src/dyna-draw-context.cpp

   1 #define __SP_DYNA_DRAW_CONTEXT_C__
   2
   3 /*
   4  * Handwriting-like drawing mode
   5  *
   6  * Authors:
   7  *   Mitsuru Oka <oka326@parkcity.ne.jp>
   8  *   Lauris Kaplinski <lauris@kaplinski.com>
   9  *   bulia byak <buliabyak@users.sf.net>
  10  *   MenTaLguY <mental@rydia.net>
  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  *
  21  * Released under GNU GPL, read the file 'COPYING' for more information
  22  */
  23
  24 #define noDYNA_DRAW_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 #include "display/curve.h"
  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-calligraphy.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 "libnr/nr-convert2geom.h"
  56 #include "xml/repr.h"
  57 #include "context-fns.h"
  58 #include "sp-item.h"
  59 #include "inkscape.h"
  60 #include "color.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 <2geom/isnan.h>
  70 #include <2geom/pathvector.h>
  71
  72 #include "dyna-draw-context.h"
  73
  74 #define DDC_RED_RGBA 0xff0000ff
  75
  76 #define TOLERANCE_CALLIGRAPHIC 0.1
  77
  78 #define DYNA_EPSILON 0.5e-6
  79 #define DYNA_EPSILON_START 0.5e-2
  80 #define DYNA_VEL_START 1e-5
  81
  82 #define DYNA_MIN_WIDTH 1.0e-6
  83
  84 static void sp_dyna_draw_context_class_init(SPDynaDrawContextClass *klass);
  85 static void sp_dyna_draw_context_init(SPDynaDrawContext *ddc);
  86 static void sp_dyna_draw_context_dispose(GObject *object);
  87
  88 static void sp_dyna_draw_context_setup(SPEventContext *ec);
  89 static void sp_dyna_draw_context_set(SPEventContext *ec, gchar const *key, gchar const *val);
  90 static gint sp_dyna_draw_context_root_handler(SPEventContext *ec, GdkEvent *event);
  91
  92 static void clear_current(SPDynaDrawContext *dc);
  93 static void set_to_accumulated(SPDynaDrawContext *dc, bool unionize);
  94 static void add_cap(SPCurve *curve, NR::Point const &from, NR::Point const &to, double rounding);
  95 static bool accumulate_calligraphic(SPDynaDrawContext *dc);
  96
  97 static void fit_and_split(SPDynaDrawContext *ddc, gboolean release);
  98
  99 static void sp_dyna_draw_reset(SPDynaDrawContext *ddc, NR::Point p);
 100 static NR::Point sp_dyna_draw_get_npoint(SPDynaDrawContext const *ddc, NR::Point v);
 101 static NR::Point sp_dyna_draw_get_vpoint(SPDynaDrawContext const *ddc, NR::Point n);
 102 static void draw_temporary_box(SPDynaDrawContext *dc);
 103
 104
 105 static SPEventContextClass *dd_parent_class = 0;
 106
 107 GType sp_dyna_draw_context_get_type(void)
 108 {
 109     static GType type = 0;
 110     if (!type) {
 111         GTypeInfo info = {
 112             sizeof(SPDynaDrawContextClass),
 113             0, // base_init
 114             0, // base_finalize
 115             (GClassInitFunc)sp_dyna_draw_context_class_init,
 116             0, // class_finalize
 117             0, // class_data
 118             sizeof(SPDynaDrawContext),
 119             0, // n_preallocs
 120             (GInstanceInitFunc)sp_dyna_draw_context_init,
 121             0 // value_table
 122         };
 123         type = g_type_register_static(SP_TYPE_COMMON_CONTEXT, "SPDynaDrawContext", &info, static_cast<GTypeFlags>(0));
 124     }
 125     return type;
 126 }
 127
 128 static void
 129 sp_dyna_draw_context_class_init(SPDynaDrawContextClass *klass)
 130 {
 131     GObjectClass *object_class = (GObjectClass *) klass;
 132     SPEventContextClass *event_context_class = (SPEventContextClass *) klass;
 133
 134     dd_parent_class = (SPEventContextClass*)g_type_class_peek_parent(klass);
 135
 136     object_class->dispose = sp_dyna_draw_context_dispose;
 137
 138     event_context_class->setup = sp_dyna_draw_context_setup;
 139     event_context_class->set = sp_dyna_draw_context_set;
 140     event_context_class->root_handler = sp_dyna_draw_context_root_handler;
 141 }
 142
 143 static void
 144 sp_dyna_draw_context_init(SPDynaDrawContext *ddc)
 145 {
 146     ddc->cursor_shape = cursor_calligraphy_xpm;
 147     ddc->hot_x = 4;
 148     ddc->hot_y = 4;
 149
 150     ddc->vel_thin = 0.1;
 151     ddc->flatness = 0.9;
 152     ddc->cap_rounding = 0.0;
 153
 154     ddc->abs_width = false;
 155     ddc->keep_selected = true;
 156
 157     ddc->hatch_spacing = 0;
 158     ddc->hatch_spacing_step = 0;
 159     new (&ddc->hatch_pointer_past) std::list<double>();
 160     new (&ddc->hatch_nearest_past) std::list<double>();
 161     ddc->hatch_last_nearest = NR::Point(0,0);
 162     ddc->hatch_last_pointer = NR::Point(0,0);
 163     ddc->hatch_vector_accumulated = NR::Point(0,0);
 164     ddc->hatch_escaped = false;
 165     ddc->hatch_area = NULL;
 166     ddc->hatch_item = NULL;
 167     ddc->hatch_livarot_path = NULL;
 168
 169     ddc->trace_bg = false;
 170 }
 171
 172 static void
 173 sp_dyna_draw_context_dispose(GObject *object)
 174 {
 175     SPDynaDrawContext *ddc = SP_DYNA_DRAW_CONTEXT(object);
 176
 177     if (ddc->hatch_area) {
 178         gtk_object_destroy(GTK_OBJECT(ddc->hatch_area));
 179         ddc->hatch_area = NULL;
 180     }
 181
 182
 183     G_OBJECT_CLASS(dd_parent_class)->dispose(object);
 184
 185     ddc->hatch_pointer_past.~list();
 186     ddc->hatch_nearest_past.~list();
 187 }
 188
 189 static void
 190 sp_dyna_draw_context_setup(SPEventContext *ec)
 191 {
 192     SPDynaDrawContext *ddc = SP_DYNA_DRAW_CONTEXT(ec);
 193
 194     if (((SPEventContextClass *) dd_parent_class)->setup)
 195         ((SPEventContextClass *) dd_parent_class)->setup(ec);
 196
 197     ddc->accumulated = new SPCurve(32);
 198     ddc->currentcurve = new SPCurve(4);
 199
 200     ddc->cal1 = new SPCurve(32);
 201     ddc->cal2 = new SPCurve(32);
 202
 203     ddc->currentshape = sp_canvas_item_new(sp_desktop_sketch(ec->desktop), SP_TYPE_CANVAS_BPATH, NULL);
 204     sp_canvas_bpath_set_fill(SP_CANVAS_BPATH(ddc->currentshape), DDC_RED_RGBA, SP_WIND_RULE_EVENODD);
 205     sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(ddc->currentshape), 0x00000000, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 206     /* fixme: Cannot we cascade it to root more clearly? */
 207     g_signal_connect(G_OBJECT(ddc->currentshape), "event", G_CALLBACK(sp_desktop_root_handler), ec->desktop);
 208
 209     {
 210         /* TODO: this can be done either with an arcto, and should maybe also be put in a general file (other tools use this as well) */
 211         SPCurve *c = new SPCurve();
 212         const double C1 = 0.552;
 213         c->moveto(-1,0);
 214         c->curveto(-1, C1, -C1, 1, 0, 1 );
 215         c->curveto(C1, 1, 1, C1, 1, 0 );
 216         c->curveto(1, -C1, C1, -1, 0, -1 );
 217         c->curveto(-C1, -1, -1, -C1, -1, 0 );
 218         c->closepath();
 219         ddc->hatch_area = sp_canvas_bpath_new(sp_desktop_controls(ec->desktop), c);
 220         c->unref();
 221         sp_canvas_bpath_set_fill(SP_CANVAS_BPATH(ddc->hatch_area), 0x00000000,(SPWindRule)0);
 222         sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(ddc->hatch_area), 0x0000007f, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 223         sp_canvas_item_hide(ddc->hatch_area);
 224     }
 225
 226     sp_event_context_read(ec, "mass");
 227     sp_event_context_read(ec, "wiggle");
 228     sp_event_context_read(ec, "angle");
 229     sp_event_context_read(ec, "width");
 230     sp_event_context_read(ec, "thinning");
 231     sp_event_context_read(ec, "tremor");
 232     sp_event_context_read(ec, "flatness");
 233     sp_event_context_read(ec, "tracebackground");
 234     sp_event_context_read(ec, "usepressure");
 235     sp_event_context_read(ec, "usetilt");
 236     sp_event_context_read(ec, "abs_width");
 237     sp_event_context_read(ec, "keep_selected");
 238     sp_event_context_read(ec, "cap_rounding");
 239
 240     ddc->is_drawing = false;
 241
 242     ddc->_message_context = new Inkscape::MessageContext((ec->desktop)->messageStack());
 243
 244     if (prefs_get_int_attribute("tools.calligraphic", "selcue", 0) != 0) {
 245         ec->enableSelectionCue();
 246     }
 247 }
 248
 249 static void
 250 sp_dyna_draw_context_set(SPEventContext *ec, gchar const *key, gchar const *val)
 251 {
 252     SPDynaDrawContext *ddc = SP_DYNA_DRAW_CONTEXT(ec);
 253
 254     if (!strcmp(key, "tracebackground")) {
 255         ddc->trace_bg = (val && strcmp(val, "0"));
 256     } else if (!strcmp(key, "keep_selected")) {
 257         ddc->keep_selected = (val && strcmp(val, "0"));
 258     } else {
 259         //pass on up to parent class to handle common attributes.
 260         if ( dd_parent_class->set ) {
 261             dd_parent_class->set(ec, key, val);
 262         }
 263     }
 264
 265     //g_print("DDC: %g %g %g %g\n", ddc->mass, ddc->drag, ddc->angle, ddc->width);
 266 }
 267
 268 static double
 269 flerp(double f0, double f1, double p)
 270 {
 271     return f0 + ( f1 - f0 ) * p;
 272 }
 273
 274 /* Get normalized point */
 275 static NR::Point
 276 sp_dyna_draw_get_npoint(SPDynaDrawContext const *dc, NR::Point v)
 277 {
 278     NR::Rect drect = SP_EVENT_CONTEXT(dc)->desktop->get_display_area();
 279     double const max = MAX ( drect.dimensions()[NR::X], drect.dimensions()[NR::Y] );
 280     return NR::Point(( v[NR::X] - drect.min()[NR::X] ) / max,  ( v[NR::Y] - drect.min()[NR::Y] ) / max);
 281 }
 282
 283 /* Get view point */
 284 static NR::Point
 285 sp_dyna_draw_get_vpoint(SPDynaDrawContext const *dc, NR::Point n)
 286 {
 287     NR::Rect drect = SP_EVENT_CONTEXT(dc)->desktop->get_display_area();
 288     double const max = MAX ( drect.dimensions()[NR::X], drect.dimensions()[NR::Y] );
 289     return NR::Point(n[NR::X] * max + drect.min()[NR::X], n[NR::Y] * max + drect.min()[NR::Y]);
 290 }
 291
 292 static void
 293 sp_dyna_draw_reset(SPDynaDrawContext *dc, NR::Point p)
 294 {
 295     dc->last = dc->cur = sp_dyna_draw_get_npoint(dc, p);
 296     dc->vel = NR::Point(0,0);
 297     dc->vel_max = 0;
 298     dc->acc = NR::Point(0,0);
 299     dc->ang = NR::Point(0,0);
 300     dc->del = NR::Point(0,0);
 301 }
 302
 303 static void
 304 sp_dyna_draw_extinput(SPDynaDrawContext *dc, GdkEvent *event)
 305 {
 306     if (gdk_event_get_axis (event, GDK_AXIS_PRESSURE, &dc->pressure))
 307         dc->pressure = CLAMP (dc->pressure, DDC_MIN_PRESSURE, DDC_MAX_PRESSURE);
 308     else
 309         dc->pressure = DDC_DEFAULT_PRESSURE;
 310
 311     if (gdk_event_get_axis (event, GDK_AXIS_XTILT, &dc->xtilt))
 312         dc->xtilt = CLAMP (dc->xtilt, DDC_MIN_TILT, DDC_MAX_TILT);
 313     else
 314         dc->xtilt = DDC_DEFAULT_TILT;
 315
 316     if (gdk_event_get_axis (event, GDK_AXIS_YTILT, &dc->ytilt))
 317         dc->ytilt = CLAMP (dc->ytilt, DDC_MIN_TILT, DDC_MAX_TILT);
 318     else
 319         dc->ytilt = DDC_DEFAULT_TILT;
 320 }
 321
 322
 323 static gboolean
 324 sp_dyna_draw_apply(SPDynaDrawContext *dc, NR::Point p)
 325 {
 326     NR::Point n = sp_dyna_draw_get_npoint(dc, p);
 327
 328     /* Calculate mass and drag */
 329     double const mass = flerp(1.0, 160.0, dc->mass);
 330     double const drag = flerp(0.0, 0.5, dc->drag * dc->drag);
 331
 332     /* Calculate force and acceleration */
 333     NR::Point force = n - dc->cur;
 334
 335     // If force is below the absolute threshold DYNA_EPSILON,
 336     // or we haven't yet reached DYNA_VEL_START (i.e. at the beginning of stroke)
 337     // _and_ the force is below the (higher) DYNA_EPSILON_START threshold,
 338     // discard this move.
 339     // This prevents flips, blobs, and jerks caused by microscopic tremor of the tablet pen,
 340     // especially bothersome at the start of the stroke where we don't yet have the inertia to
 341     // smooth them out.
 342     if ( NR::L2(force) < DYNA_EPSILON || (dc->vel_max < DYNA_VEL_START && NR::L2(force) < DYNA_EPSILON_START)) {
 343         return FALSE;
 344     }
 345
 346     dc->acc = force / mass;
 347
 348     /* Calculate new velocity */
 349     dc->vel += dc->acc;
 350
 351     if (NR::L2(dc->vel) > dc->vel_max)
 352         dc->vel_max = NR::L2(dc->vel);
 353
 354     /* Calculate angle of drawing tool */
 355
 356     double a1;
 357     if (dc->usetilt) {
 358         // 1a. calculate nib angle from input device tilt:
 359         gdouble length = std::sqrt(dc->xtilt*dc->xtilt + dc->ytilt*dc->ytilt);;
 360
 361         if (length > 0) {
 362             NR::Point ang1 = NR::Point(dc->ytilt/length, dc->xtilt/length);
 363             a1 = atan2(ang1);
 364         }
 365         else
 366             a1 = 0.0;
 367     }
 368     else {
 369         // 1b. fixed dc->angle (absolutely flat nib):
 370         double const radians = ( (dc->angle - 90) / 180.0 ) * M_PI;
 371         NR::Point ang1 = NR::Point(-sin(radians),  cos(radians));
 372         a1 = atan2(ang1);
 373     }
 374
 375     // 2. perpendicular to dc->vel (absolutely non-flat nib):
 376     gdouble const mag_vel = NR::L2(dc->vel);
 377     if ( mag_vel < DYNA_EPSILON ) {
 378         return FALSE;
 379     }
 380     NR::Point ang2 = NR::rot90(dc->vel) / mag_vel;
 381
 382     // 3. Average them using flatness parameter:
 383     // calculate angles
 384     double a2 = atan2(ang2);
 385     // flip a2 to force it to be in the same half-circle as a1
 386     bool flipped = false;
 387     if (fabs (a2-a1) > 0.5*M_PI) {
 388         a2 += M_PI;
 389         flipped = true;
 390     }
 391     // normalize a2
 392     if (a2 > M_PI)
 393         a2 -= 2*M_PI;
 394     if (a2 < -M_PI)
 395         a2 += 2*M_PI;
 396     // find the flatness-weighted bisector angle, unflip if a2 was flipped
 397     // FIXME: when dc->vel is oscillating around the fixed angle, the new_ang flips back and forth. How to avoid this?
 398     double new_ang = a1 + (1 - dc->flatness) * (a2 - a1) - (flipped? M_PI : 0);
 399
 400     // Try to detect a sudden flip when the new angle differs too much from the previous for the
 401     // current velocity; in that case discard this move
 402     double angle_delta = NR::L2(NR::Point (cos (new_ang), sin (new_ang)) - dc->ang);
 403     if ( angle_delta / NR::L2(dc->vel) > 4000 ) {
 404         return FALSE;
 405     }
 406
 407     // convert to point
 408     dc->ang = NR::Point (cos (new_ang), sin (new_ang));
 409
 410 //    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);
 411
 412     /* Apply drag */
 413     dc->vel *= 1.0 - drag;
 414
 415     /* Update position */
 416     dc->last = dc->cur;
 417     dc->cur += dc->vel;
 418
 419     return TRUE;
 420 }
 421
 422 static void
 423 sp_dyna_draw_brush(SPDynaDrawContext *dc)
 424 {
 425     g_assert( dc->npoints >= 0 && dc->npoints < SAMPLING_SIZE );
 426
 427     // How much velocity thins strokestyle
 428     double vel_thin = flerp (0, 160, dc->vel_thin);
 429
 430     // Influence of pressure on thickness
 431     double pressure_thick = (dc->usepressure ? dc->pressure : 1.0);
 432
 433     // get the real brush point, not the same as pointer (affected by hatch tracking and/or mass
 434     // drag)
 435     NR::Point brush = sp_dyna_draw_get_vpoint(dc, dc->cur);
 436     NR::Point brush_w = SP_EVENT_CONTEXT(dc)->desktop->d2w(brush);
 437
 438     double trace_thick = 1;
 439     if (dc->trace_bg) {
 440         // pick single pixel
 441         NRPixBlock pb;
 442         int x = (int) floor(brush_w[NR::X]);
 443         int y = (int) floor(brush_w[NR::Y]);
 444         nr_pixblock_setup_fast(&pb, NR_PIXBLOCK_MODE_R8G8B8A8P, x, y, x+1, y+1, TRUE);
 445         sp_canvas_arena_render_pixblock(SP_CANVAS_ARENA(sp_desktop_drawing(SP_EVENT_CONTEXT(dc)->desktop)), &pb);
 446         const unsigned char *s = NR_PIXBLOCK_PX(&pb);
 447         double R = s[0] / 255.0;
 448         double G = s[1] / 255.0;
 449         double B = s[2] / 255.0;
 450         double A = s[3] / 255.0;
 451         double max = MAX (MAX (R, G), B);
 452         double min = MIN (MIN (R, G), B);
 453         double L = A * (max + min)/2 + (1 - A); // blend with white bg
 454         trace_thick = 1 - L;
 455         //g_print ("L %g thick %g\n", L, trace_thick);
 456     }
 457
 458     double width = (pressure_thick * trace_thick - vel_thin * NR::L2(dc->vel)) * dc->width;
 459
 460     double tremble_left = 0, tremble_right = 0;
 461     if (dc->tremor > 0) {
 462         // obtain two normally distributed random variables, using polar Box-Muller transform
 463         double x1, x2, w, y1, y2;
 464         do {
 465             x1 = 2.0 * g_random_double_range(0,1) - 1.0;
 466             x2 = 2.0 * g_random_double_range(0,1) - 1.0;
 467             w = x1 * x1 + x2 * x2;
 468         } while ( w >= 1.0 );
 469         w = sqrt( (-2.0 * log( w ) ) / w );
 470         y1 = x1 * w;
 471         y2 = x2 * w;
 472
 473         // deflect both left and right edges randomly and independently, so that:
 474         // (1) dc->tremor=1 corresponds to sigma=1, decreasing dc->tremor narrows the bell curve;
 475         // (2) deflection depends on width, but is upped for small widths for better visual uniformity across widths;
 476         // (3) deflection somewhat depends on speed, to prevent fast strokes looking
 477         // comparatively smooth and slow ones excessively jittery
 478         tremble_left  = (y1)*dc->tremor * (0.15 + 0.8*width) * (0.35 + 14*NR::L2(dc->vel));
 479         tremble_right = (y2)*dc->tremor * (0.15 + 0.8*width) * (0.35 + 14*NR::L2(dc->vel));
 480     }
 481
 482     if ( width < 0.02 * dc->width ) {
 483         width = 0.02 * dc->width;
 484     }
 485
 486     double dezoomify_factor = 0.05 * 1000;
 487     if (!dc->abs_width) {
 488         dezoomify_factor /= SP_EVENT_CONTEXT(dc)->desktop->current_zoom();
 489     }
 490
 491     NR::Point del_left = dezoomify_factor * (width + tremble_left) * dc->ang;
 492     NR::Point del_right = dezoomify_factor * (width + tremble_right) * dc->ang;
 493
 494     dc->point1[dc->npoints] = brush + del_left;
 495     dc->point2[dc->npoints] = brush - del_right;
 496
 497     dc->del = 0.5*(del_left + del_right);
 498
 499     dc->npoints++;
 500 }
 501
 502 void
 503 sp_ddc_update_toolbox (SPDesktop *desktop, const gchar *id, double value)
 504 {
 505     desktop->setToolboxAdjustmentValue (id, value);
 506 }
 507
 508 static void
 509 calligraphic_cancel(SPDynaDrawContext *dc)
 510 {
 511     SPDesktop *desktop = SP_EVENT_CONTEXT(dc)->desktop;
 512     dc->dragging = FALSE;
 513     dc->is_drawing = false;
 514     sp_canvas_item_ungrab(SP_CANVAS_ITEM(desktop->acetate), 0);
 515             /* Remove all temporary line segments */
 516             while (dc->segments) {
 517                 gtk_object_destroy(GTK_OBJECT(dc->segments->data));
 518                 dc->segments = g_slist_remove(dc->segments, dc->segments->data);
 519             }
 520             /* reset accumulated curve */
 521             dc->accumulated->reset();
 522             clear_current(dc);
 523             if (dc->repr) {
 524                 dc->repr = NULL;
 525             }
 526 }
 527
 528
 529 gint
 530 sp_dyna_draw_context_root_handler(SPEventContext *event_context,
 531                                   GdkEvent *event)
 532 {
 533     SPDynaDrawContext *dc = SP_DYNA_DRAW_CONTEXT(event_context);
 534     SPDesktop *desktop = event_context->desktop;
 535
 536     gint ret = FALSE;
 537
 538     switch (event->type) {
 539         case GDK_BUTTON_PRESS:
 540             if (event->button.button == 1 && !event_context->space_panning) {
 541
 542                 SPDesktop *desktop = SP_EVENT_CONTEXT_DESKTOP(dc);
 543
 544                 if (Inkscape::have_viable_layer(desktop, dc->_message_context) == false) {
 545                     return TRUE;
 546                 }
 547
 548                 NR::Point const button_w(event->button.x,
 549                                          event->button.y);
 550                 NR::Point const button_dt(desktop->w2d(button_w));
 551                 sp_dyna_draw_reset(dc, button_dt);
 552                 sp_dyna_draw_extinput(dc, event);
 553                 sp_dyna_draw_apply(dc, button_dt);
 554                 dc->accumulated->reset();
 555                 if (dc->repr) {
 556                     dc->repr = NULL;
 557                 }
 558
 559                 /* initialize first point */
 560                 dc->npoints = 0;
 561
 562                 sp_canvas_item_grab(SP_CANVAS_ITEM(desktop->acetate),
 563                                     ( GDK_KEY_PRESS_MASK |
 564                                       GDK_BUTTON_RELEASE_MASK |
 565                                       GDK_POINTER_MOTION_MASK |
 566                                       GDK_BUTTON_PRESS_MASK ),
 567                                     NULL,
 568                                     event->button.time);
 569
 570                 ret = TRUE;
 571
 572                 sp_canvas_force_full_redraw_after_interruptions(desktop->canvas, 3);
 573                 dc->is_drawing = true;
 574             }
 575             break;
 576         case GDK_MOTION_NOTIFY:
 577         {
 578             NR::Point const motion_w(event->motion.x,
 579                                      event->motion.y);
 580             NR::Point motion_dt(desktop->w2d(motion_w));
 581             sp_dyna_draw_extinput(dc, event);
 582
 583             dc->_message_context->clear();
 584
 585             // for hatching:
 586             double hatch_dist = 0;
 587             NR::Point hatch_unit_vector(0,0);
 588             NR::Point nearest(0,0);
 589             NR::Point pointer(0,0);
 590             NR::Matrix motion_to_curve(NR::identity());
 591
 592             if (event->motion.state & GDK_CONTROL_MASK) { // hatching - sense the item
 593
 594                 SPItem *selected = sp_desktop_selection(desktop)->singleItem();
 595                 if (selected && (SP_IS_SHAPE(selected) || SP_IS_TEXT(selected))) {
 596                     // One item selected, and it's a path;
 597                     // let's try to track it as a guide
 598
 599                     if (selected != dc->hatch_item) {
 600                         dc->hatch_item = selected;
 601                         if (dc->hatch_livarot_path)
 602                             delete dc->hatch_livarot_path;
 603                         dc->hatch_livarot_path = Path_for_item (dc->hatch_item, true, true);
 604                         dc->hatch_livarot_path->ConvertWithBackData(0.01);
 605                     }
 606
 607                     // calculate pointer point in the guide item's coords
 608                     motion_to_curve = from_2geom(sp_item_dt2i_affine(selected) * sp_item_i2doc_affine(selected));
 609                     pointer = motion_dt * motion_to_curve;
 610
 611                     // calculate the nearest point on the guide path
 612                     NR::Maybe<Path::cut_position> position = get_nearest_position_on_Path(dc->hatch_livarot_path, pointer);
 613                     nearest = get_point_on_Path(dc->hatch_livarot_path, position->piece, position->t);
 614
 615
 616                     // distance from pointer to nearest
 617                     hatch_dist = NR::L2(pointer - nearest);
 618                     // unit-length vector
 619                     hatch_unit_vector = (pointer - nearest)/hatch_dist;
 620
 621                     dc->_message_context->set(Inkscape::NORMAL_MESSAGE, _("<b>Guide path selected</b>; start drawing along the guide with <b>Ctrl</b>"));
 622                 } else {
 623                     dc->_message_context->set(Inkscape::NORMAL_MESSAGE, _("<b>Select a guide path</b> to track with <b>Ctrl</b>"));
 624                 }
 625             }
 626
 627             if ( dc->is_drawing && (event->motion.state & GDK_BUTTON1_MASK) && !event_context->space_panning) {
 628                 dc->dragging = TRUE;
 629
 630                 if (event->motion.state & GDK_CONTROL_MASK && dc->hatch_item) { // hatching
 631
 632 #define SPEED_ELEMENTS 12
 633 #define SPEED_MIN 0.12
 634 #define SPEED_NORMAL 0.65
 635
 636                     // speed is the movement of the nearest point along the guide path, divided by
 637                     // the movement of the pointer at the same period; it is averaged for the last
 638                     // SPEED_ELEMENTS motion events.  Normally, as you track the guide path, speed
 639                     // is about 1, i.e. the nearest point on the path is moved by about the same
 640                     // distance as the pointer. If the speed starts to decrease, we are losing
 641                     // contact with the guide; if it drops below SPEED_MIN, we are on our own and
 642                     // not attracted to guide anymore. Most often this happens when you have
 643                     // tracked to the end of a guide calligraphic stroke and keep moving
 644                     // further. We try to handle this situation gracefully: not stick with the
 645                     // guide forever but let go of it smoothly and without sharp jerks (non-zero
 646                     // mass recommended; with zero mass, jerks are still quite noticeable).
 647
 648                     double speed = 1;
 649                     if (NR::L2(dc->hatch_last_nearest) != 0) {
 650                         // the distance nearest moved since the last motion event
 651                         double nearest_moved = NR::L2(nearest - dc->hatch_last_nearest);
 652                         // the distance pointer moved since the last motion event
 653                         double pointer_moved = NR::L2(pointer - dc->hatch_last_pointer);
 654                         // store them in stacks limited to SPEED_ELEMENTS
 655                         dc->hatch_nearest_past.push_front(nearest_moved);
 656                         if (dc->hatch_nearest_past.size() > SPEED_ELEMENTS)
 657                             dc->hatch_nearest_past.pop_back();
 658                         dc->hatch_pointer_past.push_front(pointer_moved);
 659                         if (dc->hatch_pointer_past.size() > SPEED_ELEMENTS)
 660                             dc->hatch_pointer_past.pop_back();
 661
 662                         // If the stacks are full,
 663                         if (dc->hatch_nearest_past.size() == SPEED_ELEMENTS) {
 664                             // calculate the sums of all stored movements
 665                             double nearest_sum = std::accumulate (dc->hatch_nearest_past.begin(), dc->hatch_nearest_past.end(), 0.0);
 666                             double pointer_sum = std::accumulate (dc->hatch_pointer_past.begin(), dc->hatch_pointer_past.end(), 0.0);
 667                             // and divide to get the speed
 668                             speed = nearest_sum/pointer_sum;
 669                             //g_print ("nearest sum %g  pointer_sum %g  speed %g\n", nearest_sum, pointer_sum, speed);
 670                         }
 671                     }
 672
 673                     if (   dc->hatch_escaped  // already escaped, do not reattach
 674                         || (speed < SPEED_MIN) // stuck; most likely reached end of traced stroke
 675                         || (dc->hatch_spacing > 0 && hatch_dist > 50 * dc->hatch_spacing) // went too far from the guide
 676                         ) {
 677                         // We are NOT attracted to the guide!
 678
 679                         //g_print ("\nlast_nearest %g %g   nearest %g %g  pointer %g %g  pos %d %g\n", dc->last_nearest[NR::X], dc->last_nearest[NR::Y], nearest[NR::X], nearest[NR::Y], pointer[NR::X], pointer[NR::Y], position->piece, position->t);
 680
 681                         // Remember hatch_escaped so we don't get
 682                         // attracted again until the end of this stroke
 683                         dc->hatch_escaped = true;
 684
 685                     } else {
 686
 687                         // Calculate angle cosine of this vector-to-guide and all past vectors
 688                         // summed, to detect if we accidentally flipped to the other side of the
 689                         // guide
 690                         double dot = NR::dot (pointer - nearest, dc->hatch_vector_accumulated);
 691                         dot /= NR::L2(pointer - nearest) * NR::L2(dc->hatch_vector_accumulated);
 692
 693                         if (dc->hatch_spacing != 0) { // spacing was already set
 694                             double target;
 695                             if (speed > SPEED_NORMAL) {
 696                                 // all ok, strictly obey the spacing
 697                                 target = dc->hatch_spacing;
 698                             } else {
 699                                 // looks like we're starting to lose speed,
 700                                 // so _gradually_ let go attraction to prevent jerks
 701                                 target = (dc->hatch_spacing * speed + hatch_dist * (SPEED_NORMAL - speed))/SPEED_NORMAL;
 702                             }
 703                             if (!IS_NAN(dot) && dot < -0.5) {// flip
 704                                 target = -target;
 705                             }
 706
 707                             // This is the track pointer that we will use instead of the real one
 708                             NR::Point new_pointer = nearest + target * hatch_unit_vector;
 709
 710                             // some limited feedback: allow persistent pulling to slightly change
 711                             // the spacing
 712                             dc->hatch_spacing += (hatch_dist - dc->hatch_spacing)/3500;
 713
 714                             // return it to the desktop coords
 715                             motion_dt = new_pointer * motion_to_curve.inverse();
 716
 717                         } else {
 718                             // this is the first motion event, set the dist
 719                             dc->hatch_spacing = hatch_dist;
 720                         }
 721
 722                         // remember last points
 723                         dc->hatch_last_pointer = pointer;
 724                         dc->hatch_last_nearest = nearest;
 725                         dc->hatch_vector_accumulated += (pointer - nearest);
 726                     }
 727
 728                     dc->_message_context->set(Inkscape::NORMAL_MESSAGE, dc->hatch_escaped? _("Tracking: <b>connection to guide path lost!</b>") : _("<b>Tracking</b> a guide path"));
 729
 730                 } else {
 731                     dc->_message_context->set(Inkscape::NORMAL_MESSAGE, _("<b>Drawing</b> a calligraphic stroke"));
 732                 }
 733
 734                 if (!sp_dyna_draw_apply(dc, motion_dt)) {
 735                     ret = TRUE;
 736                     break;
 737                 }
 738
 739                 if ( dc->cur != dc->last ) {
 740                     sp_dyna_draw_brush(dc);
 741                     g_assert( dc->npoints > 0 );
 742                     fit_and_split(dc, FALSE);
 743                 }
 744                 ret = TRUE;
 745             }
 746
 747             // Draw the hatching circle if necessary
 748             if (event->motion.state & GDK_CONTROL_MASK) {
 749                 if (dc->hatch_spacing == 0 && hatch_dist != 0) {
 750                     // Haven't set spacing yet: gray, center free, update radius live
 751                     NR::Point c = desktop->w2d(motion_w);
 752                     NR::Matrix const sm (NR::scale(hatch_dist, hatch_dist) * NR::translate(c));
 753                     sp_canvas_item_affine_absolute(dc->hatch_area, sm);
 754                     sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(dc->hatch_area), 0x7f7f7fff, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 755                     sp_canvas_item_show(dc->hatch_area);
 756                 } else if (dc->dragging && !dc->hatch_escaped) {
 757                     // Tracking: green, center snapped, fixed radius
 758                     NR::Point c = motion_dt;
 759                     NR::Matrix const sm (NR::scale(dc->hatch_spacing, dc->hatch_spacing) * NR::translate(c));
 760                     sp_canvas_item_affine_absolute(dc->hatch_area, sm);
 761                     sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(dc->hatch_area), 0x00FF00ff, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 762                     sp_canvas_item_show(dc->hatch_area);
 763                 } else if (dc->dragging && dc->hatch_escaped) {
 764                     // Tracking escaped: red, center free, fixed radius
 765                     NR::Point c = desktop->w2d(motion_w);
 766                     NR::Matrix const sm (NR::scale(dc->hatch_spacing, dc->hatch_spacing) * NR::translate(c));
 767
 768                     sp_canvas_item_affine_absolute(dc->hatch_area, sm);
 769                     sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(dc->hatch_area), 0xFF0000ff, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 770                     sp_canvas_item_show(dc->hatch_area);
 771                 } else {
 772                     // Not drawing but spacing set: gray, center snapped, fixed radius
 773                     NR::Point c = (nearest + dc->hatch_spacing * hatch_unit_vector) * motion_to_curve.inverse();
 774                     if (!IS_NAN(c[NR::X]) && !IS_NAN(c[NR::Y])) {
 775                         NR::Matrix const sm (NR::scale(dc->hatch_spacing, dc->hatch_spacing) * NR::translate(c));
 776                         sp_canvas_item_affine_absolute(dc->hatch_area, sm);
 777                         sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(dc->hatch_area), 0x7f7f7fff, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 778                         sp_canvas_item_show(dc->hatch_area);
 779                     }
 780                 }
 781             } else {
 782                 sp_canvas_item_hide(dc->hatch_area);
 783             }
 784         }
 785         break;
 786
 787
 788     case GDK_BUTTON_RELEASE:
 789     {
 790         NR::Point const motion_w(event->button.x, event->button.y);
 791         NR::Point const motion_dt(desktop->w2d(motion_w));
 792
 793         sp_canvas_item_ungrab(SP_CANVAS_ITEM(desktop->acetate), event->button.time);
 794         sp_canvas_end_forced_full_redraws(desktop->canvas);
 795         dc->is_drawing = false;
 796
 797         if (dc->dragging && event->button.button == 1 && !event_context->space_panning) {
 798             dc->dragging = FALSE;
 799
 800             sp_dyna_draw_apply(dc, motion_dt);
 801
 802             /* Remove all temporary line segments */
 803             while (dc->segments) {
 804                 gtk_object_destroy(GTK_OBJECT(dc->segments->data));
 805                 dc->segments = g_slist_remove(dc->segments, dc->segments->data);
 806             }
 807
 808             /* Create object */
 809             fit_and_split(dc, TRUE);
 810             if (accumulate_calligraphic(dc))
 811                 set_to_accumulated(dc, event->button.state & GDK_SHIFT_MASK); // performs document_done
 812             else
 813                 g_warning ("Failed to create path: invalid data in dc->cal1 or dc->cal2");
 814
 815             /* reset accumulated curve */
 816             dc->accumulated->reset();
 817
 818             clear_current(dc);
 819             if (dc->repr) {
 820                 dc->repr = NULL;
 821             }
 822
 823             if (!dc->hatch_pointer_past.empty()) dc->hatch_pointer_past.clear();
 824             if (!dc->hatch_nearest_past.empty()) dc->hatch_nearest_past.clear();
 825             dc->hatch_last_nearest = NR::Point(0,0);
 826             dc->hatch_last_pointer = NR::Point(0,0);
 827             dc->hatch_vector_accumulated = NR::Point(0,0);
 828             dc->hatch_escaped = false;
 829             dc->hatch_item = NULL;
 830             dc->hatch_livarot_path = NULL;
 831
 832             if (dc->hatch_spacing != 0 && !dc->keep_selected) {
 833                 // we do not select the newly drawn path, so increase spacing by step
 834                 if (dc->hatch_spacing_step == 0) {
 835                     dc->hatch_spacing_step = dc->hatch_spacing;
 836                 }
 837                 dc->hatch_spacing += dc->hatch_spacing_step;
 838             }
 839
 840             dc->_message_context->clear();
 841             ret = TRUE;
 842         }
 843         break;
 844     }
 845
 846     case GDK_KEY_PRESS:
 847         switch (get_group0_keyval (&event->key)) {
 848         case GDK_Up:
 849         case GDK_KP_Up:
 850             if (!MOD__CTRL_ONLY) {
 851                 dc->angle += 5.0;
 852                 if (dc->angle > 90.0)
 853                     dc->angle = 90.0;
 854                 sp_ddc_update_toolbox (desktop, "calligraphy-angle", dc->angle);
 855                 ret = TRUE;
 856             }
 857             break;
 858         case GDK_Down:
 859         case GDK_KP_Down:
 860             if (!MOD__CTRL_ONLY) {
 861                 dc->angle -= 5.0;
 862                 if (dc->angle < -90.0)
 863                     dc->angle = -90.0;
 864                 sp_ddc_update_toolbox (desktop, "calligraphy-angle", dc->angle);
 865                 ret = TRUE;
 866             }
 867             break;
 868         case GDK_Right:
 869         case GDK_KP_Right:
 870             if (!MOD__CTRL_ONLY) {
 871                 dc->width += 0.01;
 872                 if (dc->width > 1.0)
 873                     dc->width = 1.0;
 874                 sp_ddc_update_toolbox (desktop, "altx-calligraphy", dc->width * 100); // the same spinbutton is for alt+x
 875                 ret = TRUE;
 876             }
 877             break;
 878         case GDK_Left:
 879         case GDK_KP_Left:
 880             if (!MOD__CTRL_ONLY) {
 881                 dc->width -= 0.01;
 882                 if (dc->width < 0.01)
 883                     dc->width = 0.01;
 884                 sp_ddc_update_toolbox (desktop, "altx-calligraphy", dc->width * 100);
 885                 ret = TRUE;
 886             }
 887             break;
 888         case GDK_Home:
 889         case GDK_KP_Home:
 890             dc->width = 0.01;
 891             sp_ddc_update_toolbox (desktop, "altx-calligraphy", dc->width * 100);
 892             ret = TRUE;
 893             break;
 894         case GDK_End:
 895         case GDK_KP_End:
 896             dc->width = 1.0;
 897             sp_ddc_update_toolbox (desktop, "altx-calligraphy", dc->width * 100);
 898             ret = TRUE;
 899             break;
 900         case GDK_x:
 901         case GDK_X:
 902             if (MOD__ALT_ONLY) {
 903                 desktop->setToolboxFocusTo ("altx-calligraphy");
 904                 ret = TRUE;
 905             }
 906             break;
 907         case GDK_Escape:
 908             if (dc->is_drawing) {
 909                 // if drawing, cancel, otherwise pass it up for deselecting
 910                 calligraphic_cancel (dc);
 911                 ret = TRUE;
 912             }
 913             break;
 914         case GDK_z:
 915         case GDK_Z:
 916             if (MOD__CTRL_ONLY && dc->is_drawing) {
 917                 // if drawing, cancel, otherwise pass it up for undo
 918                 calligraphic_cancel (dc);
 919                 ret = TRUE;
 920             }
 921             break;
 922         default:
 923             break;
 924         }
 925         break;
 926
 927     case GDK_KEY_RELEASE:
 928         switch (get_group0_keyval(&event->key)) {
 929             case GDK_Control_L:
 930             case GDK_Control_R:
 931                 dc->_message_context->clear();
 932                 dc->hatch_spacing = 0;
 933                 dc->hatch_spacing_step = 0;
 934                 break;
 935             default:
 936                 break;
 937         }
 938
 939     default:
 940         break;
 941     }
 942
 943     if (!ret) {
 944         if (((SPEventContextClass *) dd_parent_class)->root_handler) {
 945             ret = ((SPEventContextClass *) dd_parent_class)->root_handler(event_context, event);
 946         }
 947     }
 948
 949     return ret;
 950 }
 951
 952
 953 static void
 954 clear_current(SPDynaDrawContext *dc)
 955 {
 956     /* reset bpath */
 957     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(dc->currentshape), NULL);
 958     /* reset curve */
 959     dc->currentcurve->reset();
 960     dc->cal1->reset();
 961     dc->cal2->reset();
 962     /* reset points */
 963     dc->npoints = 0;
 964 }
 965
 966 static void
 967 set_to_accumulated(SPDynaDrawContext *dc, bool unionize)
 968 {
 969     SPDesktop *desktop = SP_EVENT_CONTEXT(dc)->desktop;
 970
 971     if (!dc->accumulated->is_empty()) {
 972         if (!dc->repr) {
 973             /* Create object */
 974             Inkscape::XML::Document *xml_doc = sp_document_repr_doc(desktop->doc());
 975             Inkscape::XML::Node *repr = xml_doc->createElement("svg:path");
 976
 977             /* Set style */
 978             sp_desktop_apply_style_tool (desktop, repr, "tools.calligraphic", false);
 979
 980             dc->repr = repr;
 981
 982             SPItem *item=SP_ITEM(desktop->currentLayer()->appendChildRepr(dc->repr));
 983             Inkscape::GC::release(dc->repr);
 984             item->transform = SP_ITEM(desktop->currentRoot())->getRelativeTransform(desktop->currentLayer());
 985             item->updateRepr();
 986         }
 987         Geom::PathVector pathv = dc->accumulated->get_pathvector() * to_2geom(sp_desktop_dt2root_affine(desktop));
 988         gchar *str = sp_svg_write_path(pathv);
 989         g_assert( str != NULL );
 990         dc->repr->setAttribute("d", str);
 991         g_free(str);
 992
 993         if (unionize) {
 994             sp_desktop_selection(desktop)->add(dc->repr);
 995             sp_selected_path_union_skip_undo();
 996         } else {
 997             if (dc->keep_selected) {
 998                 sp_desktop_selection(desktop)->set(dc->repr);
 999             }
1000         }
1001
1002     } else {
1003         if (dc->repr) {
1004             sp_repr_unparent(dc->repr);
1005         }
1006         dc->repr = NULL;
1007     }
1008
1009     sp_document_done(sp_desktop_document(desktop), SP_VERB_CONTEXT_CALLIGRAPHIC,
1010                      _("Draw calligraphic stroke"));
1011 }
1012
1013 static void
1014 add_cap(SPCurve *curve,
1015         NR::Point const &from,
1016         NR::Point const &to,
1017         double rounding)
1018 {
1019     if (NR::L2( to - from ) > DYNA_EPSILON) {
1020         NR::Point vel = rounding * NR::rot90( to - from ) / sqrt(2.0);
1021         double mag = NR::L2(vel);
1022
1023         NR::Point v = mag * NR::rot90( to - from ) / NR::L2( to - from );
1024         curve->curveto(from + v, to + v, to);
1025     }
1026 }
1027
1028 static bool
1029 accumulate_calligraphic(SPDynaDrawContext *dc)
1030 {
1031         if (
1032             dc->cal1->is_empty() ||
1033             dc->cal2->is_empty() ||
1034             (dc->cal1->get_segment_count() <= 0) ||
1035             dc->cal1->first_path()->closed()
1036             ) {
1037             dc->cal1->reset();
1038             dc->cal2->reset();
1039             return false; // failure
1040         }
1041
1042         SPCurve *rev_cal2 = dc->cal2->create_reverse();
1043         if (
1044             (rev_cal2->get_segment_count() <= 0) ||
1045             rev_cal2->first_path()->closed()
1046             ) {
1047             rev_cal2->unref();
1048             dc->cal1->reset();
1049             dc->cal2->reset();
1050             return false; // failure
1051         }
1052
1053         Geom::CubicBezier const * dc_cal1_firstseg  = dynamic_cast<Geom::CubicBezier const *>( dc->cal1->first_segment() );
1054         Geom::CubicBezier const * rev_cal2_firstseg = dynamic_cast<Geom::CubicBezier const *>( rev_cal2->first_segment() );
1055         Geom::CubicBezier const * dc_cal1_lastseg   = dynamic_cast<Geom::CubicBezier const *>( dc->cal1->last_segment() );
1056         Geom::CubicBezier const * rev_cal2_lastseg  = dynamic_cast<Geom::CubicBezier const *>( rev_cal2->last_segment() );
1057
1058         if (
1059             !dc_cal1_firstseg ||
1060             !rev_cal2_firstseg ||
1061             !dc_cal1_lastseg ||
1062             !rev_cal2_lastseg
1063             ) {
1064             rev_cal2->unref();
1065             dc->cal1->reset();
1066             dc->cal2->reset();
1067             return false; // failure
1068         }
1069
1070         dc->accumulated->reset(); /*  Is this required ?? */
1071
1072         dc->accumulated->append(dc->cal1, false);
1073
1074         add_cap(dc->accumulated, (*dc_cal1_lastseg)[3], (*rev_cal2_firstseg)[0], dc->cap_rounding);
1075
1076         dc->accumulated->append(rev_cal2, true);
1077
1078         add_cap(dc->accumulated, (*rev_cal2_lastseg)[3], (*dc_cal1_firstseg)[0], dc->cap_rounding);
1079
1080         dc->accumulated->closepath();
1081
1082         rev_cal2->unref();
1083
1084         dc->cal1->reset();
1085         dc->cal2->reset();
1086
1087         return true; // success
1088 }
1089
1090 static double square(double const x)
1091 {
1092     return x * x;
1093 }
1094
1095 static void
1096 fit_and_split(SPDynaDrawContext *dc, gboolean release)
1097 {
1098     double const tolerance_sq = square( NR::expansion(SP_EVENT_CONTEXT(dc)->desktop->w2d()) * TOLERANCE_CALLIGRAPHIC );
1099
1100 #ifdef DYNA_DRAW_VERBOSE
1101     g_print("[F&S:R=%c]", release?'T':'F');
1102 #endif
1103
1104     if (!( dc->npoints > 0 && dc->npoints < SAMPLING_SIZE ))
1105         return; // just clicked
1106
1107     if ( dc->npoints == SAMPLING_SIZE - 1 || release ) {
1108 #define BEZIER_SIZE       4
1109 #define BEZIER_MAX_BEZIERS  8
1110 #define BEZIER_MAX_LENGTH ( BEZIER_SIZE * BEZIER_MAX_BEZIERS )
1111
1112 #ifdef DYNA_DRAW_VERBOSE
1113         g_print("[F&S:#] dc->npoints:%d, release:%s\n",
1114                 dc->npoints, release ? "TRUE" : "FALSE");
1115 #endif
1116
1117         /* Current calligraphic */
1118         if ( dc->cal1->is_empty() || dc->cal2->is_empty() ) {
1119             /* dc->npoints > 0 */
1120             /* g_print("calligraphics(1|2) reset\n"); */
1121             dc->cal1->reset();
1122             dc->cal2->reset();
1123
1124             dc->cal1->moveto(dc->point1[0]);
1125             dc->cal2->moveto(dc->point2[0]);
1126         }
1127
1128         NR::Point b1[BEZIER_MAX_LENGTH];
1129         gint const nb1 = sp_bezier_fit_cubic_r(b1, dc->point1, dc->npoints,
1130                                                tolerance_sq, BEZIER_MAX_BEZIERS);
1131         g_assert( nb1 * BEZIER_SIZE <= gint(G_N_ELEMENTS(b1)) );
1132
1133         NR::Point b2[BEZIER_MAX_LENGTH];
1134         gint const nb2 = sp_bezier_fit_cubic_r(b2, dc->point2, dc->npoints,
1135                                                tolerance_sq, BEZIER_MAX_BEZIERS);
1136         g_assert( nb2 * BEZIER_SIZE <= gint(G_N_ELEMENTS(b2)) );
1137
1138         if ( nb1 != -1 && nb2 != -1 ) {
1139             /* Fit and draw and reset state */
1140 #ifdef DYNA_DRAW_VERBOSE
1141             g_print("nb1:%d nb2:%d\n", nb1, nb2);
1142 #endif
1143             /* CanvasShape */
1144             if (! release) {
1145                 dc->currentcurve->reset();
1146                 dc->currentcurve->moveto(b1[0]);
1147                 for (NR::Point *bp1 = b1; bp1 < b1 + BEZIER_SIZE * nb1; bp1 += BEZIER_SIZE) {
1148                     dc->currentcurve->curveto(bp1[1],
1149                                      bp1[2], bp1[3]);
1150                 }
1151                 dc->currentcurve->lineto(b2[BEZIER_SIZE*(nb2-1) + 3]);
1152                 for (NR::Point *bp2 = b2 + BEZIER_SIZE * ( nb2 - 1 ); bp2 >= b2; bp2 -= BEZIER_SIZE) {
1153                     dc->currentcurve->curveto(bp2[2], bp2[1], bp2[0]);
1154                 }
1155                 // FIXME: dc->segments is always NULL at this point??
1156                 if (!dc->segments) { // first segment
1157                     add_cap(dc->currentcurve, b2[0], b1[0], dc->cap_rounding);
1158                 }
1159                 dc->currentcurve->closepath();
1160                 sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(dc->currentshape), dc->currentcurve);
1161             }
1162
1163             /* Current calligraphic */
1164             for (NR::Point *bp1 = b1; bp1 < b1 + BEZIER_SIZE * nb1; bp1 += BEZIER_SIZE) {
1165                 dc->cal1->curveto(bp1[1], bp1[2], bp1[3]);
1166             }
1167             for (NR::Point *bp2 = b2; bp2 < b2 + BEZIER_SIZE * nb2; bp2 += BEZIER_SIZE) {
1168                 dc->cal2->curveto(bp2[1], bp2[2], bp2[3]);
1169             }
1170         } else {
1171             /* fixme: ??? */
1172 #ifdef DYNA_DRAW_VERBOSE
1173             g_print("[fit_and_split] failed to fit-cubic.\n");
1174 #endif
1175             draw_temporary_box(dc);
1176
1177             for (gint i = 1; i < dc->npoints; i++) {
1178                 dc->cal1->lineto(dc->point1[i]);
1179             }
1180             for (gint i = 1; i < dc->npoints; i++) {
1181                 dc->cal2->lineto(dc->point2[i]);
1182             }
1183         }
1184
1185         /* Fit and draw and copy last point */
1186 #ifdef DYNA_DRAW_VERBOSE
1187         g_print("[%d]Yup\n", dc->npoints);
1188 #endif
1189         if (!release) {
1190             g_assert(!dc->currentcurve->is_empty());
1191
1192             SPCanvasItem *cbp = sp_canvas_item_new(sp_desktop_sketch(SP_EVENT_CONTEXT(dc)->desktop),
1193                                                    SP_TYPE_CANVAS_BPATH,
1194                                                    NULL);
1195             SPCurve *curve = dc->currentcurve->copy();
1196             sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH (cbp), curve);
1197             curve->unref();
1198
1199             guint32 fillColor = sp_desktop_get_color_tool (SP_ACTIVE_DESKTOP, "tools.calligraphic", true);
1200             //guint32 strokeColor = sp_desktop_get_color_tool (SP_ACTIVE_DESKTOP, "tools.calligraphic", false);
1201             double opacity = sp_desktop_get_master_opacity_tool (SP_ACTIVE_DESKTOP, "tools.calligraphic");
1202             double fillOpacity = sp_desktop_get_opacity_tool (SP_ACTIVE_DESKTOP, "tools.calligraphic", true);
1203             //double strokeOpacity = sp_desktop_get_opacity_tool (SP_ACTIVE_DESKTOP, "tools.calligraphic", false);
1204             sp_canvas_bpath_set_fill(SP_CANVAS_BPATH(cbp), ((fillColor & 0xffffff00) | SP_COLOR_F_TO_U(opacity*fillOpacity)), SP_WIND_RULE_EVENODD);
1205             //on second thougtht don't do stroke yet because we don't have stoke-width yet and because stoke appears between segments while drawing
1206             //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);
1207             sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(cbp), 0x00000000, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
1208             /* fixme: Cannot we cascade it to root more clearly? */
1209             g_signal_connect(G_OBJECT(cbp), "event", G_CALLBACK(sp_desktop_root_handler), SP_EVENT_CONTEXT(dc)->desktop);
1210
1211             dc->segments = g_slist_prepend(dc->segments, cbp);
1212         }
1213
1214         dc->point1[0] = dc->point1[dc->npoints - 1];
1215         dc->point2[0] = dc->point2[dc->npoints - 1];
1216         dc->npoints = 1;
1217     } else {
1218         draw_temporary_box(dc);
1219     }
1220 }
1221
1222 static void
1223 draw_temporary_box(SPDynaDrawContext *dc)
1224 {
1225     dc->currentcurve->reset();
1226
1227     dc->currentcurve->moveto(dc->point2[dc->npoints-1]);
1228     for (gint i = dc->npoints-2; i >= 0; i--) {
1229         dc->currentcurve->lineto(dc->point2[i]);
1230     }
1231     for (gint i = 0; i < dc->npoints; i++) {
1232         dc->currentcurve->lineto(dc->point1[i]);
1233     }
1234
1235     if (dc->npoints >= 2) {
1236         add_cap(dc->currentcurve, dc->point1[dc->npoints-1], dc->point2[dc->npoints-1], dc->cap_rounding);
1237     }
1238
1239     dc->currentcurve->closepath();
1240     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(dc->currentshape), dc->currentcurve);
1241 }
1242
1243 /*
1244   Local Variables:
1245   mode:c++
1246   c-file-style:"stroustrup"
1247   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
1248   indent-tabs-mode:nil
1249   fill-column:99
1250   End:
1251 */
1252 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :