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 "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 GType sp_dyna_draw_context_get_type(void)
 123 {
 124     static GType type = 0;
 125     if (!type) {
 126         GTypeInfo info = {
 127             sizeof(SPDynaDrawContextClass),
 128             0, // base_init
 129             0, // base_finalize
 130             (GClassInitFunc)sp_dyna_draw_context_class_init,
 131             0, // class_finalize
 132             0, // class_data
 133             sizeof(SPDynaDrawContext),
 134             0, // n_preallocs
 135             (GInstanceInitFunc)sp_dyna_draw_context_init,
 136             0 // value_table
 137         };
 138         type = g_type_register_static(SP_TYPE_EVENT_CONTEXT, "SPDynaDrawContext", &info, static_cast<GTypeFlags>(0));
 139     }
 140     return type;
 141 }
 142
 143 static void
 144 sp_dyna_draw_context_class_init(SPDynaDrawContextClass *klass)
 145 {
 146     GObjectClass *object_class = (GObjectClass *) klass;
 147     SPEventContextClass *event_context_class = (SPEventContextClass *) klass;
 148
 149     parent_class = (SPEventContextClass*)g_type_class_peek_parent(klass);
 150
 151     object_class->dispose = sp_dyna_draw_context_dispose;
 152
 153     event_context_class->setup = sp_dyna_draw_context_setup;
 154     event_context_class->set = sp_dyna_draw_context_set;
 155     event_context_class->root_handler = sp_dyna_draw_context_root_handler;
 156 }
 157
 158 static void
 159 sp_dyna_draw_context_init(SPDynaDrawContext *ddc)
 160 {
 161     SPEventContext *event_context = SP_EVENT_CONTEXT(ddc);
 162
 163     event_context->cursor_shape = cursor_calligraphy_xpm;
 164     event_context->hot_x = 4;
 165     event_context->hot_y = 4;
 166
 167     ddc->accumulated = NULL;
 168     ddc->segments = NULL;
 169     ddc->currentcurve = NULL;
 170     ddc->currentshape = NULL;
 171     ddc->npoints = 0;
 172     ddc->cal1 = NULL;
 173     ddc->cal2 = NULL;
 174     ddc->repr = NULL;
 175
 176     /* DynaDraw values */
 177     ddc->cur = NR::Point(0,0);
 178     ddc->last = NR::Point(0,0);
 179     ddc->vel = NR::Point(0,0);
 180     ddc->vel_max = 0;
 181     ddc->acc = NR::Point(0,0);
 182     ddc->ang = NR::Point(0,0);
 183     ddc->del = NR::Point(0,0);
 184
 185     /* attributes */
 186     ddc->dragging = FALSE;
 187
 188     ddc->mass = 0.3;
 189     ddc->drag = DRAG_DEFAULT;
 190     ddc->angle = 30.0;
 191     ddc->width = 0.2;
 192     ddc->pressure = DDC_DEFAULT_PRESSURE;
 193
 194     ddc->vel_thin = 0.1;
 195     ddc->flatness = 0.9;
 196     ddc->cap_rounding = 0.0;
 197
 198     ddc->abs_width = false;
 199     ddc->keep_selected = true;
 200
 201     ddc->hatch_spacing = 0;
 202     ddc->hatch_spacing_step = 0;
 203     new (&ddc->hatch_pointer_past) std::list<double>();
 204     new (&ddc->hatch_nearest_past) std::list<double>();
 205     ddc->hatch_last_nearest = NR::Point(0,0);
 206     ddc->hatch_last_pointer = NR::Point(0,0);
 207     ddc->hatch_vector_accumulated = NR::Point(0,0);
 208     ddc->hatch_escaped = false;
 209     ddc->hatch_area = NULL;
 210     ddc->hatch_item = NULL;
 211     ddc->hatch_livarot_path = NULL;
 212
 213     ddc->trace_bg = false;
 214 }
 215
 216 static void
 217 sp_dyna_draw_context_dispose(GObject *object)
 218 {
 219     SPDynaDrawContext *ddc = SP_DYNA_DRAW_CONTEXT(object);
 220
 221     if (ddc->hatch_area) {
 222         gtk_object_destroy(GTK_OBJECT(ddc->hatch_area));
 223         ddc->hatch_area = NULL;
 224     }
 225
 226     if (ddc->accumulated) {
 227         ddc->accumulated = ddc->accumulated->unref();
 228     }
 229
 230     while (ddc->segments) {
 231         gtk_object_destroy(GTK_OBJECT(ddc->segments->data));
 232         ddc->segments = g_slist_remove(ddc->segments, ddc->segments->data);
 233     }
 234
 235     if (ddc->currentcurve) ddc->currentcurve = ddc->currentcurve->unref();
 236     if (ddc->cal1) ddc->cal1 = ddc->cal1->unref();
 237     if (ddc->cal2) ddc->cal2 = ddc->cal2->unref();
 238
 239     if (ddc->currentshape) {
 240         gtk_object_destroy(GTK_OBJECT(ddc->currentshape));
 241         ddc->currentshape = NULL;
 242     }
 243
 244     if (ddc->_message_context) {
 245         delete ddc->_message_context;
 246     }
 247
 248     G_OBJECT_CLASS(parent_class)->dispose(object);
 249
 250     ddc->hatch_pointer_past.~list();
 251     ddc->hatch_nearest_past.~list();
 252 }
 253
 254 static void
 255 sp_dyna_draw_context_setup(SPEventContext *ec)
 256 {
 257     SPDynaDrawContext *ddc = SP_DYNA_DRAW_CONTEXT(ec);
 258
 259     if (((SPEventContextClass *) parent_class)->setup)
 260         ((SPEventContextClass *) parent_class)->setup(ec);
 261
 262     ddc->accumulated = new SPCurve(32);
 263     ddc->currentcurve = new SPCurve(4);
 264
 265     ddc->cal1 = new SPCurve(32);
 266     ddc->cal2 = new SPCurve(32);
 267
 268     ddc->currentshape = sp_canvas_item_new(sp_desktop_sketch(ec->desktop), SP_TYPE_CANVAS_BPATH, NULL);
 269     sp_canvas_bpath_set_fill(SP_CANVAS_BPATH(ddc->currentshape), DDC_RED_RGBA, SP_WIND_RULE_EVENODD);
 270     sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(ddc->currentshape), 0x00000000, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 271     /* fixme: Cannot we cascade it to root more clearly? */
 272     g_signal_connect(G_OBJECT(ddc->currentshape), "event", G_CALLBACK(sp_desktop_root_handler), ec->desktop);
 273
 274     {
 275         SPCurve *c = SPCurve::new_from_foreign_bpath(hatch_area_circle);
 276         ddc->hatch_area = sp_canvas_bpath_new(sp_desktop_controls(ec->desktop), c);
 277         c->unref();
 278         sp_canvas_bpath_set_fill(SP_CANVAS_BPATH(ddc->hatch_area), 0x00000000,(SPWindRule)0);
 279         sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(ddc->hatch_area), 0x0000007f, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 280         sp_canvas_item_hide(ddc->hatch_area);
 281     }
 282
 283     sp_event_context_read(ec, "mass");
 284     sp_event_context_read(ec, "wiggle");
 285     sp_event_context_read(ec, "angle");
 286     sp_event_context_read(ec, "width");
 287     sp_event_context_read(ec, "thinning");
 288     sp_event_context_read(ec, "tremor");
 289     sp_event_context_read(ec, "flatness");
 290     sp_event_context_read(ec, "tracebackground");
 291     sp_event_context_read(ec, "usepressure");
 292     sp_event_context_read(ec, "usetilt");
 293     sp_event_context_read(ec, "abs_width");
 294     sp_event_context_read(ec, "keep_selected");
 295     sp_event_context_read(ec, "cap_rounding");
 296
 297     ddc->is_drawing = false;
 298
 299     ddc->_message_context = new Inkscape::MessageContext((ec->desktop)->messageStack());
 300
 301     if (prefs_get_int_attribute("tools.calligraphic", "selcue", 0) != 0) {
 302         ec->enableSelectionCue();
 303     }
 304 }
 305
 306 static void
 307 sp_dyna_draw_context_set(SPEventContext *ec, gchar const *key, gchar const *val)
 308 {
 309     SPDynaDrawContext *ddc = SP_DYNA_DRAW_CONTEXT(ec);
 310
 311     if (!strcmp(key, "mass")) {
 312         double const dval = ( val ? g_ascii_strtod (val, NULL) : 0.2 );
 313         ddc->mass = CLAMP(dval, -1000.0, 1000.0);
 314     } else if (!strcmp(key, "wiggle")) {
 315         double const dval = ( val ? g_ascii_strtod (val, NULL) : (1 - DRAG_DEFAULT));
 316         ddc->drag = CLAMP((1 - dval), DRAG_MIN, DRAG_MAX); // drag is inverse to wiggle
 317     } else if (!strcmp(key, "angle")) {
 318         double const dval = ( val ? g_ascii_strtod (val, NULL) : 0.0);
 319         ddc->angle = CLAMP (dval, -90, 90);
 320     } else if (!strcmp(key, "width")) {
 321         double const dval = ( val ? g_ascii_strtod (val, NULL) : 0.1 );
 322         ddc->width = CLAMP(dval, -1000.0, 1000.0);
 323     } else if (!strcmp(key, "thinning")) {
 324         double const dval = ( val ? g_ascii_strtod (val, NULL) : 0.1 );
 325         ddc->vel_thin = CLAMP(dval, -1.0, 1.0);
 326     } else if (!strcmp(key, "tremor")) {
 327         double const dval = ( val ? g_ascii_strtod (val, NULL) : 0.0 );
 328         ddc->tremor = CLAMP(dval, 0.0, 1.0);
 329     } else if (!strcmp(key, "flatness")) {
 330         double const dval = ( val ? g_ascii_strtod (val, NULL) : 1.0 );
 331         ddc->flatness = CLAMP(dval, 0, 1.0);
 332     } else if (!strcmp(key, "tracebackground")) {
 333         ddc->trace_bg = (val && strcmp(val, "0"));
 334     } else if (!strcmp(key, "usepressure")) {
 335         ddc->usepressure = (val && strcmp(val, "0"));
 336     } else if (!strcmp(key, "usetilt")) {
 337         ddc->usetilt = (val && strcmp(val, "0"));
 338     } else if (!strcmp(key, "abs_width")) {
 339         ddc->abs_width = (val && strcmp(val, "0"));
 340     } else if (!strcmp(key, "keep_selected")) {
 341         ddc->keep_selected = (val && strcmp(val, "0"));
 342     } else if (!strcmp(key, "cap_rounding")) {
 343         ddc->cap_rounding = ( val ? g_ascii_strtod (val, NULL) : 0.0 );
 344     }
 345
 346     //g_print("DDC: %g %g %g %g\n", ddc->mass, ddc->drag, ddc->angle, ddc->width);
 347 }
 348
 349 static double
 350 flerp(double f0, double f1, double p)
 351 {
 352     return f0 + ( f1 - f0 ) * p;
 353 }
 354
 355 /* Get normalized point */
 356 static NR::Point
 357 sp_dyna_draw_get_npoint(SPDynaDrawContext const *dc, NR::Point v)
 358 {
 359     NR::Rect drect = SP_EVENT_CONTEXT(dc)->desktop->get_display_area();
 360     double const max = MAX ( drect.dimensions()[NR::X], drect.dimensions()[NR::Y] );
 361     return NR::Point(( v[NR::X] - drect.min()[NR::X] ) / max,  ( v[NR::Y] - drect.min()[NR::Y] ) / max);
 362 }
 363
 364 /* Get view point */
 365 static NR::Point
 366 sp_dyna_draw_get_vpoint(SPDynaDrawContext const *dc, NR::Point n)
 367 {
 368     NR::Rect drect = SP_EVENT_CONTEXT(dc)->desktop->get_display_area();
 369     double const max = MAX ( drect.dimensions()[NR::X], drect.dimensions()[NR::Y] );
 370     return NR::Point(n[NR::X] * max + drect.min()[NR::X], n[NR::Y] * max + drect.min()[NR::Y]);
 371 }
 372
 373 static void
 374 sp_dyna_draw_reset(SPDynaDrawContext *dc, NR::Point p)
 375 {
 376     dc->last = dc->cur = sp_dyna_draw_get_npoint(dc, p);
 377     dc->vel = NR::Point(0,0);
 378     dc->vel_max = 0;
 379     dc->acc = NR::Point(0,0);
 380     dc->ang = NR::Point(0,0);
 381     dc->del = NR::Point(0,0);
 382 }
 383
 384 static void
 385 sp_dyna_draw_extinput(SPDynaDrawContext *dc, GdkEvent *event)
 386 {
 387     if (gdk_event_get_axis (event, GDK_AXIS_PRESSURE, &dc->pressure))
 388         dc->pressure = CLAMP (dc->pressure, DDC_MIN_PRESSURE, DDC_MAX_PRESSURE);
 389     else
 390         dc->pressure = DDC_DEFAULT_PRESSURE;
 391
 392     if (gdk_event_get_axis (event, GDK_AXIS_XTILT, &dc->xtilt))
 393         dc->xtilt = CLAMP (dc->xtilt, DDC_MIN_TILT, DDC_MAX_TILT);
 394     else
 395         dc->xtilt = DDC_DEFAULT_TILT;
 396
 397     if (gdk_event_get_axis (event, GDK_AXIS_YTILT, &dc->ytilt))
 398         dc->ytilt = CLAMP (dc->ytilt, DDC_MIN_TILT, DDC_MAX_TILT);
 399     else
 400         dc->ytilt = DDC_DEFAULT_TILT;
 401 }
 402
 403
 404 static gboolean
 405 sp_dyna_draw_apply(SPDynaDrawContext *dc, NR::Point p)
 406 {
 407     NR::Point n = sp_dyna_draw_get_npoint(dc, p);
 408
 409     /* Calculate mass and drag */
 410     double const mass = flerp(1.0, 160.0, dc->mass);
 411     double const drag = flerp(0.0, 0.5, dc->drag * dc->drag);
 412
 413     /* Calculate force and acceleration */
 414     NR::Point force = n - dc->cur;
 415
 416     // If force is below the absolute threshold DYNA_EPSILON,
 417     // or we haven't yet reached DYNA_VEL_START (i.e. at the beginning of stroke)
 418     // _and_ the force is below the (higher) DYNA_EPSILON_START threshold,
 419     // discard this move.
 420     // This prevents flips, blobs, and jerks caused by microscopic tremor of the tablet pen,
 421     // especially bothersome at the start of the stroke where we don't yet have the inertia to
 422     // smooth them out.
 423     if ( NR::L2(force) < DYNA_EPSILON || (dc->vel_max < DYNA_VEL_START && NR::L2(force) < DYNA_EPSILON_START)) {
 424         return FALSE;
 425     }
 426
 427     dc->acc = force / mass;
 428
 429     /* Calculate new velocity */
 430     dc->vel += dc->acc;
 431
 432     if (NR::L2(dc->vel) > dc->vel_max)
 433         dc->vel_max = NR::L2(dc->vel);
 434
 435     /* Calculate angle of drawing tool */
 436
 437     double a1;
 438     if (dc->usetilt) {
 439         // 1a. calculate nib angle from input device tilt:
 440         gdouble length = std::sqrt(dc->xtilt*dc->xtilt + dc->ytilt*dc->ytilt);;
 441
 442         if (length > 0) {
 443             NR::Point ang1 = NR::Point(dc->ytilt/length, dc->xtilt/length);
 444             a1 = atan2(ang1);
 445         }
 446         else
 447             a1 = 0.0;
 448     }
 449     else {
 450         // 1b. fixed dc->angle (absolutely flat nib):
 451         double const radians = ( (dc->angle - 90) / 180.0 ) * M_PI;
 452         NR::Point ang1 = NR::Point(-sin(radians),  cos(radians));
 453         a1 = atan2(ang1);
 454     }
 455
 456     // 2. perpendicular to dc->vel (absolutely non-flat nib):
 457     gdouble const mag_vel = NR::L2(dc->vel);
 458     if ( mag_vel < DYNA_EPSILON ) {
 459         return FALSE;
 460     }
 461     NR::Point ang2 = NR::rot90(dc->vel) / mag_vel;
 462
 463     // 3. Average them using flatness parameter:
 464     // calculate angles
 465     double a2 = atan2(ang2);
 466     // flip a2 to force it to be in the same half-circle as a1
 467     bool flipped = false;
 468     if (fabs (a2-a1) > 0.5*M_PI) {
 469         a2 += M_PI;
 470         flipped = true;
 471     }
 472     // normalize a2
 473     if (a2 > M_PI)
 474         a2 -= 2*M_PI;
 475     if (a2 < -M_PI)
 476         a2 += 2*M_PI;
 477     // find the flatness-weighted bisector angle, unflip if a2 was flipped
 478     // FIXME: when dc->vel is oscillating around the fixed angle, the new_ang flips back and forth. How to avoid this?
 479     double new_ang = a1 + (1 - dc->flatness) * (a2 - a1) - (flipped? M_PI : 0);
 480
 481     // Try to detect a sudden flip when the new angle differs too much from the previous for the
 482     // current velocity; in that case discard this move
 483     double angle_delta = NR::L2(NR::Point (cos (new_ang), sin (new_ang)) - dc->ang);
 484     if ( angle_delta / NR::L2(dc->vel) > 4000 ) {
 485         return FALSE;
 486     }
 487
 488     // convert to point
 489     dc->ang = NR::Point (cos (new_ang), sin (new_ang));
 490
 491 //    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);
 492
 493     /* Apply drag */
 494     dc->vel *= 1.0 - drag;
 495
 496     /* Update position */
 497     dc->last = dc->cur;
 498     dc->cur += dc->vel;
 499
 500     return TRUE;
 501 }
 502
 503 static void
 504 sp_dyna_draw_brush(SPDynaDrawContext *dc)
 505 {
 506     g_assert( dc->npoints >= 0 && dc->npoints < SAMPLING_SIZE );
 507
 508     // How much velocity thins strokestyle
 509     double vel_thin = flerp (0, 160, dc->vel_thin);
 510
 511     // Influence of pressure on thickness
 512     double pressure_thick = (dc->usepressure ? dc->pressure : 1.0);
 513
 514     // get the real brush point, not the same as pointer (affected by hatch tracking and/or mass
 515     // drag)
 516     NR::Point brush = sp_dyna_draw_get_vpoint(dc, dc->cur);
 517     NR::Point brush_w = SP_EVENT_CONTEXT(dc)->desktop->d2w(brush);
 518
 519     double trace_thick = 1;
 520     if (dc->trace_bg) {
 521         // pick single pixel
 522         NRPixBlock pb;
 523         int x = (int) floor(brush_w[NR::X]);
 524         int y = (int) floor(brush_w[NR::Y]);
 525         nr_pixblock_setup_fast(&pb, NR_PIXBLOCK_MODE_R8G8B8A8P, x, y, x+1, y+1, TRUE);
 526         sp_canvas_arena_render_pixblock(SP_CANVAS_ARENA(sp_desktop_drawing(SP_EVENT_CONTEXT(dc)->desktop)), &pb);
 527         const unsigned char *s = NR_PIXBLOCK_PX(&pb);
 528         double R = s[0] / 255.0;
 529         double G = s[1] / 255.0;
 530         double B = s[2] / 255.0;
 531         double A = s[3] / 255.0;
 532         double max = MAX (MAX (R, G), B);
 533         double min = MIN (MIN (R, G), B);
 534         double L = A * (max + min)/2 + (1 - A); // blend with white bg
 535         trace_thick = 1 - L;
 536         //g_print ("L %g thick %g\n", L, trace_thick);
 537     }
 538
 539     double width = (pressure_thick * trace_thick - vel_thin * NR::L2(dc->vel)) * dc->width;
 540
 541     double tremble_left = 0, tremble_right = 0;
 542     if (dc->tremor > 0) {
 543         // obtain two normally distributed random variables, using polar Box-Muller transform
 544         double x1, x2, w, y1, y2;
 545         do {
 546             x1 = 2.0 * g_random_double_range(0,1) - 1.0;
 547             x2 = 2.0 * g_random_double_range(0,1) - 1.0;
 548             w = x1 * x1 + x2 * x2;
 549         } while ( w >= 1.0 );
 550         w = sqrt( (-2.0 * log( w ) ) / w );
 551         y1 = x1 * w;
 552         y2 = x2 * w;
 553
 554         // deflect both left and right edges randomly and independently, so that:
 555         // (1) dc->tremor=1 corresponds to sigma=1, decreasing dc->tremor narrows the bell curve;
 556         // (2) deflection depends on width, but is upped for small widths for better visual uniformity across widths;
 557         // (3) deflection somewhat depends on speed, to prevent fast strokes looking
 558         // comparatively smooth and slow ones excessively jittery
 559         tremble_left  = (y1)*dc->tremor * (0.15 + 0.8*width) * (0.35 + 14*NR::L2(dc->vel));
 560         tremble_right = (y2)*dc->tremor * (0.15 + 0.8*width) * (0.35 + 14*NR::L2(dc->vel));
 561     }
 562
 563     if ( width < 0.02 * dc->width ) {
 564         width = 0.02 * dc->width;
 565     }
 566
 567     double dezoomify_factor = 0.05 * 1000;
 568     if (!dc->abs_width) {
 569         dezoomify_factor /= SP_EVENT_CONTEXT(dc)->desktop->current_zoom();
 570     }
 571
 572     NR::Point del_left = dezoomify_factor * (width + tremble_left) * dc->ang;
 573     NR::Point del_right = dezoomify_factor * (width + tremble_right) * dc->ang;
 574
 575     dc->point1[dc->npoints] = brush + del_left;
 576     dc->point2[dc->npoints] = brush - del_right;
 577
 578     dc->del = 0.5*(del_left + del_right);
 579
 580     dc->npoints++;
 581 }
 582
 583 void
 584 sp_ddc_update_toolbox (SPDesktop *desktop, const gchar *id, double value)
 585 {
 586     desktop->setToolboxAdjustmentValue (id, value);
 587 }
 588
 589 static void
 590 calligraphic_cancel(SPDynaDrawContext *dc)
 591 {
 592     SPDesktop *desktop = SP_EVENT_CONTEXT(dc)->desktop;
 593     dc->dragging = FALSE;
 594     dc->is_drawing = false;
 595     sp_canvas_item_ungrab(SP_CANVAS_ITEM(desktop->acetate), 0);
 596             /* Remove all temporary line segments */
 597             while (dc->segments) {
 598                 gtk_object_destroy(GTK_OBJECT(dc->segments->data));
 599                 dc->segments = g_slist_remove(dc->segments, dc->segments->data);
 600             }
 601             /* reset accumulated curve */
 602             dc->accumulated->reset();
 603             clear_current(dc);
 604             if (dc->repr) {
 605                 dc->repr = NULL;
 606             }
 607 }
 608
 609
 610 gint
 611 sp_dyna_draw_context_root_handler(SPEventContext *event_context,
 612                                   GdkEvent *event)
 613 {
 614     SPDynaDrawContext *dc = SP_DYNA_DRAW_CONTEXT(event_context);
 615     SPDesktop *desktop = event_context->desktop;
 616
 617     gint ret = FALSE;
 618
 619     switch (event->type) {
 620         case GDK_BUTTON_PRESS:
 621             if (event->button.button == 1 && !event_context->space_panning) {
 622
 623                 SPDesktop *desktop = SP_EVENT_CONTEXT_DESKTOP(dc);
 624
 625                 if (Inkscape::have_viable_layer(desktop, dc->_message_context) == false) {
 626                     return TRUE;
 627                 }
 628
 629                 NR::Point const button_w(event->button.x,
 630                                          event->button.y);
 631                 NR::Point const button_dt(desktop->w2d(button_w));
 632                 sp_dyna_draw_reset(dc, button_dt);
 633                 sp_dyna_draw_extinput(dc, event);
 634                 sp_dyna_draw_apply(dc, button_dt);
 635                 dc->accumulated->reset();
 636                 if (dc->repr) {
 637                     dc->repr = NULL;
 638                 }
 639
 640                 /* initialize first point */
 641                 dc->npoints = 0;
 642
 643                 sp_canvas_item_grab(SP_CANVAS_ITEM(desktop->acetate),
 644                                     ( GDK_KEY_PRESS_MASK |
 645                                       GDK_BUTTON_RELEASE_MASK |
 646                                       GDK_POINTER_MOTION_MASK |
 647                                       GDK_BUTTON_PRESS_MASK ),
 648                                     NULL,
 649                                     event->button.time);
 650
 651                 ret = TRUE;
 652
 653                 sp_canvas_force_full_redraw_after_interruptions(desktop->canvas, 3);
 654                 dc->is_drawing = true;
 655             }
 656             break;
 657         case GDK_MOTION_NOTIFY:
 658         {
 659             NR::Point const motion_w(event->motion.x,
 660                                      event->motion.y);
 661             NR::Point motion_dt(desktop->w2d(motion_w));
 662             sp_dyna_draw_extinput(dc, event);
 663
 664             dc->_message_context->clear();
 665
 666             // for hatching:
 667             double hatch_dist = 0;
 668             NR::Point hatch_unit_vector(0,0);
 669             NR::Point nearest(0,0);
 670             NR::Point pointer(0,0);
 671             NR::Matrix motion_to_curve(NR::identity());
 672
 673             if (event->motion.state & GDK_CONTROL_MASK) { // hatching - sense the item
 674
 675                 SPItem *selected = sp_desktop_selection(desktop)->singleItem();
 676                 if (selected && (SP_IS_SHAPE(selected) || SP_IS_TEXT(selected))) {
 677                     // One item selected, and it's a path;
 678                     // let's try to track it as a guide
 679
 680                     if (selected != dc->hatch_item) {
 681                         dc->hatch_item = selected;
 682                         if (dc->hatch_livarot_path)
 683                             delete dc->hatch_livarot_path;
 684                         dc->hatch_livarot_path = Path_for_item (dc->hatch_item, true, true);
 685                         dc->hatch_livarot_path->ConvertWithBackData(0.01);
 686                     }
 687
 688                     // calculate pointer point in the guide item's coords
 689                     motion_to_curve = sp_item_dt2i_affine(selected) * sp_item_i2doc_affine(selected);
 690                     pointer = motion_dt * motion_to_curve;
 691
 692                     // calculate the nearest point on the guide path
 693                     NR::Maybe<Path::cut_position> position = get_nearest_position_on_Path(dc->hatch_livarot_path, pointer);
 694                     nearest = get_point_on_Path(dc->hatch_livarot_path, position->piece, position->t);
 695
 696
 697                     // distance from pointer to nearest
 698                     hatch_dist = NR::L2(pointer - nearest);
 699                     // unit-length vector
 700                     hatch_unit_vector = (pointer - nearest)/hatch_dist;
 701
 702                     dc->_message_context->set(Inkscape::NORMAL_MESSAGE, _("<b>Guide path selected</b>; start drawing along the guide with <b>Ctrl</b>"));
 703                 } else {
 704                     dc->_message_context->set(Inkscape::NORMAL_MESSAGE, _("<b>Select a guide path</b> to track with <b>Ctrl</b>"));
 705                 }
 706             }
 707
 708             if ( dc->is_drawing && (event->motion.state & GDK_BUTTON1_MASK) && !event_context->space_panning) {
 709                 dc->dragging = TRUE;
 710
 711                 if (event->motion.state & GDK_CONTROL_MASK && dc->hatch_item) { // hatching
 712
 713 #define SPEED_ELEMENTS 12
 714 #define SPEED_MIN 0.12
 715 #define SPEED_NORMAL 0.65
 716
 717                     // speed is the movement of the nearest point along the guide path, divided by
 718                     // the movement of the pointer at the same period; it is averaged for the last
 719                     // SPEED_ELEMENTS motion events.  Normally, as you track the guide path, speed
 720                     // is about 1, i.e. the nearest point on the path is moved by about the same
 721                     // distance as the pointer. If the speed starts to decrease, we are losing
 722                     // contact with the guide; if it drops below SPEED_MIN, we are on our own and
 723                     // not attracted to guide anymore. Most often this happens when you have
 724                     // tracked to the end of a guide calligraphic stroke and keep moving
 725                     // further. We try to handle this situation gracefully: not stick with the
 726                     // guide forever but let go of it smoothly and without sharp jerks (non-zero
 727                     // mass recommended; with zero mass, jerks are still quite noticeable).
 728
 729                     double speed = 1;
 730                     if (NR::L2(dc->hatch_last_nearest) != 0) {
 731                         // the distance nearest moved since the last motion event
 732                         double nearest_moved = NR::L2(nearest - dc->hatch_last_nearest);
 733                         // the distance pointer moved since the last motion event
 734                         double pointer_moved = NR::L2(pointer - dc->hatch_last_pointer);
 735                         // store them in stacks limited to SPEED_ELEMENTS
 736                         dc->hatch_nearest_past.push_front(nearest_moved);
 737                         if (dc->hatch_nearest_past.size() > SPEED_ELEMENTS)
 738                             dc->hatch_nearest_past.pop_back();
 739                         dc->hatch_pointer_past.push_front(pointer_moved);
 740                         if (dc->hatch_pointer_past.size() > SPEED_ELEMENTS)
 741                             dc->hatch_pointer_past.pop_back();
 742
 743                         // If the stacks are full,
 744                         if (dc->hatch_nearest_past.size() == SPEED_ELEMENTS) {
 745                             // calculate the sums of all stored movements
 746                             double nearest_sum = std::accumulate (dc->hatch_nearest_past.begin(), dc->hatch_nearest_past.end(), 0.0);
 747                             double pointer_sum = std::accumulate (dc->hatch_pointer_past.begin(), dc->hatch_pointer_past.end(), 0.0);
 748                             // and divide to get the speed
 749                             speed = nearest_sum/pointer_sum;
 750                             //g_print ("nearest sum %g  pointer_sum %g  speed %g\n", nearest_sum, pointer_sum, speed);
 751                         }
 752                     }
 753
 754                     if (   dc->hatch_escaped  // already escaped, do not reattach
 755                         || (speed < SPEED_MIN) // stuck; most likely reached end of traced stroke
 756                         || (dc->hatch_spacing > 0 && hatch_dist > 50 * dc->hatch_spacing) // went too far from the guide
 757                         ) {
 758                         // We are NOT attracted to the guide!
 759
 760                         //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);
 761
 762                         // Remember hatch_escaped so we don't get
 763                         // attracted again until the end of this stroke
 764                         dc->hatch_escaped = true;
 765
 766                     } else {
 767
 768                         // Calculate angle cosine of this vector-to-guide and all past vectors
 769                         // summed, to detect if we accidentally flipped to the other side of the
 770                         // guide
 771                         double dot = NR::dot (pointer - nearest, dc->hatch_vector_accumulated);
 772                         dot /= NR::L2(pointer - nearest) * NR::L2(dc->hatch_vector_accumulated);
 773
 774                         if (dc->hatch_spacing != 0) { // spacing was already set
 775                             double target;
 776                             if (speed > SPEED_NORMAL) {
 777                                 // all ok, strictly obey the spacing
 778                                 target = dc->hatch_spacing;
 779                             } else {
 780                                 // looks like we're starting to lose speed,
 781                                 // so _gradually_ let go attraction to prevent jerks
 782                                 target = (dc->hatch_spacing * speed + hatch_dist * (SPEED_NORMAL - speed))/SPEED_NORMAL;
 783                             }
 784                             if (!isNaN(dot) && dot < -0.5) {// flip
 785                                 target = -target;
 786                             }
 787
 788                             // This is the track pointer that we will use instead of the real one
 789                             NR::Point new_pointer = nearest + target * hatch_unit_vector;
 790
 791                             // some limited feedback: allow persistent pulling to slightly change
 792                             // the spacing
 793                             dc->hatch_spacing += (hatch_dist - dc->hatch_spacing)/3500;
 794
 795                             // return it to the desktop coords
 796                             motion_dt = new_pointer * motion_to_curve.inverse();
 797
 798                         } else {
 799                             // this is the first motion event, set the dist
 800                             dc->hatch_spacing = hatch_dist;
 801                         }
 802
 803                         // remember last points
 804                         dc->hatch_last_pointer = pointer;
 805                         dc->hatch_last_nearest = nearest;
 806                         dc->hatch_vector_accumulated += (pointer - nearest);
 807                     }
 808
 809                     dc->_message_context->set(Inkscape::NORMAL_MESSAGE, dc->hatch_escaped? _("Tracking: <b>connection to guide path lost!</b>") : _("<b>Tracking</b> a guide path"));
 810
 811                 } else {
 812                     dc->_message_context->set(Inkscape::NORMAL_MESSAGE, _("<b>Drawing</b> a calligraphic stroke"));
 813                 }
 814
 815                 if (!sp_dyna_draw_apply(dc, motion_dt)) {
 816                     ret = TRUE;
 817                     break;
 818                 }
 819
 820                 if ( dc->cur != dc->last ) {
 821                     sp_dyna_draw_brush(dc);
 822                     g_assert( dc->npoints > 0 );
 823                     fit_and_split(dc, FALSE);
 824                 }
 825                 ret = TRUE;
 826             }
 827
 828             // Draw the hatching circle if necessary
 829             if (event->motion.state & GDK_CONTROL_MASK) {
 830                 if (dc->hatch_spacing == 0 && hatch_dist != 0) {
 831                     // Haven't set spacing yet: gray, center free, update radius live
 832                     NR::Point c = desktop->w2d(motion_w);
 833                     NR::Matrix const sm (NR::scale(hatch_dist, hatch_dist) * NR::translate(c));
 834                     sp_canvas_item_affine_absolute(dc->hatch_area, sm);
 835                     sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(dc->hatch_area), 0x7f7f7fff, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 836                     sp_canvas_item_show(dc->hatch_area);
 837                 } else if (dc->dragging && !dc->hatch_escaped) {
 838                     // Tracking: green, center snapped, fixed radius
 839                     NR::Point c = motion_dt;
 840                     NR::Matrix const sm (NR::scale(dc->hatch_spacing, dc->hatch_spacing) * NR::translate(c));
 841                     sp_canvas_item_affine_absolute(dc->hatch_area, sm);
 842                     sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(dc->hatch_area), 0x00FF00ff, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 843                     sp_canvas_item_show(dc->hatch_area);
 844                 } else if (dc->dragging && dc->hatch_escaped) {
 845                     // Tracking escaped: red, center free, fixed radius
 846                     NR::Point c = desktop->w2d(motion_w);
 847                     NR::Matrix const sm (NR::scale(dc->hatch_spacing, dc->hatch_spacing) * NR::translate(c));
 848
 849                     sp_canvas_item_affine_absolute(dc->hatch_area, sm);
 850                     sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(dc->hatch_area), 0xFF0000ff, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 851                     sp_canvas_item_show(dc->hatch_area);
 852                 } else {
 853                     // Not drawing but spacing set: gray, center snapped, fixed radius
 854                     NR::Point c = (nearest + dc->hatch_spacing * hatch_unit_vector) * motion_to_curve.inverse();
 855                     if (!isNaN(c[NR::X]) && !isNaN(c[NR::Y])) {
 856                         NR::Matrix const sm (NR::scale(dc->hatch_spacing, dc->hatch_spacing) * NR::translate(c));
 857                         sp_canvas_item_affine_absolute(dc->hatch_area, sm);
 858                         sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(dc->hatch_area), 0x7f7f7fff, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 859                         sp_canvas_item_show(dc->hatch_area);
 860                     }
 861                 }
 862             } else {
 863                 sp_canvas_item_hide(dc->hatch_area);
 864             }
 865         }
 866         break;
 867
 868
 869     case GDK_BUTTON_RELEASE:
 870     {
 871         NR::Point const motion_w(event->button.x, event->button.y);
 872         NR::Point const motion_dt(desktop->w2d(motion_w));
 873
 874         sp_canvas_item_ungrab(SP_CANVAS_ITEM(desktop->acetate), event->button.time);
 875         sp_canvas_end_forced_full_redraws(desktop->canvas);
 876         dc->is_drawing = false;
 877
 878         if (dc->dragging && event->button.button == 1 && !event_context->space_panning) {
 879             dc->dragging = FALSE;
 880
 881             sp_dyna_draw_apply(dc, motion_dt);
 882
 883             /* Remove all temporary line segments */
 884             while (dc->segments) {
 885                 gtk_object_destroy(GTK_OBJECT(dc->segments->data));
 886                 dc->segments = g_slist_remove(dc->segments, dc->segments->data);
 887             }
 888
 889             /* Create object */
 890             fit_and_split(dc, TRUE);
 891             accumulate_calligraphic(dc);
 892             set_to_accumulated(dc, event->button.state & GDK_SHIFT_MASK); // performs document_done
 893
 894             /* reset accumulated curve */
 895             dc->accumulated->reset();
 896
 897             clear_current(dc);
 898             if (dc->repr) {
 899                 dc->repr = NULL;
 900             }
 901
 902             if (!dc->hatch_pointer_past.empty()) dc->hatch_pointer_past.clear();
 903             if (!dc->hatch_nearest_past.empty()) dc->hatch_nearest_past.clear();
 904             dc->hatch_last_nearest = NR::Point(0,0);
 905             dc->hatch_last_pointer = NR::Point(0,0);
 906             dc->hatch_vector_accumulated = NR::Point(0,0);
 907             dc->hatch_escaped = false;
 908             dc->hatch_item = NULL;
 909             dc->hatch_livarot_path = NULL;
 910
 911             if (dc->hatch_spacing != 0 && !dc->keep_selected) {
 912                 // we do not select the newly drawn path, so increase spacing by step
 913                 if (dc->hatch_spacing_step == 0) {
 914                     dc->hatch_spacing_step = dc->hatch_spacing;
 915                 }
 916                 dc->hatch_spacing += dc->hatch_spacing_step;
 917             }
 918
 919             dc->_message_context->clear();
 920             ret = TRUE;
 921         }
 922         break;
 923     }
 924
 925     case GDK_KEY_PRESS:
 926         switch (get_group0_keyval (&event->key)) {
 927         case GDK_Up:
 928         case GDK_KP_Up:
 929             if (!MOD__CTRL_ONLY) {
 930                 dc->angle += 5.0;
 931                 if (dc->angle > 90.0)
 932                     dc->angle = 90.0;
 933                 sp_ddc_update_toolbox (desktop, "calligraphy-angle", dc->angle);
 934                 ret = TRUE;
 935             }
 936             break;
 937         case GDK_Down:
 938         case GDK_KP_Down:
 939             if (!MOD__CTRL_ONLY) {
 940                 dc->angle -= 5.0;
 941                 if (dc->angle < -90.0)
 942                     dc->angle = -90.0;
 943                 sp_ddc_update_toolbox (desktop, "calligraphy-angle", dc->angle);
 944                 ret = TRUE;
 945             }
 946             break;
 947         case GDK_Right:
 948         case GDK_KP_Right:
 949             if (!MOD__CTRL_ONLY) {
 950                 dc->width += 0.01;
 951                 if (dc->width > 1.0)
 952                     dc->width = 1.0;
 953                 sp_ddc_update_toolbox (desktop, "altx-calligraphy", dc->width * 100); // the same spinbutton is for alt+x
 954                 ret = TRUE;
 955             }
 956             break;
 957         case GDK_Left:
 958         case GDK_KP_Left:
 959             if (!MOD__CTRL_ONLY) {
 960                 dc->width -= 0.01;
 961                 if (dc->width < 0.01)
 962                     dc->width = 0.01;
 963                 sp_ddc_update_toolbox (desktop, "altx-calligraphy", dc->width * 100);
 964                 ret = TRUE;
 965             }
 966             break;
 967         case GDK_Home:
 968         case GDK_KP_Home:
 969             dc->width = 0.01;
 970             sp_ddc_update_toolbox (desktop, "altx-calligraphy", dc->width * 100);
 971             ret = TRUE;
 972             break;
 973         case GDK_End:
 974         case GDK_KP_End:
 975             dc->width = 1.0;
 976             sp_ddc_update_toolbox (desktop, "altx-calligraphy", dc->width * 100);
 977             ret = TRUE;
 978             break;
 979         case GDK_x:
 980         case GDK_X:
 981             if (MOD__ALT_ONLY) {
 982                 desktop->setToolboxFocusTo ("altx-calligraphy");
 983                 ret = TRUE;
 984             }
 985             break;
 986         case GDK_Escape:
 987             if (dc->is_drawing) {
 988                 // if drawing, cancel, otherwise pass it up for deselecting
 989                 calligraphic_cancel (dc);
 990                 ret = TRUE;
 991             }
 992             break;
 993         case GDK_z:
 994         case GDK_Z:
 995             if (MOD__CTRL_ONLY && dc->is_drawing) {
 996                 // if drawing, cancel, otherwise pass it up for undo
 997                 calligraphic_cancel (dc);
 998                 ret = TRUE;
 999             }
1000             break;
1001         default:
1002             break;
1003         }
1004         break;
1005
1006     case GDK_KEY_RELEASE:
1007         switch (get_group0_keyval(&event->key)) {
1008             case GDK_Control_L:
1009             case GDK_Control_R:
1010                 dc->_message_context->clear();
1011                 dc->hatch_spacing = 0;
1012                 dc->hatch_spacing_step = 0;
1013                 break;
1014             default:
1015                 break;
1016         }
1017
1018     default:
1019         break;
1020     }
1021
1022     if (!ret) {
1023         if (((SPEventContextClass *) parent_class)->root_handler) {
1024             ret = ((SPEventContextClass *) parent_class)->root_handler(event_context, event);
1025         }
1026     }
1027
1028     return ret;
1029 }
1030
1031
1032 static void
1033 clear_current(SPDynaDrawContext *dc)
1034 {
1035     /* reset bpath */
1036     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(dc->currentshape), NULL);
1037     /* reset curve */
1038     dc->currentcurve->reset();
1039     dc->cal1->reset();
1040     dc->cal2->reset();
1041     /* reset points */
1042     dc->npoints = 0;
1043 }
1044
1045 static void
1046 set_to_accumulated(SPDynaDrawContext *dc, bool unionize)
1047 {
1048     SPDesktop *desktop = SP_EVENT_CONTEXT(dc)->desktop;
1049
1050     if (!dc->accumulated->is_empty()) {
1051         NArtBpath *abp;
1052         gchar *str;
1053
1054         if (!dc->repr) {
1055             /* Create object */
1056             Inkscape::XML::Document *xml_doc = sp_document_repr_doc(desktop->doc());
1057             Inkscape::XML::Node *repr = xml_doc->createElement("svg:path");
1058
1059             /* Set style */
1060             sp_desktop_apply_style_tool (desktop, repr, "tools.calligraphic", false);
1061
1062             dc->repr = repr;
1063
1064             SPItem *item=SP_ITEM(desktop->currentLayer()->appendChildRepr(dc->repr));
1065             Inkscape::GC::release(dc->repr);
1066             item->transform = SP_ITEM(desktop->currentRoot())->getRelativeTransform(desktop->currentLayer());
1067             item->updateRepr();
1068         }
1069         abp = nr_artpath_affine(dc->accumulated->first_bpath(), sp_desktop_dt2root_affine(desktop));
1070         str = sp_svg_write_path(abp);
1071         g_assert( str != NULL );
1072         g_free(abp);
1073         dc->repr->setAttribute("d", str);
1074         g_free(str);
1075
1076         if (unionize) {
1077             sp_desktop_selection(desktop)->add(dc->repr);
1078             sp_selected_path_union_skip_undo();
1079         } else {
1080             if (dc->keep_selected) {
1081                 sp_desktop_selection(desktop)->set(dc->repr);
1082             }
1083         }
1084
1085     } else {
1086         if (dc->repr) {
1087             sp_repr_unparent(dc->repr);
1088         }
1089         dc->repr = NULL;
1090     }
1091
1092     sp_document_done(sp_desktop_document(desktop), SP_VERB_CONTEXT_CALLIGRAPHIC,
1093                      _("Draw calligraphic stroke"));
1094 }
1095
1096 static void
1097 add_cap(SPCurve *curve,
1098         NR::Point const &pre, NR::Point const &from,
1099         NR::Point const &to, NR::Point const &post,
1100         double rounding)
1101 {
1102     NR::Point vel = rounding * NR::rot90( to - from ) / sqrt(2.0);
1103     double mag = NR::L2(vel);
1104
1105     NR::Point v_in = from - pre;
1106     double mag_in = NR::L2(v_in);
1107     if ( mag_in > DYNA_EPSILON ) {
1108         v_in = mag * v_in / mag_in;
1109     } else {
1110         v_in = NR::Point(0, 0);
1111     }
1112
1113     NR::Point v_out = to - post;
1114     double mag_out = NR::L2(v_out);
1115     if ( mag_out > DYNA_EPSILON ) {
1116         v_out = mag * v_out / mag_out;
1117     } else {
1118         v_out = NR::Point(0, 0);
1119     }
1120
1121     if ( NR::L2(v_in) > DYNA_EPSILON || NR::L2(v_out) > DYNA_EPSILON ) {
1122         curve->curveto(from + v_in, to + v_out, to);
1123     }
1124 }
1125
1126 static void
1127 accumulate_calligraphic(SPDynaDrawContext *dc)
1128 {
1129     if ( !dc->cal1->is_empty() && !dc->cal2->is_empty() ) {
1130         dc->accumulated->reset(); /*  Is this required ?? */
1131         SPCurve *rev_cal2 = dc->cal2->create_reverse();
1132
1133         g_assert(dc->cal1->_end > 1);
1134         g_assert(rev_cal2->_end > 1);
1135         g_assert(SP_CURVE_SEGMENT(dc->cal1, 0)->code == NR_MOVETO_OPEN);
1136         g_assert(SP_CURVE_SEGMENT(rev_cal2, 0)->code == NR_MOVETO_OPEN);
1137         g_assert(SP_CURVE_SEGMENT(dc->cal1, 1)->code == NR_CURVETO);
1138         g_assert(SP_CURVE_SEGMENT(rev_cal2, 1)->code == NR_CURVETO);
1139         g_assert(SP_CURVE_SEGMENT(dc->cal1, dc->cal1->_end-1)->code == NR_CURVETO);
1140         g_assert(SP_CURVE_SEGMENT(rev_cal2, rev_cal2->_end-1)->code == NR_CURVETO);
1141
1142         dc->accumulated->append(dc->cal1, FALSE);
1143
1144         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);
1145
1146         dc->accumulated->append(rev_cal2, TRUE);
1147
1148         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);
1149
1150         dc->accumulated->closepath();
1151
1152         rev_cal2->unref();
1153
1154         dc->cal1->reset();
1155         dc->cal2->reset();
1156     }
1157 }
1158
1159 static double square(double const x)
1160 {
1161     return x * x;
1162 }
1163
1164 static void
1165 fit_and_split(SPDynaDrawContext *dc, gboolean release)
1166 {
1167     double const tolerance_sq = square( NR::expansion(SP_EVENT_CONTEXT(dc)->desktop->w2d()) * TOLERANCE_CALLIGRAPHIC );
1168
1169 #ifdef DYNA_DRAW_VERBOSE
1170     g_print("[F&S:R=%c]", release?'T':'F');
1171 #endif
1172
1173     if (!( dc->npoints > 0 && dc->npoints < SAMPLING_SIZE ))
1174         return; // just clicked
1175
1176     if ( dc->npoints == SAMPLING_SIZE - 1 || release ) {
1177 #define BEZIER_SIZE       4
1178 #define BEZIER_MAX_BEZIERS  8
1179 #define BEZIER_MAX_LENGTH ( BEZIER_SIZE * BEZIER_MAX_BEZIERS )
1180
1181 #ifdef DYNA_DRAW_VERBOSE
1182         g_print("[F&S:#] dc->npoints:%d, release:%s\n",
1183                 dc->npoints, release ? "TRUE" : "FALSE");
1184 #endif
1185
1186         /* Current calligraphic */
1187         if ( dc->cal1->_end == 0 || dc->cal2->_end == 0 ) {
1188             /* dc->npoints > 0 */
1189             /* g_print("calligraphics(1|2) reset\n"); */
1190             dc->cal1->reset();
1191             dc->cal2->reset();
1192
1193             dc->cal1->moveto(dc->point1[0]);
1194             dc->cal2->moveto(dc->point2[0]);
1195         }
1196
1197         NR::Point b1[BEZIER_MAX_LENGTH];
1198         gint const nb1 = sp_bezier_fit_cubic_r(b1, dc->point1, dc->npoints,
1199                                                tolerance_sq, BEZIER_MAX_BEZIERS);
1200         g_assert( nb1 * BEZIER_SIZE <= gint(G_N_ELEMENTS(b1)) );
1201
1202         NR::Point b2[BEZIER_MAX_LENGTH];
1203         gint const nb2 = sp_bezier_fit_cubic_r(b2, dc->point2, dc->npoints,
1204                                                tolerance_sq, BEZIER_MAX_BEZIERS);
1205         g_assert( nb2 * BEZIER_SIZE <= gint(G_N_ELEMENTS(b2)) );
1206
1207         if ( nb1 != -1 && nb2 != -1 ) {
1208             /* Fit and draw and reset state */
1209 #ifdef DYNA_DRAW_VERBOSE
1210             g_print("nb1:%d nb2:%d\n", nb1, nb2);
1211 #endif
1212             /* CanvasShape */
1213             if (! release) {
1214                 dc->currentcurve->reset();
1215                 dc->currentcurve->moveto(b1[0]);
1216                 for (NR::Point *bp1 = b1; bp1 < b1 + BEZIER_SIZE * nb1; bp1 += BEZIER_SIZE) {
1217                     dc->currentcurve->curveto(bp1[1],
1218                                      bp1[2], bp1[3]);
1219                 }
1220                 dc->currentcurve->lineto(b2[BEZIER_SIZE*(nb2-1) + 3]);
1221                 for (NR::Point *bp2 = b2 + BEZIER_SIZE * ( nb2 - 1 ); bp2 >= b2; bp2 -= BEZIER_SIZE) {
1222                     dc->currentcurve->curveto(bp2[2], bp2[1], bp2[0]);
1223                 }
1224                 // FIXME: dc->segments is always NULL at this point??
1225                 if (!dc->segments) { // first segment
1226                     add_cap(dc->currentcurve, b2[1], b2[0], b1[0], b1[1], dc->cap_rounding);
1227                 }
1228                 dc->currentcurve->closepath();
1229                 sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(dc->currentshape), dc->currentcurve);
1230             }
1231
1232             /* Current calligraphic */
1233             for (NR::Point *bp1 = b1; bp1 < b1 + BEZIER_SIZE * nb1; bp1 += BEZIER_SIZE) {
1234                 dc->cal1->curveto(bp1[1], bp1[2], bp1[3]);
1235             }
1236             for (NR::Point *bp2 = b2; bp2 < b2 + BEZIER_SIZE * nb2; bp2 += BEZIER_SIZE) {
1237                 dc->cal2->curveto(bp2[1], bp2[2], bp2[3]);
1238             }
1239         } else {
1240             /* fixme: ??? */
1241 #ifdef DYNA_DRAW_VERBOSE
1242             g_print("[fit_and_split] failed to fit-cubic.\n");
1243 #endif
1244             draw_temporary_box(dc);
1245
1246             for (gint i = 1; i < dc->npoints; i++) {
1247                 dc->cal1->lineto(dc->point1[i]);
1248             }
1249             for (gint i = 1; i < dc->npoints; i++) {
1250                 dc->cal2->lineto(dc->point2[i]);
1251             }
1252         }
1253
1254         /* Fit and draw and copy last point */
1255 #ifdef DYNA_DRAW_VERBOSE
1256         g_print("[%d]Yup\n", dc->npoints);
1257 #endif
1258         if (!release) {
1259             g_assert(!dc->currentcurve->is_empty());
1260
1261             SPCanvasItem *cbp = sp_canvas_item_new(sp_desktop_sketch(SP_EVENT_CONTEXT(dc)->desktop),
1262                                                    SP_TYPE_CANVAS_BPATH,
1263                                                    NULL);
1264             SPCurve *curve = dc->currentcurve->copy();
1265             sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH (cbp), curve);
1266             curve->unref();
1267
1268             guint32 fillColor = sp_desktop_get_color_tool (SP_ACTIVE_DESKTOP, "tools.calligraphic", true);
1269             //guint32 strokeColor = sp_desktop_get_color_tool (SP_ACTIVE_DESKTOP, "tools.calligraphic", false);
1270             double opacity = sp_desktop_get_master_opacity_tool (SP_ACTIVE_DESKTOP, "tools.calligraphic");
1271             double fillOpacity = sp_desktop_get_opacity_tool (SP_ACTIVE_DESKTOP, "tools.calligraphic", true);
1272             //double strokeOpacity = sp_desktop_get_opacity_tool (SP_ACTIVE_DESKTOP, "tools.calligraphic", false);
1273             sp_canvas_bpath_set_fill(SP_CANVAS_BPATH(cbp), ((fillColor & 0xffffff00) | SP_COLOR_F_TO_U(opacity*fillOpacity)), SP_WIND_RULE_EVENODD);
1274             //on second thougtht don't do stroke yet because we don't have stoke-width yet and because stoke appears between segments while drawing
1275             //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);
1276             sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(cbp), 0x00000000, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
1277             /* fixme: Cannot we cascade it to root more clearly? */
1278             g_signal_connect(G_OBJECT(cbp), "event", G_CALLBACK(sp_desktop_root_handler), SP_EVENT_CONTEXT(dc)->desktop);
1279
1280             dc->segments = g_slist_prepend(dc->segments, cbp);
1281         }
1282
1283         dc->point1[0] = dc->point1[dc->npoints - 1];
1284         dc->point2[0] = dc->point2[dc->npoints - 1];
1285         dc->npoints = 1;
1286     } else {
1287         draw_temporary_box(dc);
1288     }
1289 }
1290
1291 static void
1292 draw_temporary_box(SPDynaDrawContext *dc)
1293 {
1294     dc->currentcurve->reset();
1295
1296     dc->currentcurve->moveto(dc->point1[dc->npoints-1]);
1297     for (gint i = dc->npoints-2; i >= 0; i--) {
1298         dc->currentcurve->lineto(dc->point1[i]);
1299     }
1300     for (gint i = 0; i < dc->npoints; i++) {
1301         dc->currentcurve->lineto(dc->point2[i]);
1302     }
1303     if (dc->npoints >= 2) {
1304         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);
1305     }
1306
1307     dc->currentcurve->closepath();
1308     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(dc->currentshape), dc->currentcurve);
1309 }
1310
1311 /*
1312   Local Variables:
1313   mode:c++
1314   c-file-style:"stroustrup"
1315   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
1316   indent-tabs-mode:nil
1317   fill-column:99
1318   End:
1319 */
1320 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :