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 "xml/repr.h"
  56 #include "context-fns.h"
  57 #include "sp-item.h"
  58 #include "inkscape.h"
  59 #include "color.h"
  60 #include "splivarot.h"
  61 #include "sp-item-group.h"
  62 #include "sp-shape.h"
  63 #include "sp-path.h"
  64 #include "sp-text.h"
  65 #include "display/canvas-bpath.h"
  66 #include "display/canvas-arena.h"
  67 #include "livarot/Shape.h"
  68 #include "2geom/isnan.h"
  69
  70 #include "dyna-draw-context.h"
  71
  72 #define DDC_RED_RGBA 0xff0000ff
  73
  74 #define TOLERANCE_CALLIGRAPHIC 0.1
  75
  76 #define DYNA_EPSILON 0.5e-6
  77 #define DYNA_EPSILON_START 0.5e-2
  78 #define DYNA_VEL_START 1e-5
  79
  80 #define DYNA_MIN_WIDTH 1.0e-6
  81
  82
  83 // FIXME: move it to some shared file to be reused by both calligraphy and dropper
  84 #define C1 0.552
  85 static NArtBpath const hatch_area_circle[] = {
  86     { NR_MOVETO, 0, 0, 0, 0, -1, 0 },
  87     { NR_CURVETO, -1, C1, -C1, 1, 0, 1 },
  88     { NR_CURVETO, C1, 1, 1, C1, 1, 0 },
  89     { NR_CURVETO, 1, -C1, C1, -1, 0, -1 },
  90     { NR_CURVETO, -C1, -1, -1, -C1, -1, 0 },
  91     { NR_END, 0, 0, 0, 0, 0, 0 }
  92 };
  93 #undef C1
  94
  95
  96 static void sp_dyna_draw_context_class_init(SPDynaDrawContextClass *klass);
  97 static void sp_dyna_draw_context_init(SPDynaDrawContext *ddc);
  98 static void sp_dyna_draw_context_dispose(GObject *object);
  99
 100 static void sp_dyna_draw_context_setup(SPEventContext *ec);
 101 static void sp_dyna_draw_context_set(SPEventContext *ec, gchar const *key, gchar const *val);
 102 static gint sp_dyna_draw_context_root_handler(SPEventContext *ec, GdkEvent *event);
 103
 104 static void clear_current(SPDynaDrawContext *dc);
 105 static void set_to_accumulated(SPDynaDrawContext *dc, bool unionize);
 106 static void add_cap(SPCurve *curve, NR::Point const &from, NR::Point const &to, double rounding);
 107 static void accumulate_calligraphic(SPDynaDrawContext *dc);
 108
 109 static void fit_and_split(SPDynaDrawContext *ddc, gboolean release);
 110
 111 static void sp_dyna_draw_reset(SPDynaDrawContext *ddc, NR::Point p);
 112 static NR::Point sp_dyna_draw_get_npoint(SPDynaDrawContext const *ddc, NR::Point v);
 113 static NR::Point sp_dyna_draw_get_vpoint(SPDynaDrawContext const *ddc, NR::Point n);
 114 static void draw_temporary_box(SPDynaDrawContext *dc);
 115
 116
 117 static SPEventContextClass *dd_parent_class = 0;
 118
 119 GType sp_dyna_draw_context_get_type(void)
 120 {
 121     static GType type = 0;
 122     if (!type) {
 123         GTypeInfo info = {
 124             sizeof(SPDynaDrawContextClass),
 125             0, // base_init
 126             0, // base_finalize
 127             (GClassInitFunc)sp_dyna_draw_context_class_init,
 128             0, // class_finalize
 129             0, // class_data
 130             sizeof(SPDynaDrawContext),
 131             0, // n_preallocs
 132             (GInstanceInitFunc)sp_dyna_draw_context_init,
 133             0 // value_table
 134         };
 135         type = g_type_register_static(SP_TYPE_COMMON_CONTEXT, "SPDynaDrawContext", &info, static_cast<GTypeFlags>(0));
 136     }
 137     return type;
 138 }
 139
 140 static void
 141 sp_dyna_draw_context_class_init(SPDynaDrawContextClass *klass)
 142 {
 143     GObjectClass *object_class = (GObjectClass *) klass;
 144     SPEventContextClass *event_context_class = (SPEventContextClass *) klass;
 145
 146     dd_parent_class = (SPEventContextClass*)g_type_class_peek_parent(klass);
 147
 148     object_class->dispose = sp_dyna_draw_context_dispose;
 149
 150     event_context_class->setup = sp_dyna_draw_context_setup;
 151     event_context_class->set = sp_dyna_draw_context_set;
 152     event_context_class->root_handler = sp_dyna_draw_context_root_handler;
 153 }
 154
 155 static void
 156 sp_dyna_draw_context_init(SPDynaDrawContext *ddc)
 157 {
 158     ddc->cursor_shape = cursor_calligraphy_xpm;
 159     ddc->hot_x = 4;
 160     ddc->hot_y = 4;
 161
 162     ddc->vel_thin = 0.1;
 163     ddc->flatness = 0.9;
 164     ddc->cap_rounding = 0.0;
 165
 166     ddc->abs_width = false;
 167     ddc->keep_selected = true;
 168
 169     ddc->hatch_spacing = 0;
 170     ddc->hatch_spacing_step = 0;
 171     new (&ddc->hatch_pointer_past) std::list<double>();
 172     new (&ddc->hatch_nearest_past) std::list<double>();
 173     ddc->hatch_last_nearest = NR::Point(0,0);
 174     ddc->hatch_last_pointer = NR::Point(0,0);
 175     ddc->hatch_vector_accumulated = NR::Point(0,0);
 176     ddc->hatch_escaped = false;
 177     ddc->hatch_area = NULL;
 178     ddc->hatch_item = NULL;
 179     ddc->hatch_livarot_path = NULL;
 180
 181     ddc->trace_bg = false;
 182 }
 183
 184 static void
 185 sp_dyna_draw_context_dispose(GObject *object)
 186 {
 187     SPDynaDrawContext *ddc = SP_DYNA_DRAW_CONTEXT(object);
 188
 189     if (ddc->hatch_area) {
 190         gtk_object_destroy(GTK_OBJECT(ddc->hatch_area));
 191         ddc->hatch_area = NULL;
 192     }
 193
 194
 195     G_OBJECT_CLASS(dd_parent_class)->dispose(object);
 196
 197     ddc->hatch_pointer_past.~list();
 198     ddc->hatch_nearest_past.~list();
 199 }
 200
 201 static void
 202 sp_dyna_draw_context_setup(SPEventContext *ec)
 203 {
 204     SPDynaDrawContext *ddc = SP_DYNA_DRAW_CONTEXT(ec);
 205
 206     if (((SPEventContextClass *) dd_parent_class)->setup)
 207         ((SPEventContextClass *) dd_parent_class)->setup(ec);
 208
 209     ddc->accumulated = new SPCurve(32);
 210     ddc->currentcurve = new SPCurve(4);
 211
 212     ddc->cal1 = new SPCurve(32);
 213     ddc->cal2 = new SPCurve(32);
 214
 215     ddc->currentshape = sp_canvas_item_new(sp_desktop_sketch(ec->desktop), SP_TYPE_CANVAS_BPATH, NULL);
 216     sp_canvas_bpath_set_fill(SP_CANVAS_BPATH(ddc->currentshape), DDC_RED_RGBA, SP_WIND_RULE_EVENODD);
 217     sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(ddc->currentshape), 0x00000000, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 218     /* fixme: Cannot we cascade it to root more clearly? */
 219     g_signal_connect(G_OBJECT(ddc->currentshape), "event", G_CALLBACK(sp_desktop_root_handler), ec->desktop);
 220
 221     {
 222         SPCurve *c = SPCurve::new_from_foreign_bpath(hatch_area_circle);
 223         ddc->hatch_area = sp_canvas_bpath_new(sp_desktop_controls(ec->desktop), c);
 224         c->unref();
 225         sp_canvas_bpath_set_fill(SP_CANVAS_BPATH(ddc->hatch_area), 0x00000000,(SPWindRule)0);
 226         sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(ddc->hatch_area), 0x0000007f, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 227         sp_canvas_item_hide(ddc->hatch_area);
 228     }
 229
 230     sp_event_context_read(ec, "mass");
 231     sp_event_context_read(ec, "wiggle");
 232     sp_event_context_read(ec, "angle");
 233     sp_event_context_read(ec, "width");
 234     sp_event_context_read(ec, "thinning");
 235     sp_event_context_read(ec, "tremor");
 236     sp_event_context_read(ec, "flatness");
 237     sp_event_context_read(ec, "tracebackground");
 238     sp_event_context_read(ec, "usepressure");
 239     sp_event_context_read(ec, "usetilt");
 240     sp_event_context_read(ec, "abs_width");
 241     sp_event_context_read(ec, "keep_selected");
 242     sp_event_context_read(ec, "cap_rounding");
 243
 244     ddc->is_drawing = false;
 245
 246     ddc->_message_context = new Inkscape::MessageContext((ec->desktop)->messageStack());
 247
 248     if (prefs_get_int_attribute("tools.calligraphic", "selcue", 0) != 0) {
 249         ec->enableSelectionCue();
 250     }
 251 }
 252
 253 static void
 254 sp_dyna_draw_context_set(SPEventContext *ec, gchar const *key, gchar const *val)
 255 {
 256     SPDynaDrawContext *ddc = SP_DYNA_DRAW_CONTEXT(ec);
 257
 258     if (!strcmp(key, "tracebackground")) {
 259         ddc->trace_bg = (val && strcmp(val, "0"));
 260     } else if (!strcmp(key, "keep_selected")) {
 261         ddc->keep_selected = (val && strcmp(val, "0"));
 262     } else {
 263         //pass on up to parent class to handle common attributes.
 264         if ( dd_parent_class->set ) {
 265             dd_parent_class->set(ec, key, val);
 266         }
 267     }
 268
 269     //g_print("DDC: %g %g %g %g\n", ddc->mass, ddc->drag, ddc->angle, ddc->width);
 270 }
 271
 272 static double
 273 flerp(double f0, double f1, double p)
 274 {
 275     return f0 + ( f1 - f0 ) * p;
 276 }
 277
 278 /* Get normalized point */
 279 static NR::Point
 280 sp_dyna_draw_get_npoint(SPDynaDrawContext const *dc, NR::Point v)
 281 {
 282     NR::Rect drect = SP_EVENT_CONTEXT(dc)->desktop->get_display_area();
 283     double const max = MAX ( drect.dimensions()[NR::X], drect.dimensions()[NR::Y] );
 284     return NR::Point(( v[NR::X] - drect.min()[NR::X] ) / max,  ( v[NR::Y] - drect.min()[NR::Y] ) / max);
 285 }
 286
 287 /* Get view point */
 288 static NR::Point
 289 sp_dyna_draw_get_vpoint(SPDynaDrawContext const *dc, NR::Point n)
 290 {
 291     NR::Rect drect = SP_EVENT_CONTEXT(dc)->desktop->get_display_area();
 292     double const max = MAX ( drect.dimensions()[NR::X], drect.dimensions()[NR::Y] );
 293     return NR::Point(n[NR::X] * max + drect.min()[NR::X], n[NR::Y] * max + drect.min()[NR::Y]);
 294 }
 295
 296 static void
 297 sp_dyna_draw_reset(SPDynaDrawContext *dc, NR::Point p)
 298 {
 299     dc->last = dc->cur = sp_dyna_draw_get_npoint(dc, p);
 300     dc->vel = NR::Point(0,0);
 301     dc->vel_max = 0;
 302     dc->acc = NR::Point(0,0);
 303     dc->ang = NR::Point(0,0);
 304     dc->del = NR::Point(0,0);
 305 }
 306
 307 static void
 308 sp_dyna_draw_extinput(SPDynaDrawContext *dc, GdkEvent *event)
 309 {
 310     if (gdk_event_get_axis (event, GDK_AXIS_PRESSURE, &dc->pressure))
 311         dc->pressure = CLAMP (dc->pressure, DDC_MIN_PRESSURE, DDC_MAX_PRESSURE);
 312     else
 313         dc->pressure = DDC_DEFAULT_PRESSURE;
 314
 315     if (gdk_event_get_axis (event, GDK_AXIS_XTILT, &dc->xtilt))
 316         dc->xtilt = CLAMP (dc->xtilt, DDC_MIN_TILT, DDC_MAX_TILT);
 317     else
 318         dc->xtilt = DDC_DEFAULT_TILT;
 319
 320     if (gdk_event_get_axis (event, GDK_AXIS_YTILT, &dc->ytilt))
 321         dc->ytilt = CLAMP (dc->ytilt, DDC_MIN_TILT, DDC_MAX_TILT);
 322     else
 323         dc->ytilt = DDC_DEFAULT_TILT;
 324 }
 325
 326
 327 static gboolean
 328 sp_dyna_draw_apply(SPDynaDrawContext *dc, NR::Point p)
 329 {
 330     NR::Point n = sp_dyna_draw_get_npoint(dc, p);
 331
 332     /* Calculate mass and drag */
 333     double const mass = flerp(1.0, 160.0, dc->mass);
 334     double const drag = flerp(0.0, 0.5, dc->drag * dc->drag);
 335
 336     /* Calculate force and acceleration */
 337     NR::Point force = n - dc->cur;
 338
 339     // If force is below the absolute threshold DYNA_EPSILON,
 340     // or we haven't yet reached DYNA_VEL_START (i.e. at the beginning of stroke)
 341     // _and_ the force is below the (higher) DYNA_EPSILON_START threshold,
 342     // discard this move.
 343     // This prevents flips, blobs, and jerks caused by microscopic tremor of the tablet pen,
 344     // especially bothersome at the start of the stroke where we don't yet have the inertia to
 345     // smooth them out.
 346     if ( NR::L2(force) < DYNA_EPSILON || (dc->vel_max < DYNA_VEL_START && NR::L2(force) < DYNA_EPSILON_START)) {
 347         return FALSE;
 348     }
 349
 350     dc->acc = force / mass;
 351
 352     /* Calculate new velocity */
 353     dc->vel += dc->acc;
 354
 355     if (NR::L2(dc->vel) > dc->vel_max)
 356         dc->vel_max = NR::L2(dc->vel);
 357
 358     /* Calculate angle of drawing tool */
 359
 360     double a1;
 361     if (dc->usetilt) {
 362         // 1a. calculate nib angle from input device tilt:
 363         gdouble length = std::sqrt(dc->xtilt*dc->xtilt + dc->ytilt*dc->ytilt);;
 364
 365         if (length > 0) {
 366             NR::Point ang1 = NR::Point(dc->ytilt/length, dc->xtilt/length);
 367             a1 = atan2(ang1);
 368         }
 369         else
 370             a1 = 0.0;
 371     }
 372     else {
 373         // 1b. fixed dc->angle (absolutely flat nib):
 374         double const radians = ( (dc->angle - 90) / 180.0 ) * M_PI;
 375         NR::Point ang1 = NR::Point(-sin(radians),  cos(radians));
 376         a1 = atan2(ang1);
 377     }
 378
 379     // 2. perpendicular to dc->vel (absolutely non-flat nib):
 380     gdouble const mag_vel = NR::L2(dc->vel);
 381     if ( mag_vel < DYNA_EPSILON ) {
 382         return FALSE;
 383     }
 384     NR::Point ang2 = NR::rot90(dc->vel) / mag_vel;
 385
 386     // 3. Average them using flatness parameter:
 387     // calculate angles
 388     double a2 = atan2(ang2);
 389     // flip a2 to force it to be in the same half-circle as a1
 390     bool flipped = false;
 391     if (fabs (a2-a1) > 0.5*M_PI) {
 392         a2 += M_PI;
 393         flipped = true;
 394     }
 395     // normalize a2
 396     if (a2 > M_PI)
 397         a2 -= 2*M_PI;
 398     if (a2 < -M_PI)
 399         a2 += 2*M_PI;
 400     // find the flatness-weighted bisector angle, unflip if a2 was flipped
 401     // FIXME: when dc->vel is oscillating around the fixed angle, the new_ang flips back and forth. How to avoid this?
 402     double new_ang = a1 + (1 - dc->flatness) * (a2 - a1) - (flipped? M_PI : 0);
 403
 404     // Try to detect a sudden flip when the new angle differs too much from the previous for the
 405     // current velocity; in that case discard this move
 406     double angle_delta = NR::L2(NR::Point (cos (new_ang), sin (new_ang)) - dc->ang);
 407     if ( angle_delta / NR::L2(dc->vel) > 4000 ) {
 408         return FALSE;
 409     }
 410
 411     // convert to point
 412     dc->ang = NR::Point (cos (new_ang), sin (new_ang));
 413
 414 //    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);
 415
 416     /* Apply drag */
 417     dc->vel *= 1.0 - drag;
 418
 419     /* Update position */
 420     dc->last = dc->cur;
 421     dc->cur += dc->vel;
 422
 423     return TRUE;
 424 }
 425
 426 static void
 427 sp_dyna_draw_brush(SPDynaDrawContext *dc)
 428 {
 429     g_assert( dc->npoints >= 0 && dc->npoints < SAMPLING_SIZE );
 430
 431     // How much velocity thins strokestyle
 432     double vel_thin = flerp (0, 160, dc->vel_thin);
 433
 434     // Influence of pressure on thickness
 435     double pressure_thick = (dc->usepressure ? dc->pressure : 1.0);
 436
 437     // get the real brush point, not the same as pointer (affected by hatch tracking and/or mass
 438     // drag)
 439     NR::Point brush = sp_dyna_draw_get_vpoint(dc, dc->cur);
 440     NR::Point brush_w = SP_EVENT_CONTEXT(dc)->desktop->d2w(brush);
 441
 442     double trace_thick = 1;
 443     if (dc->trace_bg) {
 444         // pick single pixel
 445         NRPixBlock pb;
 446         int x = (int) floor(brush_w[NR::X]);
 447         int y = (int) floor(brush_w[NR::Y]);
 448         nr_pixblock_setup_fast(&pb, NR_PIXBLOCK_MODE_R8G8B8A8P, x, y, x+1, y+1, TRUE);
 449         sp_canvas_arena_render_pixblock(SP_CANVAS_ARENA(sp_desktop_drawing(SP_EVENT_CONTEXT(dc)->desktop)), &pb);
 450         const unsigned char *s = NR_PIXBLOCK_PX(&pb);
 451         double R = s[0] / 255.0;
 452         double G = s[1] / 255.0;
 453         double B = s[2] / 255.0;
 454         double A = s[3] / 255.0;
 455         double max = MAX (MAX (R, G), B);
 456         double min = MIN (MIN (R, G), B);
 457         double L = A * (max + min)/2 + (1 - A); // blend with white bg
 458         trace_thick = 1 - L;
 459         //g_print ("L %g thick %g\n", L, trace_thick);
 460     }
 461
 462     double width = (pressure_thick * trace_thick - vel_thin * NR::L2(dc->vel)) * dc->width;
 463
 464     double tremble_left = 0, tremble_right = 0;
 465     if (dc->tremor > 0) {
 466         // obtain two normally distributed random variables, using polar Box-Muller transform
 467         double x1, x2, w, y1, y2;
 468         do {
 469             x1 = 2.0 * g_random_double_range(0,1) - 1.0;
 470             x2 = 2.0 * g_random_double_range(0,1) - 1.0;
 471             w = x1 * x1 + x2 * x2;
 472         } while ( w >= 1.0 );
 473         w = sqrt( (-2.0 * log( w ) ) / w );
 474         y1 = x1 * w;
 475         y2 = x2 * w;
 476
 477         // deflect both left and right edges randomly and independently, so that:
 478         // (1) dc->tremor=1 corresponds to sigma=1, decreasing dc->tremor narrows the bell curve;
 479         // (2) deflection depends on width, but is upped for small widths for better visual uniformity across widths;
 480         // (3) deflection somewhat depends on speed, to prevent fast strokes looking
 481         // comparatively smooth and slow ones excessively jittery
 482         tremble_left  = (y1)*dc->tremor * (0.15 + 0.8*width) * (0.35 + 14*NR::L2(dc->vel));
 483         tremble_right = (y2)*dc->tremor * (0.15 + 0.8*width) * (0.35 + 14*NR::L2(dc->vel));
 484     }
 485
 486     if ( width < 0.02 * dc->width ) {
 487         width = 0.02 * dc->width;
 488     }
 489
 490     double dezoomify_factor = 0.05 * 1000;
 491     if (!dc->abs_width) {
 492         dezoomify_factor /= SP_EVENT_CONTEXT(dc)->desktop->current_zoom();
 493     }
 494
 495     NR::Point del_left = dezoomify_factor * (width + tremble_left) * dc->ang;
 496     NR::Point del_right = dezoomify_factor * (width + tremble_right) * dc->ang;
 497
 498     dc->point1[dc->npoints] = brush + del_left;
 499     dc->point2[dc->npoints] = brush - del_right;
 500
 501     dc->del = 0.5*(del_left + del_right);
 502
 503     dc->npoints++;
 504 }
 505
 506 void
 507 sp_ddc_update_toolbox (SPDesktop *desktop, const gchar *id, double value)
 508 {
 509     desktop->setToolboxAdjustmentValue (id, value);
 510 }
 511
 512 static void
 513 calligraphic_cancel(SPDynaDrawContext *dc)
 514 {
 515     SPDesktop *desktop = SP_EVENT_CONTEXT(dc)->desktop;
 516     dc->dragging = FALSE;
 517     dc->is_drawing = false;
 518     sp_canvas_item_ungrab(SP_CANVAS_ITEM(desktop->acetate), 0);
 519             /* Remove all temporary line segments */
 520             while (dc->segments) {
 521                 gtk_object_destroy(GTK_OBJECT(dc->segments->data));
 522                 dc->segments = g_slist_remove(dc->segments, dc->segments->data);
 523             }
 524             /* reset accumulated curve */
 525             dc->accumulated->reset();
 526             clear_current(dc);
 527             if (dc->repr) {
 528                 dc->repr = NULL;
 529             }
 530 }
 531
 532
 533 gint
 534 sp_dyna_draw_context_root_handler(SPEventContext *event_context,
 535                                   GdkEvent *event)
 536 {
 537     SPDynaDrawContext *dc = SP_DYNA_DRAW_CONTEXT(event_context);
 538     SPDesktop *desktop = event_context->desktop;
 539
 540     gint ret = FALSE;
 541
 542     switch (event->type) {
 543         case GDK_BUTTON_PRESS:
 544             if (event->button.button == 1 && !event_context->space_panning) {
 545
 546                 SPDesktop *desktop = SP_EVENT_CONTEXT_DESKTOP(dc);
 547
 548                 if (Inkscape::have_viable_layer(desktop, dc->_message_context) == false) {
 549                     return TRUE;
 550                 }
 551
 552                 NR::Point const button_w(event->button.x,
 553                                          event->button.y);
 554                 NR::Point const button_dt(desktop->w2d(button_w));
 555                 sp_dyna_draw_reset(dc, button_dt);
 556                 sp_dyna_draw_extinput(dc, event);
 557                 sp_dyna_draw_apply(dc, button_dt);
 558                 dc->accumulated->reset();
 559                 if (dc->repr) {
 560                     dc->repr = NULL;
 561                 }
 562
 563                 /* initialize first point */
 564                 dc->npoints = 0;
 565
 566                 sp_canvas_item_grab(SP_CANVAS_ITEM(desktop->acetate),
 567                                     ( GDK_KEY_PRESS_MASK |
 568                                       GDK_BUTTON_RELEASE_MASK |
 569                                       GDK_POINTER_MOTION_MASK |
 570                                       GDK_BUTTON_PRESS_MASK ),
 571                                     NULL,
 572                                     event->button.time);
 573
 574                 ret = TRUE;
 575
 576                 sp_canvas_force_full_redraw_after_interruptions(desktop->canvas, 3);
 577                 dc->is_drawing = true;
 578             }
 579             break;
 580         case GDK_MOTION_NOTIFY:
 581         {
 582             NR::Point const motion_w(event->motion.x,
 583                                      event->motion.y);
 584             NR::Point motion_dt(desktop->w2d(motion_w));
 585             sp_dyna_draw_extinput(dc, event);
 586
 587             dc->_message_context->clear();
 588
 589             // for hatching:
 590             double hatch_dist = 0;
 591             NR::Point hatch_unit_vector(0,0);
 592             NR::Point nearest(0,0);
 593             NR::Point pointer(0,0);
 594             NR::Matrix motion_to_curve(NR::identity());
 595
 596             if (event->motion.state & GDK_CONTROL_MASK) { // hatching - sense the item
 597
 598                 SPItem *selected = sp_desktop_selection(desktop)->singleItem();
 599                 if (selected && (SP_IS_SHAPE(selected) || SP_IS_TEXT(selected))) {
 600                     // One item selected, and it's a path;
 601                     // let's try to track it as a guide
 602
 603                     if (selected != dc->hatch_item) {
 604                         dc->hatch_item = selected;
 605                         if (dc->hatch_livarot_path)
 606                             delete dc->hatch_livarot_path;
 607                         dc->hatch_livarot_path = Path_for_item (dc->hatch_item, true, true);
 608                         dc->hatch_livarot_path->ConvertWithBackData(0.01);
 609                     }
 610
 611                     // calculate pointer point in the guide item's coords
 612                     motion_to_curve = from_2geom(sp_item_dt2i_affine(selected) * sp_item_i2doc_affine(selected));
 613                     pointer = motion_dt * motion_to_curve;
 614
 615                     // calculate the nearest point on the guide path
 616                     NR::Maybe<Path::cut_position> position = get_nearest_position_on_Path(dc->hatch_livarot_path, pointer);
 617                     nearest = get_point_on_Path(dc->hatch_livarot_path, position->piece, position->t);
 618
 619
 620                     // distance from pointer to nearest
 621                     hatch_dist = NR::L2(pointer - nearest);
 622                     // unit-length vector
 623                     hatch_unit_vector = (pointer - nearest)/hatch_dist;
 624
 625                     dc->_message_context->set(Inkscape::NORMAL_MESSAGE, _("<b>Guide path selected</b>; start drawing along the guide with <b>Ctrl</b>"));
 626                 } else {
 627                     dc->_message_context->set(Inkscape::NORMAL_MESSAGE, _("<b>Select a guide path</b> to track with <b>Ctrl</b>"));
 628                 }
 629             }
 630
 631             if ( dc->is_drawing && (event->motion.state & GDK_BUTTON1_MASK) && !event_context->space_panning) {
 632                 dc->dragging = TRUE;
 633
 634                 if (event->motion.state & GDK_CONTROL_MASK && dc->hatch_item) { // hatching
 635
 636 #define SPEED_ELEMENTS 12
 637 #define SPEED_MIN 0.12
 638 #define SPEED_NORMAL 0.65
 639
 640                     // speed is the movement of the nearest point along the guide path, divided by
 641                     // the movement of the pointer at the same period; it is averaged for the last
 642                     // SPEED_ELEMENTS motion events.  Normally, as you track the guide path, speed
 643                     // is about 1, i.e. the nearest point on the path is moved by about the same
 644                     // distance as the pointer. If the speed starts to decrease, we are losing
 645                     // contact with the guide; if it drops below SPEED_MIN, we are on our own and
 646                     // not attracted to guide anymore. Most often this happens when you have
 647                     // tracked to the end of a guide calligraphic stroke and keep moving
 648                     // further. We try to handle this situation gracefully: not stick with the
 649                     // guide forever but let go of it smoothly and without sharp jerks (non-zero
 650                     // mass recommended; with zero mass, jerks are still quite noticeable).
 651
 652                     double speed = 1;
 653                     if (NR::L2(dc->hatch_last_nearest) != 0) {
 654                         // the distance nearest moved since the last motion event
 655                         double nearest_moved = NR::L2(nearest - dc->hatch_last_nearest);
 656                         // the distance pointer moved since the last motion event
 657                         double pointer_moved = NR::L2(pointer - dc->hatch_last_pointer);
 658                         // store them in stacks limited to SPEED_ELEMENTS
 659                         dc->hatch_nearest_past.push_front(nearest_moved);
 660                         if (dc->hatch_nearest_past.size() > SPEED_ELEMENTS)
 661                             dc->hatch_nearest_past.pop_back();
 662                         dc->hatch_pointer_past.push_front(pointer_moved);
 663                         if (dc->hatch_pointer_past.size() > SPEED_ELEMENTS)
 664                             dc->hatch_pointer_past.pop_back();
 665
 666                         // If the stacks are full,
 667                         if (dc->hatch_nearest_past.size() == SPEED_ELEMENTS) {
 668                             // calculate the sums of all stored movements
 669                             double nearest_sum = std::accumulate (dc->hatch_nearest_past.begin(), dc->hatch_nearest_past.end(), 0.0);
 670                             double pointer_sum = std::accumulate (dc->hatch_pointer_past.begin(), dc->hatch_pointer_past.end(), 0.0);
 671                             // and divide to get the speed
 672                             speed = nearest_sum/pointer_sum;
 673                             //g_print ("nearest sum %g  pointer_sum %g  speed %g\n", nearest_sum, pointer_sum, speed);
 674                         }
 675                     }
 676
 677                     if (   dc->hatch_escaped  // already escaped, do not reattach
 678                         || (speed < SPEED_MIN) // stuck; most likely reached end of traced stroke
 679                         || (dc->hatch_spacing > 0 && hatch_dist > 50 * dc->hatch_spacing) // went too far from the guide
 680                         ) {
 681                         // We are NOT attracted to the guide!
 682
 683                         //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);
 684
 685                         // Remember hatch_escaped so we don't get
 686                         // attracted again until the end of this stroke
 687                         dc->hatch_escaped = true;
 688
 689                     } else {
 690
 691                         // Calculate angle cosine of this vector-to-guide and all past vectors
 692                         // summed, to detect if we accidentally flipped to the other side of the
 693                         // guide
 694                         double dot = NR::dot (pointer - nearest, dc->hatch_vector_accumulated);
 695                         dot /= NR::L2(pointer - nearest) * NR::L2(dc->hatch_vector_accumulated);
 696
 697                         if (dc->hatch_spacing != 0) { // spacing was already set
 698                             double target;
 699                             if (speed > SPEED_NORMAL) {
 700                                 // all ok, strictly obey the spacing
 701                                 target = dc->hatch_spacing;
 702                             } else {
 703                                 // looks like we're starting to lose speed,
 704                                 // so _gradually_ let go attraction to prevent jerks
 705                                 target = (dc->hatch_spacing * speed + hatch_dist * (SPEED_NORMAL - speed))/SPEED_NORMAL;
 706                             }
 707                             if (!IS_NAN(dot) && dot < -0.5) {// flip
 708                                 target = -target;
 709                             }
 710
 711                             // This is the track pointer that we will use instead of the real one
 712                             NR::Point new_pointer = nearest + target * hatch_unit_vector;
 713
 714                             // some limited feedback: allow persistent pulling to slightly change
 715                             // the spacing
 716                             dc->hatch_spacing += (hatch_dist - dc->hatch_spacing)/3500;
 717
 718                             // return it to the desktop coords
 719                             motion_dt = new_pointer * motion_to_curve.inverse();
 720
 721                         } else {
 722                             // this is the first motion event, set the dist
 723                             dc->hatch_spacing = hatch_dist;
 724                         }
 725
 726                         // remember last points
 727                         dc->hatch_last_pointer = pointer;
 728                         dc->hatch_last_nearest = nearest;
 729                         dc->hatch_vector_accumulated += (pointer - nearest);
 730                     }
 731
 732                     dc->_message_context->set(Inkscape::NORMAL_MESSAGE, dc->hatch_escaped? _("Tracking: <b>connection to guide path lost!</b>") : _("<b>Tracking</b> a guide path"));
 733
 734                 } else {
 735                     dc->_message_context->set(Inkscape::NORMAL_MESSAGE, _("<b>Drawing</b> a calligraphic stroke"));
 736                 }
 737
 738                 if (!sp_dyna_draw_apply(dc, motion_dt)) {
 739                     ret = TRUE;
 740                     break;
 741                 }
 742
 743                 if ( dc->cur != dc->last ) {
 744                     sp_dyna_draw_brush(dc);
 745                     g_assert( dc->npoints > 0 );
 746                     fit_and_split(dc, FALSE);
 747                 }
 748                 ret = TRUE;
 749             }
 750
 751             // Draw the hatching circle if necessary
 752             if (event->motion.state & GDK_CONTROL_MASK) {
 753                 if (dc->hatch_spacing == 0 && hatch_dist != 0) {
 754                     // Haven't set spacing yet: gray, center free, update radius live
 755                     NR::Point c = desktop->w2d(motion_w);
 756                     NR::Matrix const sm (NR::scale(hatch_dist, hatch_dist) * NR::translate(c));
 757                     sp_canvas_item_affine_absolute(dc->hatch_area, sm);
 758                     sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(dc->hatch_area), 0x7f7f7fff, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 759                     sp_canvas_item_show(dc->hatch_area);
 760                 } else if (dc->dragging && !dc->hatch_escaped) {
 761                     // Tracking: green, center snapped, fixed radius
 762                     NR::Point c = motion_dt;
 763                     NR::Matrix const sm (NR::scale(dc->hatch_spacing, dc->hatch_spacing) * NR::translate(c));
 764                     sp_canvas_item_affine_absolute(dc->hatch_area, sm);
 765                     sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(dc->hatch_area), 0x00FF00ff, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 766                     sp_canvas_item_show(dc->hatch_area);
 767                 } else if (dc->dragging && dc->hatch_escaped) {
 768                     // Tracking escaped: red, center free, fixed radius
 769                     NR::Point c = desktop->w2d(motion_w);
 770                     NR::Matrix const sm (NR::scale(dc->hatch_spacing, dc->hatch_spacing) * NR::translate(c));
 771
 772                     sp_canvas_item_affine_absolute(dc->hatch_area, sm);
 773                     sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(dc->hatch_area), 0xFF0000ff, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 774                     sp_canvas_item_show(dc->hatch_area);
 775                 } else {
 776                     // Not drawing but spacing set: gray, center snapped, fixed radius
 777                     NR::Point c = (nearest + dc->hatch_spacing * hatch_unit_vector) * motion_to_curve.inverse();
 778                     if (!IS_NAN(c[NR::X]) && !IS_NAN(c[NR::Y])) {
 779                         NR::Matrix const sm (NR::scale(dc->hatch_spacing, dc->hatch_spacing) * NR::translate(c));
 780                         sp_canvas_item_affine_absolute(dc->hatch_area, sm);
 781                         sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(dc->hatch_area), 0x7f7f7fff, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 782                         sp_canvas_item_show(dc->hatch_area);
 783                     }
 784                 }
 785             } else {
 786                 sp_canvas_item_hide(dc->hatch_area);
 787             }
 788         }
 789         break;
 790
 791
 792     case GDK_BUTTON_RELEASE:
 793     {
 794         NR::Point const motion_w(event->button.x, event->button.y);
 795         NR::Point const motion_dt(desktop->w2d(motion_w));
 796
 797         sp_canvas_item_ungrab(SP_CANVAS_ITEM(desktop->acetate), event->button.time);
 798         sp_canvas_end_forced_full_redraws(desktop->canvas);
 799         dc->is_drawing = false;
 800
 801         if (dc->dragging && event->button.button == 1 && !event_context->space_panning) {
 802             dc->dragging = FALSE;
 803
 804             sp_dyna_draw_apply(dc, motion_dt);
 805
 806             /* Remove all temporary line segments */
 807             while (dc->segments) {
 808                 gtk_object_destroy(GTK_OBJECT(dc->segments->data));
 809                 dc->segments = g_slist_remove(dc->segments, dc->segments->data);
 810             }
 811
 812             /* Create object */
 813             fit_and_split(dc, TRUE);
 814             accumulate_calligraphic(dc);
 815             set_to_accumulated(dc, event->button.state & GDK_SHIFT_MASK); // performs document_done
 816
 817             /* reset accumulated curve */
 818             dc->accumulated->reset();
 819
 820             clear_current(dc);
 821             if (dc->repr) {
 822                 dc->repr = NULL;
 823             }
 824
 825             if (!dc->hatch_pointer_past.empty()) dc->hatch_pointer_past.clear();
 826             if (!dc->hatch_nearest_past.empty()) dc->hatch_nearest_past.clear();
 827             dc->hatch_last_nearest = NR::Point(0,0);
 828             dc->hatch_last_pointer = NR::Point(0,0);
 829             dc->hatch_vector_accumulated = NR::Point(0,0);
 830             dc->hatch_escaped = false;
 831             dc->hatch_item = NULL;
 832             dc->hatch_livarot_path = NULL;
 833
 834             if (dc->hatch_spacing != 0 && !dc->keep_selected) {
 835                 // we do not select the newly drawn path, so increase spacing by step
 836                 if (dc->hatch_spacing_step == 0) {
 837                     dc->hatch_spacing_step = dc->hatch_spacing;
 838                 }
 839                 dc->hatch_spacing += dc->hatch_spacing_step;
 840             }
 841
 842             dc->_message_context->clear();
 843             ret = TRUE;
 844         }
 845         break;
 846     }
 847
 848     case GDK_KEY_PRESS:
 849         switch (get_group0_keyval (&event->key)) {
 850         case GDK_Up:
 851         case GDK_KP_Up:
 852             if (!MOD__CTRL_ONLY) {
 853                 dc->angle += 5.0;
 854                 if (dc->angle > 90.0)
 855                     dc->angle = 90.0;
 856                 sp_ddc_update_toolbox (desktop, "calligraphy-angle", dc->angle);
 857                 ret = TRUE;
 858             }
 859             break;
 860         case GDK_Down:
 861         case GDK_KP_Down:
 862             if (!MOD__CTRL_ONLY) {
 863                 dc->angle -= 5.0;
 864                 if (dc->angle < -90.0)
 865                     dc->angle = -90.0;
 866                 sp_ddc_update_toolbox (desktop, "calligraphy-angle", dc->angle);
 867                 ret = TRUE;
 868             }
 869             break;
 870         case GDK_Right:
 871         case GDK_KP_Right:
 872             if (!MOD__CTRL_ONLY) {
 873                 dc->width += 0.01;
 874                 if (dc->width > 1.0)
 875                     dc->width = 1.0;
 876                 sp_ddc_update_toolbox (desktop, "altx-calligraphy", dc->width * 100); // the same spinbutton is for alt+x
 877                 ret = TRUE;
 878             }
 879             break;
 880         case GDK_Left:
 881         case GDK_KP_Left:
 882             if (!MOD__CTRL_ONLY) {
 883                 dc->width -= 0.01;
 884                 if (dc->width < 0.01)
 885                     dc->width = 0.01;
 886                 sp_ddc_update_toolbox (desktop, "altx-calligraphy", dc->width * 100);
 887                 ret = TRUE;
 888             }
 889             break;
 890         case GDK_Home:
 891         case GDK_KP_Home:
 892             dc->width = 0.01;
 893             sp_ddc_update_toolbox (desktop, "altx-calligraphy", dc->width * 100);
 894             ret = TRUE;
 895             break;
 896         case GDK_End:
 897         case GDK_KP_End:
 898             dc->width = 1.0;
 899             sp_ddc_update_toolbox (desktop, "altx-calligraphy", dc->width * 100);
 900             ret = TRUE;
 901             break;
 902         case GDK_x:
 903         case GDK_X:
 904             if (MOD__ALT_ONLY) {
 905                 desktop->setToolboxFocusTo ("altx-calligraphy");
 906                 ret = TRUE;
 907             }
 908             break;
 909         case GDK_Escape:
 910             if (dc->is_drawing) {
 911                 // if drawing, cancel, otherwise pass it up for deselecting
 912                 calligraphic_cancel (dc);
 913                 ret = TRUE;
 914             }
 915             break;
 916         case GDK_z:
 917         case GDK_Z:
 918             if (MOD__CTRL_ONLY && dc->is_drawing) {
 919                 // if drawing, cancel, otherwise pass it up for undo
 920                 calligraphic_cancel (dc);
 921                 ret = TRUE;
 922             }
 923             break;
 924         default:
 925             break;
 926         }
 927         break;
 928
 929     case GDK_KEY_RELEASE:
 930         switch (get_group0_keyval(&event->key)) {
 931             case GDK_Control_L:
 932             case GDK_Control_R:
 933                 dc->_message_context->clear();
 934                 dc->hatch_spacing = 0;
 935                 dc->hatch_spacing_step = 0;
 936                 break;
 937             default:
 938                 break;
 939         }
 940
 941     default:
 942         break;
 943     }
 944
 945     if (!ret) {
 946         if (((SPEventContextClass *) dd_parent_class)->root_handler) {
 947             ret = ((SPEventContextClass *) dd_parent_class)->root_handler(event_context, event);
 948         }
 949     }
 950
 951     return ret;
 952 }
 953
 954
 955 static void
 956 clear_current(SPDynaDrawContext *dc)
 957 {
 958     /* reset bpath */
 959     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(dc->currentshape), NULL);
 960     /* reset curve */
 961     dc->currentcurve->reset();
 962     dc->cal1->reset();
 963     dc->cal2->reset();
 964     /* reset points */
 965     dc->npoints = 0;
 966 }
 967
 968 static void
 969 set_to_accumulated(SPDynaDrawContext *dc, bool unionize)
 970 {
 971     SPDesktop *desktop = SP_EVENT_CONTEXT(dc)->desktop;
 972
 973     if (!dc->accumulated->is_empty()) {
 974         NArtBpath *abp;
 975         gchar *str;
 976
 977         if (!dc->repr) {
 978             /* Create object */
 979             Inkscape::XML::Document *xml_doc = sp_document_repr_doc(desktop->doc());
 980             Inkscape::XML::Node *repr = xml_doc->createElement("svg:path");
 981
 982             /* Set style */
 983             sp_desktop_apply_style_tool (desktop, repr, "tools.calligraphic", false);
 984
 985             dc->repr = repr;
 986
 987             SPItem *item=SP_ITEM(desktop->currentLayer()->appendChildRepr(dc->repr));
 988             Inkscape::GC::release(dc->repr);
 989             item->transform = SP_ITEM(desktop->currentRoot())->getRelativeTransform(desktop->currentLayer());
 990             item->updateRepr();
 991         }
 992         abp = nr_artpath_affine(dc->accumulated->get_bpath(), sp_desktop_dt2root_affine(desktop));
 993         str = sp_svg_write_path(abp);
 994         g_assert( str != NULL );
 995         g_free(abp);
 996         dc->repr->setAttribute("d", str);
 997         g_free(str);
 998
 999         if (unionize) {
1000             sp_desktop_selection(desktop)->add(dc->repr);
1001             sp_selected_path_union_skip_undo();
1002         } else {
1003             if (dc->keep_selected) {
1004                 sp_desktop_selection(desktop)->set(dc->repr);
1005             }
1006         }
1007
1008     } else {
1009         if (dc->repr) {
1010             sp_repr_unparent(dc->repr);
1011         }
1012         dc->repr = NULL;
1013     }
1014
1015     sp_document_done(sp_desktop_document(desktop), SP_VERB_CONTEXT_CALLIGRAPHIC,
1016                      _("Draw calligraphic stroke"));
1017 }
1018
1019 static void
1020 add_cap(SPCurve *curve,
1021         NR::Point const &from,
1022         NR::Point const &to,
1023         double rounding)
1024 {
1025     if (NR::L2( to - from ) > DYNA_EPSILON) {
1026         NR::Point vel = rounding * NR::rot90( to - from ) / sqrt(2.0);
1027         double mag = NR::L2(vel);
1028
1029         NR::Point v = mag * NR::rot90( to - from ) / NR::L2( to - from );
1030         curve->curveto(from + v, to + v, to);
1031     }
1032 }
1033
1034 static void
1035 accumulate_calligraphic(SPDynaDrawContext *dc)
1036 {
1037     if ( !dc->cal1->is_empty() && !dc->cal2->is_empty() ) {
1038         dc->accumulated->reset(); /*  Is this required ?? */
1039         SPCurve *rev_cal2 = dc->cal2->create_reverse();
1040
1041         g_assert(dc->cal1->get_segment_count() > 0);
1042         g_assert(rev_cal2->get_segment_count() > 0);
1043         g_assert( ! dc->cal1->first_path()->closed() );
1044         g_assert( ! rev_cal2->first_path()->closed() );
1045
1046         Geom::CubicBezier const * dc_cal1_firstseg  = dynamic_cast<Geom::CubicBezier const *>( dc->cal1->first_segment() );
1047         Geom::CubicBezier const * rev_cal2_firstseg = dynamic_cast<Geom::CubicBezier const *>( rev_cal2->first_segment() );
1048         Geom::CubicBezier const * dc_cal1_lastseg   = dynamic_cast<Geom::CubicBezier const *>( dc->cal1->last_segment() );
1049         Geom::CubicBezier const * rev_cal2_lastseg  = dynamic_cast<Geom::CubicBezier const *>( rev_cal2->last_segment() );
1050         g_assert( dc_cal1_firstseg );
1051         g_assert( rev_cal2_firstseg );
1052         g_assert( dc_cal1_lastseg );
1053         g_assert( rev_cal2_lastseg );
1054
1055         dc->accumulated->append(dc->cal1, false);
1056
1057         add_cap(dc->accumulated, (*dc_cal1_lastseg)[3], (*rev_cal2_firstseg)[3], dc->cap_rounding);
1058
1059         dc->accumulated->append(rev_cal2, true);
1060
1061         add_cap(dc->accumulated, (*rev_cal2_lastseg)[3], (*dc_cal1_firstseg)[3], dc->cap_rounding);
1062
1063         dc->accumulated->closepath();
1064
1065         rev_cal2->unref();
1066
1067         dc->cal1->reset();
1068         dc->cal2->reset();
1069     }
1070 }
1071
1072 static double square(double const x)
1073 {
1074     return x * x;
1075 }
1076
1077 static void
1078 fit_and_split(SPDynaDrawContext *dc, gboolean release)
1079 {
1080     double const tolerance_sq = square( NR::expansion(SP_EVENT_CONTEXT(dc)->desktop->w2d()) * TOLERANCE_CALLIGRAPHIC );
1081
1082 #ifdef DYNA_DRAW_VERBOSE
1083     g_print("[F&S:R=%c]", release?'T':'F');
1084 #endif
1085
1086     if (!( dc->npoints > 0 && dc->npoints < SAMPLING_SIZE ))
1087         return; // just clicked
1088
1089     if ( dc->npoints == SAMPLING_SIZE - 1 || release ) {
1090 #define BEZIER_SIZE       4
1091 #define BEZIER_MAX_BEZIERS  8
1092 #define BEZIER_MAX_LENGTH ( BEZIER_SIZE * BEZIER_MAX_BEZIERS )
1093
1094 #ifdef DYNA_DRAW_VERBOSE
1095         g_print("[F&S:#] dc->npoints:%d, release:%s\n",
1096                 dc->npoints, release ? "TRUE" : "FALSE");
1097 #endif
1098
1099         /* Current calligraphic */
1100         if ( dc->cal1->get_length() == 0 || dc->cal2->get_length() == 0 ) {
1101             /* dc->npoints > 0 */
1102             /* g_print("calligraphics(1|2) reset\n"); */
1103             dc->cal1->reset();
1104             dc->cal2->reset();
1105
1106             dc->cal1->moveto(dc->point1[0]);
1107             dc->cal2->moveto(dc->point2[0]);
1108         }
1109
1110         NR::Point b1[BEZIER_MAX_LENGTH];
1111         gint const nb1 = sp_bezier_fit_cubic_r(b1, dc->point1, dc->npoints,
1112                                                tolerance_sq, BEZIER_MAX_BEZIERS);
1113         g_assert( nb1 * BEZIER_SIZE <= gint(G_N_ELEMENTS(b1)) );
1114
1115         NR::Point b2[BEZIER_MAX_LENGTH];
1116         gint const nb2 = sp_bezier_fit_cubic_r(b2, dc->point2, dc->npoints,
1117                                                tolerance_sq, BEZIER_MAX_BEZIERS);
1118         g_assert( nb2 * BEZIER_SIZE <= gint(G_N_ELEMENTS(b2)) );
1119
1120         if ( nb1 != -1 && nb2 != -1 ) {
1121             /* Fit and draw and reset state */
1122 #ifdef DYNA_DRAW_VERBOSE
1123             g_print("nb1:%d nb2:%d\n", nb1, nb2);
1124 #endif
1125             /* CanvasShape */
1126             if (! release) {
1127                 dc->currentcurve->reset();
1128                 dc->currentcurve->moveto(b1[0]);
1129                 for (NR::Point *bp1 = b1; bp1 < b1 + BEZIER_SIZE * nb1; bp1 += BEZIER_SIZE) {
1130                     dc->currentcurve->curveto(bp1[1],
1131                                      bp1[2], bp1[3]);
1132                 }
1133                 dc->currentcurve->lineto(b2[BEZIER_SIZE*(nb2-1) + 3]);
1134                 for (NR::Point *bp2 = b2 + BEZIER_SIZE * ( nb2 - 1 ); bp2 >= b2; bp2 -= BEZIER_SIZE) {
1135                     dc->currentcurve->curveto(bp2[2], bp2[1], bp2[0]);
1136                 }
1137                 // FIXME: dc->segments is always NULL at this point??
1138                 if (!dc->segments) { // first segment
1139                     add_cap(dc->currentcurve, b2[0], b1[0], dc->cap_rounding);
1140                 }
1141                 dc->currentcurve->closepath();
1142                 sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(dc->currentshape), dc->currentcurve);
1143             }
1144
1145             /* Current calligraphic */
1146             for (NR::Point *bp1 = b1; bp1 < b1 + BEZIER_SIZE * nb1; bp1 += BEZIER_SIZE) {
1147                 dc->cal1->curveto(bp1[1], bp1[2], bp1[3]);
1148             }
1149             for (NR::Point *bp2 = b2; bp2 < b2 + BEZIER_SIZE * nb2; bp2 += BEZIER_SIZE) {
1150                 dc->cal2->curveto(bp2[1], bp2[2], bp2[3]);
1151             }
1152         } else {
1153             /* fixme: ??? */
1154 #ifdef DYNA_DRAW_VERBOSE
1155             g_print("[fit_and_split] failed to fit-cubic.\n");
1156 #endif
1157             draw_temporary_box(dc);
1158
1159             for (gint i = 1; i < dc->npoints; i++) {
1160                 dc->cal1->lineto(dc->point1[i]);
1161             }
1162             for (gint i = 1; i < dc->npoints; i++) {
1163                 dc->cal2->lineto(dc->point2[i]);
1164             }
1165         }
1166
1167         /* Fit and draw and copy last point */
1168 #ifdef DYNA_DRAW_VERBOSE
1169         g_print("[%d]Yup\n", dc->npoints);
1170 #endif
1171         if (!release) {
1172             g_assert(!dc->currentcurve->is_empty());
1173
1174             SPCanvasItem *cbp = sp_canvas_item_new(sp_desktop_sketch(SP_EVENT_CONTEXT(dc)->desktop),
1175                                                    SP_TYPE_CANVAS_BPATH,
1176                                                    NULL);
1177             SPCurve *curve = dc->currentcurve->copy();
1178             sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH (cbp), curve);
1179             curve->unref();
1180
1181             guint32 fillColor = sp_desktop_get_color_tool (SP_ACTIVE_DESKTOP, "tools.calligraphic", true);
1182             //guint32 strokeColor = sp_desktop_get_color_tool (SP_ACTIVE_DESKTOP, "tools.calligraphic", false);
1183             double opacity = sp_desktop_get_master_opacity_tool (SP_ACTIVE_DESKTOP, "tools.calligraphic");
1184             double fillOpacity = sp_desktop_get_opacity_tool (SP_ACTIVE_DESKTOP, "tools.calligraphic", true);
1185             //double strokeOpacity = sp_desktop_get_opacity_tool (SP_ACTIVE_DESKTOP, "tools.calligraphic", false);
1186             sp_canvas_bpath_set_fill(SP_CANVAS_BPATH(cbp), ((fillColor & 0xffffff00) | SP_COLOR_F_TO_U(opacity*fillOpacity)), SP_WIND_RULE_EVENODD);
1187             //on second thougtht don't do stroke yet because we don't have stoke-width yet and because stoke appears between segments while drawing
1188             //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);
1189             sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(cbp), 0x00000000, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
1190             /* fixme: Cannot we cascade it to root more clearly? */
1191             g_signal_connect(G_OBJECT(cbp), "event", G_CALLBACK(sp_desktop_root_handler), SP_EVENT_CONTEXT(dc)->desktop);
1192
1193             dc->segments = g_slist_prepend(dc->segments, cbp);
1194         }
1195
1196         dc->point1[0] = dc->point1[dc->npoints - 1];
1197         dc->point2[0] = dc->point2[dc->npoints - 1];
1198         dc->npoints = 1;
1199     } else {
1200         draw_temporary_box(dc);
1201     }
1202 }
1203
1204 static void
1205 draw_temporary_box(SPDynaDrawContext *dc)
1206 {
1207     dc->currentcurve->reset();
1208
1209     dc->currentcurve->moveto(dc->point2[dc->npoints-1]);
1210     for (gint i = dc->npoints-2; i >= 0; i--) {
1211         dc->currentcurve->lineto(dc->point2[i]);
1212     }
1213     for (gint i = 0; i < dc->npoints; i++) {
1214         dc->currentcurve->lineto(dc->point1[i]);
1215     }
1216
1217     if (dc->npoints >= 2) {
1218         add_cap(dc->currentcurve, dc->point1[dc->npoints-1], dc->point2[dc->npoints-1], dc->cap_rounding);
1219     }
1220
1221     dc->currentcurve->closepath();
1222     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(dc->currentshape), dc->currentcurve);
1223 }
1224
1225 /*
1226   Local Variables:
1227   mode:c++
1228   c-file-style:"stroustrup"
1229   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
1230   indent-tabs-mode:nil
1231   fill-column:99
1232   End:
1233 */
1234 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :