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
  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 "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 #define DRAG_MIN 0.0
  83 #define DRAG_DEFAULT 1.0
  84 #define DRAG_MAX 1.0
  85
  86 // FIXME: move it to some shared file to be reused by both calligraphy and dropper
  87 #define C1 0.552
  88 static NArtBpath const hatch_area_circle[] = {
  89     { NR_MOVETO, 0, 0, 0, 0, -1, 0 },
  90     { NR_CURVETO, -1, C1, -C1, 1, 0, 1 },
  91     { NR_CURVETO, C1, 1, 1, C1, 1, 0 },
  92     { NR_CURVETO, 1, -C1, C1, -1, 0, -1 },
  93     { NR_CURVETO, -C1, -1, -1, -C1, -1, 0 },
  94     { NR_END, 0, 0, 0, 0, 0, 0 }
  95 };
  96 #undef C1
  97
  98
  99 static void sp_dyna_draw_context_class_init(SPDynaDrawContextClass *klass);
 100 static void sp_dyna_draw_context_init(SPDynaDrawContext *ddc);
 101 static void sp_dyna_draw_context_dispose(GObject *object);
 102
 103 static void sp_dyna_draw_context_setup(SPEventContext *ec);
 104 static void sp_dyna_draw_context_set(SPEventContext *ec, gchar const *key, gchar const *val);
 105 static gint sp_dyna_draw_context_root_handler(SPEventContext *ec, GdkEvent *event);
 106
 107 static void clear_current(SPDynaDrawContext *dc);
 108 static void set_to_accumulated(SPDynaDrawContext *dc, bool unionize);
 109 static void add_cap(SPCurve *curve, NR::Point const &pre, NR::Point const &from, NR::Point const &to, NR::Point const &post, double rounding);
 110 static void accumulate_calligraphic(SPDynaDrawContext *dc);
 111
 112 static void fit_and_split(SPDynaDrawContext *ddc, gboolean release);
 113
 114 static void sp_dyna_draw_reset(SPDynaDrawContext *ddc, NR::Point p);
 115 static NR::Point sp_dyna_draw_get_npoint(SPDynaDrawContext const *ddc, NR::Point v);
 116 static NR::Point sp_dyna_draw_get_vpoint(SPDynaDrawContext const *ddc, NR::Point n);
 117 static void draw_temporary_box(SPDynaDrawContext *dc);
 118
 119
 120 static SPEventContextClass *parent_class;
 121
 122 GtkType
 123 sp_dyna_draw_context_get_type(void)
 124 {
 125     static GType type = 0;
 126     if (!type) {
 127         GTypeInfo info = {
 128             sizeof(SPDynaDrawContextClass),
 129             NULL, NULL,
 130             (GClassInitFunc) sp_dyna_draw_context_class_init,
 131             NULL, NULL,
 132             sizeof(SPDynaDrawContext),
 133             4,
 134             (GInstanceInitFunc) sp_dyna_draw_context_init,
 135             NULL,   /* value_table */
 136         };
 137         type = g_type_register_static(SP_TYPE_EVENT_CONTEXT, "SPDynaDrawContext", &info, (GTypeFlags)0);
 138     }
 139     return type;
 140 }
 141
 142 static void
 143 sp_dyna_draw_context_class_init(SPDynaDrawContextClass *klass)
 144 {
 145     GObjectClass *object_class = (GObjectClass *) klass;
 146     SPEventContextClass *event_context_class = (SPEventContextClass *) klass;
 147
 148     parent_class = (SPEventContextClass*)g_type_class_peek_parent(klass);
 149
 150     object_class->dispose = sp_dyna_draw_context_dispose;
 151
 152     event_context_class->setup = sp_dyna_draw_context_setup;
 153     event_context_class->set = sp_dyna_draw_context_set;
 154     event_context_class->root_handler = sp_dyna_draw_context_root_handler;
 155 }
 156
 157 static void
 158 sp_dyna_draw_context_init(SPDynaDrawContext *ddc)
 159 {
 160     SPEventContext *event_context = SP_EVENT_CONTEXT(ddc);
 161
 162     event_context->cursor_shape = cursor_calligraphy_xpm;
 163     event_context->hot_x = 4;
 164     event_context->hot_y = 4;
 165
 166     ddc->accumulated = NULL;
 167     ddc->segments = NULL;
 168     ddc->currentcurve = NULL;
 169     ddc->currentshape = NULL;
 170     ddc->npoints = 0;
 171     ddc->cal1 = NULL;
 172     ddc->cal2 = NULL;
 173     ddc->repr = NULL;
 174
 175     /* DynaDraw values */
 176     ddc->cur = NR::Point(0,0);
 177     ddc->last = NR::Point(0,0);
 178     ddc->vel = NR::Point(0,0);
 179     ddc->vel_max = 0;
 180     ddc->acc = NR::Point(0,0);
 181     ddc->ang = NR::Point(0,0);
 182     ddc->del = NR::Point(0,0);
 183
 184     /* attributes */
 185     ddc->dragging = FALSE;
 186
 187     ddc->mass = 0.3;
 188     ddc->drag = DRAG_DEFAULT;
 189     ddc->angle = 30.0;
 190     ddc->width = 0.2;
 191     ddc->pressure = DDC_DEFAULT_PRESSURE;
 192
 193     ddc->vel_thin = 0.1;
 194     ddc->flatness = 0.9;
 195     ddc->cap_rounding = 0.0;
 196
 197     ddc->abs_width = false;
 198     ddc->keep_selected = true;
 199
 200     ddc->hatch_spacing = 0;
 201     ddc->hatch_spacing_step = 0;
 202     new (&ddc->hatch_pointer_past) std::list<double>();
 203     new (&ddc->hatch_nearest_past) std::list<double>();
 204     ddc->hatch_last_nearest = NR::Point(0,0);
 205     ddc->hatch_last_pointer = NR::Point(0,0);
 206     ddc->hatch_vector_accumulated = NR::Point(0,0);
 207     ddc->hatch_escaped = false;
 208     ddc->hatch_area = NULL;
 209     ddc->hatch_item = NULL;
 210     ddc->hatch_livarot_path = NULL;
 211
 212     ddc->trace_bg = false;
 213 }
 214
 215 static void
 216 sp_dyna_draw_context_dispose(GObject *object)
 217 {
 218     SPDynaDrawContext *ddc = SP_DYNA_DRAW_CONTEXT(object);
 219
 220     if (ddc->hatch_area) {
 221         gtk_object_destroy(GTK_OBJECT(ddc->hatch_area));
 222         ddc->hatch_area = NULL;
 223     }
 224
 225     if (ddc->accumulated) {
 226         ddc->accumulated = ddc->accumulated->unref();
 227     }
 228
 229     while (ddc->segments) {
 230         gtk_object_destroy(GTK_OBJECT(ddc->segments->data));
 231         ddc->segments = g_slist_remove(ddc->segments, ddc->segments->data);
 232     }
 233
 234     if (ddc->currentcurve) ddc->currentcurve = ddc->currentcurve->unref();
 235     if (ddc->cal1) ddc->cal1 = ddc->cal1->unref();
 236     if (ddc->cal2) ddc->cal2 = ddc->cal2->unref();
 237
 238     if (ddc->currentshape) {
 239         gtk_object_destroy(GTK_OBJECT(ddc->currentshape));
 240         ddc->currentshape = NULL;
 241     }
 242
 243     if (ddc->_message_context) {
 244         delete ddc->_message_context;
 245     }
 246
 247     G_OBJECT_CLASS(parent_class)->dispose(object);
 248
 249     ddc->hatch_pointer_past.~list();
 250     ddc->hatch_nearest_past.~list();
 251 }
 252
 253 static void
 254 sp_dyna_draw_context_setup(SPEventContext *ec)
 255 {
 256     SPDynaDrawContext *ddc = SP_DYNA_DRAW_CONTEXT(ec);
 257
 258     if (((SPEventContextClass *) parent_class)->setup)
 259         ((SPEventContextClass *) parent_class)->setup(ec);
 260
 261     ddc->accumulated = new SPCurve(32);
 262     ddc->currentcurve = new SPCurve(4);
 263
 264     ddc->cal1 = new SPCurve(32);
 265     ddc->cal2 = new SPCurve(32);
 266
 267     ddc->currentshape = sp_canvas_item_new(sp_desktop_sketch(ec->desktop), SP_TYPE_CANVAS_BPATH, NULL);
