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 "display/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 "prefs-utils.h"
  50 #include "pixmaps/cursor-eraser.xpm"
  51 #include "libnr/n-art-bpath.h"
  52 #include "libnr/nr-path.h"
  53 #include "libnr/nr-matrix-ops.h"
  54 #include "libnr/nr-scale-translate-ops.h"
  55 #include "xml/repr.h"
  56 #include "context-fns.h"
  57 #include "sp-item.h"
  58 #include "inkscape.h"
  59 #include "color.h"
  60 #include "rubberband.h"
  61 #include "splivarot.h"
  62 #include "sp-item-group.h"
  63 #include "sp-shape.h"
  64 #include "sp-path.h"
  65 #include "sp-text.h"
  66 #include "display/canvas-bpath.h"
  67 #include "display/canvas-arena.h"
  68 #include "livarot/Shape.h"
  69 #include "isnan.h"
  70
  71 #include "eraser-context.h"
  72
  73 #define ERC_RED_RGBA 0xff0000ff
  74
  75 #define TOLERANCE_ERASER 0.1
  76
  77 #define ERASER_EPSILON 0.5e-6
  78 #define ERASER_EPSILON_START 0.5e-2
  79 #define ERASER_VEL_START 1e-5
  80
  81 #define DRAG_MIN 0.0
  82 #define DRAG_DEFAULT 1.0
  83 #define DRAG_MAX 1.0
  84
  85
  86 static void sp_eraser_context_class_init(SPEraserContextClass *klass);
  87 static void sp_eraser_context_init(SPEraserContext *erc);
  88 static void sp_eraser_context_dispose(GObject *object);
  89
  90 static void sp_eraser_context_setup(SPEventContext *ec);
  91 static void sp_eraser_context_set(SPEventContext *ec, gchar const *key, gchar const *val);
  92 static gint sp_eraser_context_root_handler(SPEventContext *ec, GdkEvent *event);
  93
  94 static void clear_current(SPEraserContext *dc);
  95 static void set_to_accumulated(SPEraserContext *dc);
  96 static void add_cap(SPCurve *curve, NR::Point const &pre, NR::Point const &from, NR::Point const &to, NR::Point const &post, double rounding);
  97 static void accumulate_eraser(SPEraserContext *dc);
  98
  99 static void fit_and_split(SPEraserContext *erc, gboolean release);
 100
 101 static void sp_eraser_reset(SPEraserContext *erc, NR::Point p);
 102 static NR::Point sp_eraser_get_npoint(SPEraserContext const *erc, NR::Point v);
 103 static NR::Point sp_eraser_get_vpoint(SPEraserContext const *erc, NR::Point n);
 104 static void draw_temporary_box(SPEraserContext *dc);
 105
 106
 107 static SPEventContextClass *eraser_parent_class = 0;
 108
 109 GType sp_eraser_context_get_type(void)
 110 {
 111     static GType type = 0;
 112     if (!type) {
 113         GTypeInfo info = {
 114             sizeof(SPEraserContextClass),
 115             0, // base_init
 116             0, // base_finalize
 117             (GClassInitFunc)sp_eraser_context_class_init,
 118             0, // class_finalize
 119             0, // class_data
 120             sizeof(SPEraserContext),
 121             0, // n_preallocs
 122             (GInstanceInitFunc)sp_eraser_context_init,
 123             0 // value_table
 124         };
 125         type = g_type_register_static(SP_TYPE_COMMON_CONTEXT, "SPEraserContext", &info, static_cast<GTypeFlags>(0));
 126     }
 127     return type;
 128 }
 129
 130 static void
 131 sp_eraser_context_class_init(SPEraserContextClass *klass)
 132 {
 133     GObjectClass *object_class = (GObjectClass *) klass;
 134     SPEventContextClass *event_context_class = (SPEventContextClass *) klass;
 135
 136     eraser_parent_class = (SPEventContextClass*)g_type_class_peek_parent(klass);
 137
 138     object_class->dispose = sp_eraser_context_dispose;
 139
 140     event_context_class->setup = sp_eraser_context_setup;
 141     event_context_class->set = sp_eraser_context_set;
 142     event_context_class->root_handler = sp_eraser_context_root_handler;
 143 }
 144
 145 static void
 146 sp_eraser_context_init(SPEraserContext *erc)
 147 {
 148     erc->cursor_shape = cursor_eraser_xpm;
 149     erc->hot_x = 4;
 150     erc->hot_y = 4;
 151 }
 152
 153 static void
 154 sp_eraser_context_dispose(GObject *object)
 155 {
 156     //SPEraserContext *erc = SP_ERASER_CONTEXT(object);
 157
 158     G_OBJECT_CLASS(eraser_parent_class)->dispose(object);
 159 }
 160
 161 static void
 162 sp_eraser_context_setup(SPEventContext *ec)
 163 {
 164     SPEraserContext *erc = SP_ERASER_CONTEXT(ec);
 165
 166     if (((SPEventContextClass *) eraser_parent_class)->setup)
 167         ((SPEventContextClass *) eraser_parent_class)->setup(ec);
 168
 169     erc->accumulated = new SPCurve(32);
 170     erc->currentcurve = new SPCurve(4);
 171
 172     erc->cal1 = new SPCurve(32);
 173     erc->cal2 = new SPCurve(32);
 174
 175     erc->currentshape = sp_canvas_item_new(sp_desktop_sketch(ec->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), ec->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((ec->desktop)->messageStack());
 209
 210     if (prefs_get_int_attribute("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, gchar const *key, gchar const *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, key, 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 NR::Point
 235 sp_eraser_get_npoint(SPEraserContext const *dc, NR::Point v)
 236 {
 237     NR::Rect drect = SP_EVENT_CONTEXT(dc)->desktop->get_display_area();
 238     double const max = MAX ( drect.dimensions()[NR::X], drect.dimensions()[NR::Y] );
 239     return NR::Point(( v[NR::X] - drect.min()[NR::X] ) / max,  ( v[NR::Y] - drect.min()[NR::Y] ) / max);
 240 }
 241
 242 /* Get view point */
 243 static NR::Point
 244 sp_eraser_get_vpoint(SPEraserContext const *dc, NR::Point n)
 245 {
 246     NR::Rect drect = SP_EVENT_CONTEXT(dc)->desktop->get_display_area();
 247     double const max = MAX ( drect.dimensions()[NR::X], drect.dimensions()[NR::Y] );
 248     return NR::Point(n[NR::X] * max + drect.min()[NR::X], n[NR::Y] * max + drect.min()[NR::Y]);
 249 }
 250
 251 static void
 252 sp_eraser_reset(SPEraserContext *dc, NR::Point p)
 253 {
 254     dc->last = dc->cur = sp_eraser_get_npoint(dc, p);
 255     dc->vel = NR::Point(0,0);
 256     dc->vel_max = 0;
 257     dc->acc = NR::Point(0,0);
 258     dc->ang = NR::Point(0,0);
 259     dc->del = NR::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, NR::Point p)
 284 {
 285     NR::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     NR::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 ( NR::L2(force) < ERASER_EPSILON || (dc->vel_max < ERASER_VEL_START && NR::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 (NR::L2(dc->vel) > dc->vel_max)
 311         dc->vel_max = NR::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             NR::Point ang1 = NR::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         NR::Point ang1 = NR::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 = NR::L2(dc->vel);
 336     if ( mag_vel < ERASER_EPSILON ) {
 337         return FALSE;
 338     }
 339     NR::Point ang2 = NR::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 = NR::L2(NR::Point (cos (new_ang), sin (new_ang)) - dc->ang);
 362     if ( angle_delta / NR::L2(dc->vel) > 4000 ) {
 363         return FALSE;
 364     }
 365
 366     // convert to point
 367     dc->ang = NR::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", NR::L2(force), NR::L2(dc->acc), dc->vel_max, NR::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     NR::Point brush = sp_eraser_get_vpoint(dc, dc->cur);
 395     NR::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 * NR::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*NR::L2(dc->vel));
 420         tremble_right = (y2)*dc->tremor * (0.15 + 0.8*width) * (0.35 + 14*NR::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     NR::Point del_left = dezoomify_factor * (width + tremble_left) * dc->ang;
 433     NR::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                 SPDesktop *desktop = SP_EVENT_CONTEXT_DESKTOP(dc);
 484
