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