src/dyna-draw-context.cpp

   1 #define __SP_DYNA_DRAW_CONTEXT_C__
   2
   3 /*
   4  * Handwriting-like drawing mode
   5  *
   6  * Authors:
   7  *   Mitsuru Oka <oka326@parkcity.ne.jp>
   8  *   Lauris Kaplinski <lauris@kaplinski.com>
   9  *   bulia byak <buliabyak@users.sf.net>
  10  *   MenTaLguY <mental@rydia.net>
  11  *
  12  * The original dynadraw code:
  13  *   Paul Haeberli <paul@sgi.com>
  14  *
  15  * Copyright (C) 1998 The Free Software Foundation
  16  * Copyright (C) 1999-2005 authors
  17  * Copyright (C) 2001-2002 Ximian, Inc.
  18  * Copyright (C) 2005-2007 bulia byak
  19  * Copyright (C) 2006 MenTaLguY
  20  *
  21  * Released under GNU GPL, read the file 'COPYING' for more information
  22  */
  23
  24 #define noDYNA_DRAW_VERBOSE
  25
  26 #include "config.h"
  27
  28 #include <gtk/gtk.h>
  29 #include <gdk/gdkkeysyms.h>
  30 #include <glibmm/i18n.h>
  31 #include <string>
  32 #include <cstring>
  33 #include <numeric>
  34
  35 #include "svg/svg.h"
  36 #include "display/canvas-bpath.h"
  37 #include "display/bezier-utils.h"
  38 #include "display/curve.h"
  39 #include <glib/gmem.h>
  40 #include "macros.h"
  41 #include "document.h"
  42 #include "selection.h"
  43 #include "desktop.h"
  44 #include "desktop-events.h"
  45 #include "desktop-handles.h"
  46 #include "desktop-affine.h"
  47 #include "desktop-style.h"
  48 #include "message-context.h"
  49 #include "prefs-utils.h"
  50 #include "pixmaps/cursor-calligraphy.xpm"
  51 #include "libnr/n-art-bpath.h"
  52 #include "libnr/nr-path.h"
  53 #include "libnr/nr-matrix-ops.h"
  54 #include "libnr/nr-scale-translate-ops.h"
  55 #include "libnr/nr-convert2geom.h"
  56 #include "xml/repr.h"
  57 #include "context-fns.h"
  58 #include "sp-item.h"
  59 #include "inkscape.h"
  60 #include "color.h"
  61 #include "splivarot.h"
  62 #include "sp-item-group.h"
  63 #include "sp-shape.h"
  64 #include "sp-path.h"
  65 #include "sp-text.h"
  66 #include "display/canvas-bpath.h"
  67 #include "display/canvas-arena.h"
  68 #include "livarot/Shape.h"
  69 #include <2geom/isnan.h>
  70 #include <2geom/pathvector.h>
  71
  72 #include "dyna-draw-context.h"
  73
  74 #define DDC_RED_RGBA 0xff0000ff
  75
  76 #define TOLERANCE_CALLIGRAPHIC 0.1
  77
  78 #define DYNA_EPSILON 0.5e-6
  79 #define DYNA_EPSILON_START 0.5e-2
  80 #define DYNA_VEL_START 1e-5
  81
  82 #define DYNA_MIN_WIDTH 1.0e-6
  83
  84
  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 &from, NR::Point const &to, 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 *dd_parent_class = 0;
 120
 121 GType sp_dyna_draw_context_get_type(void)
 122 {
 123     static GType type = 0;
 124     if (!type) {
 125         GTypeInfo info = {
 126             sizeof(SPDynaDrawContextClass),
 127             0, // base_init
 128             0, // base_finalize
 129             (GClassInitFunc)sp_dyna_draw_context_class_init,
 130             0, // class_finalize
 131             0, // class_data
 132             sizeof(SPDynaDrawContext),
 133             0, // n_preallocs
 134             (GInstanceInitFunc)sp_dyna_draw_context_init,
 135             0 // value_table
 136         };
 137         type = g_type_register_static(SP_TYPE_COMMON_CONTEXT, "SPDynaDrawContext", &info, static_cast<GTypeFlags>(0));
 138     }
 139     return type;
 140 }
 141
 142 static void
 143 sp_dyna_draw_context_class_init(SPDynaDrawContextClass *klass)
 144 {
 145     GObjectClass *object_class = (GObjectClass *) klass;
 146     SPEventContextClass *event_context_class = (SPEventContextClass *) klass;
 147
 148     dd_parent_class = (SPEventContextClass*)g_type_class_peek_parent(klass);
 149
 150     object_class->dispose = sp_dyna_draw_context_dispose;
 151
 152     event_context_class->setup = sp_dyna_draw_context_setup;
 153     event_context_class->set = sp_dyna_draw_context_set;
 154     event_context_class->root_handler = sp_dyna_draw_context_root_handler;
 155 }
 156
 157 static void
 158 sp_dyna_draw_context_init(SPDynaDrawContext *ddc)
 159 {
 160     ddc->cursor_shape = cursor_calligraphy_xpm;
 161     ddc->hot_x = 4;
 162     ddc->hot_y = 4;
 163
 164     ddc->vel_thin = 0.1;
 165     ddc->flatness = 0.9;
 166     ddc->cap_rounding = 0.0;
 167
 168     ddc->abs_width = false;
 169     ddc->keep_selected = true;
 170
 171     ddc->hatch_spacing = 0;
 172     ddc->hatch_spacing_step = 0;
 173     new (&ddc->hatch_pointer_past) std::list<double>();
 174     new (&ddc->hatch_nearest_past) std::list<double>();
 175     ddc->hatch_last_nearest = NR::Point(0,0);
 176     ddc->hatch_last_pointer = NR::Point(0,0);
 177     ddc->hatch_vector_accumulated = NR::Point(0,0);
 178     ddc->hatch_escaped = false;
 179     ddc->hatch_area = NULL;
 180     ddc->hatch_item = NULL;
 181     ddc->hatch_livarot_path = NULL;
 182
 183     ddc->trace_bg = false;
 184 }
 185
 186 static void
 187 sp_dyna_draw_context_dispose(GObject *object)
 188 {
 189     SPDynaDrawContext *ddc = SP_DYNA_DRAW_CONTEXT(object);
 190
 191     if (ddc->hatch_area) {
 192         gtk_object_destroy(GTK_OBJECT(ddc->hatch_area));
 193         ddc->hatch_area = NULL;
 194     }
 195
 196
 197     G_OBJECT_CLASS(dd_parent_class)->dispose(object);
 198
 199     ddc->hatch_pointer_past.~list();
 200     ddc->hatch_nearest_past.~list();
 201 }
 202
 203 static void
 204 sp_dyna_draw_context_setup(SPEventContext *ec)
 205 {
 206     SPDynaDrawContext *ddc = SP_DYNA_DRAW_CONTEXT(ec);
 207
 208     if (((SPEventContextClass *) dd_parent_class)->setup)
 209         ((SPEventContextClass *) dd_parent_class)->setup(ec);
 210
 211     ddc->accumulated = new SPCurve(32);
 212     ddc->currentcurve = new SPCurve(4);
 213
 214     ddc->cal1 = new SPCurve(32);
 215     ddc->cal2 = new SPCurve(32);
 216
 217     ddc->currentshape = sp_canvas_item_new(sp_desktop_sketch(ec->desktop), SP_TYPE_CANVAS_BPATH, NULL);
 218     sp_canvas_bpath_set_fill(SP_CANVAS_BPATH(ddc->currentshape), DDC_RED_RGBA, SP_WIND_RULE_EVENODD);
 219     sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(ddc->currentshape), 0x00000000, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 220     /* fixme: Cannot we cascade it to root more clearly? */
 221     g_signal_connect(G_OBJECT(ddc->currentshape), "event", G_CALLBACK(sp_desktop_root_handler), ec->desktop);
 222
 223     {
 224         SPCurve *c = SPCurve::new_from_foreign_bpath(hatch_area_circle);
 225         ddc->hatch_area = sp_canvas_bpath_new(sp_desktop_controls(ec->desktop), c);
 226         c->unref();
 227         sp_canvas_bpath_set_fill(SP_CANVAS_BPATH(ddc->hatch_area), 0x00000000,(SPWindRule)0);
 228         sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(ddc->hatch_area), 0x0000007f, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 229         sp_canvas_item_hide(ddc->hatch_area);
 230     }
 231
 232     sp_event_context_read(ec, "mass");
 233     sp_event_context_read(ec, "wiggle");
 234     sp_event_context_read(ec, "angle");
 235     sp_event_context_read(ec, "width");
 236     sp_event_context_read(ec, "thinning");
 237     sp_event_context_read(ec, "tremor");
 238     sp_event_context_read(ec, "flatness");
 239     sp_event_context_read(ec, "tracebackground");
 240     sp_event_context_read(ec, "usepressure");
 241     sp_event_context_read(ec, "usetilt");
 242     sp_event_context_read(ec, "abs_width");
 243     sp_event_context_read(ec, "keep_selected");
 244     sp_event_context_read(ec, "cap_rounding");
 245
 246     ddc->is_drawing = false;
 247
 248     ddc->_message_context = new Inkscape::MessageContext((ec->desktop)->messageStack());
 249
 250     if (prefs_get_int_attribute("tools.calligraphic", "selcue", 0) != 0) {
 251         ec->enableSelectionCue();
 252     }
 253 }
 254
 255 static void
 256 sp_dyna_draw_context_set(SPEventContext *ec, gchar const *key, gchar const *val)
 257 {
 258     SPDynaDrawContext *ddc = SP_DYNA_DRAW_CONTEXT(ec);
 259
 260     if (!strcmp(key, "tracebackground")) {
 261         ddc->trace_bg = (val && strcmp(val, "0"));
 262     } else if (!strcmp(key, "keep_selected")) {
 263         ddc->keep_selected = (val && strcmp(val, "0"));
 264     } else {
 265         //pass on up to parent class to handle common attributes.
 266         if ( dd_parent_class->set ) {
 267             dd_parent_class->set(ec, key, val);
 268         }
 269     }
 270
 271     //g_print("DDC: %g %g %g %g\n", ddc->mass, ddc->drag, ddc->angle, ddc->width);
 272 }
 273
 274 static double
 275 flerp(double f0, double f1, double p)
 276 {
 277     return f0 + ( f1 - f0 ) * p;
 278 }
 279
 280 /* Get normalized point */
 281 static NR::Point
 282 sp_dyna_draw_get_npoint(SPDynaDrawContext const *dc, NR::Point v)
 283 {
 284     NR::Rect drect = SP_EVENT_CONTEXT(dc)->desktop->get_display_area();
 285     double const max = MAX ( drect.dimensions()[NR::X], drect.dimensions()[NR::Y] );
 286     return NR::Point(( v[NR::X] - drect.min()[NR::X] ) / max,  ( v[NR::Y] - drect.min()[NR::Y] ) / max);
 287 }
 288
 289 /* Get view point */
 290 static NR::Point
 291 sp_dyna_draw_get_vpoint(SPDynaDrawContext const *dc, NR::Point n)
 292 {
 293     NR::Rect drect = SP_EVENT_CONTEXT(dc)->desktop->get_display_area();
 294     double const max = MAX ( drect.dimensions()[NR::X], drect.dimensions()[NR::Y] );
 295     return NR::Point(n[NR::X] * max + drect.min()[NR::X], n[NR::Y] * max + drect.min()[NR::Y]);
 296 }
 297
 298 static void
 299 sp_dyna_draw_reset(SPDynaDrawContext *dc, NR::Point p)
 300 {
 301     dc->last = dc->cur = sp_dyna_draw_get_npoint(dc, p);
 302     dc->vel = NR::Point(0,0);
 303     dc->vel_max = 0;
 304     dc->acc = NR::Point(0,0);
 305     dc->ang = NR::Point(0,0);
 306     dc->del = NR::Point(0,0);
 307 }
 308
 309 static void
 310 sp_dyna_draw_extinput(SPDynaDrawContext *dc, GdkEvent *event)
 311 {
 312     if (gdk_event_get_axis (event, GDK_AXIS_PRESSURE, &dc->pressure))
 313         dc->pressure = CLAMP (dc->pressure, DDC_MIN_PRESSURE, DDC_MAX_PRESSURE);
 314     else
 315         dc->pressure = DDC_DEFAULT_PRESSURE;
 316
 317     if (gdk_event_get_axis (event, GDK_AXIS_XTILT, &dc->xtilt))
 318         dc->xtilt = CLAMP (dc->xtilt, DDC_MIN_TILT, DDC_MAX_TILT);
 319     else
 320         dc->xtilt = DDC_DEFAULT_TILT;
 321
 322     if (gdk_event_get_axis (event, GDK_AXIS_YTILT, &dc->ytilt))
 323         dc->ytilt = CLAMP (dc->ytilt, DDC_MIN_TILT, DDC_MAX_TILT);
 324     else
 325         dc->ytilt = DDC_DEFAULT_TILT;
 326 }
 327
 328
 329 static gboolean
 330 sp_dyna_draw_apply(SPDynaDrawContext *dc, NR::Point p)
 331 {
 332     NR::Point n = sp_dyna_draw_get_npoint(dc, p);
 333
 334     /* Calculate mass and drag */
 335     double const mass = flerp(1.0, 160.0, dc->mass);
 336     double const drag = flerp(0.0, 0.5, dc->drag * dc->drag);
 337
 338     /* Calculate force and acceleration */
 339     NR::Point force = n - dc->cur;
 340
 341     // If force is below the absolute threshold DYNA_EPSILON,
 342     // or we haven't yet reached DYNA_VEL_START (i.e. at the beginning of stroke)
 343     // _and_ the force is below the (higher) DYNA_EPSILON_START threshold,
 344     // discard this move.
 345     // This prevents flips, blobs, and jerks caused by microscopic tremor of the tablet pen,
 346     // especially bothersome at the start of the stroke where we don't yet have the inertia to
 347     // smooth them out.
 348     if ( NR::L2(force) < DYNA_EPSILON || (dc->vel_max < DYNA_VEL_START && NR::L2(force) < DYNA_EPSILON_START)) {
 349         return FALSE;
 350     }
 351
 352     dc->acc = force / mass;
 353
 354     /* Calculate new velocity */
 355     dc->vel += dc->acc;
 356
 357     if (NR::L2(dc->vel) > dc->vel_max)
 358         dc->vel_max = NR::L2(dc->vel);
 359
 360     /* Calculate angle of drawing tool */
 361
 362     double a1;
 363     if (dc->usetilt) {
 364         // 1a. calculate nib angle from input device tilt:
 365         gdouble length = std::sqrt(dc->xtilt*dc->xtilt + dc->ytilt*dc->ytilt);;
 366
 367         if (length > 0) {
 368             NR::Point ang1 = NR::Point(dc->ytilt/length, dc->xtilt/length);
 369             a1 = atan2(ang1);
 370         }
 371         else
 372             a1 = 0.0;
 373     }
 374     else {
 375         // 1b. fixed dc->angle (absolutely flat nib):
 376         double const radians = ( (dc->angle - 90) / 180.0 ) * M_PI;
 377         NR::Point ang1 = NR::Point(-sin(radians),  cos(radians));
 378         a1 = atan2(ang1);
 379     }
 380
 381     // 2. perpendicular to dc->vel (absolutely non-flat nib):
 382     gdouble const mag_vel = NR::L2(dc->vel);
 383     if ( mag_vel < DYNA_EPSILON ) {
 384         return FALSE;
 385     }
 386     NR::Point ang2 = NR::rot90(dc->vel) / mag_vel;
 387
 388     // 3. Average them using flatness parameter:
 389     // calculate angles
 390     double a2 = atan2(ang2);
 391     // flip a2 to force it to be in the same half-circle as a1
 392     bool flipped = false;
 393     if (fabs (a2-a1) > 0.5*M_PI) {
 394         a2 += M_PI;
 395         flipped = true;
 396     }
 397     // normalize a2
 398     if (a2 > M_PI)
 399         a2 -= 2*M_PI;
 400     if (a2 < -M_PI)
 401         a2 += 2*M_PI;
 402     // find the flatness-weighted bisector angle, unflip if a2 was flipped
 403     // FIXME: when dc->vel is oscillating around the fixed angle, the new_ang flips back and forth. How to avoid this?
 404     double new_ang = a1 + (1 - dc->flatness) * (a2 - a1) - (flipped? M_PI : 0);
 405
 406     // Try to detect a sudden flip when the new angle differs too much from the previous for the
 407     // current velocity; in that case discard this move
 408     double angle_delta = NR::L2(NR::Point (cos (new_ang), sin (new_ang)) - dc->ang);
 409     if ( angle_delta / NR::L2(dc->vel) > 4000 ) {
 410         return FALSE;
 411     }
 412
 413     // convert to point
 414     dc->ang = NR::Point (cos (new_ang), sin (new_ang));
 415
 416 //    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);
 417
 418     /* Apply drag */
 419     dc->vel *= 1.0 - drag;
 420
 421     /* Update position */
 422     dc->last = dc->cur;
 423     dc->cur += dc->vel;
 424
 425     return TRUE;
 426 }
 427
 428 static void
 429 sp_dyna_draw_brush(SPDynaDrawContext *dc)
 430 {
 431     g_assert( dc->npoints >= 0 && dc->npoints < SAMPLING_SIZE );
 432
 433     // How much velocity thins strokestyle
 434     double vel_thin = flerp (0, 160, dc->vel_thin);
 435
 436     // Influence of pressure on thickness
 437     double pressure_thick = (dc->usepressure ? dc->pressure : 1.0);
 438
 439     // get the real brush point, not the same as pointer (affected by hatch tracking and/or mass
 440     // drag)
 441     NR::Point brush = sp_dyna_draw_get_vpoint(dc, dc->cur);
 442     NR::Point brush_w = SP_EVENT_CONTEXT(dc)->desktop->d2w(brush);
 443
 444     double trace_thick = 1;
 445     if (dc->trace_bg) {
 446         // pick single pixel
 447         NRPixBlock pb;
 448         int x = (int) floor(brush_w[NR::X]);
 449         int y = (int) floor(brush_w[NR::Y]);
 450         nr_pixblock_setup_fast(&pb, NR_PIXBLOCK_MODE_R8G8B8A8P, x, y, x+1, y+1, TRUE);
 451         sp_canvas_arena_render_pixblock(SP_CANVAS_ARENA(sp_desktop_drawing(SP_EVENT_CONTEXT(dc)->desktop)), &pb);
 452         const unsigned char *s = NR_PIXBLOCK_PX(&pb);
 453         double R = s[0] / 255.0;
 454         double G = s[1] / 255.0;
 455         double B = s[2] / 255.0;
 456         double A = s[3] / 255.0;
 457         double max = MAX (MAX (R, G), B);
 458         double min = MIN (MIN (R, G), B);
 459         double L = A * (max + min)/2 + (1 - A); // blend with white bg
 460         trace_thick = 1 - L;
 461         //g_print ("L %g thick %g\n", L, trace_thick);
 462     }
 463
 464     double width = (pressure_thick * trace_thick - vel_thin * NR::L2(dc->vel)) * dc->width;
 465
 466     double tremble_left = 0, tremble_right = 0;
 467     if (dc->tremor > 0) {
 468         // obtain two normally distributed random variables, using polar Box-Muller transform
 469         double x1, x2, w, y1, y2;
 470         do {
 471             x1 = 2.0 * g_random_double_range(0,1) - 1.0;
 472             x2 = 2.0 * g_random_double_range(0,1) - 1.0;
 473             w = x1 * x1 + x2 * x2;
 474         } while ( w >= 1.0 );
 475         w = sqrt( (-2.0 * log( w ) ) / w );
 476         y1 = x1 * w;
 477         y2 = x2 * w;
 478
 479         // deflect both left and right edges randomly and independently, so that:
 480         // (1) dc->tremor=1 corresponds to sigma=1, decreasing dc->tremor narrows the bell curve;
 481         // (2) deflection depends on width, but is upped for small widths for better visual uniformity across widths;
 482         // (3) deflection somewhat depends on speed, to prevent fast strokes looking
 483         // comparatively smooth and slow ones excessively jittery
 484         tremble_left  = (y1)*dc->tremor * (0.15 + 0.8*width) * (0.35 + 14*NR::L2(dc->vel));
 485         tremble_right = (y2)*dc->tremor * (0.15 + 0.8*width) * (0.35 + 14*NR::L2(dc->vel));
 486     }
 487
 488     if ( width < 0.02 * dc->width ) {
 489         width = 0.02 * dc->width;
 490     }
 491
 492     double dezoomify_factor = 0.05 * 1000;
 493     if (!dc->abs_width) {
 494         dezoomify_factor /= SP_EVENT_CONTEXT(dc)->desktop->current_zoom();
 495     }
 496
 497     NR::Point del_left = dezoomify_factor * (width + tremble_left) * dc->ang;
 498     NR::Point del_right = dezoomify_factor * (width + tremble_right) * dc->ang;
 499
 500     dc->point1[dc->npoints] = brush + del_left;
 501     dc->point2[dc->npoints] = brush - del_right;
 502
 503     dc->del = 0.5*(del_left + del_right);
 504
 505     dc->npoints++;
 506 }
 507
 508 void
 509 sp_ddc_update_toolbox (SPDesktop *desktop, const gchar *id, double value)
 510 {
 511     desktop->setToolboxAdjustmentValue (id, value);
 512 }
 513
 514 static void
 515 calligraphic_cancel(SPDynaDrawContext *dc)
 516 {
 517     SPDesktop *desktop = SP_EVENT_CONTEXT(dc)->desktop;
 518     dc->dragging = FALSE;
 519     dc->is_drawing = false;
 520     sp_canvas_item_ungrab(SP_CANVAS_ITEM(desktop->acetate), 0);
 521             /* Remove all temporary line segments */
 522             while (dc->segments) {
 523                 gtk_object_destroy(GTK_OBJECT(dc->segments->data));
 524                 dc->segments = g_slist_remove(dc->segments, dc->segments->data);
 525             }
 526             /* reset accumulated curve */
 527             dc->accumulated->reset();
 528             clear_current(dc);
 529             if (dc->repr) {
 530                 dc->repr = NULL;
 531             }
 532 }
 533
 534
 535 gint
 536 sp_dyna_draw_context_root_handler(SPEventContext *event_context,
 537                                   GdkEvent *event)
 538 {
 539     SPDynaDrawContext *dc = SP_DYNA_DRAW_CONTEXT(event_context);
 540     SPDesktop *desktop = event_context->desktop;
 541
 542     gint ret = FALSE;
 543
 544     switch (event->type) {
 545         case GDK_BUTTON_PRESS:
 546             if (event->button.button == 1 && !event_context->space_panning) {
 547
 548                 SPDesktop *desktop = SP_EVENT_CONTEXT_DESKTOP(dc);
 549
 550                 if (Inkscape::have_viable_layer(desktop, dc->_message_context) == false) {
 551                     return TRUE;
 552                 }
 553
 554                 NR::Point const button_w(event->button.x,
 555                                          event->button.y);
 556                 NR::Point const button_dt(desktop->w2d(button_w));
 557                 sp_dyna_draw_reset(dc, button_dt);
 558                 sp_dyna_draw_extinput(dc, event);
 559                 sp_dyna_draw_apply(dc, button_dt);
 560                 dc->accumulated->reset();
 561                 if (dc->repr) {
 562                     dc->repr = NULL;
 563                 }
 564
 565                 /* initialize first point */
 566                 dc->npoints = 0;
 567
 568                 sp_canvas_item_grab(SP_CANVAS_ITEM(desktop->acetate),
 569                                     ( GDK_KEY_PRESS_MASK |
 570                                       GDK_BUTTON_RELEASE_MASK |
 571                                       GDK_POINTER_MOTION_MASK |
 572                                       GDK_BUTTON_PRESS_MASK ),
 573                                     NULL,
 574                                     event->button.time);
 575
 576                 ret = TRUE;
 577
 578                 sp_canvas_force_full_redraw_after_interruptions(desktop->canvas, 3);
 579                 dc->is_drawing = true;
 580             }
 581             break;
 582         case GDK_MOTION_NOTIFY:
 583         {
 584             NR::Point const motion_w(event->motion.x,
 585                                      event->motion.y);
 586             NR::Point motion_dt(desktop->w2d(motion_w));
 587             sp_dyna_draw_extinput(dc, event);
 588
 589             dc->_message_context->clear();
 590
 591             // for hatching:
 592             double hatch_dist = 0;
 593             NR::Point hatch_unit_vector(0,0);
 594             NR::Point nearest(0,0);
 595             NR::Point pointer(0,0);
 596             NR::Matrix motion_to_curve(NR::identity());
 597
 598             if (event->motion.state & GDK_CONTROL_MASK) { // hatching - sense the item
 599
 600                 SPItem *selected = sp_desktop_selection(desktop)->singleItem();
 601                 if (selected && (SP_IS_SHAPE(selected) || SP_IS_TEXT(selected))) {
 602                     // One item selected, and it's a path;
 603                     // let's try to track it as a guide
 604
 605                     if (selected != dc->hatch_item) {
 606                         dc->hatch_item = selected;
 607                         if (dc->hatch_livarot_path)
 608                             delete dc->hatch_livarot_path;
 609                         dc->hatch_livarot_path = Path_for_item (dc->hatch_item, true, true);
 610                         dc->hatch_livarot_path->ConvertWithBackData(0.01);
 611                     }
 612
 613                     // calculate pointer point in the guide item's coords
 614                     motion_to_curve = from_2geom(sp_item_dt2i_affine(selected) * sp_item_i2doc_affine(selected));
 615                     pointer = motion_dt * motion_to_curve;
 616
 617                     // calculate the nearest point on the guide path
 618                     NR::Maybe<Path::cut_position> position = get_nearest_position_on_Path(dc->hatch_livarot_path, pointer);
 619                     nearest = get_point_on_Path(dc->hatch_livarot_path, position->piece, position->t);
 620
 621
 622                     // distance from pointer to nearest
 623                     hatch_dist = NR::L2(pointer - nearest);
 624                     // unit-length vector
 625                     hatch_unit_vector = (pointer - nearest)/hatch_dist;
 626
 627                     dc->_message_context->set(Inkscape::NORMAL_MESSAGE, _("<b>Guide path selected</b>; start drawing along the guide with <b>Ctrl</b>"));
 628                 } else {
 629                     dc->_message_context->set(Inkscape::NORMAL_MESSAGE, _("<b>Select a guide path</b> to track with <b>Ctrl</b>"));
 630                 }
 631             }
 632
 633             if ( dc->is_drawing && (event->motion.state & GDK_BUTTON1_MASK) && !event_context->space_panning) {
 634                 dc->dragging = TRUE;
 635
 636                 if (event->motion.state & GDK_CONTROL_MASK && dc->hatch_item) { // hatching
 637
 638 #define SPEED_ELEMENTS 12
 639 #define SPEED_MIN 0.12
 640 #define SPEED_NORMAL 0.65
 641
 642                     // speed is the movement of the nearest point along the guide path, divided by
 643                     // the movement of the pointer at the same period; it is averaged for the last
 644                     // SPEED_ELEMENTS motion events.  Normally, as you track the guide path, speed
 645                     // is about 1, i.e. the nearest point on the path is moved by about the same
 646                     // distance as the pointer. If the speed starts to decrease, we are losing
 647                     // contact with the guide; if it drops below SPEED_MIN, we are on our own and
 648                     // not attracted to guide anymore. Most often this happens when you have
 649                     // tracked to the end of a guide calligraphic stroke and keep moving
 650                     // further. We try to handle this situation gracefully: not stick with the
 651                     // guide forever but let go of it smoothly and without sharp jerks (non-zero
 652                     // mass recommended; with zero mass, jerks are still quite noticeable).
 653
 654                     double speed = 1;
 655                     if (NR::L2(dc->hatch_last_nearest) != 0) {
 656                         // the distance nearest moved since the last motion event
 657                         double nearest_moved = NR::L2(nearest - dc->hatch_last_nearest);
 658                         // the distance pointer moved since the last motion event
 659                         double pointer_moved = NR::L2(pointer - dc->hatch_last_pointer);
 660                         // store them in stacks limited to SPEED_ELEMENTS
 661                         dc->hatch_nearest_past.push_front(nearest_moved);
 662                         if (dc->hatch_nearest_past.size() > SPEED_ELEMENTS)
 663                             dc->hatch_nearest_past.pop_back();
 664                         dc->hatch_pointer_past.push_front(pointer_moved);
 665                         if (dc->hatch_pointer_past.size() > SPEED_ELEMENTS)
 666                             dc->hatch_pointer_past.pop_back();
 667
 668                         // If the stacks are full,
 669                         if (dc->hatch_nearest_past.size() == SPEED_ELEMENTS) {
 670                             // calculate the sums of all stored movements
 671                             double nearest_sum = std::accumulate (dc->hatch_nearest_past.begin(), dc->hatch_nearest_past.end(), 0.0);
 672                             double pointer_sum = std::accumulate (dc->hatch_pointer_past.begin(), dc->hatch_pointer_past.end(), 0.0);
 673                             // and divide to get the speed
 674                             speed = nearest_sum/pointer_sum;
 675                             //g_print ("nearest sum %g  pointer_sum %g  speed %g\n", nearest_sum, pointer_sum, speed);
 676                         }
 677                     }
 678
 679                     if (   dc->hatch_escaped  // already escaped, do not reattach
 680                         || (speed < SPEED_MIN) // stuck; most likely reached end of traced stroke
 681                         || (dc->hatch_spacing > 0 && hatch_dist > 50 * dc->hatch_spacing) // went too far from the guide
 682                         ) {
 683                         // We are NOT attracted to the guide!
 684
 685                         //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);
 686
 687                         // Remember hatch_escaped so we don't get
 688                         // attracted again until the end of this stroke
 689                         dc->hatch_escaped = true;
 690
 691                     } else {
 692
 693                         // Calculate angle cosine of this vector-to-guide and all past vectors
 694                         // summed, to detect if we accidentally flipped to the other side of the
 695                         // guide
 696                         double dot = NR::dot (pointer - nearest, dc->hatch_vector_accumulated);
 697                         dot /= NR::L2(pointer - nearest) * NR::L2(dc->hatch_vector_accumulated);
 698
 699                         if (dc->hatch_spacing != 0) { // spacing was already set
 700                             double target;
 701                             if (speed > SPEED_NORMAL) {
 702                                 // all ok, strictly obey the spacing
 703                                 target = dc->hatch_spacing;
 704                             } else {
 705                                 // looks like we're starting to lose speed,
 706                                 // so _gradually_ let go attraction to prevent jerks
 707                                 target = (dc->hatch_spacing * speed + hatch_dist * (SPEED_NORMAL - speed))/SPEED_NORMAL;
 708                             }
 709                             if (!IS_NAN(dot) && dot < -0.5) {// flip
 710                                 target = -target;
 711                             }
 712
 713                             // This is the track pointer that we will use instead of the real one
 714                             NR::Point new_pointer = nearest + target * hatch_unit_vector;
 715
 716                             // some limited feedback: allow persistent pulling to slightly change
 717                             // the spacing
 718                             dc->hatch_spacing += (hatch_dist - dc->hatch_spacing)/3500;
 719
 720                             // return it to the desktop coords
 721                             motion_dt = new_pointer * motion_to_curve.inverse();
 722
 723                         } else {
 724                             // this is the first motion event, set the dist
 725                             dc->hatch_spacing = hatch_dist;
 726                         }
 727
 728                         // remember last points
 729                         dc->hatch_last_pointer = pointer;
 730                         dc->hatch_last_nearest = nearest;
 731                         dc->hatch_vector_accumulated += (pointer - nearest);
 732                     }
 733
 734                     dc->_message_context->set(Inkscape::NORMAL_MESSAGE, dc->hatch_escaped? _("Tracking: <b>connection to guide path lost!</b>") : _("<b>Tracking</b> a guide path"));
 735
 736                 } else {
 737                     dc->_message_context->set(Inkscape::NORMAL_MESSAGE, _("<b>Drawing</b> a calligraphic stroke"));
 738                 }
 739
 740                 if (!sp_dyna_draw_apply(dc, motion_dt)) {
 741                     ret = TRUE;
 742                     break;
 743                 }
 744
 745                 if ( dc->cur != dc->last ) {
 746                     sp_dyna_draw_brush(dc);
 747                     g_assert( dc->npoints > 0 );
 748                     fit_and_split(dc, FALSE);
 749                 }
 750                 ret = TRUE;
 751             }
 752
 753             // Draw the hatching circle if necessary
 754             if (event->motion.state & GDK_CONTROL_MASK) {
 755                 if (dc->hatch_spacing == 0 && hatch_dist != 0) {
 756                     // Haven't set spacing yet: gray, center free, update radius live
 757                     NR::Point c = desktop->w2d(motion_w);
 758                     NR::Matrix const sm (NR::scale(hatch_dist, hatch_dist) * NR::translate(c));
 759                     sp_canvas_item_affine_absolute(dc->hatch_area, sm);
 760                     sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(dc->hatch_area), 0x7f7f7fff, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 761                     sp_canvas_item_show(dc->hatch_area);
 762                 } else if (dc->dragging && !dc->hatch_escaped) {
 763                     // Tracking: green, center snapped, fixed radius
 764                     NR::Point c = motion_dt;
 765                     NR::Matrix const sm (NR::scale(dc->hatch_spacing, dc->hatch_spacing) * NR::translate(c));
 766                     sp_canvas_item_affine_absolute(dc->hatch_area, sm);
 767                     sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(dc->hatch_area), 0x00FF00ff, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 768                     sp_canvas_item_show(dc->hatch_area);
 769                 } else if (dc->dragging && dc->hatch_escaped) {
 770                     // Tracking escaped: red, center free, fixed radius
 771                     NR::Point c = desktop->w2d(motion_w);
 772                     NR::Matrix const sm (NR::scale(dc->hatch_spacing, dc->hatch_spacing) * NR::translate(c));
 773
 774                     sp_canvas_item_affine_absolute(dc->hatch_area, sm);
 775                     sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(dc->hatch_area), 0xFF0000ff, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 776                     sp_canvas_item_show(dc->hatch_area);
 777                 } else {
 778                     // Not drawing but spacing set: gray, center snapped, fixed radius
 779                     NR::Point c = (nearest + dc->hatch_spacing * hatch_unit_vector) * motion_to_curve.inverse();
 780                     if (!IS_NAN(c[NR::X]) && !IS_NAN(c[NR::Y])) {
 781                         NR::Matrix const sm (NR::scale(dc->hatch_spacing, dc->hatch_spacing) * NR::translate(c));
 782                         sp_canvas_item_affine_absolute(dc->hatch_area, sm);
 783                         sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(dc->hatch_area), 0x7f7f7fff, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 784                         sp_canvas_item_show(dc->hatch_area);
 785                     }
 786                 }
 787             } else {
 788                 sp_canvas_item_hide(dc->hatch_area);
 789             }
 790         }
 791         break;
 792
 793
 794     case GDK_BUTTON_RELEASE:
 795     {
 796         NR::Point const motion_w(event->button.x, event->button.y);
 797         NR::Point const motion_dt(desktop->w2d(motion_w));
 798
 799         sp_canvas_item_ungrab(SP_CANVAS_ITEM(desktop->acetate), event->button.time);
 800         sp_canvas_end_forced_full_redraws(desktop->canvas);
 801         dc->is_drawing = false;
 802
 803         if (dc->dragging && event->button.button == 1 && !event_context->space_panning) {
 804             dc->dragging = FALSE;
 805
 806             sp_dyna_draw_apply(dc, motion_dt);
 807
 808             /* Remove all temporary line segments */
 809             while (dc->segments) {
 810                 gtk_object_destroy(GTK_OBJECT(dc->segments->data));
 811                 dc->segments = g_slist_remove(dc->segments, dc->segments->data);
 812             }
 813
 814             /* Create object */
 815             fit_and_split(dc, TRUE);
 816             accumulate_calligraphic(dc);
 817             set_to_accumulated(dc, event->button.state & GDK_SHIFT_MASK); // performs document_done
 818
 819             /* reset accumulated curve */
 820             dc->accumulated->reset();
 821
 822             clear_current(dc);
 823             if (dc->repr) {
 824                 dc->repr = NULL;
 825             }
 826
 827             if (!dc->hatch_pointer_past.empty()) dc->hatch_pointer_past.clear();
 828             if (!dc->hatch_nearest_past.empty()) dc->hatch_nearest_past.clear();
 829             dc->hatch_last_nearest = NR::Point(0,0);
 830             dc->hatch_last_pointer = NR::Point(0,0);
 831             dc->hatch_vector_accumulated = NR::Point(0,0);
 832             dc->hatch_escaped = false;
 833             dc->hatch_item = NULL;
 834             dc->hatch_livarot_path = NULL;
 835
 836             if (dc->hatch_spacing != 0 && !dc->keep_selected) {
 837                 // we do not select the newly drawn path, so increase spacing by step
 838                 if (dc->hatch_spacing_step == 0) {
 839                     dc->hatch_spacing_step = dc->hatch_spacing;
 840                 }
 841                 dc->hatch_spacing += dc->hatch_spacing_step;
 842             }
 843
 844             dc->_message_context->clear();
 845             ret = TRUE;
 846         }
 847         break;
 848     }
 849
 850     case GDK_KEY_PRESS:
 851         switch (get_group0_keyval (&event->key)) {
 852         case GDK_Up:
 853         case GDK_KP_Up:
 854             if (!MOD__CTRL_ONLY) {
 855                 dc->angle += 5.0;
 856                 if (dc->angle > 90.0)
 857                     dc->angle = 90.0;
 858                 sp_ddc_update_toolbox (desktop, "calligraphy-angle", dc->angle);
 859                 ret = TRUE;
 860             }
 861             break;
 862         case GDK_Down:
 863         case GDK_KP_Down:
 864             if (!MOD__CTRL_ONLY) {
 865                 dc->angle -= 5.0;
 866                 if (dc->angle < -90.0)
 867                     dc->angle = -90.0;
 868                 sp_ddc_update_toolbox (desktop, "calligraphy-angle", dc->angle);
 869                 ret = TRUE;
 870             }
 871             break;
 872         case GDK_Right:
 873         case GDK_KP_Right:
 874             if (!MOD__CTRL_ONLY) {
 875                 dc->width += 0.01;
 876                 if (dc->width > 1.0)
 877                     dc->width = 1.0;
 878                 sp_ddc_update_toolbox (desktop, "altx-calligraphy", dc->width * 100); // the same spinbutton is for alt+x
 879                 ret = TRUE;
 880             }
 881             break;
 882         case GDK_Left:
 883         case GDK_KP_Left:
 884             if (!MOD__CTRL_ONLY) {
 885                 dc->width -= 0.01;
 886                 if (dc->width < 0.01)
 887                     dc->width = 0.01;
 888                 sp_ddc_update_toolbox (desktop, "altx-calligraphy", dc->width * 100);
 889                 ret = TRUE;
 890             }
 891             break;
 892         case GDK_Home:
 893         case GDK_KP_Home:
 894             dc->width = 0.01;
 895             sp_ddc_update_toolbox (desktop, "altx-calligraphy", dc->width * 100);
 896             ret = TRUE;
 897             break;
 898         case GDK_End:
 899         case GDK_KP_End:
 900             dc->width = 1.0;
 901             sp_ddc_update_toolbox (desktop, "altx-calligraphy", dc->width * 100);
 902             ret = TRUE;
 903             break;
 904         case GDK_x:
 905         case GDK_X:
 906             if (MOD__ALT_ONLY) {
 907                 desktop->setToolboxFocusTo ("altx-calligraphy");
 908                 ret = TRUE;
 909             }
 910             break;
 911         case GDK_Escape:
 912             if (dc->is_drawing) {
 913                 // if drawing, cancel, otherwise pass it up for deselecting
 914                 calligraphic_cancel (dc);
 915                 ret = TRUE;
 916             }
 917             break;
 918         case GDK_z:
 919         case GDK_Z:
 920             if (MOD__CTRL_ONLY && dc->is_drawing) {
 921                 // if drawing, cancel, otherwise pass it up for undo
 922                 calligraphic_cancel (dc);
 923                 ret = TRUE;
 924             }
 925             break;
 926         default:
 927             break;
 928         }
 929         break;
 930
 931     case GDK_KEY_RELEASE:
 932         switch (get_group0_keyval(&event->key)) {
 933             case GDK_Control_L:
 934             case GDK_Control_R:
 935                 dc->_message_context->clear();
 936                 dc->hatch_spacing = 0;
 937                 dc->hatch_spacing_step = 0;
 938                 break;
 939             default:
 940                 break;
 941         }
 942
 943     default:
 944         break;
 945     }
 946
 947     if (!ret) {
 948         if (((SPEventContextClass *) dd_parent_class)->root_handler) {
 949             ret = ((SPEventContextClass *) dd_parent_class)->root_handler(event_context, event);
 950         }
 951     }
 952
 953     return ret;
 954 }
 955
 956
 957 static void
 958 clear_current(SPDynaDrawContext *dc)
 959 {
 960     /* reset bpath */
 961     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(dc->currentshape), NULL);
 962     /* reset curve */
 963     dc->currentcurve->reset();
 964     dc->cal1->reset();
 965     dc->cal2->reset();
 966     /* reset points */
 967     dc->npoints = 0;
 968 }
 969
 970 static void
 971 set_to_accumulated(SPDynaDrawContext *dc, bool unionize)
 972 {
 973     SPDesktop *desktop = SP_EVENT_CONTEXT(dc)->desktop;
 974
 975     if (!dc->accumulated->is_empty()) {
 976         if (!dc->repr) {
 977             /* Create object */
 978             Inkscape::XML::Document *xml_doc = sp_document_repr_doc(desktop->doc());
 979             Inkscape::XML::Node *repr = xml_doc->createElement("svg:path");
 980
 981             /* Set style */
 982             sp_desktop_apply_style_tool (desktop, repr, "tools.calligraphic", false);
 983
 984             dc->repr = repr;
 985
 986             SPItem *item=SP_ITEM(desktop->currentLayer()->appendChildRepr(dc->repr));
 987             Inkscape::GC::release(dc->repr);
 988             item->transform = SP_ITEM(desktop->currentRoot())->getRelativeTransform(desktop->currentLayer());
 989             item->updateRepr();
 990         }
 991         Geom::PathVector pathv = dc->accumulated->get_pathvector() * to_2geom(sp_desktop_dt2root_affine(desktop));
 992         gchar *str = sp_svg_write_path(pathv);
 993         g_assert( str != NULL );
 994         dc->repr->setAttribute("d", str);
 995         g_free(str);
 996
 997         if (unionize) {
 998             sp_desktop_selection(desktop)->add(dc->repr);
 999             sp_selected_path_union_skip_undo();
1000         } else {
1001             if (dc->keep_selected) {
1002                 sp_desktop_selection(desktop)->set(dc->repr);
1003             }
1004         }
1005
1006     } else {
1007         if (dc->repr) {
1008             sp_repr_unparent(dc->repr);
1009         }
1010         dc->repr = NULL;
1011     }
1012
1013     sp_document_done(sp_desktop_document(desktop), SP_VERB_CONTEXT_CALLIGRAPHIC,
1014                      _("Draw calligraphic stroke"));
1015 }
1016
1017 static void
1018 add_cap(SPCurve *curve,
1019         NR::Point const &from,
1020         NR::Point const &to,
1021         double rounding)
1022 {
1023     if (NR::L2( to - from ) > DYNA_EPSILON) {
1024         NR::Point vel = rounding * NR::rot90( to - from ) / sqrt(2.0);
1025         double mag = NR::L2(vel);
1026
1027         NR::Point v = mag * NR::rot90( to - from ) / NR::L2( to - from );
1028         curve->curveto(from + v, to + v, to);
1029     }
1030 }
1031
1032 static void
1033 accumulate_calligraphic(SPDynaDrawContext *dc)
1034 {
1035     if ( !dc->cal1->is_empty() && !dc->cal2->is_empty() ) {
1036         dc->accumulated->reset(); /*  Is this required ?? */
1037         SPCurve *rev_cal2 = dc->cal2->create_reverse();
1038
1039         g_assert(dc->cal1->get_segment_count() > 0);
1040         g_assert(rev_cal2->get_segment_count() > 0);
1041         g_assert( ! dc->cal1->first_path()->closed() );
1042         g_assert( ! rev_cal2->first_path()->closed() );
1043
1044         Geom::CubicBezier const * dc_cal1_firstseg  = dynamic_cast<Geom::CubicBezier const *>( dc->cal1->first_segment() );
1045         Geom::CubicBezier const * rev_cal2_firstseg = dynamic_cast<Geom::CubicBezier const *>( rev_cal2->first_segment() );
1046         Geom::CubicBezier const * dc_cal1_lastseg   = dynamic_cast<Geom::CubicBezier const *>( dc->cal1->last_segment() );
1047         Geom::CubicBezier const * rev_cal2_lastseg  = dynamic_cast<Geom::CubicBezier const *>( rev_cal2->last_segment() );
1048         g_assert( dc_cal1_firstseg );
1049         g_assert( rev_cal2_firstseg );
1050         g_assert( dc_cal1_lastseg );
1051         g_assert( rev_cal2_lastseg );
1052
1053         dc->accumulated->append(dc->cal1, false);
1054
1055         add_cap(dc->accumulated, (*dc_cal1_lastseg)[3], (*rev_cal2_firstseg)[3], dc->cap_rounding);
1056
1057         dc->accumulated->append(rev_cal2, true);
1058
1059         add_cap(dc->accumulated, (*rev_cal2_lastseg)[3], (*dc_cal1_firstseg)[3], dc->cap_rounding);
1060
1061         dc->accumulated->closepath();
1062
1063         rev_cal2->unref();
1064
1065         dc->cal1->reset();
1066         dc->cal2->reset();
1067     }
1068 }
1069
1070 static double square(double const x)
1071 {
1072     return x * x;
1073 }
1074
1075 static void
1076 fit_and_split(SPDynaDrawContext *dc, gboolean release)
1077 {
1078     double const tolerance_sq = square( NR::expansion(SP_EVENT_CONTEXT(dc)->desktop->w2d()) * TOLERANCE_CALLIGRAPHIC );
1079
1080 #ifdef DYNA_DRAW_VERBOSE
1081     g_print("[F&S:R=%c]", release?'T':'F');
1082 #endif
1083
1084     if (!( dc->npoints > 0 && dc->npoints < SAMPLING_SIZE ))
1085         return; // just clicked
1086
1087     if ( dc->npoints == SAMPLING_SIZE - 1 || release ) {
1088 #define BEZIER_SIZE       4
1089 #define BEZIER_MAX_BEZIERS  8
1090 #define BEZIER_MAX_LENGTH ( BEZIER_SIZE * BEZIER_MAX_BEZIERS )
1091
1092 #ifdef DYNA_DRAW_VERBOSE
1093         g_print("[F&S:#] dc->npoints:%d, release:%s\n",
1094                 dc->npoints, release ? "TRUE" : "FALSE");
1095 #endif
1096
1097         /* Current calligraphic */
1098         if ( dc->cal1->get_length() == 0 || dc->cal2->get_length() == 0 ) {
1099             /* dc->npoints > 0 */
1100             /* g_print("calligraphics(1|2) reset\n"); */
1101             dc->cal1->reset();
1102             dc->cal2->reset();
1103
1104             dc->cal1->moveto(dc->point1[0]);
1105             dc->cal2->moveto(dc->point2[0]);
1106         }
1107
1108         NR::Point b1[BEZIER_MAX_LENGTH];
1109         gint const nb1 = sp_bezier_fit_cubic_r(b1, dc->point1, dc->npoints,
1110                                                tolerance_sq, BEZIER_MAX_BEZIERS);
1111         g_assert( nb1 * BEZIER_SIZE <= gint(G_N_ELEMENTS(b1)) );
1112
1113         NR::Point b2[BEZIER_MAX_LENGTH];
1114         gint const nb2 = sp_bezier_fit_cubic_r(b2, dc->point2, dc->npoints,
1115                                                tolerance_sq, BEZIER_MAX_BEZIERS);
1116         g_assert( nb2 * BEZIER_SIZE <= gint(G_N_ELEMENTS(b2)) );
1117
1118         if ( nb1 != -1 && nb2 != -1 ) {
1119             /* Fit and draw and reset state */
1120 #ifdef DYNA_DRAW_VERBOSE
1121             g_print("nb1:%d nb2:%d\n", nb1, nb2);
1122 #endif
1123             /* CanvasShape */
1124             if (! release) {
1125                 dc->currentcurve->reset();
1126                 dc->currentcurve->moveto(b1[0]);
1127                 for (NR::Point *bp1 = b1; bp1 < b1 + BEZIER_SIZE * nb1; bp1 += BEZIER_SIZE) {
1128                     dc->currentcurve->curveto(bp1[1],
1129                                      bp1[2], bp1[3]);
1130                 }
1131                 dc->currentcurve->lineto(b2[BEZIER_SIZE*(nb2-1) + 3]);
1132                 for (NR::Point *bp2 = b2 + BEZIER_SIZE * ( nb2 - 1 ); bp2 >= b2; bp2 -= BEZIER_SIZE) {
1133                     dc->currentcurve->curveto(bp2[2], bp2[1], bp2[0]);
1134                 }
1135                 // FIXME: dc->segments is always NULL at this point??
1136                 if (!dc->segments) { // first segment
1137                     add_cap(dc->currentcurve, b2[0], b1[0], dc->cap_rounding);
1138                 }
1139                 dc->currentcurve->closepath();
1140                 sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(dc->currentshape), dc->currentcurve);
1141             }
1142
1143             /* Current calligraphic */
1144             for (NR::Point *bp1 = b1; bp1 < b1 + BEZIER_SIZE * nb1; bp1 += BEZIER_SIZE) {
1145                 dc->cal1->curveto(bp1[1], bp1[2], bp1[3]);
1146             }
1147             for (NR::Point *bp2 = b2; bp2 < b2 + BEZIER_SIZE * nb2; bp2 += BEZIER_SIZE) {
1148                 dc->cal2->curveto(bp2[1], bp2[2], bp2[3]);
1149             }
1150         } else {
1151             /* fixme: ??? */
1152 #ifdef DYNA_DRAW_VERBOSE
1153             g_print("[fit_and_split] failed to fit-cubic.\n");
1154 #endif
1155             draw_temporary_box(dc);
1156
1157             for (gint i = 1; i < dc->npoints; i++) {
1158                 dc->cal1->lineto(dc->point1[i]);
1159             }
1160             for (gint i = 1; i < dc->npoints; i++) {
1161                 dc->cal2->lineto(dc->point2[i]);
1162             }
1163         }
1164
1165         /* Fit and draw and copy last point */
1166 #ifdef DYNA_DRAW_VERBOSE
1167         g_print("[%d]Yup\n", dc->npoints);
1168 #endif
1169         if (!release) {
1170             g_assert(!dc->currentcurve->is_empty());
1171
1172             SPCanvasItem *cbp = sp_canvas_item_new(sp_desktop_sketch(SP_EVENT_CONTEXT(dc)->desktop),
1173                                                    SP_TYPE_CANVAS_BPATH,
1174                                                    NULL);
1175             SPCurve *curve = dc->currentcurve->copy();
1176             sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH (cbp), curve);
1177             curve->unref();
1178
1179             guint32 fillColor = sp_desktop_get_color_tool (SP_ACTIVE_DESKTOP, "tools.calligraphic", true);
1180             //guint32 strokeColor = sp_desktop_get_color_tool (SP_ACTIVE_DESKTOP, "tools.calligraphic", false);
1181             double opacity = sp_desktop_get_master_opacity_tool (SP_ACTIVE_DESKTOP, "tools.calligraphic");
1182             double fillOpacity = sp_desktop_get_opacity_tool (SP_ACTIVE_DESKTOP, "tools.calligraphic", true);
1183             //double strokeOpacity = sp_desktop_get_opacity_tool (SP_ACTIVE_DESKTOP, "tools.calligraphic", false);
1184             sp_canvas_bpath_set_fill(SP_CANVAS_BPATH(cbp), ((fillColor & 0xffffff00) | SP_COLOR_F_TO_U(opacity*fillOpacity)), SP_WIND_RULE_EVENODD);
1185             //on second thougtht don't do stroke yet because we don't have stoke-width yet and because stoke appears between segments while drawing
1186             //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);
1187             sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(cbp), 0x00000000, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
1188             /* fixme: Cannot we cascade it to root more clearly? */
1189             g_signal_connect(G_OBJECT(cbp), "event", G_CALLBACK(sp_desktop_root_handler), SP_EVENT_CONTEXT(dc)->desktop);
1190
1191             dc->segments = g_slist_prepend(dc->segments, cbp);
1192         }
1193
1194         dc->point1[0] = dc->point1[dc->npoints - 1];
1195         dc->point2[0] = dc->point2[dc->npoints - 1];
1196         dc->npoints = 1;
1197     } else {
1198         draw_temporary_box(dc);
1199     }
1200 }
1201
1202 static void
1203 draw_temporary_box(SPDynaDrawContext *dc)
1204 {
1205     dc->currentcurve->reset();
1206
1207     dc->currentcurve->moveto(dc->point2[dc->npoints-1]);
1208     for (gint i = dc->npoints-2; i >= 0; i--) {
1209         dc->currentcurve->lineto(dc->point2[i]);
1210     }
1211     for (gint i = 0; i < dc->npoints; i++) {
1212         dc->currentcurve->lineto(dc->point1[i]);
1213     }
1214
1215     if (dc->npoints >= 2) {
1216         add_cap(dc->currentcurve, dc->point1[dc->npoints-1], dc->point2[dc->npoints-1], dc->cap_rounding);
1217     }
1218
1219     dc->currentcurve->closepath();
1220     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(dc->currentshape), dc->currentcurve);
1221 }
1222
1223 /*
1224   Local Variables:
1225   mode:c++
1226   c-file-style:"stroustrup"
1227   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
1228   indent-tabs-mode:nil
1229   fill-column:99
1230   End:
1231 */
1232 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :