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
  32 #include <numeric>
  33
  34 #include "svg/svg.h"
  35 #include "display/canvas-bpath.h"
  36 #include "display/bezier-utils.h"
  37
  38 #include <glib/gmem.h>
  39 #include "macros.h"
  40 #include "document.h"
  41 #include "selection.h"
  42 #include "desktop.h"
  43 #include "desktop-events.h"
  44 #include "desktop-handles.h"
  45 #include "desktop-affine.h"
  46 #include "desktop-style.h"
  47 #include "message-context.h"
  48 #include "prefs-utils.h"
  49 #include "pixmaps/cursor-calligraphy.xpm"
  50 #include "libnr/n-art-bpath.h"
  51 #include "libnr/nr-path.h"
  52 #include "libnr/nr-matrix-ops.h"
  53 #include "libnr/nr-scale-translate-ops.h"
  54 #include "xml/repr.h"
  55 #include "context-fns.h"
  56 #include "sp-item.h"
  57 #include "inkscape.h"
  58 #include "color.h"
  59 #include "splivarot.h"
  60 #include "sp-item-group.h"
  61 #include "sp-shape.h"
  62 #include "sp-path.h"
  63 #include "sp-text.h"
  64 #include "display/canvas-bpath.h"
  65 #include "display/canvas-arena.h"
  66 #include "livarot/Shape.h"
  67 #include "isnan.h"
  68
  69 #include "dyna-draw-context.h"
  70
  71 #define DDC_RED_RGBA 0xff0000ff
  72
  73 #define TOLERANCE_CALLIGRAPHIC 0.1
  74
  75 #define DYNA_EPSILON 0.5e-6
  76 #define DYNA_EPSILON_START 0.5e-2
  77 #define DYNA_VEL_START 1e-5
  78
  79 #define DYNA_MIN_WIDTH 1.0e-6
  80
  81 #define DRAG_MIN 0.0
  82 #define DRAG_DEFAULT 1.0
  83 #define DRAG_MAX 1.0
  84
  85 // FIXME: move it to some shared file to be reused by both calligraphy and dropper
  86 #define C1 0.552
  87 static NArtBpath const hatch_area_circle[] = {
  88     { NR_MOVETO, 0, 0, 0, 0, -1, 0 },
  89     { NR_CURVETO, -1, C1, -C1, 1, 0, 1 },
  90     { NR_CURVETO, C1, 1, 1, C1, 1, 0 },
  91     { NR_CURVETO, 1, -C1, C1, -1, 0, -1 },
  92     { NR_CURVETO, -C1, -1, -1, -C1, -1, 0 },
  93     { NR_END, 0, 0, 0, 0, 0, 0 }
  94 };
  95 #undef C1
  96
  97
  98 static void sp_dyna_draw_context_class_init(SPDynaDrawContextClass *klass);
  99 static void sp_dyna_draw_context_init(SPDynaDrawContext *ddc);
 100 static void sp_dyna_draw_context_dispose(GObject *object);
 101
 102 static void sp_dyna_draw_context_setup(SPEventContext *ec);
 103 static void sp_dyna_draw_context_set(SPEventContext *ec, gchar const *key, gchar const *val);
 104 static gint sp_dyna_draw_context_root_handler(SPEventContext *ec, GdkEvent *event);
 105
 106 static void clear_current(SPDynaDrawContext *dc);
 107 static void set_to_accumulated(SPDynaDrawContext *dc, bool unionize);
 108 static void add_cap(SPCurve *curve, NR::Point const &pre, NR::Point const &from, NR::Point const &to, NR::Point const &post, double rounding);
 109 static void accumulate_calligraphic(SPDynaDrawContext *dc);
 110
 111 static void fit_and_split(SPDynaDrawContext *ddc, gboolean release);
 112
 113 static void sp_dyna_draw_reset(SPDynaDrawContext *ddc, NR::Point p);
 114 static NR::Point sp_dyna_draw_get_npoint(SPDynaDrawContext const *ddc, NR::Point v);
 115 static NR::Point sp_dyna_draw_get_vpoint(SPDynaDrawContext const *ddc, NR::Point n);
 116 static void draw_temporary_box(SPDynaDrawContext *dc);
 117
 118
 119 static SPEventContextClass *parent_class;
 120
 121 GtkType
 122 sp_dyna_draw_context_get_type(void)
 123 {
 124     static GType type = 0;
 125     if (!type) {
 126         GTypeInfo info = {
 127             sizeof(SPDynaDrawContextClass),
 128             NULL, NULL,
 129             (GClassInitFunc) sp_dyna_draw_context_class_init,
 130             NULL, NULL,
 131             sizeof(SPDynaDrawContext),
 132             4,
 133             (GInstanceInitFunc) sp_dyna_draw_context_init,
 134             NULL,   /* value_table */
 135         };
 136         type = g_type_register_static(SP_TYPE_EVENT_CONTEXT, "SPDynaDrawContext", &info, (GTypeFlags)0);
 137     }
 138     return type;
 139 }
 140
 141 static void
 142 sp_dyna_draw_context_class_init(SPDynaDrawContextClass *klass)
 143 {
 144     GObjectClass *object_class = (GObjectClass *) klass;
 145     SPEventContextClass *event_context_class = (SPEventContextClass *) klass;
 146
 147     parent_class = (SPEventContextClass*)g_type_class_peek_parent(klass);
 148
 149     object_class->dispose = sp_dyna_draw_context_dispose;
 150
 151     event_context_class->setup = sp_dyna_draw_context_setup;
 152     event_context_class->set = sp_dyna_draw_context_set;
 153     event_context_class->root_handler = sp_dyna_draw_context_root_handler;
 154 }
 155
 156 static void
 157 sp_dyna_draw_context_init(SPDynaDrawContext *ddc)
 158 {
 159     SPEventContext *event_context = SP_EVENT_CONTEXT(ddc);
 160
 161     event_context->cursor_shape = cursor_calligraphy_xpm;
 162     event_context->hot_x = 4;
 163     event_context->hot_y = 4;
 164
 165     ddc->accumulated = NULL;
 166     ddc->segments = NULL;
 167     ddc->currentcurve = NULL;
 168     ddc->currentshape = NULL;
 169     ddc->npoints = 0;
 170     ddc->cal1 = NULL;
 171     ddc->cal2 = NULL;
 172     ddc->repr = NULL;
 173
 174     /* DynaDraw values */
 175     ddc->cur = NR::Point(0,0);
 176     ddc->last = NR::Point(0,0);
 177     ddc->vel = NR::Point(0,0);
 178     ddc->vel_max = 0;
 179     ddc->acc = NR::Point(0,0);
 180     ddc->ang = NR::Point(0,0);
 181     ddc->del = NR::Point(0,0);
 182
 183     /* attributes */
 184     ddc->dragging = FALSE;
 185
 186     ddc->mass = 0.3;
 187     ddc->drag = DRAG_DEFAULT;
 188     ddc->angle = 30.0;
 189     ddc->width = 0.2;
 190     ddc->pressure = DDC_DEFAULT_PRESSURE;
 191
 192     ddc->vel_thin = 0.1;
 193     ddc->flatness = 0.9;
 194     ddc->cap_rounding = 0.0;
 195
 196     ddc->abs_width = false;
 197     ddc->keep_selected = true;
 198
 199     ddc->hatch_spacing = 0;
 200     ddc->hatch_spacing_step = 0;
 201     new (&ddc->hatch_pointer_past) std::list<double>();
 202     new (&ddc->hatch_nearest_past) std::list<double>();
 203     ddc->hatch_last_nearest = NR::Point(0,0);
 204     ddc->hatch_last_pointer = NR::Point(0,0);
 205     ddc->hatch_vector_accumulated = NR::Point(0,0);
 206     ddc->hatch_escaped = false;
 207     ddc->hatch_area = NULL;
 208     ddc->hatch_item = NULL;
 209     ddc->hatch_livarot_path = NULL;
 210
 211     ddc->trace_bg = false;
 212 }
 213
 214 static void
 215 sp_dyna_draw_context_dispose(GObject *object)
 216 {
 217     SPDynaDrawContext *ddc = SP_DYNA_DRAW_CONTEXT(object);
 218
 219     if (ddc->hatch_area) {
 220         gtk_object_destroy(GTK_OBJECT(ddc->hatch_area));
 221         ddc->hatch_area = NULL;
 222     }
 223
 224     if (ddc->accumulated) {
 225         ddc->accumulated = sp_curve_unref(ddc->accumulated);
 226     }
 227
 228     while (ddc->segments) {
 229         gtk_object_destroy(GTK_OBJECT(ddc->segments->data));
 230         ddc->segments = g_slist_remove(ddc->segments, ddc->segments->data);
 231     }
 232
 233     if (ddc->currentcurve) ddc->currentcurve = sp_curve_unref(ddc->currentcurve);
 234     if (ddc->cal1) ddc->cal1 = sp_curve_unref(ddc->cal1);
 235     if (ddc->cal2) ddc->cal2 = sp_curve_unref(ddc->cal2);
 236
 237     if (ddc->currentshape) {
 238         gtk_object_destroy(GTK_OBJECT(ddc->currentshape));
 239         ddc->currentshape = NULL;
 240     }
 241
 242     if (ddc->_message_context) {
 243         delete ddc->_message_context;
 244     }
 245
 246     G_OBJECT_CLASS(parent_class)->dispose(object);
 247
 248     ddc->hatch_pointer_past.~list();
 249     ddc->hatch_nearest_past.~list();
 250 }
 251
 252 static void
 253 sp_dyna_draw_context_setup(SPEventContext *ec)
 254 {
 255     SPDynaDrawContext *ddc = SP_DYNA_DRAW_CONTEXT(ec);
 256
 257     if (((SPEventContextClass *) parent_class)->setup)
 258         ((SPEventContextClass *) parent_class)->setup(ec);
 259
 260     ddc->accumulated = sp_curve_new_sized(32);
 261     ddc->currentcurve = sp_curve_new_sized(4);
 262
 263     ddc->cal1 = sp_curve_new_sized(32);
 264     ddc->cal2 = sp_curve_new_sized(32);
 265
 266     ddc->currentshape = sp_canvas_item_new(sp_desktop_sketch(ec->desktop), SP_TYPE_CANVAS_BPATH, NULL);
 267     sp_canvas_bpath_set_fill(SP_CANVAS_BPATH(ddc->currentshape), DDC_RED_RGBA, SP_WIND_RULE_EVENODD);
 268     sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(ddc->currentshape), 0x00000000, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 269     /* fixme: Cannot we cascade it to root more clearly? */
 270     g_signal_connect(G_OBJECT(ddc->currentshape), "event", G_CALLBACK(sp_desktop_root_handler), ec->desktop);
 271
 272     {
 273         SPCurve *c = sp_curve_new_from_foreign_bpath(hatch_area_circle);
 274         ddc->hatch_area = sp_canvas_bpath_new(sp_desktop_controls(ec->desktop), c);
 275         sp_curve_unref(c);
 276         sp_canvas_bpath_set_fill(SP_CANVAS_BPATH(ddc->hatch_area), 0x00000000,(SPWindRule)0);
 277         sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(ddc->hatch_area), 0x0000007f, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 278         sp_canvas_item_hide(ddc->hatch_area);
 279     }
 280
 281     sp_event_context_read(ec, "mass");
 282     sp_event_context_read(ec, "wiggle");
 283     sp_event_context_read(ec, "angle");
 284     sp_event_context_read(ec, "width");
 285     sp_event_context_read(ec, "thinning");
 286     sp_event_context_read(ec, "tremor");
 287     sp_event_context_read(ec, "flatness");
 288     sp_event_context_read(ec, "tracebackground");
 289     sp_event_context_read(ec, "usepressure");
 290     sp_event_context_read(ec, "usetilt");
 291     sp_event_context_read(ec, "abs_width");
 292     sp_event_context_read(ec, "keep_selected");
 293     sp_event_context_read(ec, "cap_rounding");
 294
 295     ddc->is_drawing = false;
 296
 297     ddc->_message_context = new Inkscape::MessageContext((ec->desktop)->messageStack());
 298
 299     if (prefs_get_int_attribute("tools.calligraphic", "selcue", 0) != 0) {
 300         ec->enableSelectionCue();
 301     }
 302 }
 303
 304 static void
 305 sp_dyna_draw_context_set(SPEventContext *ec, gchar const *key, gchar const *val)
 306 {
 307     SPDynaDrawContext *ddc = SP_DYNA_DRAW_CONTEXT(ec);
 308
 309     if (!strcmp(key, "mass")) {
 310         double const dval = ( val ? g_ascii_strtod (val, NULL) : 0.2 );
 311         ddc->mass = CLAMP(dval, -1000.0, 1000.0);
 312     } else if (!strcmp(key, "wiggle")) {
 313         double const dval = ( val ? g_ascii_strtod (val, NULL) : (1 - DRAG_DEFAULT));
 314         ddc->drag = CLAMP((1 - dval), DRAG_MIN, DRAG_MAX); // drag is inverse to wiggle
 315     } else if (!strcmp(key, "angle")) {
 316         double const dval = ( val ? g_ascii_strtod (val, NULL) : 0.0);
 317         ddc->angle = CLAMP (dval, -90, 90);
 318     } else if (!strcmp(key, "width")) {
 319         double const dval = ( val ? g_ascii_strtod (val, NULL) : 0.1 );
 320         ddc->width = CLAMP(dval, -1000.0, 1000.0);
 321     } else if (!strcmp(key, "thinning")) {
 322         double const dval = ( val ? g_ascii_strtod (val, NULL) : 0.1 );
 323         ddc->vel_thin = CLAMP(dval, -1.0, 1.0);
 324     } else if (!strcmp(key, "tremor")) {
 325         double const dval = ( val ? g_ascii_strtod (val, NULL) : 0.0 );
 326         ddc->tremor = CLAMP(dval, 0.0, 1.0);
 327     } else if (!strcmp(key, "flatness")) {
 328         double const dval = ( val ? g_ascii_strtod (val, NULL) : 1.0 );
 329         ddc->flatness = CLAMP(dval, 0, 1.0);
 330     } else if (!strcmp(key, "tracebackground")) {
 331         ddc->trace_bg = (val && strcmp(val, "0"));
 332     } else if (!strcmp(key, "usepressure")) {
 333         ddc->usepressure = (val && strcmp(val, "0"));
 334     } else if (!strcmp(key, "usetilt")) {
 335         ddc->usetilt = (val && strcmp(val, "0"));
 336     } else if (!strcmp(key, "abs_width")) {
 337         ddc->abs_width = (val && strcmp(val, "0"));
 338     } else if (!strcmp(key, "keep_selected")) {
 339         ddc->keep_selected = (val && strcmp(val, "0"));
 340     } else if (!strcmp(key, "cap_rounding")) {
 341         ddc->cap_rounding = ( val ? g_ascii_strtod (val, NULL) : 0.0 );
 342     }
 343
 344     //g_print("DDC: %g %g %g %g\n", ddc->mass, ddc->drag, ddc->angle, ddc->width);
 345 }
 346
 347 static double
 348 flerp(double f0, double f1, double p)
 349 {
 350     return f0 + ( f1 - f0 ) * p;
 351 }
 352
 353 /* Get normalized point */
 354 static NR::Point
 355 sp_dyna_draw_get_npoint(SPDynaDrawContext const *dc, NR::Point v)
 356 {
 357     NR::Rect drect = SP_EVENT_CONTEXT(dc)->desktop->get_display_area();
 358     double const max = MAX ( drect.dimensions()[NR::X], drect.dimensions()[NR::Y] );
 359     return NR::Point(( v[NR::X] - drect.min()[NR::X] ) / max,  ( v[NR::Y] - drect.min()[NR::Y] ) / max);
 360 }
 361
 362 /* Get view point */
 363 static NR::Point
 364 sp_dyna_draw_get_vpoint(SPDynaDrawContext const *dc, NR::Point n)
 365 {
 366     NR::Rect drect = SP_EVENT_CONTEXT(dc)->desktop->get_display_area();
 367     double const max = MAX ( drect.dimensions()[NR::X], drect.dimensions()[NR::Y] );
 368     return NR::Point(n[NR::X] * max + drect.min()[NR::X], n[NR::Y] * max + drect.min()[NR::Y]);
 369 }
 370
 371 static void
 372 sp_dyna_draw_reset(SPDynaDrawContext *dc, NR::Point p)
 373 {
 374     dc->last = dc->cur = sp_dyna_draw_get_npoint(dc, p);
 375     dc->vel = NR::Point(0,0);
 376     dc->vel_max = 0;
 377     dc->acc = NR::Point(0,0);
 378     dc->ang = NR::Point(0,0);
 379     dc->del = NR::Point(0,0);
 380 }
 381
 382 static void
 383 sp_dyna_draw_extinput(SPDynaDrawContext *dc, GdkEvent *event)
 384 {
 385     if (gdk_event_get_axis (event, GDK_AXIS_PRESSURE, &dc->pressure))
 386         dc->pressure = CLAMP (dc->pressure, DDC_MIN_PRESSURE, DDC_MAX_PRESSURE);
 387     else
 388         dc->pressure = DDC_DEFAULT_PRESSURE;
 389
 390     if (gdk_event_get_axis (event, GDK_AXIS_XTILT, &dc->xtilt))
 391         dc->xtilt = CLAMP (dc->xtilt, DDC_MIN_TILT, DDC_MAX_TILT);
 392     else
 393         dc->xtilt = DDC_DEFAULT_TILT;
 394
 395     if (gdk_event_get_axis (event, GDK_AXIS_YTILT, &dc->ytilt))
 396         dc->ytilt = CLAMP (dc->ytilt, DDC_MIN_TILT, DDC_MAX_TILT);
 397     else
 398         dc->ytilt = DDC_DEFAULT_TILT;
 399 }
 400
 401
 402 static gboolean
 403 sp_dyna_draw_apply(SPDynaDrawContext *dc, NR::Point p)
 404 {
 405     NR::Point n = sp_dyna_draw_get_npoint(dc, p);
 406
 407     /* Calculate mass and drag */
 408     double const mass = flerp(1.0, 160.0, dc->mass);
 409     double const drag = flerp(0.0, 0.5, dc->drag * dc->drag);
 410
 411     /* Calculate force and acceleration */
 412     NR::Point force = n - dc->cur;
 413
 414     // If force is below the absolute threshold DYNA_EPSILON,
 415     // or we haven't yet reached DYNA_VEL_START (i.e. at the beginning of stroke)
 416     // _and_ the force is below the (higher) DYNA_EPSILON_START threshold,
 417     // discard this move.
 418     // This prevents flips, blobs, and jerks caused by microscopic tremor of the tablet pen,
 419     // especially bothersome at the start of the stroke where we don't yet have the inertia to
 420     // smooth them out.
 421     if ( NR::L2(force) < DYNA_EPSILON || (dc->vel_max < DYNA_VEL_START && NR::L2(force) < DYNA_EPSILON_START)) {
 422         return FALSE;
 423     }
 424
 425     dc->acc = force / mass;
 426
 427     /* Calculate new velocity */
 428     dc->vel += dc->acc;
 429
 430     if (NR::L2(dc->vel) > dc->vel_max)
 431         dc->vel_max = NR::L2(dc->vel);
 432
 433     /* Calculate angle of drawing tool */
 434
 435     double a1;
 436     if (dc->usetilt) {
 437         // 1a. calculate nib angle from input device tilt:
 438         gdouble length = std::sqrt(dc->xtilt*dc->xtilt + dc->ytilt*dc->ytilt);;
 439
 440         if (length > 0) {
 441             NR::Point ang1 = NR::Point(dc->ytilt/length, dc->xtilt/length);
 442             a1 = atan2(ang1);
 443         }
 444         else
 445             a1 = 0.0;
 446     }
 447     else {
 448         // 1b. fixed dc->angle (absolutely flat nib):
 449         double const radians = ( (dc->angle - 90) / 180.0 ) * M_PI;
 450         NR::Point ang1 = NR::Point(-sin(radians),  cos(radians));
 451         a1 = atan2(ang1);
 452     }
 453
 454     // 2. perpendicular to dc->vel (absolutely non-flat nib):
 455     gdouble const mag_vel = NR::L2(dc->vel);
 456     if ( mag_vel < DYNA_EPSILON ) {
 457         return FALSE;
 458     }
 459     NR::Point ang2 = NR::rot90(dc->vel) / mag_vel;
 460
 461     // 3. Average them using flatness parameter:
 462     // calculate angles
 463     double a2 = atan2(ang2);
 464     // flip a2 to force it to be in the same half-circle as a1
 465     bool flipped = false;
 466     if (fabs (a2-a1) > 0.5*M_PI) {
 467         a2 += M_PI;
 468         flipped = true;
 469     }
 470     // normalize a2
 471     if (a2 > M_PI)
 472         a2 -= 2*M_PI;
 473     if (a2 < -M_PI)
 474         a2 += 2*M_PI;
 475     // find the flatness-weighted bisector angle, unflip if a2 was flipped
 476     // FIXME: when dc->vel is oscillating around the fixed angle, the new_ang flips back and forth. How to avoid this?
 477     double new_ang = a1 + (1 - dc->flatness) * (a2 - a1) - (flipped? M_PI : 0);
 478
 479     // Try to detect a sudden flip when the new angle differs too much from the previous for the
 480     // current velocity; in that case discard this move
 481     double angle_delta = NR::L2(NR::Point (cos (new_ang), sin (new_ang)) - dc->ang);
 482     if ( angle_delta / NR::L2(dc->vel) > 4000 ) {
 483         return FALSE;
 484     }
 485
 486     // convert to point
 487     dc->ang = NR::Point (cos (new_ang), sin (new_ang));
 488
 489 //    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);
 490
 491     /* Apply drag */
 492     dc->vel *= 1.0 - drag;
 493
 494     /* Update position */
 495     dc->last = dc->cur;
 496     dc->cur += dc->vel;
 497
 498     return TRUE;
 499 }
 500
 501 static void
 502 sp_dyna_draw_brush(SPDynaDrawContext *dc)
 503 {
 504     g_assert( dc->npoints >= 0 && dc->npoints < SAMPLING_SIZE );
 505
 506     // How much velocity thins strokestyle
 507     double vel_thin = flerp (0, 160, dc->vel_thin);
 508
 509     // Influence of pressure on thickness
 510     double pressure_thick = (dc->usepressure ? dc->pressure : 1.0);
 511
 512     // get the real brush point, not the same as pointer (affected by hatch tracking and/or mass
 513     // drag)
 514     NR::Point brush = sp_dyna_draw_get_vpoint(dc, dc->cur);
 515     NR::Point brush_w = SP_EVENT_CONTEXT(dc)->desktop->d2w(brush);
 516
 517     double trace_thick = 1;
 518     if (dc->trace_bg) {
 519         // pick single pixel
 520         NRPixBlock pb;
 521         int x = (int) floor(brush_w[NR::X]);
 522         int y = (int) floor(brush_w[NR::Y]);
 523         nr_pixblock_setup_fast(&pb, NR_PIXBLOCK_MODE_R8G8B8A8P, x, y, x+1, y+1, TRUE);
 524         sp_canvas_arena_render_pixblock(SP_CANVAS_ARENA(sp_desktop_drawing(SP_EVENT_CONTEXT(dc)->desktop)), &pb);
 525         const unsigned char *s = NR_PIXBLOCK_PX(&pb);
 526         double R = s[0] / 255.0;
 527         double G = s[1] / 255.0;
 528         double B = s[2] / 255.0;
 529         double A = s[3] / 255.0;
 530         double max = MAX (MAX (R, G), B);
 531         double min = MIN (MIN (R, G), B);
 532         double L = A * (max + min)/2 + (1 - A); // blend with white bg
 533         trace_thick = 1 - L;
 534         //g_print ("L %g thick %g\n", L, trace_thick);
 535     }
 536
 537     double width = (pressure_thick * trace_thick - vel_thin * NR::L2(dc->vel)) * dc->width;
 538
 539     double tremble_left = 0, tremble_right = 0;
 540     if (dc->tremor > 0) {
 541         // obtain two normally distributed random variables, using polar Box-Muller transform
 542         double x1, x2, w, y1, y2;
 543         do {
 544             x1 = 2.0 * g_random_double_range(0,1) - 1.0;
 545             x2 = 2.0 * g_random_double_range(0,1) - 1.0;
 546             w = x1 * x1 + x2 * x2;
 547         } while ( w >= 1.0 );
 548         w = sqrt( (-2.0 * log( w ) ) / w );
 549         y1 = x1 * w;
 550         y2 = x2 * w;
 551
 552         // deflect both left and right edges randomly and independently, so that:
 553         // (1) dc->tremor=1 corresponds to sigma=1, decreasing dc->tremor narrows the bell curve;
 554         // (2) deflection depends on width, but is upped for small widths for better visual uniformity across widths;
 555         // (3) deflection somewhat depends on speed, to prevent fast strokes looking
 556         // comparatively smooth and slow ones excessively jittery
 557         tremble_left  = (y1)*dc->tremor * (0.15 + 0.8*width) * (0.35 + 14*NR::L2(dc->vel));
 558         tremble_right = (y2)*dc->tremor * (0.15 + 0.8*width) * (0.35 + 14*NR::L2(dc->vel));
 559     }
 560
 561     if ( width < 0.02 * dc->width ) {
 562         width = 0.02 * dc->width;
 563     }
 564
 565     double dezoomify_factor = 0.05 * 1000;
 566     if (!dc->abs_width) {
 567         dezoomify_factor /= SP_EVENT_CONTEXT(dc)->desktop->current_zoom();
 568     }
 569
 570     NR::Point del_left = dezoomify_factor * (width + tremble_left) * dc->ang;
 571     NR::Point del_right = dezoomify_factor * (width + tremble_right) * dc->ang;
 572
 573     dc->point1[dc->npoints] = brush + del_left;
 574     dc->point2[dc->npoints] = brush - del_right;
 575
 576     dc->del = 0.5*(del_left + del_right);
 577
 578     dc->npoints++;
 579 }
 580
 581 void
 582 sp_ddc_update_toolbox (SPDesktop *desktop, const gchar *id, double value)
 583 {
 584     desktop->setToolboxAdjustmentValue (id, value);
 585 }
 586
 587 static void
 588 calligraphic_cancel(SPDynaDrawContext *dc)
 589 {
 590     SPDesktop *desktop = SP_EVENT_CONTEXT(dc)->desktop;
 591     dc->dragging = FALSE;
 592     dc->is_drawing = false;
 593     sp_canvas_item_ungrab(SP_CANVAS_ITEM(desktop->acetate), 0);
 594             /* Remove all temporary line segments */
 595             while (dc->segments) {
 596                 gtk_object_destroy(GTK_OBJECT(dc->segments->data));
 597                 dc->segments = g_slist_remove(dc->segments, dc->segments->data);
 598             }
 599             /* reset accumulated curve */
 600             sp_curve_reset(dc->accumulated);
 601             clear_current(dc);
 602             if (dc->repr) {
 603                 dc->repr = NULL;
 604             }
 605 }
 606
 607
 608 gint
 609 sp_dyna_draw_context_root_handler(SPEventContext *event_context,
 610                                   GdkEvent *event)
 611 {
 612     SPDynaDrawContext *dc = SP_DYNA_DRAW_CONTEXT(event_context);
 613     SPDesktop *desktop = event_context->desktop;
 614
 615     gint ret = FALSE;
 616
 617     switch (event->type) {
 618         case GDK_BUTTON_PRESS:
 619             if (event->button.button == 1 && !event_context->space_panning) {
 620
 621                 SPDesktop *desktop = SP_EVENT_CONTEXT_DESKTOP(dc);
 622
 623                 if (Inkscape::have_viable_layer(desktop, dc->_message_context) == false) {
 624                     return TRUE;
 625                 }
 626
 627                 NR::Point const button_w(event->button.x,
 628                                          event->button.y);
 629                 NR::Point const button_dt(desktop->w2d(button_w));
 630                 sp_dyna_draw_reset(dc, button_dt);
 631                 sp_dyna_draw_extinput(dc, event);
 632                 sp_dyna_draw_apply(dc, button_dt);
 633                 sp_curve_reset(dc->accumulated);
 634                 if (dc->repr) {
 635                     dc->repr = NULL;
 636                 }
 637
 638                 /* initialize first point */
 639                 dc->npoints = 0;
 640
 641                 sp_canvas_item_grab(SP_CANVAS_ITEM(desktop->acetate),
 642                                     ( GDK_KEY_PRESS_MASK |
 643                                       GDK_BUTTON_RELEASE_MASK |
 644                                       GDK_POINTER_MOTION_MASK |
 645                                       GDK_BUTTON_PRESS_MASK ),
 646                                     NULL,
 647                                     event->button.time);
 648
 649                 ret = TRUE;
 650
 651                 sp_canvas_force_full_redraw_after_interruptions(desktop->canvas, 3);
 652                 dc->is_drawing = true;
 653             }
 654             break;
 655         case GDK_MOTION_NOTIFY:
 656         {
 657             NR::Point const motion_w(event->motion.x,
 658                                      event->motion.y);
 659             NR::Point motion_dt(desktop->w2d(motion_w));
 660             sp_dyna_draw_extinput(dc, event);
 661
 662             dc->_message_context->clear();
 663
 664             // for hatching:
 665             double hatch_dist = 0;
 666             NR::Point hatch_unit_vector(0,0);
 667             NR::Point nearest(0,0);
 668             NR::Point pointer(0,0);
 669             NR::Matrix motion_to_curve(NR::identity());
 670
 671             if (event->motion.state & GDK_CONTROL_MASK) { // hatching - sense the item
 672
 673                 SPItem *selected = sp_desktop_selection(desktop)->singleItem();
 674                 if (selected && (SP_IS_SHAPE(selected) || SP_IS_TEXT(selected))) {
 675                     // One item selected, and it's a path;
 676                     // let's try to track it as a guide
 677
 678                     if (selected != dc->hatch_item) {
 679                         dc->hatch_item = selected;
 680                         if (dc->hatch_livarot_path)
 681                             delete dc->hatch_livarot_path;
 682                         dc->hatch_livarot_path = Path_for_item (dc->hatch_item, true, true);
 683                         dc->hatch_livarot_path->ConvertWithBackData(0.01);
 684                     }
 685
 686                     // calculate pointer point in the guide item's coords
 687                     motion_to_curve = sp_item_dt2i_affine(selected) * sp_item_i2doc_affine(selected);
 688                     pointer = motion_dt * motion_to_curve;
 689
 690                     // calculate the nearest point on the guide path
 691                     NR::Maybe<Path::cut_position> position = get_nearest_position_on_Path(dc->hatch_livarot_path, pointer);
 692                     nearest = get_point_on_Path(dc->hatch_livarot_path, position->piece, position->t);
 693
 694
 695                     // distance from pointer to nearest
 696                     hatch_dist = NR::L2(pointer - nearest);
 697                     // unit-length vector
 698                     hatch_unit_vector = (pointer - nearest)/hatch_dist;
 699
 700                     dc->_message_context->set(Inkscape::NORMAL_MESSAGE, _("<b>Guide path selected</b>; start drawing along the guide with <b>Ctrl</b>"));
 701                 } else {
 702                     dc->_message_context->set(Inkscape::NORMAL_MESSAGE, _("<b>Select a guide path</b> to track with <b>Ctrl</b>"));
 703                 }
 704             }
 705
 706             if ( dc->is_drawing && (event->motion.state & GDK_BUTTON1_MASK) && !event_context->space_panning) {
 707                 dc->dragging = TRUE;
 708
 709                 if (event->motion.state & GDK_CONTROL_MASK && dc->hatch_item) { // hatching
 710
 711 #define SPEED_ELEMENTS 12
 712 #define SPEED_MIN 0.12
 713 #define SPEED_NORMAL 0.65
 714
 715                     // speed is the movement of the nearest point along the guide path, divided by
 716                     // the movement of the pointer at the same period; it is averaged for the last
 717                     // SPEED_ELEMENTS motion events.  Normally, as you track the guide path, speed
 718                     // is about 1, i.e. the nearest point on the path is moved by about the same
 719                     // distance as the pointer. If the speed starts to decrease, we are losing
 720                     // contact with the guide; if it drops below SPEED_MIN, we are on our own and
 721                     // not attracted to guide anymore. Most often this happens when you have
 722                     // tracked to the end of a guide calligraphic stroke and keep moving
 723                     // further. We try to handle this situation gracefully: not stick with the
 724                     // guide forever but let go of it smoothly and without sharp jerks (non-zero
 725                     // mass recommended; with zero mass, jerks are still quite noticeable).
 726
 727                     double speed = 1;
 728                     if (NR::L2(dc->hatch_last_nearest) != 0) {
 729                         // the distance nearest moved since the last motion event
 730                         double nearest_moved = NR::L2(nearest - dc->hatch_last_nearest);
 731                         // the distance pointer moved since the last motion event
 732                         double pointer_moved = NR::L2(pointer - dc->hatch_last_pointer);
 733                         // store them in stacks limited to SPEED_ELEMENTS
 734                         dc->hatch_nearest_past.push_front(nearest_moved);
 735                         if (dc->hatch_nearest_past.size() > SPEED_ELEMENTS)
 736                             dc->hatch_nearest_past.pop_back();
 737                         dc->hatch_pointer_past.push_front(pointer_moved);
 738                         if (dc->hatch_pointer_past.size() > SPEED_ELEMENTS)
 739                             dc->hatch_pointer_past.pop_back();
 740
 741                         // If the stacks are full,
 742                         if (dc->hatch_nearest_past.size() == SPEED_ELEMENTS) {
 743                             // calculate the sums of all stored movements
 744                             double nearest_sum = std::accumulate (dc->hatch_nearest_past.begin(), dc->hatch_nearest_past.end(), 0.0);
 745                             double pointer_sum = std::accumulate (dc->hatch_pointer_past.begin(), dc->hatch_pointer_past.end(), 0.0);
 746                             // and divide to get the speed
 747                             speed = nearest_sum/pointer_sum;
 748                             //g_print ("nearest sum %g  pointer_sum %g  speed %g\n", nearest_sum, pointer_sum, speed);
 749                         }
 750                     }
 751
 752                     if (   dc->hatch_escaped  // already escaped, do not reattach
 753                         || (speed < SPEED_MIN) // stuck; most likely reached end of traced stroke
 754                         || (dc->hatch_spacing > 0 && hatch_dist > 50 * dc->hatch_spacing) // went too far from the guide
 755                         ) {
 756                         // We are NOT attracted to the guide!
 757
 758                         //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);
 759
 760                         // Remember hatch_escaped so we don't get
 761                         // attracted again until the end of this stroke
 762                         dc->hatch_escaped = true;
 763
 764                     } else {
 765
 766                         // Calculate angle cosine of this vector-to-guide and all past vectors
 767                         // summed, to detect if we accidentally flipped to the other side of the
 768                         // guide
 769                         double dot = NR::dot (pointer - nearest, dc->hatch_vector_accumulated);
 770                         dot /= NR::L2(pointer - nearest) * NR::L2(dc->hatch_vector_accumulated);
 771
 772                         if (dc->hatch_spacing != 0) { // spacing was already set
 773                             double target;
 774                             if (speed > SPEED_NORMAL) {
 775                                 // all ok, strictly obey the spacing
 776                                 target = dc->hatch_spacing;
 777                             } else {
 778                                 // looks like we're starting to lose speed,
 779                                 // so _gradually_ let go attraction to prevent jerks
 780                                 target = (dc->hatch_spacing * speed + hatch_dist * (SPEED_NORMAL - speed))/SPEED_NORMAL;
 781                             }
 782                             if (!isNaN(dot) && dot < -0.5) {// flip
 783                                 target = -target;
 784                             }
 785
 786                             // This is the track pointer that we will use instead of the real one
 787                             NR::Point new_pointer = nearest + target * hatch_unit_vector;
 788
 789                             // some limited feedback: allow persistent pulling to slightly change
 790                             // the spacing
 791                             dc->hatch_spacing += (hatch_dist - dc->hatch_spacing)/3500;
 792
 793                             // return it to the desktop coords
 794                             motion_dt = new_pointer * motion_to_curve.inverse();
 795
 796                         } else {
 797                             // this is the first motion event, set the dist
 798                             dc->hatch_spacing = hatch_dist;
 799                         }
 800
 801                         // remember last points
 802                         dc->hatch_last_pointer = pointer;
 803                         dc->hatch_last_nearest = nearest;
 804                         dc->hatch_vector_accumulated += (pointer - nearest);
 805                     }
 806
 807                     dc->_message_context->set(Inkscape::NORMAL_MESSAGE, dc->hatch_escaped? _("Tracking: <b>connection to guide path lost!</b>") : _("<b>Tracking</b> a guide path"));
 808
 809                 } else {
 810                     dc->_message_context->set(Inkscape::NORMAL_MESSAGE, _("<b>Drawing</b> a calligraphic stroke"));
 811                 }
 812
 813                 if (!sp_dyna_draw_apply(dc, motion_dt)) {
 814                     ret = TRUE;
 815                     break;
 816                 }
 817
 818                 if ( dc->cur != dc->last ) {
 819                     sp_dyna_draw_brush(dc);
 820                     g_assert( dc->npoints > 0 );
 821                     fit_and_split(dc, FALSE);
 822                 }
 823                 ret = TRUE;
 824             }
 825
 826             // Draw the hatching circle if necessary
 827             if (event->motion.state & GDK_CONTROL_MASK) {
 828                 if (dc->hatch_spacing == 0 && hatch_dist != 0) {
 829                     // Haven't set spacing yet: gray, center free, update radius live
 830                     NR::Point c = desktop->w2d(motion_w);
 831                     NR::Matrix const sm (NR::scale(hatch_dist, hatch_dist) * NR::translate(c));
 832                     sp_canvas_item_affine_absolute(dc->hatch_area, sm);
 833                     sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(dc->hatch_area), 0x7f7f7fff, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 834                     sp_canvas_item_show(dc->hatch_area);
 835                 } else if (dc->dragging && !dc->hatch_escaped) {
 836                     // Tracking: green, center snapped, fixed radius
 837                     NR::Point c = motion_dt;
 838                     NR::Matrix const sm (NR::scale(dc->hatch_spacing, dc->hatch_spacing) * NR::translate(c));
 839                     sp_canvas_item_affine_absolute(dc->hatch_area, sm);
 840                     sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(dc->hatch_area), 0x00FF00ff, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 841                     sp_canvas_item_show(dc->hatch_area);
 842                 } else if (dc->dragging && dc->hatch_escaped) {
 843                     // Tracking escaped: red, center free, fixed radius
 844                     NR::Point c = desktop->w2d(motion_w);
 845                     NR::Matrix const sm (NR::scale(dc->hatch_spacing, dc->hatch_spacing) * NR::translate(c));
 846
 847                     sp_canvas_item_affine_absolute(dc->hatch_area, sm);
 848                     sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(dc->hatch_area), 0xFF0000ff, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 849                     sp_canvas_item_show(dc->hatch_area);
 850                 } else {
 851                     // Not drawing but spacing set: gray, center snapped, fixed radius
 852                     NR::Point c = (nearest + dc->hatch_spacing * hatch_unit_vector) * motion_to_curve.inverse();
 853                     if (!isNaN(c[NR::X]) && !isNaN(c[NR::Y])) {
 854                         NR::Matrix const sm (NR::scale(dc->hatch_spacing, dc->hatch_spacing) * NR::translate(c));
 855                         sp_canvas_item_affine_absolute(dc->hatch_area, sm);
 856                         sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(dc->hatch_area), 0x7f7f7fff, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 857                         sp_canvas_item_show(dc->hatch_area);
 858                     }
 859                 }
 860             } else {
 861                 sp_canvas_item_hide(dc->hatch_area);
 862             }
 863         }
 864         break;
 865
 866
 867     case GDK_BUTTON_RELEASE:
 868     {
 869         NR::Point const motion_w(event->button.x, event->button.y);
 870         NR::Point const motion_dt(desktop->w2d(motion_w));
 871
 872         sp_canvas_item_ungrab(SP_CANVAS_ITEM(desktop->acetate), event->button.time);
 873         sp_canvas_end_forced_full_redraws(desktop->canvas);
 874         dc->is_drawing = false;
 875
 876         if (dc->dragging && event->button.button == 1 && !event_context->space_panning) {
 877             dc->dragging = FALSE;
 878
 879             sp_dyna_draw_apply(dc, motion_dt);
 880
 881             /* Remove all temporary line segments */
 882             while (dc->segments) {
 883                 gtk_object_destroy(GTK_OBJECT(dc->segments->data));
 884                 dc->segments = g_slist_remove(dc->segments, dc->segments->data);
 885             }
 886
 887             /* Create object */
 888             fit_and_split(dc, TRUE);
 889             accumulate_calligraphic(dc);
 890             set_to_accumulated(dc, event->button.state & GDK_SHIFT_MASK); // performs document_done
 891
 892             /* reset accumulated curve */
 893             sp_curve_reset(dc->accumulated);
 894
 895             clear_current(dc);
 896             if (dc->repr) {
 897                 dc->repr = NULL;
 898             }
 899
 900             if (!dc->hatch_pointer_past.empty()) dc->hatch_pointer_past.clear();
 901             if (!dc->hatch_nearest_past.empty()) dc->hatch_nearest_past.clear();
 902             dc->hatch_last_nearest = NR::Point(0,0);
 903             dc->hatch_last_pointer = NR::Point(0,0);
 904             dc->hatch_vector_accumulated = NR::Point(0,0);
 905             dc->hatch_escaped = false;
 906             dc->hatch_item = NULL;
 907             dc->hatch_livarot_path = NULL;
 908
 909             if (dc->hatch_spacing != 0 && !dc->keep_selected) {
 910                 // we do not select the newly drawn path, so increase spacing by step
 911                 if (dc->hatch_spacing_step == 0) {
 912                     dc->hatch_spacing_step = dc->hatch_spacing;
 913                 }
 914                 dc->hatch_spacing += dc->hatch_spacing_step;
 915             }
 916
 917             dc->_message_context->clear();
 918             ret = TRUE;
 919         }
 920         break;
 921     }
 922
 923     case GDK_KEY_PRESS:
 924         switch (get_group0_keyval (&event->key)) {
 925         case GDK_Up:
 926         case GDK_KP_Up:
 927             if (!MOD__CTRL_ONLY) {
 928                 dc->angle += 5.0;
 929                 if (dc->angle > 90.0)
 930                     dc->angle = 90.0;
 931                 sp_ddc_update_toolbox (desktop, "calligraphy-angle", dc->angle);
 932                 ret = TRUE;
 933             }
 934             break;
 935         case GDK_Down:
 936         case GDK_KP_Down:
 937             if (!MOD__CTRL_ONLY) {
 938                 dc->angle -= 5.0;
 939                 if (dc->angle < -90.0)
 940                     dc->angle = -90.0;
 941                 sp_ddc_update_toolbox (desktop, "calligraphy-angle", dc->angle);
 942                 ret = TRUE;
 943             }
 944             break;
 945         case GDK_Right:
 946         case GDK_KP_Right:
 947             if (!MOD__CTRL_ONLY) {
 948                 dc->width += 0.01;
 949                 if (dc->width > 1.0)
 950                     dc->width = 1.0;
 951                 sp_ddc_update_toolbox (desktop, "altx-calligraphy", dc->width * 100); // the same spinbutton is for alt+x
 952                 ret = TRUE;
 953             }
 954             break;
 955         case GDK_Left:
 956         case GDK_KP_Left:
 957             if (!MOD__CTRL_ONLY) {
 958                 dc->width -= 0.01;
 959                 if (dc->width < 0.01)
 960                     dc->width = 0.01;
 961                 sp_ddc_update_toolbox (desktop, "altx-calligraphy", dc->width * 100);
 962                 ret = TRUE;
 963             }
 964             break;
 965         case GDK_Home:
 966         case GDK_KP_Home:
 967             dc->width = 0.01;
 968             sp_ddc_update_toolbox (desktop, "altx-calligraphy", dc->width * 100);
 969             ret = TRUE;
 970             break;
 971         case GDK_End:
 972         case GDK_KP_End:
 973             dc->width = 1.0;
 974             sp_ddc_update_toolbox (desktop, "altx-calligraphy", dc->width * 100);
 975             ret = TRUE;
 976             break;
 977         case GDK_x:
 978         case GDK_X:
 979             if (MOD__ALT_ONLY) {
 980                 desktop->setToolboxFocusTo ("altx-calligraphy");
 981                 ret = TRUE;
 982             }
 983             break;
 984         case GDK_Escape:
 985             if (dc->is_drawing) {
 986                 // if drawing, cancel, otherwise pass it up for deselecting
 987                 calligraphic_cancel (dc);
 988                 ret = TRUE;
 989             }
 990             break;
 991         case GDK_z:
 992         case GDK_Z:
 993             if (MOD__CTRL_ONLY && dc->is_drawing) {
 994                 // if drawing, cancel, otherwise pass it up for undo
 995                 calligraphic_cancel (dc);
 996                 ret = TRUE;
 997             }
 998             break;
 999         default:
1000             break;
1001         }
1002         break;
1003
1004     case GDK_KEY_RELEASE:
1005         switch (get_group0_keyval(&event->key)) {
1006             case GDK_Control_L:
1007             case GDK_Control_R:
1008                 dc->_message_context->clear();
1009                 dc->hatch_spacing = 0;
1010                 dc->hatch_spacing_step = 0;
1011                 break;
1012             default:
1013                 break;
1014         }
1015
1016     default:
1017         break;
1018     }
1019
1020     if (!ret) {
1021         if (((SPEventContextClass *) parent_class)->root_handler) {
1022             ret = ((SPEventContextClass *) parent_class)->root_handler(event_context, event);
1023         }
1024     }
1025
1026     return ret;
1027 }
1028
1029
1030 static void
1031 clear_current(SPDynaDrawContext *dc)
1032 {
1033     /* reset bpath */
1034     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(dc->currentshape), NULL);
1035     /* reset curve */
1036     sp_curve_reset(dc->currentcurve);
1037     sp_curve_reset(dc->cal1);
1038     sp_curve_reset(dc->cal2);
1039     /* reset points */
1040     dc->npoints = 0;
1041 }
1042
1043 static void
1044 set_to_accumulated(SPDynaDrawContext *dc, bool unionize)
1045 {
1046     SPDesktop *desktop = SP_EVENT_CONTEXT(dc)->desktop;
1047
1048     if (!sp_curve_empty(dc->accumulated)) {
1049         NArtBpath *abp;
1050         gchar *str;
1051
1052         if (!dc->repr) {
1053             /* Create object */
1054             Inkscape::XML::Document *xml_doc = sp_document_repr_doc(desktop->doc());
1055             Inkscape::XML::Node *repr = xml_doc->createElement("svg:path");
1056
1057             /* Set style */
1058             sp_desktop_apply_style_tool (desktop, repr, "tools.calligraphic", false);
1059
1060             dc->repr = repr;
1061
1062             SPItem *item=SP_ITEM(desktop->currentLayer()->appendChildRepr(dc->repr));
1063             Inkscape::GC::release(dc->repr);
1064             item->transform = SP_ITEM(desktop->currentRoot())->getRelativeTransform(desktop->currentLayer());
1065             item->updateRepr();
1066         }
1067         abp = nr_artpath_affine(sp_curve_first_bpath(dc->accumulated), sp_desktop_dt2root_affine(desktop));
1068         str = sp_svg_write_path(abp);
1069         g_assert( str != NULL );
1070         g_free(abp);
1071         dc->repr->setAttribute("d", str);
1072         g_free(str);
1073
1074         if (unionize) {
1075             sp_desktop_selection(desktop)->add(dc->repr);
1076             sp_selected_path_union_skip_undo();
1077         } else {
1078             if (dc->keep_selected) {
1079                 sp_desktop_selection(desktop)->set(dc->repr);
1080             }
1081         }
1082
1083     } else {
1084         if (dc->repr) {
1085             sp_repr_unparent(dc->repr);
1086         }
1087         dc->repr = NULL;
1088     }
1089
1090     sp_document_done(sp_desktop_document(desktop), SP_VERB_CONTEXT_CALLIGRAPHIC,
1091                      _("Draw calligraphic stroke"));
1092 }
1093
1094 static void
1095 add_cap(SPCurve *curve,
1096         NR::Point const &pre, NR::Point const &from,
1097         NR::Point const &to, NR::Point const &post,
1098         double rounding)
1099 {
1100     NR::Point vel = rounding * NR::rot90( to - from ) / sqrt(2.0);
1101     double mag = NR::L2(vel);
1102
1103     NR::Point v_in = from - pre;
1104     double mag_in = NR::L2(v_in);
1105     if ( mag_in > DYNA_EPSILON ) {
1106         v_in = mag * v_in / mag_in;
1107     } else {
1108         v_in = NR::Point(0, 0);
1109     }
1110
1111     NR::Point v_out = to - post;
1112     double mag_out = NR::L2(v_out);
1113     if ( mag_out > DYNA_EPSILON ) {
1114         v_out = mag * v_out / mag_out;
1115     } else {
1116         v_out = NR::Point(0, 0);
1117     }
1118
1119     if ( NR::L2(v_in) > DYNA_EPSILON || NR::L2(v_out) > DYNA_EPSILON ) {
1120         sp_curve_curveto(curve, from + v_in, to + v_out, to);
1121     }
1122 }
1123
1124 static void
1125 accumulate_calligraphic(SPDynaDrawContext *dc)
1126 {
1127     if ( !sp_curve_empty(dc->cal1) && !sp_curve_empty(dc->cal2) ) {
1128         sp_curve_reset(dc->accumulated); /*  Is this required ?? */
1129         SPCurve *rev_cal2 = sp_curve_reverse(dc->cal2);
1130
1131         g_assert(dc->cal1->end > 1);
1132         g_assert(rev_cal2->end > 1);
1133         g_assert(SP_CURVE_SEGMENT(dc->cal1, 0)->code == NR_MOVETO_OPEN);
1134         g_assert(SP_CURVE_SEGMENT(rev_cal2, 0)->code == NR_MOVETO_OPEN);
1135         g_assert(SP_CURVE_SEGMENT(dc->cal1, 1)->code == NR_CURVETO);
1136         g_assert(SP_CURVE_SEGMENT(rev_cal2, 1)->code == NR_CURVETO);
1137         g_assert(SP_CURVE_SEGMENT(dc->cal1, dc->cal1->end-1)->code == NR_CURVETO);
1138         g_assert(SP_CURVE_SEGMENT(rev_cal2, rev_cal2->end-1)->code == NR_CURVETO);
1139
1140         sp_curve_append(dc->accumulated, dc->cal1, FALSE);
1141
1142         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);
1143
1144         sp_curve_append(dc->accumulated, rev_cal2, TRUE);
1145
1146         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);
1147
1148         sp_curve_closepath(dc->accumulated);
1149
1150         sp_curve_unref(rev_cal2);
1151
1152         sp_curve_reset(dc->cal1);
1153         sp_curve_reset(dc->cal2);
1154     }
1155 }
1156
1157 static double square(double const x)
1158 {
1159     return x * x;
1160 }
1161
1162 static void
1163 fit_and_split(SPDynaDrawContext *dc, gboolean release)
1164 {
1165     double const tolerance_sq = square( NR::expansion(SP_EVENT_CONTEXT(dc)->desktop->w2d()) * TOLERANCE_CALLIGRAPHIC );
1166
1167 #ifdef DYNA_DRAW_VERBOSE
1168     g_print("[F&S:R=%c]", release?'T':'F');
1169 #endif
1170
1171     if (!( dc->npoints > 0 && dc->npoints < SAMPLING_SIZE ))
1172         return; // just clicked
1173
1174     if ( dc->npoints == SAMPLING_SIZE - 1 || release ) {
1175 #define BEZIER_SIZE       4
1176 #define BEZIER_MAX_BEZIERS  8
1177 #define BEZIER_MAX_LENGTH ( BEZIER_SIZE * BEZIER_MAX_BEZIERS )
1178
1179 #ifdef DYNA_DRAW_VERBOSE
1180         g_print("[F&S:#] dc->npoints:%d, release:%s\n",
1181                 dc->npoints, release ? "TRUE" : "FALSE");
1182 #endif
1183
1184         /* Current calligraphic */
1185         if ( dc->cal1->end == 0 || dc->cal2->end == 0 ) {
1186             /* dc->npoints > 0 */
1187             /* g_print("calligraphics(1|2) reset\n"); */
1188             sp_curve_reset(dc->cal1);
1189             sp_curve_reset(dc->cal2);
1190
1191             sp_curve_moveto(dc->cal1, dc->point1[0]);
1192             sp_curve_moveto(dc->cal2, dc->point2[0]);
1193         }
1194
1195         NR::Point b1[BEZIER_MAX_LENGTH];
1196         gint const nb1 = sp_bezier_fit_cubic_r(b1, dc->point1, dc->npoints,
1197                                                tolerance_sq, BEZIER_MAX_BEZIERS);
1198         g_assert( nb1 * BEZIER_SIZE <= gint(G_N_ELEMENTS(b1)) );
1199
1200         NR::Point b2[BEZIER_MAX_LENGTH];
1201         gint const nb2 = sp_bezier_fit_cubic_r(b2, dc->point2, dc->npoints,
1202                                                tolerance_sq, BEZIER_MAX_BEZIERS);
1203         g_assert( nb2 * BEZIER_SIZE <= gint(G_N_ELEMENTS(b2)) );
1204
1205         if ( nb1 != -1 && nb2 != -1 ) {
1206             /* Fit and draw and reset state */
1207 #ifdef DYNA_DRAW_VERBOSE
1208             g_print("nb1:%d nb2:%d\n", nb1, nb2);
1209 #endif
1210             /* CanvasShape */
1211             if (! release) {
1212                 sp_curve_reset(dc->currentcurve);
1213                 sp_curve_moveto(dc->currentcurve, b1[0]);
1214                 for (NR::Point *bp1 = b1; bp1 < b1 + BEZIER_SIZE * nb1; bp1 += BEZIER_SIZE) {
1215                     sp_curve_curveto(dc->currentcurve, bp1[1],
1216                                      bp1[2], bp1[3]);
1217                 }
1218                 sp_curve_lineto(dc->currentcurve,
1219                                 b2[BEZIER_SIZE*(nb2-1) + 3]);
1220                 for (NR::Point *bp2 = b2 + BEZIER_SIZE * ( nb2 - 1 ); bp2 >= b2; bp2 -= BEZIER_SIZE) {
1221                     sp_curve_curveto(dc->currentcurve, 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                 sp_curve_closepath(dc->currentcurve);
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                 sp_curve_curveto(dc->cal1, bp1[1], bp1[2], bp1[3]);
1234             }
1235             for (NR::Point *bp2 = b2; bp2 < b2 + BEZIER_SIZE * nb2; bp2 += BEZIER_SIZE) {
1236                 sp_curve_curveto(dc->cal2, 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                 sp_curve_lineto(dc->cal1, dc->point1[i]);
1247             }
1248             for (gint i = 1; i < dc->npoints; i++) {
1249                 sp_curve_lineto(dc->cal2, 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(!sp_curve_empty(dc->currentcurve));
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 = sp_curve_copy(dc->currentcurve);
1264             sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH (cbp), curve);
1265             sp_curve_unref(curve);
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     sp_curve_reset(dc->currentcurve);
1294
1295     sp_curve_moveto(dc->currentcurve, dc->point1[dc->npoints-1]);
1296     for (gint i = dc->npoints-2; i >= 0; i--) {
1297         sp_curve_lineto(dc->currentcurve, dc->point1[i]);
1298     }
1299     for (gint i = 0; i < dc->npoints; i++) {
1300         sp_curve_lineto(dc->currentcurve, 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     sp_curve_closepath(dc->currentcurve);
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 :