 485                 if (Inkscape::have_viable_layer(desktop, dc->_message_context) == false) {
 486                     return TRUE;
 487                 }
 488
 489                 NR::Point const button_w(event->button.x,
 490                                          event->button.y);
 491                 NR::Point const button_dt(desktop->w2d(button_w));
 492                 sp_eraser_reset(dc, button_dt);
 493                 sp_eraser_extinput(dc, event);
 494                 sp_eraser_apply(dc, button_dt);
 495                 dc->accumulated->reset();
 496                 if (dc->repr) {
 497                     dc->repr = NULL;
 498                 }
 499
 500                 Inkscape::Rubberband::get()->start(desktop, button_dt);
 501                 Inkscape::Rubberband::get()->setMode(RUBBERBAND_MODE_TOUCHPATH);
 502
 503                 /* initialize first point */
 504                 dc->npoints = 0;
 505
 506                 sp_canvas_item_grab(SP_CANVAS_ITEM(desktop->acetate),
 507                                     ( GDK_KEY_PRESS_MASK |
 508                                       GDK_BUTTON_RELEASE_MASK |
 509                                       GDK_POINTER_MOTION_MASK |
 510                                       GDK_BUTTON_PRESS_MASK ),
 511                                     NULL,
 512                                     event->button.time);
 513
 514                 ret = TRUE;
 515
 516                 sp_canvas_force_full_redraw_after_interruptions(desktop->canvas, 3);
 517                 dc->is_drawing = true;
 518             }
 519             break;
 520         case GDK_MOTION_NOTIFY:
 521         {
 522             NR::Point const motion_w(event->motion.x,
 523                                      event->motion.y);
 524             NR::Point motion_dt(desktop->w2d(motion_w));
 525             sp_eraser_extinput(dc, event);
 526
 527             dc->_message_context->clear();
 528
 529             if ( dc->is_drawing && (event->motion.state & GDK_BUTTON1_MASK) && !event_context->space_panning) {
 530                 dc->dragging = TRUE;
 531
 532                 dc->_message_context->set(Inkscape::NORMAL_MESSAGE, _("<b>Drawing</b> an eraser stroke"));
 533
 534                 if (!sp_eraser_apply(dc, motion_dt)) {
 535                     ret = TRUE;
 536                     break;
 537                 }
 538
 539                 if ( dc->cur != dc->last ) {
 540                     sp_eraser_brush(dc);
 541                     g_assert( dc->npoints > 0 );
 542                     fit_and_split(dc, FALSE);
 543                 }
 544                 ret = TRUE;
 545             }
 546             Inkscape::Rubberband::get()->move(motion_dt);
 547         }
 548         break;
 549
 550
 551     case GDK_BUTTON_RELEASE:
 552     {
 553         NR::Point const motion_w(event->button.x, event->button.y);
 554         NR::Point const motion_dt(desktop->w2d(motion_w));
 555
 556         sp_canvas_item_ungrab(SP_CANVAS_ITEM(desktop->acetate), event->button.time);
 557         sp_canvas_end_forced_full_redraws(desktop->canvas);
 558         dc->is_drawing = false;
 559
 560         if (dc->dragging && event->button.button == 1 && !event_context->space_panning) {
 561             dc->dragging = FALSE;
 562
 563             NR::Maybe<NR::Rect> const b = Inkscape::Rubberband::get()->getRectangle();
 564
 565             sp_eraser_apply(dc, motion_dt);
 566
 567             /* Remove all temporary line segments */
 568             while (dc->segments) {
 569                 gtk_object_destroy(GTK_OBJECT(dc->segments->data));
 570                 dc->segments = g_slist_remove(dc->segments, dc->segments->data);
 571             }
 572
 573             /* Create object */
 574             fit_and_split(dc, TRUE);
 575             accumulate_eraser(dc);
 576             set_to_accumulated(dc); // performs document_done
 577
 578             /* reset accumulated curve */
 579             dc->accumulated->reset();
 580
 581             clear_current(dc);
 582             if (dc->repr) {
 583                 dc->repr = NULL;
 584             }
 585
 586             Inkscape::Rubberband::get()->stop();
 587             dc->_message_context->clear();
 588             ret = TRUE;
 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()->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         NArtBpath *abp;
 722         gchar *str;
 723
 724         if (!dc->repr) {
 725             /* Create object */
 726             Inkscape::XML::Document *xml_doc = sp_document_repr_doc(desktop->doc());
 727             Inkscape::XML::Node *repr = xml_doc->createElement("svg:path");
 728
 729             /* Set style */
 730             sp_desktop_apply_style_tool (desktop, repr, "tools.eraser", false);
 731
 732             dc->repr = repr;
 733
 734             SPItem *item=SP_ITEM(desktop->currentLayer()->appendChildRepr(dc->repr));
 735             Inkscape::GC::release(dc->repr);
 736             item->transform = SP_ITEM(desktop->currentRoot())->getRelativeTransform(desktop->currentLayer());
 737             item->updateRepr();
 738         }
 739         abp = nr_artpath_affine(dc->accumulated->get_bpath(), sp_desktop_dt2root_affine(desktop));
 740         str = sp_svg_write_path(abp);
 741         g_assert( str != NULL );
 742         g_free(abp);
 743         dc->repr->setAttribute("d", str);
 744         g_free(str);
 745
 746         if ( dc->repr ) {
 747             bool wasSelection = false;
 748             Inkscape::Selection *selection = sp_desktop_selection(desktop);
 749             gint eraserMode = (prefs_get_int_attribute("tools.eraser", "mode", 0) != 0) ? 1 : 0;
 750             Inkscape::XML::Document *xml_doc = sp_document_repr_doc(desktop->doc());
 751
 752             SPItem* acid = SP_ITEM(desktop->doc()->getObjectByRepr(dc->repr));
 753             NR::Maybe<NR::Rect> eraserBbox = acid->getBounds(NR::identity());
 754             NR::Rect bounds = (*eraserBbox) * desktop->doc2dt();
 755             std::vector<SPItem*> remainingItems;
 756             GSList* toWorkOn = 0;
 757             if (selection->isEmpty()) {
 758                 if ( eraserMode ) {
 759                     toWorkOn = sp_document_partial_items_in_box(sp_desktop_document(desktop), desktop->dkey, bounds);
 760                 } else {
 761                     Inkscape::Rubberband::Rubberband *r = Inkscape::Rubberband::get();
 762                     toWorkOn = sp_document_items_at_points(sp_desktop_document(desktop), desktop->dkey, r->getPoints());
 763                 }
 764                 toWorkOn = g_slist_remove( toWorkOn, acid );
 765             } else {
 766                 toWorkOn = g_slist_copy(const_cast<GSList*>(selection->itemList()));
 767                 wasSelection = true;
 768             }
 769
 770             if ( g_slist_length(toWorkOn) > 0 ) {
 771                 if ( eraserMode ) {
 772                     for (GSList *i = toWorkOn ; i ; i = i->next ) {
 773                         SPItem *item = SP_ITEM(i->data);
 774                         if ( eraserMode ) {
 775                             NR::Maybe<NR::Rect> bbox = item->getBounds(NR::identity());
 776                             if (bbox && bbox->intersects(*eraserBbox)) {
 777                                 Inkscape::XML::Node* dup = dc->repr->duplicate(xml_doc);
 778                                 dc->repr->parent()->appendChild(dup);
 779                                 Inkscape::GC::release(dup); // parent takes over
 780
 781                                 selection->set(item);
 782                                 selection->add(dup);
 783                                 sp_selected_path_diff_skip_undo();
 784                                 workDone = true; // TODO set this only if something was cut.
 785                                 if ( !selection->isEmpty() ) {
 786                                     // If the item was not completely erased, track the new remainder.
 787                                     GSList *nowSel = g_slist_copy(const_cast<GSList *>(selection->itemList()));
 788                                     for (GSList const *i2 = nowSel ; i2 ; i2 = i2->next ) {
 789                                         remainingItems.push_back(SP_ITEM(i2->data));
 790                                     }
 791                                     g_slist_free(nowSel);
 792                                 }
 793                             } else {
 794                                 remainingItems.push_back(item);
 795                             }
 796                         }
 797                     }
 798                 } else {
 799                     for (GSList *i = toWorkOn ; i ; i = i->next ) {
 800                         sp_object_ref( SP_ITEM(i->data), 0 );
 801                     }
 802                     for (GSList *i = toWorkOn ; i ; i = i->next ) {
 803                         SPItem *item = SP_ITEM(i->data);
 804                         item->deleteObject(true);
 805                         sp_object_unref(item);
 806                         workDone = true;
 807                     }
 808                 }
 809
 810                 g_slist_free(toWorkOn);
 811
 812                 if ( !eraserMode ) {
 813                     //sp_selection_delete();
 814                     remainingItems.clear();
 815                 }
 816
 817                 selection->clear();
 818                 if ( wasSelection ) {
 819                     if ( !remainingItems.empty() ) {
 820                         selection->add(remainingItems.begin(), remainingItems.end());
 821                     }
 822                 }
 823             }
 824
 825             // Remove the eraser stroke itself:
 826             sp_repr_unparent( dc->repr );
 827             dc->repr = 0;
 828         }
 829     } else {
 830         if (dc->repr) {
 831             sp_repr_unparent(dc->repr);
 832             dc->repr = 0;
 833         }
 834     }
 835
 836
 837     if ( workDone ) {
 838         sp_document_done(sp_desktop_document(desktop), SP_VERB_CONTEXT_ERASER,
 839                          _("Draw eraser stroke"));
 840     } else {
 841         sp_document_cancel(sp_desktop_document(desktop));
 842     }
 843 }
 844
 845 static void
 846 add_cap(SPCurve *curve,
 847         NR::Point const &pre, NR::Point const &from,
 848         NR::Point const &to, NR::Point const &post,
 849         double rounding)
 850 {
 851     NR::Point vel = rounding * NR::rot90( to - from ) / sqrt(2.0);
 852     double mag = NR::L2(vel);
 853
 854     NR::Point v_in = from - pre;
 855     double mag_in = NR::L2(v_in);
 856     if ( mag_in > ERASER_EPSILON ) {
 857         v_in = mag * v_in / mag_in;
 858     } else {
 859         v_in = NR::Point(0, 0);
 860     }
 861
 862     NR::Point v_out = to - post;
 863     double mag_out = NR::L2(v_out);
 864     if ( mag_out > ERASER_EPSILON ) {
 865         v_out = mag * v_out / mag_out;
 866     } else {
 867         v_out = NR::Point(0, 0);
 868     }
 869
 870     if ( NR::L2(v_in) > ERASER_EPSILON || NR::L2(v_out) > ERASER_EPSILON ) {
 871         curve->curveto(from + v_in, to + v_out, to);
 872     }
 873 }
 874
 875 static void
 876 accumulate_eraser(SPEraserContext *dc)
 877 {
 878     if ( !dc->cal1->is_empty() && !dc->cal2->is_empty() ) {
 879         dc->accumulated->reset(); /*  Is this required ?? */
 880         SPCurve *rev_cal2 = dc->cal2->create_reverse();
 881
 882         g_assert(dc->cal1->get_length() > 1);
 883         g_assert(rev_cal2->get_length() > 1);
 884         g_assert(SP_CURVE_SEGMENT(dc->cal1, 0)->code == NR_MOVETO_OPEN);
 885         g_assert(SP_CURVE_SEGMENT(rev_cal2, 0)->code == NR_MOVETO_OPEN);
 886         g_assert(SP_CURVE_SEGMENT(dc->cal1, 1)->code == NR_CURVETO);
 887         g_assert(SP_CURVE_SEGMENT(rev_cal2, 1)->code == NR_CURVETO);
 888         g_assert(SP_CURVE_SEGMENT(dc->cal1, dc->cal1->get_length()-1)->code == NR_CURVETO);
 889         g_assert(SP_CURVE_SEGMENT(rev_cal2, rev_cal2->get_length()-1)->code == NR_CURVETO);
 890
 891         dc->accumulated->append(dc->cal1, FALSE);
 892
 893         add_cap(dc->accumulated, SP_CURVE_SEGMENT(dc->cal1, dc->cal1->get_length()-1)->c(2), SP_CURVE_SEGMENT(dc->cal1, dc->cal1->get_length()-1)->c(3), SP_CURVE_SEGMENT(rev_cal2, 0)->c(3), SP_CURVE_SEGMENT(rev_cal2, 1)->c(1), dc->cap_rounding);
 894
 895         dc->accumulated->append(rev_cal2, TRUE);
 896
 897         add_cap(dc->accumulated, SP_CURVE_SEGMENT(rev_cal2, rev_cal2->get_length()-1)->c(2), SP_CURVE_SEGMENT(rev_cal2, rev_cal2->get_length()-1)->c(3), SP_CURVE_SEGMENT(dc->cal1, 0)->c(3), SP_CURVE_SEGMENT(dc->cal1, 1)->c(1), dc->cap_rounding);
 898
 899         dc->accumulated->closepath();
 900
 901         rev_cal2->unref();
 902
 903         dc->cal1->reset();
 904         dc->cal2->reset();
 905     }
 906 }
 907
 908 static double square(double const x)
 909 {
 910     return x * x;
 911 }
 912
 913 static void
 914 fit_and_split(SPEraserContext *dc, gboolean release)
 915 {
 916     double const tolerance_sq = square( NR::expansion(SP_EVENT_CONTEXT(dc)->desktop->w2d()) * TOLERANCE_ERASER );
 917
 918 #ifdef ERASER_VERBOSE
 919     g_print("[F&S:R=%c]", release?'T':'F');
 920 #endif
 921
 922     if (!( dc->npoints > 0 && dc->npoints < SAMPLING_SIZE ))
 923         return; // just clicked
 924
 925     if ( dc->npoints == SAMPLING_SIZE - 1 || release ) {
 926 #define BEZIER_SIZE       4
 927 #define BEZIER_MAX_BEZIERS  8
 928 #define BEZIER_MAX_LENGTH ( BEZIER_SIZE * BEZIER_MAX_BEZIERS )
 929
 930 #ifdef ERASER_VERBOSE
 931         g_print("[F&S:#] dc->npoints:%d, release:%s\n",
 932                 dc->npoints, release ? "TRUE" : "FALSE");
 933 #endif
 934
 935         /* Current eraser */
 936         if ( dc->cal1->get_length() == 0 || dc->cal2->get_length() == 0 ) {
 937             /* dc->npoints > 0 */
 938             /* g_print("erasers(1|2) reset\n"); */
 939             dc->cal1->reset();
 940             dc->cal2->reset();
 941
 942             dc->cal1->moveto(dc->point1[0]);
 943             dc->cal2->moveto(dc->point2[0]);
 944         }
 945
 946         NR::Point b1[BEZIER_MAX_LENGTH];
 947         gint const nb1 = sp_bezier_fit_cubic_r(b1, dc->point1, dc->npoints,
 948                                                tolerance_sq, BEZIER_MAX_BEZIERS);
 949         g_assert( nb1 * BEZIER_SIZE <= gint(G_N_ELEMENTS(b1)) );
 950
 951         NR::Point b2[BEZIER_MAX_LENGTH];
 952         gint const nb2 = sp_bezier_fit_cubic_r(b2, dc->point2, dc->npoints,
 953                                                tolerance_sq, BEZIER_MAX_BEZIERS);
 954         g_assert( nb2 * BEZIER_SIZE <= gint(G_N_ELEMENTS(b2)) );
 955
 956         if ( nb1 != -1 && nb2 != -1 ) {
 957             /* Fit and draw and reset state */
 958 #ifdef ERASER_VERBOSE
 959             g_print("nb1:%d nb2:%d\n", nb1, nb2);
 960 #endif
 961             /* CanvasShape */
 962             if (! release) {
 963                 dc->currentcurve->reset();
 964                 dc->currentcurve->moveto(b1[0]);
 965                 for (NR::Point *bp1 = b1; bp1 < b1 + BEZIER_SIZE * nb1; bp1 += BEZIER_SIZE) {
 966                     dc->currentcurve->curveto(bp1[1],
 967                                      bp1[2], bp1[3]);
 968                 }
 969                 dc->currentcurve->lineto(b2[BEZIER_SIZE*(nb2-1) + 3]);
 970                 for (NR::Point *bp2 = b2 + BEZIER_SIZE * ( nb2 - 1 ); bp2 >= b2; bp2 -= BEZIER_SIZE) {
 971                     dc->currentcurve->curveto(bp2[2], bp2[1], bp2[0]);
 972                 }
 973                 // FIXME: dc->segments is always NULL at this point??
 974                 if (!dc->segments) { // first segment
 975                     add_cap(dc->currentcurve, b2[1], b2[0], b1[0], b1[1], dc->cap_rounding);
 976                 }
 977                 dc->currentcurve->closepath();
 978                 sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(dc->currentshape), dc->currentcurve);
 979             }
 980
 981             /* Current eraser */
 982             for (NR::Point *bp1 = b1; bp1 < b1 + BEZIER_SIZE * nb1; bp1 += BEZIER_SIZE) {
 983                 dc->cal1->curveto(bp1[1], bp1[2], bp1[3]);
 984             }
 985             for (NR::Point *bp2 = b2; bp2 < b2 + BEZIER_SIZE * nb2; bp2 += BEZIER_SIZE) {
 986                 dc->cal2->curveto(bp2[1], bp2[2], bp2[3]);
 987             }
 988         } else {
 989             /* fixme: ??? */
 990 #ifdef ERASER_VERBOSE
 991             g_print("[fit_and_split] failed to fit-cubic.\n");
 992 #endif
 993             draw_temporary_box(dc);
 994
 995             for (gint i = 1; i < dc->npoints; i++) {
 996                 dc->cal1->lineto(dc->point1[i]);
 997             }
 998             for (gint i = 1; i < dc->npoints; i++) {
 999                 dc->cal2->lineto(dc->point2[i]);
1000             }
1001         }
1002
1003         /* Fit and draw and copy last point */
1004 #ifdef ERASER_VERBOSE
1005         g_print("[%d]Yup\n", dc->npoints);
1006 #endif
1007         if (!release) {
1008             gint eraserMode = (prefs_get_int_attribute("tools.eraser", "mode", 0) != 0) ? 1 : 0;
1009             g_assert(!dc->currentcurve->is_empty());
1010
1011             SPCanvasItem *cbp = sp_canvas_item_new(sp_desktop_sketch(SP_EVENT_CONTEXT(dc)->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 (SP_ACTIVE_DESKTOP, "tools.eraser", true);
1019             //guint32 strokeColor = sp_desktop_get_color_tool (SP_ACTIVE_DESKTOP, "tools.eraser", false);
1020             double opacity = sp_desktop_get_master_opacity_tool (SP_ACTIVE_DESKTOP, "tools.eraser");
1021             double fillOpacity = sp_desktop_get_opacity_tool (SP_ACTIVE_DESKTOP, "tools.eraser", true);
1022             //double strokeOpacity = sp_desktop_get_opacity_tool (SP_ACTIVE_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), SP_EVENT_CONTEXT(dc)->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 :