 268     sp_canvas_bpath_set_fill(SP_CANVAS_BPATH(ddc->currentshape), DDC_RED_RGBA, SP_WIND_RULE_EVENODD);
 269     sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(ddc->currentshape), 0x00000000, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 270     /* fixme: Cannot we cascade it to root more clearly? */
 271     g_signal_connect(G_OBJECT(ddc->currentshape), "event", G_CALLBACK(sp_desktop_root_handler), ec->desktop);
 272
 273     {
 274         SPCurve *c = SPCurve::new_from_foreign_bpath(hatch_area_circle);
 275         ddc->hatch_area = sp_canvas_bpath_new(sp_desktop_controls(ec->desktop), c);
 276         c->unref();
 277         sp_canvas_bpath_set_fill(SP_CANVAS_BPATH(ddc->hatch_area), 0x00000000,(SPWindRule)0);
 278         sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(ddc->hatch_area), 0x0000007f, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 279         sp_canvas_item_hide(ddc->hatch_area);
 280     }
 281
 282     sp_event_context_read(ec, "mass");
 283     sp_event_context_read(ec, "wiggle");
 284     sp_event_context_read(ec, "angle");
 285     sp_event_context_read(ec, "width");
 286     sp_event_context_read(ec, "thinning");
 287     sp_event_context_read(ec, "tremor");
 288     sp_event_context_read(ec, "flatness");
 289     sp_event_context_read(ec, "tracebackground");
 290     sp_event_context_read(ec, "usepressure");
 291     sp_event_context_read(ec, "usetilt");
 292     sp_event_context_read(ec, "abs_width");
 293     sp_event_context_read(ec, "keep_selected");
 294     sp_event_context_read(ec, "cap_rounding");
 295
 296     ddc->is_drawing = false;
 297
 298     ddc->_message_context = new Inkscape::MessageContext((ec->desktop)->messageStack());
 299
 300     if (prefs_get_int_attribute("tools.calligraphic", "selcue", 0) != 0) {
 301         ec->enableSelectionCue();
 302     }
 303 }
 304
 305 static void
 306 sp_dyna_draw_context_set(SPEventContext *ec, gchar const *key, gchar const *val)
 307 {
 308     SPDynaDrawContext *ddc = SP_DYNA_DRAW_CONTEXT(ec);
 309
 310     if (!strcmp(key, "mass")) {
 311         double const dval = ( val ? g_ascii_strtod (val, NULL) : 0.2 );
 312         ddc->mass = CLAMP(dval, -1000.0, 1000.0);
 313     } else if (!strcmp(key, "wiggle")) {
 314         double const dval = ( val ? g_ascii_strtod (val, NULL) : (1 - DRAG_DEFAULT));
 315         ddc->drag = CLAMP((1 - dval), DRAG_MIN, DRAG_MAX); // drag is inverse to wiggle
 316     } else if (!strcmp(key, "angle")) {
 317         double const dval = ( val ? g_ascii_strtod (val, NULL) : 0.0);
 318         ddc->angle = CLAMP (dval, -90, 90);
 319     } else if (!strcmp(key, "width")) {
 320         double const dval = ( val ? g_ascii_strtod (val, NULL) : 0.1 );
 321         ddc->width = CLAMP(dval, -1000.0, 1000.0);
 322     } else if (!strcmp(key, "thinning")) {
 323         double const dval = ( val ? g_ascii_strtod (val, NULL) : 0.1 );
 324         ddc->vel_thin = CLAMP(dval, -1.0, 1.0);
 325     } else if (!strcmp(key, "tremor")) {
 326         double const dval = ( val ? g_ascii_strtod (val, NULL) : 0.0 );
 327         ddc->tremor = CLAMP(dval, 0.0, 1.0);
 328     } else if (!strcmp(key, "flatness")) {
 329         double const dval = ( val ? g_ascii_strtod (val, NULL) : 1.0 );
 330         ddc->flatness = CLAMP(dval, 0, 1.0);
 331     } else if (!strcmp(key, "tracebackground")) {
 332         ddc->trace_bg = (val && strcmp(val, "0"));
 333     } else if (!strcmp(key, "usepressure")) {
 334         ddc->usepressure = (val && strcmp(val, "0"));
 335     } else if (!strcmp(key, "usetilt")) {
 336         ddc->usetilt = (val && strcmp(val, "0"));
 337     } else if (!strcmp(key, "abs_width")) {
 338         ddc->abs_width = (val && strcmp(val, "0"));
 339     } else if (!strcmp(key, "keep_selected")) {
 340         ddc->keep_selected = (val && strcmp(val, "0"));
 341     } else if (!strcmp(key, "cap_rounding")) {
 342         ddc->cap_rounding = ( val ? g_ascii_strtod (val, NULL) : 0.0 );
 343     }
 344
 345     //g_print("DDC: %g %g %g %g\n", ddc->mass, ddc->drag, ddc->angle, ddc->width);
 346 }
 347
 348 static double
 349 flerp(double f0, double f1, double p)
 350 {
 351     return f0 + ( f1 - f0 ) * p;
 352 }
 353
 354 /* Get normalized point */
 355 static NR::Point
 356 sp_dyna_draw_get_npoint(SPDynaDrawContext const *dc, NR::Point v)
 357 {
 358     NR::Rect drect = SP_EVENT_CONTEXT(dc)->desktop->get_display_area();
 359     double const max = MAX ( drect.dimensions()[NR::X], drect.dimensions()[NR::Y] );
 360     return NR::Point(( v[NR::X] - drect.min()[NR::X] ) / max,  ( v[NR::Y] - drect.min()[NR::Y] ) / max);
 361 }
 362
 363 /* Get view point */
 364 static NR::Point
 365 sp_dyna_draw_get_vpoint(SPDynaDrawContext const *dc, NR::Point n)
 366 {
 367     NR::Rect drect = SP_EVENT_CONTEXT(dc)->desktop->get_display_area();
 368     double const max = MAX ( drect.dimensions()[NR::X], drect.dimensions()[NR::Y] );
 369     return NR::Point(n[NR::X] * max + drect.min()[NR::X], n[NR::Y] * max + drect.min()[NR::Y]);
 370 }
 371
 372 static void
 373 sp_dyna_draw_reset(SPDynaDrawContext *dc, NR::Point p)
 374 {
 375     dc->last = dc->cur = sp_dyna_draw_get_npoint(dc, p);
 376     dc->vel = NR::Point(0,0);
 377     dc->vel_max = 0;
 378     dc->acc = NR::Point(0,0);
 379     dc->ang = NR::Point(0,0);
 380     dc->del = NR::Point(0,0);
 381 }
 382
 383 static void
 384 sp_dyna_draw_extinput(SPDynaDrawContext *dc, GdkEvent *event)
 385 {
 386     if (gdk_event_get_axis (event, GDK_AXIS_PRESSURE, &dc->pressure))
 387         dc->pressure = CLAMP (dc->pressure, DDC_MIN_PRESSURE, DDC_MAX_PRESSURE);
 388     else
 389         dc->pressure = DDC_DEFAULT_PRESSURE;
 390
 391     if (gdk_event_get_axis (event, GDK_AXIS_XTILT, &dc->xtilt))
 392         dc->xtilt = CLAMP (dc->xtilt, DDC_MIN_TILT, DDC_MAX_TILT);
 393     else
 394         dc->xtilt = DDC_DEFAULT_TILT;
 395
 396     if (gdk_event_get_axis (event, GDK_AXIS_YTILT, &dc->ytilt))
 397         dc->ytilt = CLAMP (dc->ytilt, DDC_MIN_TILT, DDC_MAX_TILT);
 398     else
 399         dc->ytilt = DDC_DEFAULT_TILT;
 400 }
 401
 402
 403 static gboolean
 404 sp_dyna_draw_apply(SPDynaDrawContext *dc, NR::Point p)
 405 {
 406     NR::Point n = sp_dyna_draw_get_npoint(dc, p);
 407
 408     /* Calculate mass and drag */
 409     double const mass = flerp(1.0, 160.0, dc->mass);
 410     double const drag = flerp(0.0, 0.5, dc->drag * dc->drag);
 411
 412     /* Calculate force and acceleration */
 413     NR::Point force = n - dc->cur;
 414
 415     // If force is below the absolute threshold DYNA_EPSILON,
 416     // or we haven't yet reached DYNA_VEL_START (i.e. at the beginning of stroke)
 417     // _and_ the force is below the (higher) DYNA_EPSILON_START threshold,
 418     // discard this move.
 419     // This prevents flips, blobs, and jerks caused by microscopic tremor of the tablet pen,
 420     // especially bothersome at the start of the stroke where we don't yet have the inertia to
 421     // smooth them out.
 422     if ( NR::L2(force) < DYNA_EPSILON || (dc->vel_max < DYNA_VEL_START && NR::L2(force) < DYNA_EPSILON_START)) {
 423         return FALSE;
 424     }
 425
 426     dc->acc = force / mass;
 427
 428     /* Calculate new velocity */
 429     dc->vel += dc->acc;
 430
 431     if (NR::L2(dc->vel) > dc->vel_max)
 432         dc->vel_max = NR::L2(dc->vel);
 433
 434     /* Calculate angle of drawing tool */
 435
 436     double a1;
 437     if (dc->usetilt) {
 438         // 1a. calculate nib angle from input device tilt:
 439         gdouble length = std::sqrt(dc->xtilt*dc->xtilt + dc->ytilt*dc->ytilt);;
 440
 441         if (length > 0) {
 442             NR::Point ang1 = NR::Point(dc->ytilt/length, dc->xtilt/length);
 443             a1 = atan2(ang1);
 444         }
 445         else
 446             a1 = 0.0;
 447     }
 448     else {
 449         // 1b. fixed dc->angle (absolutely flat nib):
 450         double const radians = ( (dc->angle - 90) / 180.0 ) * M_PI;
 451         NR::Point ang1 = NR::Point(-sin(radians),  cos(radians));
 452         a1 = atan2(ang1);
 453     }
 454
 455     // 2. perpendicular to dc->vel (absolutely non-flat nib):
 456     gdouble const mag_vel = NR::L2(dc->vel);
 457     if ( mag_vel < DYNA_EPSILON ) {
 458         return FALSE;
 459     }
 460     NR::Point ang2 = NR::rot90(dc->vel) / mag_vel;
 461
 462     // 3. Average them using flatness parameter:
 463     // calculate angles
 464     double a2 = atan2(ang2);
 465     // flip a2 to force it to be in the same half-circle as a1
 466     bool flipped = false;
 467     if (fabs (a2-a1) > 0.5*M_PI) {
 468         a2 += M_PI;
 469         flipped = true;
 470     }
 471     // normalize a2
 472     if (a2 > M_PI)
 473         a2 -= 2*M_PI;
 474     if (a2 < -M_PI)
 475         a2 += 2*M_PI;
 476     // find the flatness-weighted bisector angle, unflip if a2 was flipped
 477     // FIXME: when dc->vel is oscillating around the fixed angle, the new_ang flips back and forth. How to avoid this?
 478     double new_ang = a1 + (1 - dc->flatness) * (a2 - a1) - (flipped? M_PI : 0);
 479
 480     // Try to detect a sudden flip when the new angle differs too much from the previous for the
 481     // current velocity; in that case discard this move
 482     double angle_delta = NR::L2(NR::Point (cos (new_ang), sin (new_ang)) - dc->ang);
 483     if ( angle_delta / NR::L2(dc->vel) > 4000 ) {
 484         return FALSE;
 485     }
 486
 487     // convert to point
 488     dc->ang = NR::Point (cos (new_ang), sin (new_ang));
 489
 490 //    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);
 491
 492     /* Apply drag */
 493     dc->vel *= 1.0 - drag;
 494
 495     /* Update position */
 496     dc->last = dc->cur;
 497     dc->cur += dc->vel;
 498
 499     return TRUE;
 500 }
 501
 502 static void
 503 sp_dyna_draw_brush(SPDynaDrawContext *dc)
 504 {
 505     g_assert( dc->npoints >= 0 && dc->npoints < SAMPLING_SIZE );
 506
 507     // How much velocity thins strokestyle
 508     double vel_thin = flerp (0, 160, dc->vel_thin);
 509
 510     // Influence of pressure on thickness
 511     double pressure_thick = (dc->usepressure ? dc->pressure : 1.0);
 512
 513     // get the real brush point, not the same as pointer (affected by hatch tracking and/or mass
 514     // drag)
 515     NR::Point brush = sp_dyna_draw_get_vpoint(dc, dc->cur);
 516     NR::Point brush_w = SP_EVENT_CONTEXT(dc)->desktop->d2w(brush);
 517
 518     double trace_thick = 1;
 519     if (dc->trace_bg) {
 520         // pick single pixel
 521         NRPixBlock pb;
 522         int x = (int) floor(brush_w[NR::X]);
 523         int y = (int) floor(brush_w[NR::Y]);
 524         nr_pixblock_setup_fast(&pb, NR_PIXBLOCK_MODE_R8G8B8A8P, x, y, x+1, y+1, TRUE);
 525         sp_canvas_arena_render_pixblock(SP_CANVAS_ARENA(sp_desktop_drawing(SP_EVENT_CONTEXT(dc)->desktop)), &pb);
 526         const unsigned char *s = NR_PIXBLOCK_PX(&pb);
 527         double R = s[0] / 255.0;
 528         double G = s[1] / 255.0;
 529         double B = s[2] / 255.0;
 530         double A = s[3] / 255.0;
 531         double max = MAX (MAX (R, G), B);
 532         double min = MIN (MIN (R, G), B);
 533         double L = A * (max + min)/2 + (1 - A); // blend with white bg
 534         trace_thick = 1 - L;
 535         //g_print ("L %g thick %g\n", L, trace_thick);
 536     }
 537
 538     double width = (pressure_thick * trace_thick - vel_thin * NR::L2(dc->vel)) * dc->width;
 539
 540     double tremble_left = 0, tremble_right = 0;
 541     if (dc->tremor > 0) {
 542         // obtain two normally distributed random variables, using polar Box-Muller transform
 543         double x1, x2, w, y1, y2;
 544         do {
 545             x1 = 2.0 * g_random_double_range(0,1) - 1.0;
 546             x2 = 2.0 * g_random_double_range(0,1) - 1.0;
 547             w = x1 * x1 + x2 * x2;
 548         } while ( w >= 1.0 );
 549         w = sqrt( (-2.0 * log( w ) ) / w );
 550         y1 = x1 * w;
 551         y2 = x2 * w;
 552
 553         // deflect both left and right edges randomly and independently, so that:
 554         // (1) dc->tremor=1 corresponds to sigma=1, decreasing dc->tremor narrows the bell curve;
 555         // (2) deflection depends on width, but is upped for small widths for better visual uniformity across widths;
 556         // (3) deflection somewhat depends on speed, to prevent fast strokes looking
 557         // comparatively smooth and slow ones excessively jittery
 558         tremble_left  = (y1)*dc->tremor * (0.15 + 0.8*width) * (0.35 + 14*NR::L2(dc->vel));
 559         tremble_right = (y2)*dc->tremor * (0.15 + 0.8*width) * (0.35 + 14*NR::L2(dc->vel));
 560     }
 561
 562     if ( width < 0.02 * dc->width ) {
 563         width = 0.02 * dc->width;
 564     }
 565
 566     double dezoomify_factor = 0.05 * 1000;
 567     if (!dc->abs_width) {
 568         dezoomify_factor /= SP_EVENT_CONTEXT(dc)->desktop->current_zoom();
 569     }
 570
 571     NR::Point del_left = dezoomify_factor * (width + tremble_left) * dc->ang;
 572     NR::Point del_right = dezoomify_factor * (width + tremble_right) * dc->ang;
 573
 574     dc->point1[dc->npoints] = brush + del_left;
 575     dc->point2[dc->npoints] = brush - del_right;
 576
 577     dc->del = 0.5*(del_left + del_right);
 578
 579     dc->npoints++;
 580 }
 581
 582 void
 583 sp_ddc_update_toolbox (SPDesktop *desktop, const gchar *id, double value)
 584 {
 585     desktop->setToolboxAdjustmentValue (id, value);
 586 }
 587
 588 static void
 589 calligraphic_cancel(SPDynaDrawContext *dc)
 590 {
 591     SPDesktop *desktop = SP_EVENT_CONTEXT(dc)->desktop;
 592     dc->dragging = FALSE;
 593     dc->is_drawing = false;
 594     sp_canvas_item_ungrab(SP_CANVAS_ITEM(desktop->acetate), 0);
 595             /* Remove all temporary line segments */
 596             while (dc->segments) {
 597                 gtk_object_destroy(GTK_OBJECT(dc->segments->data));
 598                 dc->segments = g_slist_remove(dc->segments, dc->segments->data);
 599             }
 600             /* reset accumulated curve */
 601             dc->accumulated->reset();
 602             clear_current(dc);
 603             if (dc->repr) {
 604                 dc->repr = NULL;
 605             }
 606 }
 607
 608
 609 gint
 610 sp_dyna_draw_context_root_handler(SPEventContext *event_context,
 611                                   GdkEvent *event)
 612 {
 613     SPDynaDrawContext *dc = SP_DYNA_DRAW_CONTEXT(event_context);
 614     SPDesktop *desktop = event_context->desktop;
 615
 616     gint ret = FALSE;
 617
 618     switch (event->type) {
 619         case GDK_BUTTON_PRESS:
 620             if (event->button.button == 1 && !event_context->space_panning) {
 621
 622                 SPDesktop *desktop = SP_EVENT_CONTEXT_DESKTOP(dc);
 623
 624                 if (Inkscape::have_viable_layer(desktop, dc->_message_context) == false) {
 625                     return TRUE;
 626                 }
 627
 628                 NR::Point const button_w(event->button.x,
 629                                          event->button.y);
 630                 NR::Point const button_dt(desktop->w2d(button_w));
 631                 sp_dyna_draw_reset(dc, button_dt);
 632                 sp_dyna_draw_extinput(dc, event);
 633                 sp_dyna_draw_apply(dc, button_dt);
 634                 dc->accumulated->reset();
 635                 if (dc->repr) {
 636                     dc->repr = NULL;
 637                 }
 638
 639                 /* initialize first point */
 640                 dc->npoints = 0;
 641
 642                 sp_canvas_item_grab(SP_CANVAS_ITEM(desktop->acetate),
 643                                     ( GDK_KEY_PRESS_MASK |
 644                                       GDK_BUTTON_RELEASE_MASK |
 645                                       GDK_POINTER_MOTION_MASK |
 646                                       GDK_BUTTON_PRESS_MASK ),
 647                                     NULL,
 648                                     event->button.time);
 649
 650                 ret = TRUE;
 651
 652                 sp_canvas_force_full_redraw_after_interruptions(desktop->canvas, 3);
 653                 dc->is_drawing = true;
 654             }
 655             break;
 656         case GDK_MOTION_NOTIFY:
 657         {
 658             NR::Point const motion_w(event->motion.x,
 659                                      event->motion.y);
 660             NR::Point motion_dt(desktop->w2d(motion_w));
 661             sp_dyna_draw_extinput(dc, event);
 662
 663             dc->_message_context->clear();
 664
 665             // for hatching:
 666             double hatch_dist = 0;
 667             NR::Point hatch_unit_vector(0,0);
 668             NR::Point nearest(0,0);
 669             NR::Point pointer(0,0);
 670             NR::Matrix motion_to_curve(NR::identity());
 671
 672             if (event->motion.state & GDK_CONTROL_MASK) { // hatching - sense the item
 673
 674                 SPItem *selected = sp_desktop_selection(desktop)->singleItem();
 675                 if (selected && (SP_IS_SHAPE(selected) || SP_IS_TEXT(selected))) {
 676                     // One item selected, and it's a path;
 677                     // let's try to track it as a guide
 678
 679                     if (selected != dc->hatch_item) {
 680                         dc->hatch_item = selected;
 681                         if (dc->hatch_livarot_path)
 682                             delete dc->hatch_livarot_path;
 683                         dc->hatch_livarot_path = Path_for_item (dc->hatch_item, true, true);
 684                         dc->hatch_livarot_path->ConvertWithBackData(0.01);
 685                     }
 686
 687                     // calculate pointer point in the guide item's coords
 688                     motion_to_curve = sp_item_dt2i_affine(selected) * sp_item_i2doc_affine(selected);
 689                     pointer = motion_dt * motion_to_curve;
 690
 691                     // calculate the nearest point on the guide path
 692                     NR::Maybe<Path::cut_position> position = get_nearest_position_on_Path(dc->hatch_livarot_path, pointer);
 693                     nearest = get_point_on_Path(dc->hatch_livarot_path, position->piece, position->t);
 694
 695
 696                     // distance from pointer to nearest
 697                     hatch_dist = NR::L2(pointer - nearest);
 698                     // unit-length vector
 699                     hatch_unit_vector = (pointer - nearest)/hatch_dist;
 700
 701                     dc->_message_context->set(Inkscape::NORMAL_MESSAGE, _("<b>Guide path selected</b>; start drawing along the guide with <b>Ctrl</b>"));
 702                 } else {
 703                     dc->_message_context->set(Inkscape::NORMAL_MESSAGE, _("<b>Select a guide path</b> to track with <b>Ctrl</b>"));
 704                 }
 705             }
 706
 707             if ( dc->is_drawing && (event->motion.state & GDK_BUTTON1_MASK) && !event_context->space_panning) {
 708                 dc->dragging = TRUE;
 709
 710                 if (event->motion.state & GDK_CONTROL_MASK && dc->hatch_item) { // hatching
 711
 712 #define SPEED_ELEMENTS 12
 713 #define SPEED_MIN 0.12
 714 #define SPEED_NORMAL 0.65
 715
 716                     // speed is the movement of the nearest point along the guide path, divided by
 717                     // the movement of the pointer at the same period; it is averaged for the last
 718                     // SPEED_ELEMENTS motion events.  Normally, as you track the guide path, speed
 719                     // is about 1, i.e. the nearest point on the path is moved by about the same
 720                     // distance as the pointer. If the speed starts to decrease, we are losing
 721                     // contact with the guide; if it drops below SPEED_MIN, we are on our own and
 722                     // not attracted to guide anymore. Most often this happens when you have
 723                     // tracked to the end of a guide calligraphic stroke and keep moving
 724                     // further. We try to handle this situation gracefully: not stick with the
 725                     // guide forever but let go of it smoothly and without sharp jerks (non-zero
 726                     // mass recommended; with zero mass, jerks are still quite noticeable).
 727
 728                     double speed = 1;
 729                     if (NR::L2(dc->hatch_last_nearest) != 0) {
 730                         // the distance nearest moved since the last motion event
 731                         double nearest_moved = NR::L2(nearest - dc->hatch_last_nearest);
 732                         // the distance pointer moved since the last motion event
 733                         double pointer_moved = NR::L2(pointer - dc->hatch_last_pointer);
 734                         // store them in stacks limited to SPEED_ELEMENTS
 735                         dc->hatch_nearest_past.push_front(nearest_moved);
 736                         if (dc->hatch_nearest_past.size() > SPEED_ELEMENTS)
 737                             dc->hatch_nearest_past.pop_back();
 738                         dc->hatch_pointer_past.push_front(pointer_moved);
 739                         if (dc->hatch_pointer_past.size() > SPEED_ELEMENTS)
 740                             dc->hatch_pointer_past.pop_back();
 741
 742                         // If the stacks are full,
 743                         if (dc->hatch_nearest_past.size() == SPEED_ELEMENTS) {
 744                             // calculate the sums of all stored movements
 745                             double nearest_sum = std::accumulate (dc->hatch_nearest_past.begin(), dc->hatch_nearest_past.end(), 0.0);
 746                             double pointer_sum = std::accumulate (dc->hatch_pointer_past.begin(), dc->hatch_pointer_past.end(), 0.0);
 747                             // and divide to get the speed
 748                             speed = nearest_sum/pointer_sum;
 749                             //g_print ("nearest sum %g  pointer_sum %g  speed %g\n", nearest_sum, pointer_sum, speed);
 750                         }
 751                     }
 752
 753                     if (   dc->hatch_escaped  // already escaped, do not reattach
 754                         || (speed < SPEED_MIN) // stuck; most likely reached end of traced stroke
 755                         || (dc->hatch_spacing > 0 && hatch_dist > 50 * dc->hatch_spacing) // went too far from the guide
 756                         ) {
 757                         // We are NOT attracted to the guide!
 758
 759                         //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);
 760
 761                         // Remember hatch_escaped so we don't get
 762                         // attracted again until the end of this stroke
 763                         dc->hatch_escaped = true;
 764
 765                     } else {
 766
 767                         // Calculate angle cosine of this vector-to-guide and all past vectors
 768                         // summed, to detect if we accidentally flipped to the other side of the
 769                         // guide
 770                         double dot = NR::dot (pointer - nearest, dc->hatch_vector_accumulated);
 771                         dot /= NR::L2(pointer - nearest) * NR::L2(dc->hatch_vector_accumulated);
 772
 773                         if (dc->hatch_spacing != 0) { // spacing was already set
 774                             double target;
 775                             if (speed > SPEED_NORMAL) {
 776                                 // all ok, strictly obey the spacing
 777                                 target = dc->hatch_spacing;
 778                             } else {
 779                                 // looks like we're starting to lose speed,
 780                                 // so _gradually_ let go attraction to prevent jerks
 781                                 target = (dc->hatch_spacing * speed + hatch_dist * (SPEED_NORMAL - speed))/SPEED_NORMAL;
 782                             }
 783                             if (!isNaN(dot) && dot < -0.5) {// flip
 784                                 target = -target;
 785                             }
 786
 787                             // This is the track pointer that we will use instead of the real one
 788                             NR::Point new_pointer = nearest + target * hatch_unit_vector;
 789
 790                             // some limited feedback: allow persistent pulling to slightly change
 791                             // the spacing
 792                             dc->hatch_spacing += (hatch_dist - dc->hatch_spacing)/3500;
 793
 794                             // return it to the desktop coords
 795                             motion_dt = new_pointer * motion_to_curve.inverse();
 796
 797                         } else {
 798                             // this is the first motion event, set the dist
 799                             dc->hatch_spacing = hatch_dist;
 800                         }
 801
 802                         // remember last points
 803                         dc->hatch_last_pointer = pointer;
 804                         dc->hatch_last_nearest = nearest;
 805                         dc->hatch_vector_accumulated += (pointer - nearest);
 806                     }
 807
 808                     dc->_message_context->set(Inkscape::NORMAL_MESSAGE, dc->hatch_escaped? _("Tracking: <b>connection to guide path lost!</b>") : _("<b>Tracking</b> a guide path"));
 809
 810                 } else {
 811                     dc->_message_context->set(Inkscape::NORMAL_MESSAGE, _("<b>Drawing</b> a calligraphic stroke"));
 812                 }
 813
 814                 if (!sp_dyna_draw_apply(dc, motion_dt)) {
 815                     ret = TRUE;
 816                     break;
 817                 }
 818
 819                 if ( dc->cur != dc->last ) {
 820                     sp_dyna_draw_brush(dc);
 821                     g_assert( dc->npoints > 0 );
 822                     fit_and_split(dc, FALSE);
 823                 }
 824                 ret = TRUE;
 825             }
 826
 827             // Draw the hatching circle if necessary
 828             if (event->motion.state & GDK_CONTROL_MASK) {
 829                 if (dc->hatch_spacing == 0 && hatch_dist != 0) {
 830                     // Haven't set spacing yet: gray, center free, update radius live
 831                     NR::Point c = desktop->w2d(motion_w);
 832                     NR::Matrix const sm (NR::scale(hatch_dist, hatch_dist) * NR::translate(c));
 833                     sp_canvas_item_affine_absolute(dc->hatch_area, sm);
 834                     sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(dc->hatch_area), 0x7f7f7fff, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 835                     sp_canvas_item_show(dc->hatch_area);
 836                 } else if (dc->dragging && !dc->hatch_escaped) {
 837                     // Tracking: green, center snapped, fixed radius
 838                     NR::Point c = motion_dt;
 839                     NR::Matrix const sm (NR::scale(dc->hatch_spacing, dc->hatch_spacing) * NR::translate(c));
 840                     sp_canvas_item_affine_absolute(dc->hatch_area, sm);
 841                     sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(dc->hatch_area), 0x00FF00ff, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 842                     sp_canvas_item_show(dc->hatch_area);
 843                 } else if (dc->dragging && dc->hatch_escaped) {
 844                     // Tracking escaped: red, center free, fixed radius
 845                     NR::Point c = desktop->w2d(motion_w);
 846                     NR::Matrix const sm (NR::scale(dc->hatch_spacing, dc->hatch_spacing) * NR::translate(c));
 847
 848                     sp_canvas_item_affine_absolute(dc->hatch_area, sm);
 849                     sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(dc->hatch_area), 0xFF0000ff, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 850                     sp_canvas_item_show(dc->hatch_area);
 851                 } else {
 852                     // Not drawing but spacing set: gray, center snapped, fixed radius
 853                     NR::Point c = (nearest + dc->hatch_spacing * hatch_unit_vector) * motion_to_curve.inverse();
 854                     if (!isNaN(c[NR::X]) && !isNaN(c[NR::Y])) {
 855                         NR::Matrix const sm (NR::scale(dc->hatch_spacing, dc->hatch_spacing) * NR::translate(c));
 856                         sp_canvas_item_affine_absolute(dc->hatch_area, sm);
 857                         sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(dc->hatch_area), 0x7f7f7fff, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 858                         sp_canvas_item_show(dc->hatch_area);
 859                     }
 860                 }
 861             } else {
 862                 sp_canvas_item_hide(dc->hatch_area);
 863             }
 864         }
 865         break;
 866
 867
 868     case GDK_BUTTON_RELEASE:
 869     {
 870         NR::Point const motion_w(event->button.x, event->button.y);
 871         NR::Point const motion_dt(desktop->w2d(motion_w));
 872
 873         sp_canvas_item_ungrab(SP_CANVAS_ITEM(desktop->acetate), event->button.time);
 874         sp_canvas_end_forced_full_redraws(desktop->canvas);
 875         dc->is_drawing = false;
 876
 877         if (dc->dragging && event->button.button == 1 && !event_context->space_panning) {
 878             dc->dragging = FALSE;
 879
 880             sp_dyna_draw_apply(dc, motion_dt);
 881
 882             /* Remove all temporary line segments */
 883             while (dc->segments) {
 884                 gtk_object_destroy(GTK_OBJECT(dc->segments->data));
 885                 dc->segments = g_slist_remove(dc->segments, dc->segments->data);
 886             }
 887
 888             /* Create object */
 889             fit_and_split(dc, TRUE);
 890             accumulate_calligraphic(dc);
 891             set_to_accumulated(dc, event->button.state & GDK_SHIFT_MASK); // performs document_done
 892
 893             /* reset accumulated curve */
 894             dc->accumulated->reset();
 895
 896             clear_current(dc);
 897             if (dc->repr) {
 898                 dc->repr = NULL;
 899             }
 900
 901             if (!dc->hatch_pointer_past.empty()) dc->hatch_pointer_past.clear();
 902             if (!dc->hatch_nearest_past.empty()) dc->hatch_nearest_past.clear();
 903             dc->hatch_last_nearest = NR::Point(0,0);
 904             dc->hatch_last_pointer = NR::Point(0,0);
 905             dc->hatch_vector_accumulated = NR::Point(0,0);
 906             dc->hatch_escaped = false;
 907             dc->hatch_item = NULL;
 908             dc->hatch_livarot_path = NULL;
 909
 910             if (dc->hatch_spacing != 0 && !dc->keep_selected) {
 911                 // we do not select the newly drawn path, so increase spacing by step
 912                 if (dc->hatch_spacing_step == 0) {
 913                     dc->hatch_spacing_step = dc->hatch_spacing;
 914                 }
 915                 dc->hatch_spacing += dc->hatch_spacing_step;
 916             }
 917
 918             dc->_message_context->clear();
 919             ret = TRUE;
 920         }
 921         break;
 922     }
 923
 924     case GDK_KEY_PRESS:
 925         switch (get_group0_keyval (&event->key)) {
 926         case GDK_Up:
 927         case GDK_KP_Up:
 928             if (!MOD__CTRL_ONLY) {
 929                 dc->angle += 5.0;
 930                 if (dc->angle > 90.0)
 931                     dc->angle = 90.0;
 932                 sp_ddc_update_toolbox (desktop, "calligraphy-angle", dc->angle);
 933                 ret = TRUE;
 934             }
 935             break;
 936         case GDK_Down:
 937         case GDK_KP_Down:
 938             if (!MOD__CTRL_ONLY) {
 939                 dc->angle -= 5.0;
 940                 if (dc->angle < -90.0)
 941                     dc->angle = -90.0;
 942                 sp_ddc_update_toolbox (desktop, "calligraphy-angle", dc->angle);
 943                 ret = TRUE;
 944             }
 945             break;
 946         case GDK_Right:
 947         case GDK_KP_Right:
 948             if (!MOD__CTRL_ONLY) {
 949                 dc->width += 0.01;
 950                 if (dc->width > 1.0)
 951                     dc->width = 1.0;
 952                 sp_ddc_update_toolbox (desktop, "altx-calligraphy", dc->width * 100); // the same spinbutton is for alt+x
 953                 ret = TRUE;
 954             }
 955             break;
 956         case GDK_Left:
 957         case GDK_KP_Left:
 958             if (!MOD__CTRL_ONLY) {
 959                 dc->width -= 0.01;
 960                 if (dc->width < 0.01)
 961                     dc->width = 0.01;
 962                 sp_ddc_update_toolbox (desktop, "altx-calligraphy", dc->width * 100);
 963                 ret = TRUE;
 964             }
 965             break;
 966         case GDK_Home:
 967         case GDK_KP_Home:
 968             dc->width = 0.01;
 969             sp_ddc_update_toolbox (desktop, "altx-calligraphy", dc->width * 100);
 970             ret = TRUE;
 971             break;
 972         case GDK_End:
 973         case GDK_KP_End:
 974             dc->width = 1.0;
 975             sp_ddc_update_toolbox (desktop, "altx-calligraphy", dc->width * 100);
 976             ret = TRUE;
 977             break;
 978         case GDK_x:
 979         case GDK_X:
 980             if (MOD__ALT_ONLY) {
 981                 desktop->setToolboxFocusTo ("altx-calligraphy");
 982                 ret = TRUE;
 983             }
 984             break;
 985         case GDK_Escape:
 986             if (dc->is_drawing) {
 987                 // if drawing, cancel, otherwise pass it up for deselecting
 988                 calligraphic_cancel (dc);
 989                 ret = TRUE;
 990             }
 991             break;
 992         case GDK_z:
 993         case GDK_Z:
 994             if (MOD__CTRL_ONLY && dc->is_drawing) {
 995                 // if drawing, cancel, otherwise pass it up for undo
 996                 calligraphic_cancel (dc);
 997                 ret = TRUE;
 998             }
 999             break;
1000         default:
1001             break;
1002         }
1003         break;
1004
1005     case GDK_KEY_RELEASE:
1006         switch (get_group0_keyval(&event->key)) {
1007             case GDK_Control_L:
1008             case GDK_Control_R:
1009                 dc->_message_context->clear();
1010                 dc->hatch_spacing = 0;
1011                 dc->hatch_spacing_step = 0;
1012                 break;
1013             default:
1014                 break;
1015         }
1016
1017     default:
1018         break;
1019     }
1020
1021     if (!ret) {
1022         if (((SPEventContextClass *) parent_class)->root_handler) {
1023             ret = ((SPEventContextClass *) parent_class)->root_handler(event_context, event);
1024         }
1025     }
1026
1027     return ret;
1028 }
1029
1030
1031 static void
1032 clear_current(SPDynaDrawContext *dc)
1033 {
1034     /* reset bpath */
1035     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(dc->currentshape), NULL);
1036     /* reset curve */
1037     dc->currentcurve->reset();
1038     dc->cal1->reset();
1039     dc->cal2->reset();
1040     /* reset points */
1041     dc->npoints = 0;
1042 }
1043
1044 static void
1045 set_to_accumulated(SPDynaDrawContext *dc, bool unionize)
1046 {
1047     SPDesktop *desktop = SP_EVENT_CONTEXT(dc)->desktop;
1048
1049     if (!dc->accumulated->is_empty()) {
1050         NArtBpath *abp;
1051         gchar *str;
1052
1053         if (!dc->repr) {
1054             /* Create object */
1055             Inkscape::XML::Document *xml_doc = sp_document_repr_doc(desktop->doc());
1056             Inkscape::XML::Node *repr = xml_doc->createElement("svg:path");
1057
1058             /* Set style */
1059             sp_desktop_apply_style_tool (desktop, repr, "tools.calligraphic", false);
1060
1061             dc->repr = repr;
1062
1063             SPItem *item=SP_ITEM(desktop->currentLayer()->appendChildRepr(dc->repr));
1064             Inkscape::GC::release(dc->repr);
1065             item->transform = SP_ITEM(desktop->currentRoot())->getRelativeTransform(desktop->currentLayer());
1066             item->updateRepr();
1067         }
1068         abp = nr_artpath_affine(dc->accumulated->first_bpath(), sp_desktop_dt2root_affine(desktop));
1069         str = sp_svg_write_path(abp);
1070         g_assert( str != NULL );
1071         g_free(abp);
1072         dc->repr->setAttribute("d", str);
1073         g_free(str);
1074
1075         if (unionize) {
1076             sp_desktop_selection(desktop)->add(dc->repr);
1077             sp_selected_path_union_skip_undo();
1078         } else {
1079             if (dc->keep_selected) {
1080                 sp_desktop_selection(desktop)->set(dc->repr);
1081             }
1082         }
1083
1084     } else {
1085         if (dc->repr) {
1086             sp_repr_unparent(dc->repr);
1087         }
1088         dc->repr = NULL;
1089     }
1090
1091     sp_document_done(sp_desktop_document(desktop), SP_VERB_CONTEXT_CALLIGRAPHIC,
1092                      _("Draw calligraphic stroke"));
1093 }
1094
1095 static void
1096 add_cap(SPCurve *curve,
1097         NR::Point const &pre, NR::Point const &from,
1098         NR::Point const &to, NR::Point const &post,
1099         double rounding)
1100 {
1101     NR::Point vel = rounding * NR::rot90( to - from ) / sqrt(2.0);
1102     double mag = NR::L2(vel);
1103
1104     NR::Point v_in = from - pre;
1105     double mag_in = NR::L2(v_in);
1106     if ( mag_in > DYNA_EPSILON ) {
1107         v_in = mag * v_in / mag_in;
1108     } else {
1109         v_in = NR::Point(0, 0);
1110     }
1111
1112     NR::Point v_out = to - post;
1113     double mag_out = NR::L2(v_out);
1114     if ( mag_out > DYNA_EPSILON ) {
1115         v_out = mag * v_out / mag_out;
1116     } else {
1117         v_out = NR::Point(0, 0);
1118     }
1119
1120     if ( NR::L2(v_in) > DYNA_EPSILON || NR::L2(v_out) > DYNA_EPSILON ) {
1121         curve->curveto(from + v_in, to + v_out, to);
1122     }
1123 }
1124
1125 static void
1126 accumulate_calligraphic(SPDynaDrawContext *dc)
1127 {
1128     if ( !dc->cal1->is_empty() && !dc->cal2->is_empty() ) {
1129         dc->accumulated->reset(); /*  Is this required ?? */
1130         SPCurve *rev_cal2 = dc->cal2->reverse();
1131
1132         g_assert(dc->cal1->end > 1);
1133         g_assert(rev_cal2->end > 1);
1134         g_assert(SP_CURVE_SEGMENT(dc->cal1, 0)->code == NR_MOVETO_OPEN);
1135         g_assert(SP_CURVE_SEGMENT(rev_cal2, 0)->code == NR_MOVETO_OPEN);
1136         g_assert(SP_CURVE_SEGMENT(dc->cal1, 1)->code == NR_CURVETO);
1137         g_assert(SP_CURVE_SEGMENT(rev_cal2, 1)->code == NR_CURVETO);
1138         g_assert(SP_CURVE_SEGMENT(dc->cal1, dc->cal1->end-1)->code == NR_CURVETO);
1139         g_assert(SP_CURVE_SEGMENT(rev_cal2, rev_cal2->end-1)->code == NR_CURVETO);
1140
1141         dc->accumulated->append(dc->cal1, FALSE);
1142
1143         add_cap(dc->accumulated, SP_CURVE_SEGMENT(dc->cal1, dc->cal1->end-1)->c(2), SP_CURVE_SEGMENT(dc->cal1, dc->cal1->end-1)->c(3), SP_CURVE_SEGMENT(rev_cal2, 0)->c(3), SP_CURVE_SEGMENT(rev_cal2, 1)->c(1), dc->cap_rounding);
1144
1145         dc->accumulated->append(rev_cal2, TRUE);
1146
1147         add_cap(dc->accumulated, SP_CURVE_SEGMENT(rev_cal2, rev_cal2->end-1)->c(2), SP_CURVE_SEGMENT(rev_cal2, rev_cal2->end-1)->c(3), SP_CURVE_SEGMENT(dc->cal1, 0)->c(3), SP_CURVE_SEGMENT(dc->cal1, 1)->c(1), dc->cap_rounding);
1148
1149         dc->accumulated->closepath();
1150
1151         rev_cal2->unref();
1152
1153         dc->cal1->reset();
1154         dc->cal2->reset();
1155     }
1156 }
1157
1158 static double square(double const x)
1159 {
1160     return x * x;
1161 }
1162
1163 static void
1164 fit_and_split(SPDynaDrawContext *dc, gboolean release)
1165 {
1166     double const tolerance_sq = square( NR::expansion(SP_EVENT_CONTEXT(dc)->desktop->w2d()) * TOLERANCE_CALLIGRAPHIC );
1167
1168 #ifdef DYNA_DRAW_VERBOSE
1169     g_print("[F&S:R=%c]", release?'T':'F');
1170 #endif
1171
1172     if (!( dc->npoints > 0 && dc->npoints < SAMPLING_SIZE ))
1173         return; // just clicked
1174
1175     if ( dc->npoints == SAMPLING_SIZE - 1 || release ) {
1176 #define BEZIER_SIZE       4
1177 #define BEZIER_MAX_BEZIERS  8
1178 #define BEZIER_MAX_LENGTH ( BEZIER_SIZE * BEZIER_MAX_BEZIERS )
1179
1180 #ifdef DYNA_DRAW_VERBOSE
1181         g_print("[F&S:#] dc->npoints:%d, release:%s\n",
1182                 dc->npoints, release ? "TRUE" : "FALSE");
1183 #endif
1184
1185         /* Current calligraphic */
1186         if ( dc->cal1->end == 0 || dc->cal2->end == 0 ) {
1187             /* dc->npoints > 0 */
1188             /* g_print("calligraphics(1|2) reset\n"); */
1189             dc->cal1->reset();
1190             dc->cal2->reset();
1191
1192             dc->cal1->moveto(dc->point1[0]);
1193             dc->cal2->moveto(dc->point2[0]);
1194         }
1195
1196         NR::Point b1[BEZIER_MAX_LENGTH];
1197         gint const nb1 = sp_bezier_fit_cubic_r(b1, dc->point1, dc->npoints,
1198                                                tolerance_sq, BEZIER_MAX_BEZIERS);
1199         g_assert( nb1 * BEZIER_SIZE <= gint(G_N_ELEMENTS(b1)) );
1200
1201         NR::Point b2[BEZIER_MAX_LENGTH];
1202         gint const nb2 = sp_bezier_fit_cubic_r(b2, dc->point2, dc->npoints,
1203                                                tolerance_sq, BEZIER_MAX_BEZIERS);
1204         g_assert( nb2 * BEZIER_SIZE <= gint(G_N_ELEMENTS(b2)) );
1205
1206         if ( nb1 != -1 && nb2 != -1 ) {
1207             /* Fit and draw and reset state */
1208 #ifdef DYNA_DRAW_VERBOSE
1209             g_print("nb1:%d nb2:%d\n", nb1, nb2);
1210 #endif
1211             /* CanvasShape */
1212             if (! release) {
1213                 dc->currentcurve->reset();
1214                 dc->currentcurve->moveto(b1[0]);
1215                 for (NR::Point *bp1 = b1; bp1 < b1 + BEZIER_SIZE * nb1; bp1 += BEZIER_SIZE) {
1216                     dc->currentcurve->curveto(bp1[1],
1217                                      bp1[2], bp1[3]);
1218                 }
1219                 dc->currentcurve->lineto(b2[BEZIER_SIZE*(nb2-1) + 3]);
1220                 for (NR::Point *bp2 = b2 + BEZIER_SIZE * ( nb2 - 1 ); bp2 >= b2; bp2 -= BEZIER_SIZE) {
1221                     dc->currentcurve->curveto(bp2[2], bp2[1], bp2[0]);
1222                 }
1223                 // FIXME: dc->segments is always NULL at this point??
1224                 if (!dc->segments) { // first segment
1225                     add_cap(dc->currentcurve, b2[1], b2[0], b1[0], b1[1], dc->cap_rounding);
1226                 }
1227                 dc->currentcurve->closepath();
1228                 sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(dc->currentshape), dc->currentcurve);
1229             }
1230
1231             /* Current calligraphic */
1232             for (NR::Point *bp1 = b1; bp1 < b1 + BEZIER_SIZE * nb1; bp1 += BEZIER_SIZE) {
1233                 dc->cal1->curveto(bp1[1], bp1[2], bp1[3]);
1234             }
1235             for (NR::Point *bp2 = b2; bp2 < b2 + BEZIER_SIZE * nb2; bp2 += BEZIER_SIZE) {
1236                 dc->cal2->curveto(bp2[1], bp2[2], bp2[3]);
1237             }
1238         } else {
1239             /* fixme: ??? */
1240 #ifdef DYNA_DRAW_VERBOSE
1241             g_print("[fit_and_split] failed to fit-cubic.\n");
1242 #endif
1243             draw_temporary_box(dc);
1244
1245             for (gint i = 1; i < dc->npoints; i++) {
1246                 dc->cal1->lineto(dc->point1[i]);
1247             }
1248             for (gint i = 1; i < dc->npoints; i++) {
1249                 dc->cal2->lineto(dc->point2[i]);
1250             }
1251         }
1252
1253         /* Fit and draw and copy last point */
1254 #ifdef DYNA_DRAW_VERBOSE
1255         g_print("[%d]Yup\n", dc->npoints);
1256 #endif
1257         if (!release) {
1258             g_assert(!dc->currentcurve->is_empty());
1259
1260             SPCanvasItem *cbp = sp_canvas_item_new(sp_desktop_sketch(SP_EVENT_CONTEXT(dc)->desktop),
1261                                                    SP_TYPE_CANVAS_BPATH,
1262                                                    NULL);
1263             SPCurve *curve = dc->currentcurve->copy();
1264             sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH (cbp), curve);
1265             curve->unref();
1266
1267             guint32 fillColor = sp_desktop_get_color_tool (SP_ACTIVE_DESKTOP, "tools.calligraphic", true);
1268             //guint32 strokeColor = sp_desktop_get_color_tool (SP_ACTIVE_DESKTOP, "tools.calligraphic", false);
1269             double opacity = sp_desktop_get_master_opacity_tool (SP_ACTIVE_DESKTOP, "tools.calligraphic");
1270             double fillOpacity = sp_desktop_get_opacity_tool (SP_ACTIVE_DESKTOP, "tools.calligraphic", true);
1271             //double strokeOpacity = sp_desktop_get_opacity_tool (SP_ACTIVE_DESKTOP, "tools.calligraphic", false);
1272             sp_canvas_bpath_set_fill(SP_CANVAS_BPATH(cbp), ((fillColor & 0xffffff00) | SP_COLOR_F_TO_U(opacity*fillOpacity)), SP_WIND_RULE_EVENODD);
1273             //on second thougtht don't do stroke yet because we don't have stoke-width yet and because stoke appears between segments while drawing
1274             //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);
1275             sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(cbp), 0x00000000, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
1276             /* fixme: Cannot we cascade it to root more clearly? */
1277             g_signal_connect(G_OBJECT(cbp), "event", G_CALLBACK(sp_desktop_root_handler), SP_EVENT_CONTEXT(dc)->desktop);
1278
1279             dc->segments = g_slist_prepend(dc->segments, cbp);
1280         }
1281
1282         dc->point1[0] = dc->point1[dc->npoints - 1];
1283         dc->point2[0] = dc->point2[dc->npoints - 1];
1284         dc->npoints = 1;
1285     } else {
1286         draw_temporary_box(dc);
1287     }
1288 }
1289
1290 static void
1291 draw_temporary_box(SPDynaDrawContext *dc)
1292 {
1293     dc->currentcurve->reset();
1294
1295     dc->currentcurve->moveto(dc->point1[dc->npoints-1]);
1296     for (gint i = dc->npoints-2; i >= 0; i--) {
1297         dc->currentcurve->lineto(dc->point1[i]);
1298     }
1299     for (gint i = 0; i < dc->npoints; i++) {
1300         dc->currentcurve->lineto(dc->point2[i]);
1301     }
1302     if (dc->npoints >= 2) {
1303         add_cap(dc->currentcurve, dc->point2[dc->npoints-2], dc->point2[dc->npoints-1], dc->point1[dc->npoints-1], dc->point1[dc->npoints-2], dc->cap_rounding);
1304     }
1305
1306     dc->currentcurve->closepath();
1307     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(dc->currentshape), dc->currentcurve);
1308 }
1309
1310 /*
1311   Local Variables:
1312   mode:c++
1313   c-file-style:"stroustrup"
1314   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
1315   indent-tabs-mode:nil
1316   fill-column:99
1317   End:
1318 */
1319 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :