506                                       GDK_BUTTON_PRESS_MASK ),
 507                                     NULL,
 508                                     event->button.time);
 509
 510                 ret = TRUE;
 511
 512                 sp_canvas_force_full_redraw_after_interruptions(desktop->canvas, 3);
 513                 dc->is_drawing = true;
 514             }
 515             break;
 516         case GDK_MOTION_NOTIFY:
 517         {
 518             Geom::Point const motion_w(event->motion.x,
 519                                      event->motion.y);
 520             Geom::Point motion_dt(desktop->w2d(motion_w));
 521             sp_eraser_extinput(dc, event);
 522
 523             dc->_message_context->clear();
 524
 525             if ( dc->is_drawing && (event->motion.state & GDK_BUTTON1_MASK) && !event_context->space_panning) {
 526                 dc->dragging = TRUE;
 527
 528                 dc->_message_context->set(Inkscape::NORMAL_MESSAGE, _("<b>Drawing</b> an eraser stroke"));
 529
 530                 if (!sp_eraser_apply(dc, motion_dt)) {
 531                     ret = TRUE;
 532                     break;
 533                 }
 534
 535                 if ( dc->cur != dc->last ) {
 536                     sp_eraser_brush(dc);
 537                     g_assert( dc->npoints > 0 );
 538                     fit_and_split(dc, FALSE);
 539                 }
 540                 ret = TRUE;
 541             }
 542             Inkscape::Rubberband::get(desktop)->move(motion_dt);
 543         }
 544         break;
 545
 546
 547     case GDK_BUTTON_RELEASE:
 548     {
 549         Geom::Point const motion_w(event->button.x, event->button.y);
 550         Geom::Point const motion_dt(desktop->w2d(motion_w));
 551
 552         sp_canvas_item_ungrab(SP_CANVAS_ITEM(desktop->acetate), event->button.time);
 553         sp_canvas_end_forced_full_redraws(desktop->canvas);
 554         dc->is_drawing = false;
 555
 556         if (dc->dragging && event->button.button == 1 && !event_context->space_panning) {
 557             dc->dragging = FALSE;
 558
 559             sp_eraser_apply(dc, motion_dt);
 560
 561             /* Remove all temporary line segments */
 562             while (dc->segments) {
 563                 gtk_object_destroy(GTK_OBJECT(dc->segments->data));
 564                 dc->segments = g_slist_remove(dc->segments, dc->segments->data);
 565             }
 566
 567             /* Create object */
 568             fit_and_split(dc, TRUE);
 569             accumulate_eraser(dc);
 570             set_to_accumulated(dc); // performs document_done
 571
 572             /* reset accumulated curve */
 573             dc->accumulated->reset();
 574
 575             clear_current(dc);
 576             if (dc->repr) {
 577                 dc->repr = NULL;
 578             }
 579
 580             Inkscape::Rubberband::get(desktop)->stop();
 581             dc->_message_context->clear();
 582             ret = TRUE;
 583         }
 584         break;
 585     }
 586
 587     case GDK_KEY_PRESS:
 588         switch (get_group0_keyval (&event->key)) {
 589         case GDK_Up:
 590         case GDK_KP_Up:
 591             if (!MOD__CTRL_ONLY) {
 592                 dc->angle += 5.0;
 593                 if (dc->angle > 90.0)
 594                     dc->angle = 90.0;
 595                 sp_erc_update_toolbox (desktop, "eraser-angle", dc->angle);
 596                 ret = TRUE;
 597             }
 598             break;
 599         case GDK_Down:
 600         case GDK_KP_Down:
 601             if (!MOD__CTRL_ONLY) {
 602                 dc->angle -= 5.0;
 603                 if (dc->angle < -90.0)
 604                     dc->angle = -90.0;
 605                 sp_erc_update_toolbox (desktop, "eraser-angle", dc->angle);
 606                 ret = TRUE;
 607             }
 608             break;
 609         case GDK_Right:
 610         case GDK_KP_Right:
 611             if (!MOD__CTRL_ONLY) {
 612                 dc->width += 0.01;
 613                 if (dc->width > 1.0)
 614                     dc->width = 1.0;
 615                 sp_erc_update_toolbox (desktop, "altx-eraser", dc->width * 100); // the same spinbutton is for alt+x
 616                 ret = TRUE;
 617             }
 618             break;
 619         case GDK_Left:
 620         case GDK_KP_Left:
 621             if (!MOD__CTRL_ONLY) {
 622                 dc->width -= 0.01;
 623                 if (dc->width < 0.01)
 624                     dc->width = 0.01;
 625                 sp_erc_update_toolbox (desktop, "altx-eraser", dc->width * 100);
 626                 ret = TRUE;
 627             }
 628             break;
 629         case GDK_Home:
 630         case GDK_KP_Home:
 631             dc->width = 0.01;
 632             sp_erc_update_toolbox (desktop, "altx-eraser", dc->width * 100);
 633             ret = TRUE;
 634             break;
 635         case GDK_End:
 636         case GDK_KP_End:
 637             dc->width = 1.0;
 638             sp_erc_update_toolbox (desktop, "altx-eraser", dc->width * 100);
 639             ret = TRUE;
 640             break;
 641         case GDK_x:
 642         case GDK_X:
 643             if (MOD__ALT_ONLY) {
 644                 desktop->setToolboxFocusTo ("altx-eraser");
 645                 ret = TRUE;
 646             }
 647             break;
 648         case GDK_Escape:
 649             Inkscape::Rubberband::get(desktop)->stop();
 650             if (dc->is_drawing) {
 651                 // if drawing, cancel, otherwise pass it up for deselecting
 652                 eraser_cancel (dc);
 653                 ret = TRUE;
 654             }
 655             break;
 656         case GDK_z:
 657         case GDK_Z:
 658             if (MOD__CTRL_ONLY && dc->is_drawing) {
 659                 // if drawing, cancel, otherwise pass it up for undo
 660                 eraser_cancel (dc);
 661                 ret = TRUE;
 662             }
 663             break;
 664         default:
 665             break;
 666         }
 667         break;
 668
 669     case GDK_KEY_RELEASE:
 670         switch (get_group0_keyval(&event->key)) {
 671             case GDK_Control_L:
 672             case GDK_Control_R:
 673                 dc->_message_context->clear();
 674                 break;
 675             default:
 676                 break;
 677         }
 678
 679     default:
 680         break;
 681     }
 682
 683     if (!ret) {
 684         if (((SPEventContextClass *) eraser_parent_class)->root_handler) {
 685             ret = ((SPEventContextClass *) eraser_parent_class)->root_handler(event_context, event);
 686         }
 687     }
 688
 689     return ret;
 690 }
 691
 692
 693 static void
 694 clear_current(SPEraserContext *dc)
 695 {
 696     // reset bpath
 697     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(dc->currentshape), NULL);
 698
 699     // reset curve
 700     dc->currentcurve->reset();
 701     dc->cal1->reset();
 702     dc->cal2->reset();
 703
 704     // reset points
 705     dc->npoints = 0;
 706 }
 707
 708 static void
 709 set_to_accumulated(SPEraserContext *dc)
 710 {
 711     SPDesktop *desktop = SP_EVENT_CONTEXT(dc)->desktop;
 712     bool workDone = false;
 713
 714     if (!dc->accumulated->is_empty()) {
 715         if (!dc->repr) {
 716             /* Create object */
 717             Inkscape::XML::Document *xml_doc = sp_document_repr_doc(desktop->doc());
 718             Inkscape::XML::Node *repr = xml_doc->createElement("svg:path");
 719
 720             /* Set style */
 721             sp_desktop_apply_style_tool (desktop, repr, "/tools/eraser", false);
 722
 723             dc->repr = repr;
 724
 725             SPItem *item=SP_ITEM(desktop->currentLayer()->appendChildRepr(dc->repr));
 726             Inkscape::GC::release(dc->repr);
 727             item->transform = sp_item_i2doc_affine(SP_ITEM(desktop->currentLayer())).inverse();
 728             item->updateRepr();
 729         }
 730         Geom::PathVector pathv = dc->accumulated->get_pathvector() * sp_desktop_dt2doc_affine(desktop);
 731         gchar *str = sp_svg_write_path(pathv);
 732         g_assert( str != NULL );
 733         dc->repr->setAttribute("d", str);
 734         g_free(str);
 735
 736         if ( dc->repr ) {
 737             bool wasSelection = false;
 738             Inkscape::Selection *selection = sp_desktop_selection(desktop);
 739             Inkscape::Preferences *prefs = Inkscape::Preferences::get();
 740
 741             gint eraserMode = prefs->getBool("/tools/eraser/mode") ? 1 : 0;
 742             Inkscape::XML::Document *xml_doc = sp_document_repr_doc(desktop->doc());
 743
 744             SPItem* acid = SP_ITEM(desktop->doc()->getObjectByRepr(dc->repr));
 745             Geom::OptRect eraserBbox = acid->getBounds(Geom::identity());
 746             Geom::Rect bounds = (*eraserBbox) * desktop->doc2dt();
 747             std::vector<SPItem*> remainingItems;
 748             GSList* toWorkOn = 0;
 749             if (selection->isEmpty()) {
 750                 if ( eraserMode ) {
 751                     toWorkOn = sp_document_partial_items_in_box(sp_desktop_document(desktop), desktop->dkey, bounds);
 752                 } else {
 753                     Inkscape::Rubberband::Rubberband *r = Inkscape::Rubberband::get(desktop);
 754                     toWorkOn = sp_document_items_at_points(sp_desktop_document(desktop), desktop->dkey, r->getPoints());
 755                 }
 756                 toWorkOn = g_slist_remove( toWorkOn, acid );
 757             } else {
 758                 toWorkOn = g_slist_copy(const_cast<GSList*>(selection->itemList()));
 759                 wasSelection = true;
 760             }
 761
 762             if ( g_slist_length(toWorkOn) > 0 ) {
 763                 if ( eraserMode ) {
 764                     for (GSList *i = toWorkOn ; i ; i = i->next ) {
 765                         SPItem *item = SP_ITEM(i->data);
 766                         if ( eraserMode ) {
 767                             Geom::OptRect bbox = item->getBounds(Geom::identity());
 768                             if (bbox && bbox->intersects(*eraserBbox)) {
 769                                 Inkscape::XML::Node* dup = dc->repr->duplicate(xml_doc);
 770                                 dc->repr->parent()->appendChild(dup);
 771                                 Inkscape::GC::release(dup); // parent takes over
 772
 773                                 selection->set(item);
 774                                 selection->add(dup);
 775                                 sp_selected_path_diff_skip_undo(desktop);
 776                                 workDone = true; // TODO set this only if something was cut.
 777                                 if ( !selection->isEmpty() ) {
 778                                     // If the item was not completely erased, track the new remainder.
 779                                     GSList *nowSel = g_slist_copy(const_cast<GSList *>(selection->itemList()));
 780                                     for (GSList const *i2 = nowSel ; i2 ; i2 = i2->next ) {
 781                                         remainingItems.push_back(SP_ITEM(i2->data));
 782                                     }
 783                                     g_slist_free(nowSel);
 784                                 }
 785                             } else {
 786                                 remainingItems.push_back(item);
 787                             }
 788                         }
 789                     }
 790                 } else {
 791                     for (GSList *i = toWorkOn ; i ; i = i->next ) {
 792                         sp_object_ref( SP_ITEM(i->data), 0 );
 793                     }
 794                     for (GSList *i = toWorkOn ; i ; i = i->next ) {
 795                         SPItem *item = SP_ITEM(i->data);
 796                         item->deleteObject(true);
 797                         sp_object_unref(item);
 798                         workDone = true;
 799                     }
 800                 }
 801
 802                 g_slist_free(toWorkOn);
 803
 804                 if ( !eraserMode ) {
 805                     //sp_selection_delete(desktop);
 806                     remainingItems.clear();
 807                 }
 808
 809                 selection->clear();
 810                 if ( wasSelection ) {
 811                     if ( !remainingItems.empty() ) {
 812                         selection->add(remainingItems.begin(), remainingItems.end());
 813                     }
 814                 }
 815             }
 816
 817             // Remove the eraser stroke itself:
 818             sp_repr_unparent( dc->repr );
 819             dc->repr = 0;
 820         }
 821     } else {
 822         if (dc->repr) {
 823             sp_repr_unparent(dc->repr);
 824             dc->repr = 0;
 825         }
 826     }
 827
 828
 829     if ( workDone ) {
 830         sp_document_done(sp_desktop_document(desktop), SP_VERB_CONTEXT_ERASER,
 831                          _("Draw eraser stroke"));
 832     } else {
 833         sp_document_cancel(sp_desktop_document(desktop));
 834     }
 835 }
 836
 837 static void
 838 add_cap(SPCurve *curve,
 839         Geom::Point const &pre, Geom::Point const &from,
 840         Geom::Point const &to, Geom::Point const &post,
 841         double rounding)
 842 {
 843     Geom::Point vel = rounding * Geom::rot90( to - from ) / sqrt(2.0);
 844     double mag = Geom::L2(vel);
 845
 846     Geom::Point v_in = from - pre;
 847     double mag_in = Geom::L2(v_in);
 848     if ( mag_in > ERASER_EPSILON ) {
 849         v_in = mag * v_in / mag_in;
 850     } else {
 851         v_in = Geom::Point(0, 0);
 852     }
 853
 854     Geom::Point v_out = to - post;
 855     double mag_out = Geom::L2(v_out);
 856     if ( mag_out > ERASER_EPSILON ) {
 857         v_out = mag * v_out / mag_out;
 858     } else {
 859         v_out = Geom::Point(0, 0);
 860     }
 861
 862     if ( Geom::L2(v_in) > ERASER_EPSILON || Geom::L2(v_out) > ERASER_EPSILON ) {
 863         curve->curveto(from + v_in, to + v_out, to);
 864     }
 865 }
 866
 867 static void
 868 accumulate_eraser(SPEraserContext *dc)
 869 {
 870     if ( !dc->cal1->is_empty() && !dc->cal2->is_empty() ) {
 871         dc->accumulated->reset(); /*  Is this required ?? */
 872         SPCurve *rev_cal2 = dc->cal2->create_reverse();
 873
 874         g_assert(dc->cal1->get_segment_count() > 0);
 875         g_assert(rev_cal2->get_segment_count() > 0);
 876         g_assert( ! dc->cal1->first_path()->closed() );
 877         g_assert( ! rev_cal2->first_path()->closed() );
 878
 879         Geom::CubicBezier const * dc_cal1_firstseg  = dynamic_cast<Geom::CubicBezier const *>( dc->cal1->first_segment() );
 880         Geom::CubicBezier const * rev_cal2_firstseg = dynamic_cast<Geom::CubicBezier const *>( rev_cal2->first_segment() );
 881         Geom::CubicBezier const * dc_cal1_lastseg   = dynamic_cast<Geom::CubicBezier const *>( dc->cal1->last_segment() );
 882         Geom::CubicBezier const * rev_cal2_lastseg  = dynamic_cast<Geom::CubicBezier const *>( rev_cal2->last_segment() );
 883         g_assert( dc_cal1_firstseg );
 884         g_assert( rev_cal2_firstseg );
 885         g_assert( dc_cal1_lastseg );
 886         g_assert( rev_cal2_lastseg );
 887
 888         dc->accumulated->append(dc->cal1, FALSE);
 889
 890         add_cap(dc->accumulated, (*dc_cal1_lastseg)[2], (*dc_cal1_lastseg)[3], (*rev_cal2_firstseg)[0], (*rev_cal2_firstseg)[1], dc->cap_rounding);
 891
 892         dc->accumulated->append(rev_cal2, TRUE);
 893
 894         add_cap(dc->accumulated, (*rev_cal2_lastseg)[2], (*rev_cal2_lastseg)[3], (*dc_cal1_firstseg)[0], (*dc_cal1_firstseg)[1], dc->cap_rounding);
 895
 896         dc->accumulated->closepath();
 897
 898         rev_cal2->unref();
 899
 900         dc->cal1->reset();
 901         dc->cal2->reset();
 902     }
 903 }
 904
 905 static double square(double const x)
 906 {
 907     return x * x;
 908 }
 909
 910 static void
 911 fit_and_split(SPEraserContext *dc, gboolean release)
 912 {
 913     SPDesktop *desktop = SP_EVENT_CONTEXT(dc)->desktop;
 914
 915     double const tolerance_sq = square( desktop->w2d().descrim() * TOLERANCE_ERASER );
 916
 917 #ifdef ERASER_VERBOSE
 918     g_print("[F&S:R=%c]", release?'T':'F');
 919 #endif
 920
 921     if (!( dc->npoints > 0 && dc->npoints < SAMPLING_SIZE ))
 922         return; // just clicked
 923
 924     if ( dc->npoints == SAMPLING_SIZE - 1 || release ) {
 925 #define BEZIER_SIZE       4
 926 #define BEZIER_MAX_BEZIERS  8
 927 #define BEZIER_MAX_LENGTH ( BEZIER_SIZE * BEZIER_MAX_BEZIERS )
 928
 929 #ifdef ERASER_VERBOSE
 930         g_print("[F&S:#] dc->npoints:%d, release:%s\n",
 931                 dc->npoints, release ? "TRUE" : "FALSE");
 932 #endif
 933
 934         /* Current eraser */
 935         if ( dc->cal1->is_empty() || dc->cal2->is_empty() ) {
 936             /* dc->npoints > 0 */
 937             /* g_print("erasers(1|2) reset\n"); */
 938             dc->cal1->reset();
 939             dc->cal2->reset();
 940
 941             dc->cal1->moveto(dc->point1[0]);
 942             dc->cal2->moveto(dc->point2[0]);
 943         }
 944
 945         Geom::Point b1[BEZIER_MAX_LENGTH];
 946         gint const nb1 = Geom::bezier_fit_cubic_r(b1, dc->point1, dc->npoints,
 947                                                tolerance_sq, BEZIER_MAX_BEZIERS);
 948         g_assert( nb1 * BEZIER_SIZE <= gint(G_N_ELEMENTS(b1)) );
 949
 950         Geom::Point b2[BEZIER_MAX_LENGTH];
 951         gint const nb2 = Geom::bezier_fit_cubic_r(b2, dc->point2, dc->npoints,
 952                                                tolerance_sq, BEZIER_MAX_BEZIERS);
 953         g_assert( nb2 * BEZIER_SIZE <= gint(G_N_ELEMENTS(b2)) );
 954
 955         if ( nb1 != -1 && nb2 != -1 ) {
 956             /* Fit and draw and reset state */
 957 #ifdef ERASER_VERBOSE
 958             g_print("nb1:%d nb2:%d\n", nb1, nb2);
 959 #endif
 960             /* CanvasShape */
 961             if (! release) {
 962                 dc->currentcurve->reset();
 963                 dc->currentcurve->moveto(b1[0]);
 964                 for (Geom::Point *bp1 = b1; bp1 < b1 + BEZIER_SIZE * nb1; bp1 += BEZIER_SIZE) {
 965                     dc->currentcurve->curveto(bp1[1],
 966                                      bp1[2], bp1[3]);
 967                 }
 968                 dc->currentcurve->lineto(b2[BEZIER_SIZE*(nb2-1) + 3]);
 969                 for (Geom::Point *bp2 = b2 + BEZIER_SIZE * ( nb2 - 1 ); bp2 >= b2; bp2 -= BEZIER_SIZE) {
 970                     dc->currentcurve->curveto(bp2[2], bp2[1], bp2[0]);
 971                 }
 972                 // FIXME: dc->segments is always NULL at this point??
 973                 if (!dc->segments) { // first segment
 974                     add_cap(dc->currentcurve, b2[1], b2[0], b1[0], b1[1], dc->cap_rounding);
 975                 }
 976                 dc->currentcurve->closepath();
 977                 sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(dc->currentshape), dc->currentcurve);
 978             }
 979
 980             /* Current eraser */
 981             for (Geom::Point *bp1 = b1; bp1 < b1 + BEZIER_SIZE * nb1; bp1 += BEZIER_SIZE) {
 982                 dc->cal1->curveto(bp1[1], bp1[2], bp1[3]);
 983             }
 984             for (Geom::Point *bp2 = b2; bp2 < b2 + BEZIER_SIZE * nb2; bp2 += BEZIER_SIZE) {
 985                 dc->cal2->curveto(bp2[1], bp2[2], bp2[3]);
 986             }
 987         } else {
 988             /* fixme: ??? */
 989 #ifdef ERASER_VERBOSE
 990             g_print("[fit_and_split] failed to fit-cubic.\n");
 991 #endif
 992             draw_temporary_box(dc);
 993
 994             for (gint i = 1; i < dc->npoints; i++) {
 995                 dc->cal1->lineto(dc->point1[i]);
 996             }
 997             for (gint i = 1; i < dc->npoints; i++) {
 998                 dc->cal2->lineto(dc->point2[i]);
 999             }
1000         }
1001
1002         /* Fit and draw and copy last point */
1003 #ifdef ERASER_VERBOSE
1004         g_print("[%d]Yup\n", dc->npoints);
1005 #endif
1006         if (!release) {
1007             Inkscape::Preferences *prefs = Inkscape::Preferences::get();
1008             gint eraserMode = prefs->getBool("/tools/eraser/mode") ? 1 : 0;
1009             g_assert(!dc->currentcurve->is_empty());
1010
1011             SPCanvasItem *cbp = sp_canvas_item_new(sp_desktop_sketch(desktop),
1012                                                    SP_TYPE_CANVAS_BPATH,
1013                                                    NULL);
1014             SPCurve *curve = dc->currentcurve->copy();
1015             sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH (cbp), curve);
1016             curve->unref();
1017
1018             guint32 fillColor = sp_desktop_get_color_tool (desktop, "/tools/eraser", true);
1019             //guint32 strokeColor = sp_desktop_get_color_tool (desktop, "/tools/eraser", false);
1020             double opacity = sp_desktop_get_master_opacity_tool (desktop, "/tools/eraser");
1021             double fillOpacity = sp_desktop_get_opacity_tool (desktop, "/tools/eraser", true);
1022             //double strokeOpacity = sp_desktop_get_opacity_tool (desktop, "/tools/eraser", false);
1023             sp_canvas_bpath_set_fill(SP_CANVAS_BPATH(cbp), ((fillColor & 0xffffff00) | SP_COLOR_F_TO_U(opacity*fillOpacity)), SP_WIND_RULE_EVENODD);
1024             //on second thougtht don't do stroke yet because we don't have stoke-width yet and because stoke appears between segments while drawing
1025             //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);
1026             sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(cbp), 0x00000000, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
1027             /* fixme: Cannot we cascade it to root more clearly? */
1028             g_signal_connect(G_OBJECT(cbp), "event", G_CALLBACK(sp_desktop_root_handler), desktop);
1029
1030             dc->segments = g_slist_prepend(dc->segments, cbp);
1031
1032             if ( !eraserMode ) {
1033                 sp_canvas_item_hide(cbp);
1034                 sp_canvas_item_hide(dc->currentshape);
1035             }
1036         }
1037
1038         dc->point1[0] = dc->point1[dc->npoints - 1];
1039         dc->point2[0] = dc->point2[dc->npoints - 1];
1040         dc->npoints = 1;
1041     } else {
1042         draw_temporary_box(dc);
1043     }
1044 }
1045
1046 static void
1047 draw_temporary_box(SPEraserContext *dc)
1048 {
1049     dc->currentcurve->reset();
1050
1051     dc->currentcurve->moveto(dc->point1[dc->npoints-1]);
1052     for (gint i = dc->npoints-2; i >= 0; i--) {
1053         dc->currentcurve->lineto(dc->point1[i]);
1054     }
1055     for (gint i = 0; i < dc->npoints; i++) {
1056         dc->currentcurve->lineto(dc->point2[i]);
1057     }
1058     if (dc->npoints >= 2) {
1059         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);
1060     }
1061
1062     dc->currentcurve->closepath();
1063     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(dc->currentshape), dc->currentcurve);
1064 }
1065
1066 /*
1067   Local Variables:
1068   mode:c++
1069   c-file-style:"stroustrup"
1070   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
1071   indent-tabs-mode:nil
1072   fill-column:99
1073   End:
1074 */
1075 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :