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 #include "inkscape.h"
  49
  50 #define DDC_RED_RGBA 0xff0000ff
  51
  52 #define SAMPLE_TIMEOUT 10
  53 #define TOLERANCE_LINE 1.0
  54 #define TOLERANCE_CALLIGRAPHIC 3.0
  55 #define DYNA_EPSILON 1.0e-6
  56
  57 #define DYNA_MIN_WIDTH 1.0e-6
  58
  59 #define DRAG_MIN 0.0
  60 #define DRAG_DEFAULT 1.0
  61 #define DRAG_MAX 1.0
  62
  63 static void sp_dyna_draw_context_class_init(SPDynaDrawContextClass *klass);
  64 static void sp_dyna_draw_context_init(SPDynaDrawContext *ddc);
  65 static void sp_dyna_draw_context_dispose(GObject *object);
  66
  67 static void sp_dyna_draw_context_setup(SPEventContext *ec);
  68 static void sp_dyna_draw_context_set(SPEventContext *ec, gchar const *key, gchar const *val);
  69 static gint sp_dyna_draw_context_root_handler(SPEventContext *ec, GdkEvent *event);
  70
  71 static void clear_current(SPDynaDrawContext *dc);
  72 static void set_to_accumulated(SPDynaDrawContext *dc);
  73 static void accumulate_calligraphic(SPDynaDrawContext *dc);
  74
  75 static void fit_and_split(SPDynaDrawContext *ddc, gboolean release);
  76 static void fit_and_split_calligraphics(SPDynaDrawContext *ddc, gboolean release);
  77
  78 static void sp_dyna_draw_reset(SPDynaDrawContext *ddc, NR::Point p);
  79 static NR::Point sp_dyna_draw_get_npoint(SPDynaDrawContext const *ddc, NR::Point v);
  80 static NR::Point sp_dyna_draw_get_vpoint(SPDynaDrawContext const *ddc, NR::Point n);
  81 static void draw_temporary_box(SPDynaDrawContext *dc);
  82
  83
  84 static SPEventContextClass *parent_class;
  85
  86 GtkType
  87 sp_dyna_draw_context_get_type(void)
  88 {
  89     static GType type = 0;
  90     if (!type) {
  91         GTypeInfo info = {
  92             sizeof(SPDynaDrawContextClass),
  93             NULL, NULL,
  94             (GClassInitFunc) sp_dyna_draw_context_class_init,
  95             NULL, NULL,
  96             sizeof(SPDynaDrawContext),
  97             4,
  98             (GInstanceInitFunc) sp_dyna_draw_context_init,
  99             NULL,   /* value_table */
 100         };
 101         type = g_type_register_static(SP_TYPE_EVENT_CONTEXT, "SPDynaDrawContext", &info, (GTypeFlags)0);
 102     }
 103     return type;
 104 }
 105
 106 static void
 107 sp_dyna_draw_context_class_init(SPDynaDrawContextClass *klass)
 108 {
 109     GObjectClass *object_class = (GObjectClass *) klass;
 110     SPEventContextClass *event_context_class = (SPEventContextClass *) klass;
 111
 112     parent_class = (SPEventContextClass*)g_type_class_peek_parent(klass);
 113
 114     object_class->dispose = sp_dyna_draw_context_dispose;
 115
 116     event_context_class->setup = sp_dyna_draw_context_setup;
 117     event_context_class->set = sp_dyna_draw_context_set;
 118     event_context_class->root_handler = sp_dyna_draw_context_root_handler;
 119 }
 120
 121 static void
 122 sp_dyna_draw_context_init(SPDynaDrawContext *ddc)
 123 {
 124     SPEventContext *event_context = SP_EVENT_CONTEXT(ddc);
 125
 126     event_context->cursor_shape = cursor_calligraphy_xpm;
 127     event_context->hot_x = 4;
 128     event_context->hot_y = 4;
 129
 130     ddc->accumulated = NULL;
 131     ddc->segments = NULL;
 132     ddc->currentcurve = NULL;
 133     ddc->currentshape = NULL;
 134     ddc->npoints = 0;
 135     ddc->cal1 = NULL;
 136     ddc->cal2 = NULL;
 137     ddc->repr = NULL;
 138
 139     /* DynaDraw values */
 140     ddc->cur = NR::Point(0,0);
 141     ddc->last = NR::Point(0,0);
 142     ddc->vel = NR::Point(0,0);
 143     ddc->acc = NR::Point(0,0);
 144     ddc->ang = NR::Point(0,0);
 145     ddc->del = NR::Point(0,0);
 146
 147     /* attributes */
 148     ddc->dragging = FALSE;
 149
 150     ddc->mass = 0.3;
 151     ddc->drag = DRAG_DEFAULT;
 152     ddc->angle = 30.0;
 153     ddc->width = 0.2;
 154
 155     ddc->vel_thin = 0.1;
 156     ddc->flatness = 0.9;
 157
 158     ddc->abs_width = false;
 159 }
 160
 161 static void
 162 sp_dyna_draw_context_dispose(GObject *object)
 163 {
 164     SPDynaDrawContext *ddc = SP_DYNA_DRAW_CONTEXT(object);
 165
 166     if (ddc->accumulated) {
 167         ddc->accumulated = sp_curve_unref(ddc->accumulated);
 168     }
 169
 170     while (ddc->segments) {
 171         gtk_object_destroy(GTK_OBJECT(ddc->segments->data));
 172         ddc->segments = g_slist_remove(ddc->segments, ddc->segments->data);
 173     }
 174
 175     if (ddc->currentcurve) ddc->currentcurve = sp_curve_unref(ddc->currentcurve);
 176     if (ddc->cal1) ddc->cal1 = sp_curve_unref(ddc->cal1);
 177     if (ddc->cal2) ddc->cal2 = sp_curve_unref(ddc->cal2);
 178
 179     if (ddc->currentshape) {
 180         gtk_object_destroy(GTK_OBJECT(ddc->currentshape));
 181         ddc->currentshape = NULL;
 182     }
 183
 184     if (ddc->_message_context) {
 185         delete ddc->_message_context;
 186     }
 187
 188     G_OBJECT_CLASS(parent_class)->dispose(object);
 189 }
 190
 191 static void
 192 sp_dyna_draw_context_setup(SPEventContext *ec)
 193 {
 194     SPDynaDrawContext *ddc = SP_DYNA_DRAW_CONTEXT(ec);
 195
 196     if (((SPEventContextClass *) parent_class)->setup)
 197         ((SPEventContextClass *) parent_class)->setup(ec);
 198
 199     ddc->accumulated = sp_curve_new_sized(32);
 200     ddc->currentcurve = sp_curve_new_sized(4);
 201
 202     ddc->cal1 = sp_curve_new_sized(32);
 203     ddc->cal2 = sp_curve_new_sized(32);
 204
 205     ddc->currentshape = sp_canvas_item_new(sp_desktop_sketch(ec->desktop), SP_TYPE_CANVAS_BPATH, NULL);
 206     sp_canvas_bpath_set_fill(SP_CANVAS_BPATH(ddc->currentshape), DDC_RED_RGBA, SP_WIND_RULE_EVENODD);
 207     sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(ddc->currentshape), 0x00000000, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 208     /* fixme: Cannot we cascade it to root more clearly? */
 209     g_signal_connect(G_OBJECT(ddc->currentshape), "event", G_CALLBACK(sp_desktop_root_handler), ec->desktop);
 210
 211     sp_event_context_read(ec, "mass");
 212     sp_event_context_read(ec, "drag");
 213     sp_event_context_read(ec, "angle");
 214     sp_event_context_read(ec, "width");
 215     sp_event_context_read(ec, "thinning");
 216     sp_event_context_read(ec, "tremor");
 217     sp_event_context_read(ec, "flatness");
 218     sp_event_context_read(ec, "usepressure");
 219     sp_event_context_read(ec, "usetilt");
 220     sp_event_context_read(ec, "abs_width");
 221
 222     ddc->is_drawing = false;
 223
 224     ddc->_message_context = new Inkscape::MessageContext((ec->desktop)->messageStack());
 225 }
 226
 227 static void
 228 sp_dyna_draw_context_set(SPEventContext *ec, gchar const *key, gchar const *val)
 229 {
 230     SPDynaDrawContext *ddc = SP_DYNA_DRAW_CONTEXT(ec);
 231
 232     if (!strcmp(key, "mass")) {
 233         double const dval = ( val ? g_ascii_strtod (val, NULL) : 0.2 );
 234         ddc->mass = CLAMP(dval, -1000.0, 1000.0);
 235     } else if (!strcmp(key, "drag")) {
 236         double const dval = ( val ? g_ascii_strtod (val, NULL) : DRAG_DEFAULT );
 237         ddc->drag = CLAMP(dval, DRAG_MIN, DRAG_MAX);
 238     } else if (!strcmp(key, "angle")) {
 239         double const dval = ( val ? g_ascii_strtod (val, NULL) : 0.0);
 240         ddc->angle = CLAMP (dval, -90, 90);
 241     } else if (!strcmp(key, "width")) {
 242         double const dval = ( val ? g_ascii_strtod (val, NULL) : 0.1 );
 243         ddc->width = CLAMP(dval, -1000.0, 1000.0);
 244     } else if (!strcmp(key, "thinning")) {
 245         double const dval = ( val ? g_ascii_strtod (val, NULL) : 0.1 );
 246         ddc->vel_thin = CLAMP(dval, -1.0, 1.0);
 247     } else if (!strcmp(key, "tremor")) {
 248         double const dval = ( val ? g_ascii_strtod (val, NULL) : 0.0 );
 249         ddc->tremor = CLAMP(dval, 0.0, 1.0);
 250     } else if (!strcmp(key, "flatness")) {
 251         double const dval = ( val ? g_ascii_strtod (val, NULL) : 1.0 );
 252         ddc->flatness = CLAMP(dval, 0, 1.0);
 253     } else if (!strcmp(key, "usepressure")) {
 254         ddc->usepressure = (val && strcmp(val, "0"));
 255     } else if (!strcmp(key, "usetilt")) {
 256         ddc->usetilt = (val && strcmp(val, "0"));
 257     } else if (!strcmp(key, "abs_width")) {
 258         ddc->abs_width = (val && strcmp(val, "0"));
 259     }
 260
 261     //g_print("DDC: %g %g %g %g\n", ddc->mass, ddc->drag, ddc->angle, ddc->width);
 262 }
 263
 264 static double
 265 flerp(double f0, double f1, double p)
 266 {
 267     return f0 + ( f1 - f0 ) * p;
 268 }
 269
 270 /* Get normalized point */
 271 static NR::Point
 272 sp_dyna_draw_get_npoint(SPDynaDrawContext const *dc, NR::Point v)
 273 {
 274     NR::Rect drect = SP_EVENT_CONTEXT(dc)->desktop->get_display_area();
 275     double const max = MAX ( drect.dimensions()[NR::X], drect.dimensions()[NR::Y] );
 276     return NR::Point(( v[NR::X] - drect.min()[NR::X] ) / max,  ( v[NR::Y] - drect.min()[NR::Y] ) / max);
 277 }
 278
 279 /* Get view point */
 280 static NR::Point
 281 sp_dyna_draw_get_vpoint(SPDynaDrawContext const *dc, NR::Point n)
 282 {
 283     NR::Rect drect = SP_EVENT_CONTEXT(dc)->desktop->get_display_area();
 284     double const max = MAX ( drect.dimensions()[NR::X], drect.dimensions()[NR::Y] );
 285     return NR::Point(n[NR::X] * max + drect.min()[NR::X], n[NR::Y] * max + drect.min()[NR::Y]);
 286 }
 287
 288 static void
 289 sp_dyna_draw_reset(SPDynaDrawContext *dc, NR::Point p)
 290 {
 291     dc->last = dc->cur = sp_dyna_draw_get_npoint(dc, p);
 292     dc->vel = NR::Point(0,0);
 293     dc->acc = NR::Point(0,0);
 294     dc->ang = NR::Point(0,0);
 295     dc->del = NR::Point(0,0);
 296 }
 297
 298 static void
 299 sp_dyna_draw_extinput(SPDynaDrawContext *dc, GdkEvent *event)
 300 {
 301     if (gdk_event_get_axis (event, GDK_AXIS_PRESSURE, &dc->pressure))
 302         dc->pressure = CLAMP (dc->pressure, DDC_MIN_PRESSURE, DDC_MAX_PRESSURE);
 303     else
 304         dc->pressure = DDC_DEFAULT_PRESSURE;
 305
 306     if (gdk_event_get_axis (event, GDK_AXIS_XTILT, &dc->xtilt))
 307         dc->xtilt = CLAMP (dc->xtilt, DDC_MIN_TILT, DDC_MAX_TILT);
 308     else
 309         dc->xtilt = DDC_DEFAULT_TILT;
 310
 311     if (gdk_event_get_axis (event, GDK_AXIS_YTILT, &dc->ytilt))
 312         dc->ytilt = CLAMP (dc->ytilt, DDC_MIN_TILT, DDC_MAX_TILT);
 313     else
 314         dc->ytilt = DDC_DEFAULT_TILT;
 315 }
 316
 317
 318 static gboolean
 319 sp_dyna_draw_apply(SPDynaDrawContext *dc, NR::Point p)
 320 {
 321     NR::Point n = sp_dyna_draw_get_npoint(dc, p);
 322
 323     /* Calculate mass and drag */
 324     double const mass = flerp(1.0, 160.0, dc->mass);
 325     double const drag = flerp(0.0, 0.5, dc->drag * dc->drag);
 326
 327     /* Calculate force and acceleration */
 328     NR::Point force = n - dc->cur;
 329     if ( NR::L2(force) < DYNA_EPSILON ) {
 330         return FALSE;
 331     }
 332
 333     dc->acc = force / mass;
 334
 335     /* Calculate new velocity */
 336     dc->vel += dc->acc;
 337
 338     /* Calculate angle of drawing tool */
 339
 340     double a1;
 341     if (dc->usetilt) {
 342         // 1a. calculate nib angle from input device tilt:
 343         gdouble length = std::sqrt(dc->xtilt*dc->xtilt + dc->ytilt*dc->ytilt);;
 344
 345         if (length > 0) {
 346             NR::Point ang1 = NR::Point(dc->ytilt/length, dc->xtilt/length);
 347             a1 = atan2(ang1);
 348         }
 349         else
 350             a1 = 0.0;
 351     }
 352     else {
 353         // 1b. fixed dc->angle (absolutely flat nib):
 354         double const radians = ( (dc->angle - 90) / 180.0 ) * M_PI;
 355         NR::Point ang1 = NR::Point(-sin(radians),  cos(radians));
 356         a1 = atan2(ang1);
 357     }
 358
 359     // 2. perpendicular to dc->vel (absolutely non-flat nib):
 360     gdouble const mag_vel = NR::L2(dc->vel);
 361     if ( mag_vel < DYNA_EPSILON ) {
 362         return FALSE;
 363     }
 364     NR::Point ang2 = NR::rot90(dc->vel) / mag_vel;
 365
 366     // 3. Average them using flatness parameter:
 367     // calculate angles
 368     double a2 = atan2(ang2);
 369     // flip a2 to force it to be in the same half-circle as a1
 370     bool flipped = false;
 371     if (fabs (a2-a1) > 0.5*M_PI) {
 372         a2 += M_PI;
 373         flipped = true;
 374     }
 375     // normalize a2
 376     if (a2 > M_PI)
 377         a2 -= 2*M_PI;
 378     if (a2 < -M_PI)
 379         a2 += 2*M_PI;
 380     // find the flatness-weighted bisector angle, unflip if a2 was flipped
 381     // FIXME: when dc->vel is oscillating around the fixed angle, the new_ang flips back and forth. How to avoid this?
 382     double new_ang = a1 + (1 - dc->flatness) * (a2 - a1) - (flipped? M_PI : 0);
 383     // convert to point
 384     dc->ang = NR::Point (cos (new_ang), sin (new_ang));
 385
 386     /* Apply drag */
 387     dc->vel *= 1.0 - drag;
 388
 389     /* Update position */
 390     dc->last = dc->cur;
 391     dc->cur += dc->vel;
 392
 393     return TRUE;
 394 }
 395
 396 static void
 397 sp_dyna_draw_brush(SPDynaDrawContext *dc)
 398 {
 399     g_assert( dc->npoints >= 0 && dc->npoints < SAMPLING_SIZE );
 400
 401     // How much velocity thins strokestyle
 402     double vel_thin = flerp (0, 160, dc->vel_thin);
 403
 404     // Influence of pressure on thickness
 405     double pressure_thick = (dc->usepressure ? dc->pressure : 1.0);
 406
 407     double width = ( pressure_thick - vel_thin * NR::L2(dc->vel) ) * dc->width;
 408
 409     double tremble_left = 0, tremble_right = 0;
 410     if (dc->tremor > 0) {
 411         // obtain two normally distributed random variables, using polar Box-Muller transform
 412         double x1, x2, w, y1, y2;
 413         do {
 414             x1 = 2.0 * g_random_double_range(0,1) - 1.0;
 415             x2 = 2.0 * g_random_double_range(0,1) - 1.0;
 416             w = x1 * x1 + x2 * x2;
 417         } while ( w >= 1.0 );
 418         w = sqrt( (-2.0 * log( w ) ) / w );
 419         y1 = x1 * w;
 420         y2 = x2 * w;
 421
 422         // deflect both left and right edges randomly and independently, so that:
 423         // (1) dc->tremor=1 corresponds to sigma=1, decreasing dc->tremor narrows the bell curve;
 424         // (2) deflection depends on width, but is upped for small widths for better visual uniformity across widths;
 425         // (3) deflection somewhat depends on speed, to prevent fast strokes looking
 426         // comparatively smooth and slow ones excessively jittery
 427         tremble_left  = (y1)*dc->tremor * (0.15 + 0.8*width) * (0.35 + 14*NR::L2(dc->vel));
 428         tremble_right = (y2)*dc->tremor * (0.15 + 0.8*width) * (0.35 + 14*NR::L2(dc->vel));
 429     }
 430
 431     if ( width < 0.02 * dc->width ) {
 432         width = 0.02 * dc->width;
 433     }
 434
 435     double dezoomify_factor = 0.05 * 1000;
 436     if (!dc->abs_width) {
 437         dezoomify_factor /= SP_EVENT_CONTEXT(dc)->desktop->current_zoom();
 438     }
 439
 440     NR::Point del_left = dezoomify_factor * (width + tremble_left) * dc->ang;
 441     NR::Point del_right = dezoomify_factor * (width + tremble_right) * dc->ang;
 442
 443     NR::Point abs_middle = sp_dyna_draw_get_vpoint(dc, dc->cur);
 444
 445     dc->point1[dc->npoints] = abs_middle + del_left;
 446     dc->point2[dc->npoints] = abs_middle - del_right;
 447
 448     dc->del = 0.5*(del_left + del_right);
 449
 450     dc->npoints++;
 451 }
 452
 453 void
 454 sp_ddc_update_toolbox (SPDesktop *desktop, const gchar *id, double value)
 455 {
 456     desktop->setToolboxAdjustmentValue (id, value);
 457 }
 458
 459 gint
 460 sp_dyna_draw_context_root_handler(SPEventContext *event_context,
 461                                   GdkEvent *event)
 462 {
 463     SPDynaDrawContext *dc = SP_DYNA_DRAW_CONTEXT(event_context);
 464     SPDesktop *desktop = event_context->desktop;
 465
 466     gint ret = FALSE;
 467
 468     switch (event->type) {
 469     case GDK_BUTTON_PRESS:
 470         if ( event->button.button == 1 ) {
 471
 472             SPDesktop *desktop = SP_EVENT_CONTEXT_DESKTOP(dc);
 473
 474             if (Inkscape::have_viable_layer(desktop, dc->_message_context) == false) {
 475                 return TRUE;
 476             }
 477
 478             NR::Point const button_w(event->button.x,
 479                                      event->button.y);
 480             NR::Point const button_dt(desktop->w2d(button_w));
 481             sp_dyna_draw_reset(dc, button_dt);
 482             sp_dyna_draw_extinput(dc, event);
 483             sp_dyna_draw_apply(dc, button_dt);
 484             sp_curve_reset(dc->accumulated);
 485             if (dc->repr) {
 486                 dc->repr = NULL;
 487             }
 488
 489             /* initialize first point */
 490             dc->npoints = 0;
 491
 492             sp_canvas_item_grab(SP_CANVAS_ITEM(desktop->acetate),
 493                                 ( GDK_KEY_PRESS_MASK |
 494                                   GDK_BUTTON_RELEASE_MASK |
 495                                   GDK_POINTER_MOTION_MASK |
 496                                   GDK_BUTTON_PRESS_MASK ),
 497                                 NULL,
 498                                 event->button.time);
 499
 500             ret = TRUE;
 501
 502             dc->is_drawing = true;
 503         }
 504         break;
 505     case GDK_MOTION_NOTIFY:
 506         if ( dc->is_drawing && ( event->motion.state & GDK_BUTTON1_MASK ) ) {
 507             dc->dragging = TRUE;
 508
 509             NR::Point const motion_w(event->motion.x,
 510                                      event->motion.y);
 511             NR::Point const motion_dt(desktop->w2d(motion_w));
 512
 513             sp_dyna_draw_extinput(dc, event);
 514             if (!sp_dyna_draw_apply(dc, motion_dt)) {
 515                 ret = TRUE;
 516                 break;
 517             }
 518
 519             if ( dc->cur != dc->last ) {
 520                 sp_dyna_draw_brush(dc);
 521                 g_assert( dc->npoints > 0 );
 522                 fit_and_split(dc, FALSE);
 523             }
 524             ret = TRUE;
 525         }
 526         break;
 527
 528     case GDK_BUTTON_RELEASE:
 529         sp_canvas_item_ungrab(SP_CANVAS_ITEM(desktop->acetate), event->button.time);
 530         dc->is_drawing = false;
 531         if ( dc->dragging && event->button.button == 1 ) {
 532             dc->dragging = FALSE;
 533
 534             /* Remove all temporary line segments */
 535             while (dc->segments) {
 536                 gtk_object_destroy(GTK_OBJECT(dc->segments->data));
 537                 dc->segments = g_slist_remove(dc->segments, dc->segments->data);
 538             }
 539             /* Create object */
 540             fit_and_split(dc, TRUE);
 541             accumulate_calligraphic(dc);
 542             set_to_accumulated(dc); /* temporal implementation */
 543             /* reset accumulated curve */
 544             sp_curve_reset(dc->accumulated);
 545             clear_current(dc);
 546             if (dc->repr) {
 547                 dc->repr = NULL;
 548             }
 549             ret = TRUE;
 550         }
 551         break;
 552     case GDK_KEY_PRESS:
 553         switch (get_group0_keyval (&event->key)) {
 554         case GDK_Up:
 555         case GDK_KP_Up:
 556             if (!MOD__CTRL_ONLY) {
 557                 dc->angle += 5.0;
 558                 if (dc->angle > 90.0)
 559                     dc->angle = 90.0;
 560                 sp_ddc_update_toolbox (desktop, "calligraphy-angle", dc->angle);
 561                 ret = TRUE;
 562             }
 563             break;
 564         case GDK_Down:
 565         case GDK_KP_Down:
 566             if (!MOD__CTRL_ONLY) {
 567                 dc->angle -= 5.0;
 568                 if (dc->angle < -90.0)
 569                     dc->angle = -90.0;
 570                 sp_ddc_update_toolbox (desktop, "calligraphy-angle", dc->angle);
 571                 ret = TRUE;
 572             }
 573             break;
 574         case GDK_Right:
 575         case GDK_KP_Right:
 576             if (!MOD__CTRL_ONLY) {
 577                 dc->width += 0.01;
 578                 if (dc->width > 1.0)
 579                     dc->width = 1.0;
 580                 sp_ddc_update_toolbox (desktop, "altx-calligraphy", dc->width * 100); // the same spinbutton is for alt+x
 581                 ret = TRUE;
 582             }
 583             break;
 584         case GDK_Left:
 585         case GDK_KP_Left:
 586             if (!MOD__CTRL_ONLY) {
 587                 dc->width -= 0.01;
 588                 if (dc->width < 0.01)
 589                     dc->width = 0.01;
 590                 sp_ddc_update_toolbox (desktop, "altx-calligraphy", dc->width * 100);
 591                 ret = TRUE;
 592             }
 593             break;
 594         case GDK_x:
 595         case GDK_X:
 596             if (MOD__ALT_ONLY) {
 597                 desktop->setToolboxFocusTo ("altx-calligraphy");
 598                 ret = TRUE;
 599             }
 600             break;
 601         case GDK_Escape:
 602             sp_desktop_selection(desktop)->clear();
 603             break;
 604
 605         default:
 606             break;
 607         }
 608     default:
 609         break;
 610     }
 611
 612     if (!ret) {
 613         if (((SPEventContextClass *) parent_class)->root_handler) {
 614             ret = ((SPEventContextClass *) parent_class)->root_handler(event_context, event);
 615         }
 616     }
 617
 618     return ret;
 619 }
 620
 621
 622 static void
 623 clear_current(SPDynaDrawContext *dc)
 624 {
 625     /* reset bpath */
 626     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(dc->currentshape), NULL);
 627     /* reset curve */
 628     sp_curve_reset(dc->currentcurve);
 629     sp_curve_reset(dc->cal1);
 630     sp_curve_reset(dc->cal2);
 631     /* reset points */
 632     dc->npoints = 0;
 633 }
 634
 635 static void
 636 set_to_accumulated(SPDynaDrawContext *dc)
 637 {
 638     SPDesktop *desktop = SP_EVENT_CONTEXT(dc)->desktop;
 639
 640     if (!sp_curve_empty(dc->accumulated)) {
 641         NArtBpath *abp;
 642         gchar *str;
 643
 644         if (!dc->repr) {
 645             /* Create object */
 646             Inkscape::XML::Node *repr = sp_repr_new("svg:path");
 647
 648             /* Set style */
 649             sp_desktop_apply_style_tool (desktop, repr, "tools.calligraphic", false);
 650
 651             dc->repr = repr;
 652
 653             SPItem *item=SP_ITEM(desktop->currentLayer()->appendChildRepr(dc->repr));
 654             Inkscape::GC::release(dc->repr);
 655             item->transform = SP_ITEM(desktop->currentRoot())->getRelativeTransform(desktop->currentLayer());
 656             item->updateRepr();
 657             sp_desktop_selection(desktop)->set(dc->repr);
 658         }
 659         abp = nr_artpath_affine(sp_curve_first_bpath(dc->accumulated), sp_desktop_dt2root_affine(desktop));
 660         str = sp_svg_write_path(abp);
 661         g_assert( str != NULL );
 662         nr_free(abp);
 663         dc->repr->setAttribute("d", str);
 664         g_free(str);
 665     } else {
 666         if (dc->repr) {
 667             sp_repr_unparent(dc->repr);
 668         }
 669         dc->repr = NULL;
 670     }
 671
 672     sp_document_done(sp_desktop_document(desktop));
 673 }
 674
 675 static void
 676 accumulate_calligraphic(SPDynaDrawContext *dc)
 677 {
 678     if ( !sp_curve_empty(dc->cal1) && !sp_curve_empty(dc->cal2) ) {
 679         sp_curve_reset(dc->accumulated); /*  Is this required ?? */
 680         SPCurve *rev_cal2 = sp_curve_reverse(dc->cal2);
 681         sp_curve_append(dc->accumulated, dc->cal1, FALSE);
 682         sp_curve_append(dc->accumulated, rev_cal2, TRUE);
 683         sp_curve_closepath(dc->accumulated);
 684
 685         sp_curve_unref(rev_cal2);
 686
 687         sp_curve_reset(dc->cal1);
 688         sp_curve_reset(dc->cal2);
 689     }
 690 }
 691
 692 static void
 693 fit_and_split(SPDynaDrawContext *dc,
 694               gboolean release)
 695 {
 696     fit_and_split_calligraphics(dc, release);
 697 }
 698
 699 static double square(double const x)
 700 {
 701     return x * x;
 702 }
 703
 704 static void
 705 fit_and_split_calligraphics(SPDynaDrawContext *dc, gboolean release)
 706 {
 707     double const tolerance_sq = square( NR::expansion(SP_EVENT_CONTEXT(dc)->desktop->w2d()) * TOLERANCE_CALLIGRAPHIC );
 708
 709 #ifdef DYNA_DRAW_VERBOSE
 710     g_print("[F&S:R=%c]", release?'T':'F');
 711 #endif
 712
 713     if (!( dc->npoints > 0 && dc->npoints < SAMPLING_SIZE ))
 714         return; // just clicked
 715
 716     if ( dc->npoints == SAMPLING_SIZE - 1 || release ) {
 717 #define BEZIER_SIZE       4
 718 #define BEZIER_MAX_BEZIERS  8
 719 #define BEZIER_MAX_LENGTH ( BEZIER_SIZE * BEZIER_MAX_BEZIERS )
 720
 721 #ifdef DYNA_DRAW_VERBOSE
 722         g_print("[F&S:#] dc->npoints:%d, release:%s\n",
 723                 dc->npoints, release ? "TRUE" : "FALSE");
 724 #endif
 725
 726         /* Current calligraphic */
 727         if ( dc->cal1->end == 0 || dc->cal2->end == 0 ) {
 728             /* dc->npoints > 0 */
 729             /* g_print("calligraphics(1|2) reset\n"); */
 730             sp_curve_reset(dc->cal1);
 731             sp_curve_reset(dc->cal2);
 732
 733             sp_curve_moveto(dc->cal1, dc->point1[0]);
 734             sp_curve_moveto(dc->cal2, dc->point2[0]);
 735         }
 736
 737         NR::Point b1[BEZIER_MAX_LENGTH];
 738         gint const nb1 = sp_bezier_fit_cubic_r(b1, dc->point1, dc->npoints,
 739                                                tolerance_sq, BEZIER_MAX_BEZIERS);
 740         g_assert( nb1 * BEZIER_SIZE <= gint(G_N_ELEMENTS(b1)) );
 741
 742         NR::Point b2[BEZIER_MAX_LENGTH];
 743         gint const nb2 = sp_bezier_fit_cubic_r(b2, dc->point2, dc->npoints,
 744                                                tolerance_sq, BEZIER_MAX_BEZIERS);
 745         g_assert( nb2 * BEZIER_SIZE <= gint(G_N_ELEMENTS(b2)) );
 746
 747         if ( nb1 != -1 && nb2 != -1 ) {
 748             /* Fit and draw and reset state */
 749 #ifdef DYNA_DRAW_VERBOSE
 750             g_print("nb1:%d nb2:%d\n", nb1, nb2);
 751 #endif
 752             /* CanvasShape */
 753             if (! release) {
 754                 sp_curve_reset(dc->currentcurve);
 755                 sp_curve_moveto(dc->currentcurve, b1[0]);
 756                 for (NR::Point *bp1 = b1; bp1 < b1 + BEZIER_SIZE * nb1; bp1 += BEZIER_SIZE) {
 757                     sp_curve_curveto(dc->currentcurve, bp1[1],
 758                                      bp1[2], bp1[3]);
 759                 }
 760                 sp_curve_lineto(dc->currentcurve,
 761                                 b2[BEZIER_SIZE*(nb2-1) + 3]);
 762                 for (NR::Point *bp2 = b2 + BEZIER_SIZE * ( nb2 - 1 ); bp2 >= b2; bp2 -= BEZIER_SIZE) {
 763                     sp_curve_curveto(dc->currentcurve, bp2[2], bp2[1], bp2[0]);
 764                 }
 765                 sp_curve_closepath(dc->currentcurve);
 766                 sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(dc->currentshape), dc->currentcurve);
 767             }
 768
 769             /* Current calligraphic */
 770             for (NR::Point *bp1 = b1; bp1 < b1 + BEZIER_SIZE * nb1; bp1 += BEZIER_SIZE) {
 771                 sp_curve_curveto(dc->cal1, bp1[1], bp1[2], bp1[3]);
 772             }
 773             for (NR::Point *bp2 = b2; bp2 < b2 + BEZIER_SIZE * nb2; bp2 += BEZIER_SIZE) {
 774                 sp_curve_curveto(dc->cal2, bp2[1], bp2[2], bp2[3]);
 775             }
 776         } else {
 777             /* fixme: ??? */
 778 #ifdef DYNA_DRAW_VERBOSE
 779             g_print("[fit_and_split_calligraphics] failed to fit-cubic.\n");
 780 #endif
 781             draw_temporary_box(dc);
 782
 783             for (gint i = 1; i < dc->npoints; i++) {
 784                 sp_curve_lineto(dc->cal1, dc->point1[i]);
 785             }
 786             for (gint i = 1; i < dc->npoints; i++) {
 787                 sp_curve_lineto(dc->cal2, dc->point2[i]);
 788             }
 789         }
 790
 791         /* Fit and draw and copy last point */
 792 #ifdef DYNA_DRAW_VERBOSE
 793         g_print("[%d]Yup\n", dc->npoints);
 794 #endif
 795         if (!release) {
 796             g_assert(!sp_curve_empty(dc->currentcurve));
 797
 798             SPCanvasItem *cbp = sp_canvas_item_new(sp_desktop_sketch(SP_EVENT_CONTEXT(dc)->desktop),
 799                                                    SP_TYPE_CANVAS_BPATH,
 800                                                    NULL);
 801             SPCurve *curve = sp_curve_copy(dc->currentcurve);
 802             sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH (cbp), curve);
 803             sp_curve_unref(curve);
 804             guint32 fillColor = sp_desktop_get_color_tool(SP_ACTIVE_DESKTOP, "tools.calligraphic", true);
 805             sp_canvas_bpath_set_fill(SP_CANVAS_BPATH(cbp), fillColor , SP_WIND_RULE_EVENODD);
 806
 807             sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(cbp), 0x00000000, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 808             /* fixme: Cannot we cascade it to root more clearly? */
 809             g_signal_connect(G_OBJECT(cbp), "event", G_CALLBACK(sp_desktop_root_handler), SP_EVENT_CONTEXT(dc)->desktop);
 810
 811             dc->segments = g_slist_prepend(dc->segments, cbp);
 812         }
 813
 814         dc->point1[0] = dc->point1[dc->npoints - 1];
 815         dc->point2[0] = dc->point2[dc->npoints - 1];
 816         dc->npoints = 1;
 817     } else {
 818         draw_temporary_box(dc);
 819     }
 820 }
 821
 822 static void
 823 draw_temporary_box(SPDynaDrawContext *dc)
 824 {
 825     sp_curve_reset(dc->currentcurve);
 826     sp_curve_moveto(dc->currentcurve, dc->point1[0]);
 827     for (gint i = 1; i < dc->npoints; i++) {
 828         sp_curve_lineto(dc->currentcurve, dc->point1[i]);
 829     }
 830     for (gint i = dc->npoints-1; i >= 0; i--) {
 831         sp_curve_lineto(dc->currentcurve, dc->point2[i]);
 832     }
 833     sp_curve_closepath(dc->currentcurve);
 834     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(dc->currentshape), dc->currentcurve);
 835 }
 836
 837 /*
 838   Local Variables:
 839   mode:c++
 840   c-file-style:"stroustrup"
 841   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
 842   indent-tabs-mode:nil
 843   fill-column:99
 844   End:
 845 */
 846 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :