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  *
  11  * The original dynadraw code:
  12  *   Paul Haeberli <paul@sgi.com>
  13  *
  14  * Copyright (C) 1998 The Free Software Foundation
  15  * Copyright (C) 1999-2005 authors
  16  * Copyright (C) 2001-2002 Ximian, Inc.
  17  *
  18  * Released under GNU GPL, read the file 'COPYING' for more information
  19  */
  20
  21 #define noDYNA_DRAW_VERBOSE
  22
  23 #include "config.h"
  24
  25 #include <gtk/gtk.h>
  26 #include <gdk/gdkkeysyms.h>
  27
  28 #include "svg/svg.h"
  29 #include "display/canvas-bpath.h"
  30 #include "display/bezier-utils.h"
  31
  32 #include "macros.h"
  33 #include "document.h"
  34 #include "selection.h"
  35 #include "desktop.h"
  36 #include "desktop-events.h"
  37 #include "desktop-handles.h"
  38 #include "desktop-affine.h"
  39 #include "desktop-style.h"
  40 #include "message-context.h"
  41 #include "pixmaps/cursor-calligraphy.xpm"
  42 #include "dyna-draw-context.h"
  43 #include "libnr/n-art-bpath.h"
  44 #include "libnr/nr-path.h"
  45 #include "xml/repr.h"
  46 #include "context-fns.h"
  47 #include "sp-item.h"
  48
  49 #define DDC_RED_RGBA 0xff0000ff
  50
  51 #define SAMPLE_TIMEOUT 10
  52 #define TOLERANCE_LINE 1.0
  53 #define TOLERANCE_CALLIGRAPHIC 3.0
  54 #define DYNA_EPSILON 1.0e-6
  55
  56 #define DYNA_MIN_WIDTH 1.0e-6
  57
  58 #define DRAG_MIN 0.0
  59 #define DRAG_DEFAULT 1.0
  60 #define DRAG_MAX 1.0
  61
  62 static void sp_dyna_draw_context_class_init(SPDynaDrawContextClass *klass);
  63 static void sp_dyna_draw_context_init(SPDynaDrawContext *ddc);
  64 static void sp_dyna_draw_context_dispose(GObject *object);
  65
  66 static void sp_dyna_draw_context_setup(SPEventContext *ec);
  67 static void sp_dyna_draw_context_set(SPEventContext *ec, gchar const *key, gchar const *val);
  68 static gint sp_dyna_draw_context_root_handler(SPEventContext *ec, GdkEvent *event);
  69
  70 static void clear_current(SPDynaDrawContext *dc);
  71 static void set_to_accumulated(SPDynaDrawContext *dc);
  72 static void accumulate_calligraphic(SPDynaDrawContext *dc);
  73
  74 static void fit_and_split(SPDynaDrawContext *ddc, gboolean release);
  75 static void fit_and_split_calligraphics(SPDynaDrawContext *ddc, gboolean release);
  76
  77 static void sp_dyna_draw_reset(SPDynaDrawContext *ddc, NR::Point p);
  78 static NR::Point sp_dyna_draw_get_npoint(SPDynaDrawContext const *ddc, NR::Point v);
  79 static NR::Point sp_dyna_draw_get_vpoint(SPDynaDrawContext const *ddc, NR::Point n);
  80 static void draw_temporary_box(SPDynaDrawContext *dc);
  81
  82
  83 static SPEventContextClass *parent_class;
  84
  85 GtkType
  86 sp_dyna_draw_context_get_type(void)
  87 {
  88     static GType type = 0;
  89     if (!type) {
  90         GTypeInfo info = {
  91             sizeof(SPDynaDrawContextClass),
  92             NULL, NULL,
  93             (GClassInitFunc) sp_dyna_draw_context_class_init,
  94             NULL, NULL,
  95             sizeof(SPDynaDrawContext),
  96             4,
  97             (GInstanceInitFunc) sp_dyna_draw_context_init,
  98             NULL,   /* value_table */
  99         };
 100         type = g_type_register_static(SP_TYPE_EVENT_CONTEXT, "SPDynaDrawContext", &info, (GTypeFlags)0);
 101     }
 102     return type;
 103 }
 104
 105 static void
 106 sp_dyna_draw_context_class_init(SPDynaDrawContextClass *klass)
 107 {
 108     GObjectClass *object_class = (GObjectClass *) klass;
 109     SPEventContextClass *event_context_class = (SPEventContextClass *) klass;
 110
 111     parent_class = (SPEventContextClass*)g_type_class_peek_parent(klass);
 112
 113     object_class->dispose = sp_dyna_draw_context_dispose;
 114
 115     event_context_class->setup = sp_dyna_draw_context_setup;
 116     event_context_class->set = sp_dyna_draw_context_set;
 117     event_context_class->root_handler = sp_dyna_draw_context_root_handler;
 118 }
 119
 120 static void
 121 sp_dyna_draw_context_init(SPDynaDrawContext *ddc)
 122 {
 123     SPEventContext *event_context = SP_EVENT_CONTEXT(ddc);
 124
 125     event_context->cursor_shape = cursor_calligraphy_xpm;
 126     event_context->hot_x = 4;
 127     event_context->hot_y = 4;
 128
 129     ddc->accumulated = NULL;
 130     ddc->segments = NULL;
 131     ddc->currentcurve = NULL;
 132     ddc->currentshape = NULL;
 133     ddc->npoints = 0;
 134     ddc->cal1 = NULL;
 135     ddc->cal2 = NULL;
 136     ddc->repr = NULL;
 137
 138     /* DynaDraw values */
 139     ddc->cur = NR::Point(0,0);
 140     ddc->last = NR::Point(0,0);
 141     ddc->vel = NR::Point(0,0);
 142     ddc->acc = NR::Point(0,0);
 143     ddc->ang = NR::Point(0,0);
 144     ddc->del = NR::Point(0,0);
 145
 146     /* attributes */
 147     ddc->dragging = FALSE;
 148
 149     ddc->mass = 0.3;
 150     ddc->drag = DRAG_DEFAULT;
 151     ddc->angle = 30.0;
 152     ddc->width = 0.2;
 153
 154     ddc->vel_thin = 0.1;
 155     ddc->flatness = 0.9;
 156
 157     ddc->abs_width = false;
 158 }
 159
 160 static void
 161 sp_dyna_draw_context_dispose(GObject *object)
 162 {
 163     SPDynaDrawContext *ddc = SP_DYNA_DRAW_CONTEXT(object);
 164
 165     if (ddc->accumulated) {
 166         ddc->accumulated = sp_curve_unref(ddc->accumulated);
 167     }
 168
 169     while (ddc->segments) {
 170         gtk_object_destroy(GTK_OBJECT(ddc->segments->data));
 171         ddc->segments = g_slist_remove(ddc->segments, ddc->segments->data);
 172     }
 173
 174     if (ddc->currentcurve) ddc->currentcurve = sp_curve_unref(ddc->currentcurve);
 175     if (ddc->cal1) ddc->cal1 = sp_curve_unref(ddc->cal1);
 176     if (ddc->cal2) ddc->cal2 = sp_curve_unref(ddc->cal2);
 177
 178     if (ddc->currentshape) {
 179         gtk_object_destroy(GTK_OBJECT(ddc->currentshape));
 180         ddc->currentshape = NULL;
 181     }
 182
 183     if (ddc->_message_context) {
 184         delete ddc->_message_context;
 185     }
 186
 187     G_OBJECT_CLASS(parent_class)->dispose(object);
 188 }
 189
 190 static void
 191 sp_dyna_draw_context_setup(SPEventContext *ec)
 192 {
 193     SPDynaDrawContext *ddc = SP_DYNA_DRAW_CONTEXT(ec);
 194
 195     if (((SPEventContextClass *) parent_class)->setup)
 196         ((SPEventContextClass *) parent_class)->setup(ec);
 197
 198     ddc->accumulated = sp_curve_new_sized(32);
 199     ddc->currentcurve = sp_curve_new_sized(4);
 200
 201     ddc->cal1 = sp_curve_new_sized(32);
 202     ddc->cal2 = sp_curve_new_sized(32);
 203
 204     ddc->currentshape = sp_canvas_item_new(sp_desktop_sketch(ec->desktop), SP_TYPE_CANVAS_BPATH, NULL);
 205     sp_canvas_bpath_set_fill(SP_CANVAS_BPATH(ddc->currentshape), DDC_RED_RGBA, SP_WIND_RULE_EVENODD);
 206     sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(ddc->currentshape), 0x00000000, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 207     /* fixme: Cannot we cascade it to root more clearly? */
 208     g_signal_connect(G_OBJECT(ddc->currentshape), "event", G_CALLBACK(sp_desktop_root_handler), ec->desktop);
 209
 210     sp_event_context_read(ec, "mass");
 211     sp_event_context_read(ec, "drag");
 212     sp_event_context_read(ec, "angle");
 213     sp_event_context_read(ec, "width");
 214     sp_event_context_read(ec, "thinning");
 215     sp_event_context_read(ec, "tremor");
 216     sp_event_context_read(ec, "flatness");
 217     sp_event_context_read(ec, "usepressure");
 218     sp_event_context_read(ec, "usetilt");
 219     sp_event_context_read(ec, "abs_width");
 220
 221     ddc->is_drawing = false;
 222
 223     ddc->_message_context = new Inkscape::MessageContext((ec->desktop)->messageStack());
 224 }
 225
 226 static void
 227 sp_dyna_draw_context_set(SPEventContext *ec, gchar const *key, gchar const *val)
 228 {
 229     SPDynaDrawContext *ddc = SP_DYNA_DRAW_CONTEXT(ec);
 230
 231     if (!strcmp(key, "mass")) {
 232         double const dval = ( val ? g_ascii_strtod (val, NULL) : 0.2 );
 233         ddc->mass = CLAMP(dval, -1000.0, 1000.0);
 234     } else if (!strcmp(key, "drag")) {
 235         double const dval = ( val ? g_ascii_strtod (val, NULL) : DRAG_DEFAULT );
 236         ddc->drag = CLAMP(dval, DRAG_MIN, DRAG_MAX);
 237     } else if (!strcmp(key, "angle")) {
 238         double const dval = ( val ? g_ascii_strtod (val, NULL) : 0.0);
 239         ddc->angle = CLAMP (dval, -90, 90);
 240     } else if (!strcmp(key, "width")) {
 241         double const dval = ( val ? g_ascii_strtod (val, NULL) : 0.1 );
 242         ddc->width = CLAMP(dval, -1000.0, 1000.0);
 243     } else if (!strcmp(key, "thinning")) {
 244         double const dval = ( val ? g_ascii_strtod (val, NULL) : 0.1 );
 245         ddc->vel_thin = CLAMP(dval, -1.0, 1.0);
 246     } else if (!strcmp(key, "tremor")) {
 247         double const dval = ( val ? g_ascii_strtod (val, NULL) : 0.0 );
 248         ddc->tremor = CLAMP(dval, 0.0, 1.0);
 249     } else if (!strcmp(key, "flatness")) {
 250         double const dval = ( val ? g_ascii_strtod (val, NULL) : 1.0 );
 251         ddc->flatness = CLAMP(dval, 0, 1.0);
 252     } else if (!strcmp(key, "usepressure")) {
 253         ddc->usepressure = (val && strcmp(val, "0"));
 254     } else if (!strcmp(key, "usetilt")) {
 255         ddc->usetilt = (val && strcmp(val, "0"));
 256     } else if (!strcmp(key, "abs_width")) {
 257         ddc->abs_width = (val && strcmp(val, "0"));
 258     }
 259
 260     //g_print("DDC: %g %g %g %g\n", ddc->mass, ddc->drag, ddc->angle, ddc->width);
 261 }
 262
 263 static double
 264 flerp(double f0, double f1, double p)
 265 {
 266     return f0 + ( f1 - f0 ) * p;
 267 }
 268
 269 /* Get normalized point */
 270 static NR::Point
 271 sp_dyna_draw_get_npoint(SPDynaDrawContext const *dc, NR::Point v)
 272 {
 273     NR::Rect drect = SP_EVENT_CONTEXT(dc)->desktop->get_display_area();
 274     double const max = MAX ( drect.dimensions()[NR::X], drect.dimensions()[NR::Y] );
 275     return NR::Point(( v[NR::X] - drect.min()[NR::X] ) / max,  ( v[NR::Y] - drect.min()[NR::Y] ) / max);
 276 }
 277
 278 /* Get view point */
 279 static NR::Point
 280 sp_dyna_draw_get_vpoint(SPDynaDrawContext const *dc, NR::Point n)
 281 {
 282     NR::Rect drect = SP_EVENT_CONTEXT(dc)->desktop->get_display_area();
 283     double const max = MAX ( drect.dimensions()[NR::X], drect.dimensions()[NR::Y] );
 284     return NR::Point(n[NR::X] * max + drect.min()[NR::X], n[NR::Y] * max + drect.min()[NR::Y]);
 285 }
 286
 287 static void
 288 sp_dyna_draw_reset(SPDynaDrawContext *dc, NR::Point p)
 289 {
 290     dc->last = dc->cur = sp_dyna_draw_get_npoint(dc, p);
 291     dc->vel = NR::Point(0,0);
 292     dc->acc = NR::Point(0,0);
 293     dc->ang = NR::Point(0,0);
 294     dc->del = NR::Point(0,0);
 295 }
 296
 297 static void
 298 sp_dyna_draw_extinput(SPDynaDrawContext *dc, GdkEvent *event)
 299 {
 300     if (gdk_event_get_axis (event, GDK_AXIS_PRESSURE, &dc->pressure))
 301         dc->pressure = CLAMP (dc->pressure, DDC_MIN_PRESSURE, DDC_MAX_PRESSURE);
 302     else
 303         dc->pressure = DDC_DEFAULT_PRESSURE;
 304
 305     if (gdk_event_get_axis (event, GDK_AXIS_XTILT, &dc->xtilt))
 306         dc->xtilt = CLAMP (dc->xtilt, DDC_MIN_TILT, DDC_MAX_TILT);
 307     else
 308         dc->xtilt = DDC_DEFAULT_TILT;
 309
 310     if (gdk_event_get_axis (event, GDK_AXIS_YTILT, &dc->ytilt))
 311         dc->ytilt = CLAMP (dc->ytilt, DDC_MIN_TILT, DDC_MAX_TILT);
 312     else
 313         dc->ytilt = DDC_DEFAULT_TILT;
 314 }
 315
 316
 317 static gboolean
 318 sp_dyna_draw_apply(SPDynaDrawContext *dc, NR::Point p)
 319 {
 320     NR::Point n = sp_dyna_draw_get_npoint(dc, p);
 321
 322     /* Calculate mass and drag */
 323     double const mass = flerp(1.0, 160.0, dc->mass);
 324     double const drag = flerp(0.0, 0.5, dc->drag * dc->drag);
 325
 326     /* Calculate force and acceleration */
 327     NR::Point force = n - dc->cur;
 328     if ( NR::L2(force) < DYNA_EPSILON ) {
 329         return FALSE;
 330     }
 331
 332     dc->acc = force / mass;
 333
 334     /* Calculate new velocity */
 335     dc->vel += dc->acc;
 336
 337     /* Calculate angle of drawing tool */
 338
 339     double a1;
 340     if (dc->usetilt) {
 341         // 1a. calculate nib angle from input device tilt:
 342         gdouble length = std::sqrt(dc->xtilt*dc->xtilt + dc->ytilt*dc->ytilt);;
 343
 344         if (length > 0) {
 345             NR::Point ang1 = NR::Point(dc->ytilt/length, dc->xtilt/length);
 346             a1 = atan2(ang1);
 347         }
 348         else
 349             a1 = 0.0;
 350     }
 351     else {
 352         // 1b. fixed dc->angle (absolutely flat nib):
 353         double const radians = ( (dc->angle - 90) / 180.0 ) * M_PI;
 354         NR::Point ang1 = NR::Point(-sin(radians),  cos(radians));
 355         a1 = atan2(ang1);
 356     }
 357
 358     // 2. perpendicular to dc->vel (absolutely non-flat nib):
 359     gdouble const mag_vel = NR::L2(dc->vel);
 360     if ( mag_vel < DYNA_EPSILON ) {
 361         return FALSE;
 362     }
 363     NR::Point ang2 = NR::rot90(dc->vel) / mag_vel;
 364
 365     // 3. Average them using flatness parameter:
 366     // calculate angles
 367     double a2 = atan2(ang2);
 368     // flip a2 to force it to be in the same half-circle as a1
 369     bool flipped = false;
 370     if (fabs (a2-a1) > 0.5*M_PI) {
 371         a2 += M_PI;
 372         flipped = true;
 373     }
 374     // normalize a2
 375     if (a2 > M_PI)
 376         a2 -= 2*M_PI;
 377     if (a2 < -M_PI)
 378         a2 += 2*M_PI;
 379     // find the flatness-weighted bisector angle, unflip if a2 was flipped
 380     // FIXME: when dc->vel is oscillating around the fixed angle, the new_ang flips back and forth. How to avoid this?
 381     double new_ang = a1 + (1 - dc->flatness) * (a2 - a1) - (flipped? M_PI : 0);
 382     // convert to point
 383     dc->ang = NR::Point (cos (new_ang), sin (new_ang));
 384
 385     /* Apply drag */
 386     dc->vel *= 1.0 - drag;
 387
 388     /* Update position */
 389     dc->last = dc->cur;
 390     dc->cur += dc->vel;
 391
 392     return TRUE;
 393 }
 394
 395 static void
 396 sp_dyna_draw_brush(SPDynaDrawContext *dc)
 397 {
 398     g_assert( dc->npoints >= 0 && dc->npoints < SAMPLING_SIZE );
 399
 400     // How much velocity thins strokestyle
 401     double vel_thin = flerp (0, 160, dc->vel_thin);
 402
 403     // Influence of pressure on thickness
 404     double pressure_thick = (dc->usepressure ? dc->pressure : 1.0);
 405
 406     double width = ( pressure_thick - vel_thin * NR::L2(dc->vel) ) * dc->width;
 407
 408     double tremble_left = 0, tremble_right = 0;
 409     if (dc->tremor > 0) {
 410         // obtain two normally distributed random variables, using polar Box-Muller transform
 411         double x1, x2, w, y1, y2;
 412         do {
 413             x1 = 2.0 * g_random_double_range(0,1) - 1.0;
 414             x2 = 2.0 * g_random_double_range(0,1) - 1.0;
 415             w = x1 * x1 + x2 * x2;
 416         } while ( w >= 1.0 );
 417         w = sqrt( (-2.0 * log( w ) ) / w );
 418         y1 = x1 * w;
 419         y2 = x2 * w;
 420
 421         // deflect both left and right edges randomly and independently, so that:
 422         // (1) dc->tremor=1 corresponds to sigma=1, decreasing dc->tremor narrows the bell curve;
 423         // (2) deflection depends on width, but is upped for small widths for better visual uniformity across widths;
 424         // (3) deflection somewhat depends on speed, to prevent fast strokes looking
 425         // comparatively smooth and slow ones excessively jittery
 426         tremble_left  = (y1)*dc->tremor * (0.15 + 0.8*width) * (0.35 + 14*NR::L2(dc->vel));
 427         tremble_right = (y2)*dc->tremor * (0.15 + 0.8*width) * (0.35 + 14*NR::L2(dc->vel));
 428     }
 429
 430     if ( width < 0.02 * dc->width ) {
 431         width = 0.02 * dc->width;
 432     }
 433
 434     double dezoomify_factor = 0.05 * 1000;
 435     if (!dc->abs_width) {
 436         dezoomify_factor /= SP_EVENT_CONTEXT(dc)->desktop->current_zoom();
 437     }
 438
 439     NR::Point del_left = dezoomify_factor * (width + tremble_left) * dc->ang;
 440     NR::Point del_right = dezoomify_factor * (width + tremble_right) * dc->ang;
 441
 442     NR::Point abs_middle = sp_dyna_draw_get_vpoint(dc, dc->cur);
 443
 444     dc->point1[dc->npoints] = abs_middle + del_left;
 445     dc->point2[dc->npoints] = abs_middle - del_right;
 446
 447     dc->del = 0.5*(del_left + del_right);
 448
 449     dc->npoints++;
 450 }
 451
 452 void
 453 sp_ddc_update_toolbox (SPDesktop *desktop, const gchar *id, double value)
 454 {
 455     desktop->setToolboxAdjustmentValue (id, value);
 456 }
 457
 458 gint
 459 sp_dyna_draw_context_root_handler(SPEventContext *event_context,
 460                                   GdkEvent *event)
 461 {
 462     SPDynaDrawContext *dc = SP_DYNA_DRAW_CONTEXT(event_context);
 463     SPDesktop *desktop = event_context->desktop;
 464
 465     gint ret = FALSE;
 466
 467     switch (event->type) {
 468     case GDK_BUTTON_PRESS:
 469         if ( event->button.button == 1 ) {
 470
 471             SPDesktop *desktop = SP_EVENT_CONTEXT_DESKTOP(dc);
 472
 473             if (Inkscape::have_viable_layer(desktop, dc->_message_context) == false) {
 474                 return TRUE;
 475             }
 476
 477             NR::Point const button_w(event->button.x,
 478                                      event->button.y);
 479             NR::Point const button_dt(desktop->w2d(button_w));
 480             sp_dyna_draw_reset(dc, button_dt);
 481             sp_dyna_draw_extinput(dc, event);
 482             sp_dyna_draw_apply(dc, button_dt);
 483             sp_curve_reset(dc->accumulated);
 484             if (dc->repr) {
 485                 dc->repr = NULL;
 486             }
 487
 488             /* initialize first point */
 489             dc->npoints = 0;
 490
 491             sp_canvas_item_grab(SP_CANVAS_ITEM(desktop->acetate),
 492                                 ( GDK_KEY_PRESS_MASK |
 493                                   GDK_BUTTON_RELEASE_MASK |
 494                                   GDK_POINTER_MOTION_MASK |
 495                                   GDK_BUTTON_PRESS_MASK ),
 496                                 NULL,
 497                                 event->button.time);
 498
 499             ret = TRUE;
 500
 501             dc->is_drawing = true;
 502         }
 503         break;
 504     case GDK_MOTION_NOTIFY:
 505         if ( dc->is_drawing && ( event->motion.state & GDK_BUTTON1_MASK ) ) {
 506             dc->dragging = TRUE;
 507
 508             NR::Point const motion_w(event->motion.x,
 509                                      event->motion.y);
 510             NR::Point const motion_dt(desktop->w2d(motion_w));
 511
 512             sp_dyna_draw_extinput(dc, event);
 513             if (!sp_dyna_draw_apply(dc, motion_dt)) {
 514                 ret = TRUE;
 515                 break;
 516             }
 517
 518             if ( dc->cur != dc->last ) {
 519                 sp_dyna_draw_brush(dc);
 520                 g_assert( dc->npoints > 0 );
 521                 fit_and_split(dc, FALSE);
 522             }
 523             ret = TRUE;
 524         }
 525         break;
 526
 527     case GDK_BUTTON_RELEASE:
 528         sp_canvas_item_ungrab(SP_CANVAS_ITEM(desktop->acetate), event->button.time);
 529         dc->is_drawing = false;
 530         if ( dc->dragging && event->button.button == 1 ) {
 531             dc->dragging = FALSE;
 532
 533             /* Remove all temporary line segments */
 534             while (dc->segments) {
 535                 gtk_object_destroy(GTK_OBJECT(dc->segments->data));
 536                 dc->segments = g_slist_remove(dc->segments, dc->segments->data);
 537             }
 538             /* Create object */
 539             fit_and_split(dc, TRUE);
 540             accumulate_calligraphic(dc);
 541             set_to_accumulated(dc); /* temporal implementation */
 542             /* reset accumulated curve */
 543             sp_curve_reset(dc->accumulated);
 544             clear_current(dc);
 545             if (dc->repr) {
 546                 dc->repr = NULL;
 547             }
 548             ret = TRUE;
 549         }
 550         break;
 551     case GDK_KEY_PRESS:
 552         switch (get_group0_keyval (&event->key)) {
 553         case GDK_Up:
 554         case GDK_KP_Up:
 555             if (!MOD__CTRL_ONLY) {
 556                 dc->angle += 5.0;
 557                 if (dc->angle > 90.0)
 558                     dc->angle = 90.0;
 559                 sp_ddc_update_toolbox (desktop, "calligraphy-angle", dc->angle);
 560                 ret = TRUE;
 561             }
 562             break;
 563         case GDK_Down:
 564         case GDK_KP_Down:
 565             if (!MOD__CTRL_ONLY) {
 566                 dc->angle -= 5.0;
 567                 if (dc->angle < -90.0)
 568                     dc->angle = -90.0;
 569                 sp_ddc_update_toolbox (desktop, "calligraphy-angle", dc->angle);
 570                 ret = TRUE;
 571             }
 572             break;
 573         case GDK_Right:
 574         case GDK_KP_Right:
 575             if (!MOD__CTRL_ONLY) {
 576                 dc->width += 0.01;
 577                 if (dc->width > 1.0)
 578                     dc->width = 1.0;
 579                 sp_ddc_update_toolbox (desktop, "altx-calligraphy", dc->width * 100); // the same spinbutton is for alt+x
 580                 ret = TRUE;
 581             }
 582             break;
 583         case GDK_Left:
 584         case GDK_KP_Left:
 585             if (!MOD__CTRL_ONLY) {
 586                 dc->width -= 0.01;
 587                 if (dc->width < 0.01)
 588                     dc->width = 0.01;
 589                 sp_ddc_update_toolbox (desktop, "altx-calligraphy", dc->width * 100);
 590                 ret = TRUE;
 591             }
 592             break;
 593         case GDK_x:
 594         case GDK_X:
 595             if (MOD__ALT_ONLY) {
 596                 desktop->setToolboxFocusTo ("altx-calligraphy");
 597                 ret = TRUE;
 598             }
 599             break;
 600         case GDK_Escape:
 601             sp_desktop_selection(desktop)->clear();
 602             break;
 603
 604         default:
 605             break;
 606         }
 607     default:
 608         break;
 609     }
 610
 611     if (!ret) {
 612         if (((SPEventContextClass *) parent_class)->root_handler) {
 613             ret = ((SPEventContextClass *) parent_class)->root_handler(event_context, event);
 614         }
 615     }
 616
 617     return ret;
 618 }
 619
 620
 621 static void
 622 clear_current(SPDynaDrawContext *dc)
 623 {
 624     /* reset bpath */
 625     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(dc->currentshape), NULL);
 626     /* reset curve */
 627     sp_curve_reset(dc->currentcurve);
 628     sp_curve_reset(dc->cal1);
 629     sp_curve_reset(dc->cal2);
 630     /* reset points */
 631     dc->npoints = 0;
 632 }
 633
 634 static void
 635 set_to_accumulated(SPDynaDrawContext *dc)
 636 {
 637     SPDesktop *desktop = SP_EVENT_CONTEXT(dc)->desktop;
 638
 639     if (!sp_curve_empty(dc->accumulated)) {
 640         NArtBpath *abp;
 641         gchar *str;
 642
 643         if (!dc->repr) {
 644             /* Create object */
 645             Inkscape::XML::Node *repr = sp_repr_new("svg:path");
 646
 647             /* Set style */
 648             sp_desktop_apply_style_tool (desktop, repr, "tools.calligraphic", false);
 649
 650             dc->repr = repr;
 651
 652             SPItem *item=SP_ITEM(desktop->currentLayer()->appendChildRepr(dc->repr));
 653             Inkscape::GC::release(dc->repr);
 654             item->transform = SP_ITEM(desktop->currentRoot())->getRelativeTransform(desktop->currentLayer());
 655             item->updateRepr();
 656             sp_desktop_selection(desktop)->set(dc->repr);
 657         }
 658         abp = nr_artpath_affine(sp_curve_first_bpath(dc->accumulated), sp_desktop_dt2root_affine(desktop));
 659         str = sp_svg_write_path(abp);
 660         g_assert( str != NULL );
 661         nr_free(abp);
 662         dc->repr->setAttribute("d", str);
 663         g_free(str);
 664     } else {
 665         if (dc->repr) {
 666             sp_repr_unparent(dc->repr);
 667         }
 668         dc->repr = NULL;
 669     }
 670
 671     sp_document_done(sp_desktop_document(desktop));
 672 }
 673
 674 static void
 675 accumulate_calligraphic(SPDynaDrawContext *dc)
 676 {
 677     if ( !sp_curve_empty(dc->cal1) && !sp_curve_empty(dc->cal2) ) {
 678         sp_curve_reset(dc->accumulated); /*  Is this required ?? */
 679         SPCurve *rev_cal2 = sp_curve_reverse(dc->cal2);
 680         sp_curve_append(dc->accumulated, dc->cal1, FALSE);
 681         sp_curve_append(dc->accumulated, rev_cal2, TRUE);
 682         sp_curve_closepath(dc->accumulated);
 683
 684         sp_curve_unref(rev_cal2);
 685
 686         sp_curve_reset(dc->cal1);
 687         sp_curve_reset(dc->cal2);
 688     }
 689 }
 690
 691 static void
 692 fit_and_split(SPDynaDrawContext *dc,
 693               gboolean release)
 694 {
 695     fit_and_split_calligraphics(dc, release);
 696 }
 697
 698 static double square(double const x)
 699 {
 700     return x * x;
 701 }
 702
 703 static void
 704 fit_and_split_calligraphics(SPDynaDrawContext *dc, gboolean release)
 705 {
 706     double const tolerance_sq = square( NR::expansion(SP_EVENT_CONTEXT(dc)->desktop->w2d()) * TOLERANCE_CALLIGRAPHIC );
 707
 708 #ifdef DYNA_DRAW_VERBOSE
 709     g_print("[F&S:R=%c]", release?'T':'F');
 710 #endif
 711
 712     if (!( dc->npoints > 0 && dc->npoints < SAMPLING_SIZE ))
 713         return; // just clicked
 714
 715     if ( dc->npoints == SAMPLING_SIZE - 1 || release ) {
 716 #define BEZIER_SIZE       4
 717 #define BEZIER_MAX_BEZIERS  8
 718 #define BEZIER_MAX_LENGTH ( BEZIER_SIZE * BEZIER_MAX_BEZIERS )
 719
 720 #ifdef DYNA_DRAW_VERBOSE
 721         g_print("[F&S:#] dc->npoints:%d, release:%s\n",
 722                 dc->npoints, release ? "TRUE" : "FALSE");
 723 #endif
 724
 725         /* Current calligraphic */
 726         if ( dc->cal1->end == 0 || dc->cal2->end == 0 ) {
 727             /* dc->npoints > 0 */
 728             /* g_print("calligraphics(1|2) reset\n"); */
 729             sp_curve_reset(dc->cal1);
 730             sp_curve_reset(dc->cal2);
 731
 732             sp_curve_moveto(dc->cal1, dc->point1[0]);
 733             sp_curve_moveto(dc->cal2, dc->point2[0]);
 734         }
 735
 736         NR::Point b1[BEZIER_MAX_LENGTH];
 737         gint const nb1 = sp_bezier_fit_cubic_r(b1, dc->point1, dc->npoints,
 738                                                tolerance_sq, BEZIER_MAX_BEZIERS);
 739         g_assert( nb1 * BEZIER_SIZE <= gint(G_N_ELEMENTS(b1)) );
 740
 741         NR::Point b2[BEZIER_MAX_LENGTH];
 742         gint const nb2 = sp_bezier_fit_cubic_r(b2, dc->point2, dc->npoints,
 743                                                tolerance_sq, BEZIER_MAX_BEZIERS);
 744         g_assert( nb2 * BEZIER_SIZE <= gint(G_N_ELEMENTS(b2)) );
 745
 746         if ( nb1 != -1 && nb2 != -1 ) {
 747             /* Fit and draw and reset state */
 748 #ifdef DYNA_DRAW_VERBOSE
 749             g_print("nb1:%d nb2:%d\n", nb1, nb2);
 750 #endif
 751             /* CanvasShape */
 752             if (! release) {
 753                 sp_curve_reset(dc->currentcurve);
 754                 sp_curve_moveto(dc->currentcurve, b1[0]);
 755                 for (NR::Point *bp1 = b1; bp1 < b1 + BEZIER_SIZE * nb1; bp1 += BEZIER_SIZE) {
 756                     sp_curve_curveto(dc->currentcurve, bp1[1],
 757                                      bp1[2], bp1[3]);
 758                 }
 759                 sp_curve_lineto(dc->currentcurve,
 760                                 b2[BEZIER_SIZE*(nb2-1) + 3]);
 761                 for (NR::Point *bp2 = b2 + BEZIER_SIZE * ( nb2 - 1 ); bp2 >= b2; bp2 -= BEZIER_SIZE) {
 762                     sp_curve_curveto(dc->currentcurve, bp2[2], bp2[1], bp2[0]);
 763                 }
 764                 sp_curve_closepath(dc->currentcurve);
 765                 sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(dc->currentshape), dc->currentcurve);
 766             }
 767
 768             /* Current calligraphic */
 769             for (NR::Point *bp1 = b1; bp1 < b1 + BEZIER_SIZE * nb1; bp1 += BEZIER_SIZE) {
 770                 sp_curve_curveto(dc->cal1, bp1[1], bp1[2], bp1[3]);
 771             }
 772             for (NR::Point *bp2 = b2; bp2 < b2 + BEZIER_SIZE * nb2; bp2 += BEZIER_SIZE) {
 773                 sp_curve_curveto(dc->cal2, bp2[1], bp2[2], bp2[3]);
 774             }
 775         } else {
 776             /* fixme: ??? */
 777 #ifdef DYNA_DRAW_VERBOSE
 778             g_print("[fit_and_split_calligraphics] failed to fit-cubic.\n");
 779 #endif
 780             draw_temporary_box(dc);
 781
 782             for (gint i = 1; i < dc->npoints; i++) {
 783                 sp_curve_lineto(dc->cal1, dc->point1[i]);
 784             }
 785             for (gint i = 1; i < dc->npoints; i++) {
 786                 sp_curve_lineto(dc->cal2, dc->point2[i]);
 787             }
 788         }
 789
 790         /* Fit and draw and copy last point */
 791 #ifdef DYNA_DRAW_VERBOSE
 792         g_print("[%d]Yup\n", dc->npoints);
 793 #endif
 794         if (!release) {
 795             g_assert(!sp_curve_empty(dc->currentcurve));
 796
 797             SPCanvasItem *cbp = sp_canvas_item_new(sp_desktop_sketch(SP_EVENT_CONTEXT(dc)->desktop),
 798                                                    SP_TYPE_CANVAS_BPATH,
 799                                                    NULL);
 800             SPCurve *curve = sp_curve_copy(dc->currentcurve);
 801             sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH (cbp), curve);
 802             sp_curve_unref(curve);
 803             sp_canvas_bpath_set_fill(SP_CANVAS_BPATH(cbp), 0x000000ff, SP_WIND_RULE_EVENODD);
 804             sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(cbp), 0x00000000, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 805             /* fixme: Cannot we cascade it to root more clearly? */
 806             g_signal_connect(G_OBJECT(cbp), "event", G_CALLBACK(sp_desktop_root_handler), SP_EVENT_CONTEXT(dc)->desktop);
 807
 808             dc->segments = g_slist_prepend(dc->segments, cbp);
 809         }
 810
 811         dc->point1[0] = dc->point1[dc->npoints - 1];
 812         dc->point2[0] = dc->point2[dc->npoints - 1];
 813         dc->npoints = 1;
 814     } else {
 815         draw_temporary_box(dc);
 816     }
 817 }
 818
 819 static void
 820 draw_temporary_box(SPDynaDrawContext *dc)
 821 {
 822     sp_curve_reset(dc->currentcurve);
 823     sp_curve_moveto(dc->currentcurve, dc->point1[0]);
 824     for (gint i = 1; i < dc->npoints; i++) {
 825         sp_curve_lineto(dc->currentcurve, dc->point1[i]);
 826     }
 827     for (gint i = dc->npoints-1; i >= 0; i--) {
 828         sp_curve_lineto(dc->currentcurve, dc->point2[i]);
 829     }
 830     sp_curve_closepath(dc->currentcurve);
 831     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(dc->currentshape), dc->currentcurve);
 832 }
 833
 834 /*
 835   Local Variables:
 836   mode:c++
 837   c-file-style:"stroustrup"
 838   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
 839   indent-tabs-mode:nil
 840   fill-column:99
 841   End:
 842 */
 843 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :