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->use_timeout = FALSE;
 148     ddc->timer_id = 0;
 149     ddc->dragging = FALSE;
 150
 151     ddc->mass = 0.3;
 152     ddc->drag = DRAG_DEFAULT;
 153     ddc->angle = 30.0;
 154     ddc->width = 0.2;
 155
 156     ddc->vel_thin = 0.1;
 157     ddc->flatness = 0.9;
 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
 220     ddc->is_drawing = false;
 221
 222     ddc->_message_context = new Inkscape::MessageContext((ec->desktop)->messageStack());
 223 }
 224
 225 static void
 226 sp_dyna_draw_context_set(SPEventContext *ec, gchar const *key, gchar const *val)
 227 {
 228     SPDynaDrawContext *ddc = SP_DYNA_DRAW_CONTEXT(ec);
 229
 230     if (!strcmp(key, "mass")) {
 231         double const dval = ( val ? g_ascii_strtod (val, NULL) : 0.2 );
 232         ddc->mass = CLAMP(dval, -1000.0, 1000.0);
 233     } else if (!strcmp(key, "drag")) {
 234         double const dval = ( val ? g_ascii_strtod (val, NULL) : DRAG_DEFAULT );
 235         ddc->drag = CLAMP(dval, DRAG_MIN, DRAG_MAX);
 236     } else if (!strcmp(key, "angle")) {
 237         double const dval = ( val ? g_ascii_strtod (val, NULL) : 0.0);
 238         ddc->angle = CLAMP (dval, -90, 90);
 239     } else if (!strcmp(key, "width")) {
 240         double const dval = ( val ? g_ascii_strtod (val, NULL) : 0.1 );
 241         ddc->width = CLAMP(dval, -1000.0, 1000.0);
 242     } else if (!strcmp(key, "thinning")) {
 243         double const dval = ( val ? g_ascii_strtod (val, NULL) : 0.1 );
 244         ddc->vel_thin = CLAMP(dval, -1.0, 1.0);
 245     } else if (!strcmp(key, "tremor")) {
 246         double const dval = ( val ? g_ascii_strtod (val, NULL) : 0.0 );
 247         ddc->tremor = CLAMP(dval, 0.0, 1.0);
 248     } else if (!strcmp(key, "flatness")) {
 249         double const dval = ( val ? g_ascii_strtod (val, NULL) : 1.0 );
 250         ddc->flatness = CLAMP(dval, 0, 1.0);
 251     } else if (!strcmp(key, "usepressure")) {
 252         ddc->usepressure = (val && strcmp(val, "0"));
 253     } else if (!strcmp(key, "usetilt")) {
 254         ddc->usetilt = (val && strcmp(val, "0"));
 255     }
 256
 257     //g_print("DDC: %g %g %g %g\n", ddc->mass, ddc->drag, ddc->angle, ddc->width);
 258 }
 259
 260 static double
 261 flerp(double f0, double f1, double p)
 262 {
 263     return f0 + ( f1 - f0 ) * p;
 264 }
 265
 266 /* Get normalized point */
 267 static NR::Point
 268 sp_dyna_draw_get_npoint(SPDynaDrawContext const *dc, NR::Point v)
 269 {
 270     NR::Rect drect = SP_EVENT_CONTEXT(dc)->desktop->get_display_area();
 271     double const max = MAX ( drect.dimensions()[NR::X], drect.dimensions()[NR::Y] );
 272     return NR::Point(( v[NR::X] - drect.min()[NR::X] ) / max,  ( v[NR::Y] - drect.min()[NR::Y] ) / max);
 273 }
 274
 275 /* Get view point */
 276 static NR::Point
 277 sp_dyna_draw_get_vpoint(SPDynaDrawContext const *dc, NR::Point n)
 278 {
 279     NR::Rect drect = SP_EVENT_CONTEXT(dc)->desktop->get_display_area();
 280     double const max = MAX ( drect.dimensions()[NR::X], drect.dimensions()[NR::Y] );
 281     return NR::Point(n[NR::X] * max + drect.min()[NR::X], n[NR::Y] * max + drect.min()[NR::Y]);
 282 }
 283
 284 static void
 285 sp_dyna_draw_reset(SPDynaDrawContext *dc, NR::Point p)
 286 {
 287     dc->last = dc->cur = sp_dyna_draw_get_npoint(dc, p);
 288     dc->vel = NR::Point(0,0);
 289     dc->acc = NR::Point(0,0);
 290     dc->ang = NR::Point(0,0);
 291     dc->del = NR::Point(0,0);
 292 }
 293
 294 static void
 295 sp_dyna_draw_extinput(SPDynaDrawContext *dc, GdkEvent *event)
 296 {
 297     if (gdk_event_get_axis (event, GDK_AXIS_PRESSURE, &dc->pressure))
 298         dc->pressure = CLAMP (dc->pressure, DDC_MIN_PRESSURE, DDC_MAX_PRESSURE);
 299     else
 300         dc->pressure = DDC_DEFAULT_PRESSURE;
 301
 302     if (gdk_event_get_axis (event, GDK_AXIS_XTILT, &dc->xtilt))
 303         dc->xtilt = CLAMP (dc->xtilt, DDC_MIN_TILT, DDC_MAX_TILT);
 304     else
 305         dc->xtilt = DDC_DEFAULT_TILT;
 306
 307     if (gdk_event_get_axis (event, GDK_AXIS_YTILT, &dc->ytilt))
 308         dc->ytilt = CLAMP (dc->ytilt, DDC_MIN_TILT, DDC_MAX_TILT);
 309     else
 310         dc->ytilt = DDC_DEFAULT_TILT;
 311 }
 312
 313
 314 static gboolean
 315 sp_dyna_draw_apply(SPDynaDrawContext *dc, NR::Point p)
 316 {
 317     NR::Point n = sp_dyna_draw_get_npoint(dc, p);
 318
 319     /* Calculate mass and drag */
 320     double const mass = flerp(1.0, 160.0, dc->mass);
 321     double const drag = flerp(0.0, 0.5, dc->drag * dc->drag);
 322
 323     /* Calculate force and acceleration */
 324     NR::Point force = n - dc->cur;
 325     if ( NR::L2(force) < DYNA_EPSILON ) {
 326         return FALSE;
 327     }
 328
 329     dc->acc = force / mass;
 330
 331     /* Calculate new velocity */
 332     dc->vel += dc->acc;
 333
 334     /* Calculate angle of drawing tool */
 335
 336     double a1;
 337     if (dc->usetilt) {
 338         // 1a. calculate nib angle from input device tilt:
 339         gdouble length = std::sqrt(dc->xtilt*dc->xtilt + dc->ytilt*dc->ytilt);;
 340
 341         if (length > 0) {
 342             NR::Point ang1 = NR::Point(dc->ytilt/length, dc->xtilt/length);
 343             a1 = atan2(ang1);
 344         }
 345         else
 346             a1 = 0.0;
 347     }
 348     else {
 349         // 1b. fixed dc->angle (absolutely flat nib):
 350         double const radians = ( (dc->angle - 90) / 180.0 ) * M_PI;
 351         NR::Point ang1 = NR::Point(-sin(radians),  cos(radians));
 352         a1 = atan2(ang1);
 353     }
 354
 355     // 2. perpendicular to dc->vel (absolutely non-flat nib):
 356     gdouble const mag_vel = NR::L2(dc->vel);
 357     if ( mag_vel < DYNA_EPSILON ) {
 358         return FALSE;
 359     }
 360     NR::Point ang2 = NR::rot90(dc->vel) / mag_vel;
 361
 362     // 3. Average them using flatness parameter:
 363     // calculate angles
 364     double a2 = atan2(ang2);
 365     // flip a2 to force it to be in the same half-circle as a1
 366     bool flipped = false;
 367     if (fabs (a2-a1) > 0.5*M_PI) {
 368         a2 += M_PI;
 369         flipped = true;
 370     }
 371     // normalize a2
 372     if (a2 > M_PI)
 373         a2 -= 2*M_PI;
 374     if (a2 < -M_PI)
 375         a2 += 2*M_PI;
 376     // find the flatness-weighted bisector angle, unflip if a2 was flipped
 377     // FIXME: when dc->vel is oscillating around the fixed angle, the new_ang flips back and forth. How to avoid this?
 378     double new_ang = a1 + (1 - dc->flatness) * (a2 - a1) - (flipped? M_PI : 0);
 379     // convert to point
 380     dc->ang = NR::Point (cos (new_ang), sin (new_ang));
 381
 382     /* Apply drag */
 383     dc->vel *= 1.0 - drag;
 384
 385     /* Update position */
 386     dc->last = dc->cur;
 387     dc->cur += dc->vel;
 388
 389     return TRUE;
 390 }
 391
 392 static void
 393 sp_dyna_draw_brush(SPDynaDrawContext *dc)
 394 {
 395     g_assert( dc->npoints >= 0 && dc->npoints < SAMPLING_SIZE );
 396
 397     // How much velocity thins strokestyle
 398     double vel_thin = flerp (0, 160, dc->vel_thin);
 399
 400     // Influence of pressure on thickness
 401     double pressure_thick = (dc->usepressure ? dc->pressure : 1.0);
 402
 403     double width = ( pressure_thick - vel_thin * NR::L2(dc->vel) ) * dc->width;
 404
 405     double tremble_left = 0, tremble_right = 0;
 406     if (dc->tremor > 0) {
 407         // obtain two normally distributed random variables, using polar Box-Muller transform
 408         double x1, x2, w, y1, y2;
 409         do {
 410             x1 = 2.0 * g_random_double_range(0,1) - 1.0;
 411             x2 = 2.0 * g_random_double_range(0,1) - 1.0;
 412             w = x1 * x1 + x2 * x2;
 413         } while ( w >= 1.0 );
 414         w = sqrt( (-2.0 * log( w ) ) / w );
 415         y1 = x1 * w;
 416         y2 = x2 * w;
 417
 418         // deflect both left and right edges randomly and independently, so that:
 419         // (1) dc->tremor=1 corresponds to sigma=1, decreasing dc->tremor narrows the bell curve;
 420         // (2) deflection depends on width, but is upped for small widths for better visual uniformity across widths;
 421         // (3) deflection somewhat depends on speed, to prevent fast strokes looking
 422         // comparatively smooth and slow ones excessively jittery
 423         tremble_left  = (y1)*dc->tremor * (0.15 + 0.8*width) * (0.35 + 14*NR::L2(dc->vel));
 424         tremble_right = (y2)*dc->tremor * (0.15 + 0.8*width) * (0.35 + 14*NR::L2(dc->vel));
 425     }
 426
 427     if ( width < 0.02 * dc->width ) {
 428         width = 0.02 * dc->width;
 429     }
 430
 431     NR::Point del_left = 0.05 * (width + tremble_left) * dc->ang;
 432     NR::Point del_right = 0.05 * (width + tremble_right) * dc->ang;
 433
 434     dc->point1[dc->npoints] = sp_dyna_draw_get_vpoint(dc, dc->cur + del_left);
 435     dc->point2[dc->npoints] = sp_dyna_draw_get_vpoint(dc, dc->cur - del_right);
 436
 437     dc->del = 0.5*(del_left + del_right);
 438
 439     dc->npoints++;
 440 }
 441
 442 static gint
 443 sp_dyna_draw_timeout_handler(gpointer data)
 444 {
 445     SPDynaDrawContext *dc = SP_DYNA_DRAW_CONTEXT(data);
 446     SPDesktop *desktop = SP_EVENT_CONTEXT(dc)->desktop;
 447     SPCanvas *canvas = SP_CANVAS(sp_desktop_canvas(desktop));
 448
 449     dc->dragging = TRUE;
 450
 451     int x, y;
 452     gtk_widget_get_pointer(GTK_WIDGET(canvas), &x, &y);
 453     NR::Point p = sp_canvas_window_to_world(canvas, NR::Point(x, y));
 454     p = desktop->w2d(p);
 455     if (! sp_dyna_draw_apply(dc, p)) {
 456         return TRUE;
 457     }
 458
 459     if ( dc->cur != dc->last ) {
 460         sp_dyna_draw_brush(dc);
 461         g_assert( dc->npoints > 0 );
 462         fit_and_split(dc, FALSE);
 463     }
 464
 465     return TRUE;
 466 }
 467
 468 void
 469 sp_ddc_update_toolbox (SPDesktop *desktop, const gchar *id, double value)
 470 {
 471     desktop->setToolboxAdjustmentValue (id, value);
 472 }
 473
 474 gint
 475 sp_dyna_draw_context_root_handler(SPEventContext *event_context,
 476                                   GdkEvent *event)
 477 {
 478     SPDynaDrawContext *dc = SP_DYNA_DRAW_CONTEXT(event_context);
 479     SPDesktop *desktop = event_context->desktop;
 480
 481     gint ret = FALSE;
 482
 483     switch (event->type) {
 484     case GDK_BUTTON_PRESS:
 485         if ( event->button.button == 1 ) {
 486
 487             SPDesktop *desktop = SP_EVENT_CONTEXT_DESKTOP(dc);
 488
 489             if (Inkscape::have_viable_layer(desktop, dc->_message_context) == false) {
 490                 return TRUE;
 491             }
 492
 493             NR::Point const button_w(event->button.x,
 494                                      event->button.y);
 495             NR::Point const button_dt(desktop->w2d(button_w));
 496             sp_dyna_draw_reset(dc, button_dt);
 497             sp_dyna_draw_extinput(dc, event);
 498             sp_dyna_draw_apply(dc, button_dt);
 499             sp_curve_reset(dc->accumulated);
 500             if (dc->repr) {
 501                 dc->repr = NULL;
 502             }
 503
 504             /* initialize first point */
 505             dc->npoints = 0;
 506
 507             sp_canvas_item_grab(SP_CANVAS_ITEM(desktop->acetate),
 508                                 ( dc->use_timeout
 509                                   ? ( GDK_KEY_PRESS_MASK |
 510                                       GDK_BUTTON_RELEASE_MASK |
 511                                       GDK_BUTTON_PRESS_MASK    )
 512                                   : ( GDK_KEY_PRESS_MASK |
 513                                       GDK_BUTTON_RELEASE_MASK |
 514                                       GDK_POINTER_MOTION_MASK |
 515                                       GDK_BUTTON_PRESS_MASK    ) ),
 516                                 NULL,
 517                                 event->button.time);
 518
 519             if ( dc->use_timeout && !dc->timer_id ) {
 520                 dc->timer_id = gtk_timeout_add(SAMPLE_TIMEOUT, sp_dyna_draw_timeout_handler, dc);
 521             }
 522             ret = TRUE;
 523
 524             dc->is_drawing = true;
 525         }
 526         break;
 527     case GDK_MOTION_NOTIFY:
 528         if ( dc->is_drawing && !dc->use_timeout && ( event->motion.state & GDK_BUTTON1_MASK ) ) {
 529             dc->dragging = TRUE;
 530
 531             NR::Point const motion_w(event->motion.x,
 532                                      event->motion.y);
 533             NR::Point const motion_dt(desktop->w2d(motion_w));
 534
 535             sp_dyna_draw_extinput(dc, event);
 536             if (!sp_dyna_draw_apply(dc, motion_dt)) {
 537                 ret = TRUE;
 538                 break;
 539             }
 540
 541             if ( dc->cur != dc->last ) {
 542                 sp_dyna_draw_brush(dc);
 543                 g_assert( dc->npoints > 0 );
 544                 fit_and_split(dc, FALSE);
 545             }
 546             ret = TRUE;
 547         }
 548         break;
 549
 550     case GDK_BUTTON_RELEASE:
 551         sp_canvas_item_ungrab(SP_CANVAS_ITEM(desktop->acetate), event->button.time);
 552         dc->is_drawing = false;
 553         if ( event->button.button == 1
 554              && dc->use_timeout
 555              && dc->timer_id != 0 )
 556         {
 557             gtk_timeout_remove(dc->timer_id);
 558             dc->timer_id = 0;
 559         }
 560         if ( dc->dragging && event->button.button == 1 ) {
 561             dc->dragging = FALSE;
 562
 563             /* Remove all temporary line segments */
 564             while (dc->segments) {
 565                 gtk_object_destroy(GTK_OBJECT(dc->segments->data));
 566                 dc->segments = g_slist_remove(dc->segments, dc->segments->data);
 567             }
 568             /* Create object */
 569             fit_and_split(dc, TRUE);
 570             accumulate_calligraphic(dc);
 571             set_to_accumulated(dc); /* temporal implementation */
 572             /* reset accumulated curve */
 573             sp_curve_reset(dc->accumulated);
 574             clear_current(dc);
 575             if (dc->repr) {
 576                 dc->repr = NULL;
 577             }
 578             ret = TRUE;
 579         }
 580         break;
 581     case GDK_KEY_PRESS:
 582         switch (get_group0_keyval (&event->key)) {
 583         case GDK_Up:
 584         case GDK_KP_Up:
 585             if (!MOD__CTRL_ONLY) {
 586                 dc->angle += 5.0;
 587                 if (dc->angle > 90.0)
 588                     dc->angle = 90.0;
 589                 sp_ddc_update_toolbox (desktop, "calligraphy-angle", dc->angle);
 590                 ret = TRUE;
 591             }
 592             break;
 593         case GDK_Down:
 594         case GDK_KP_Down:
 595             if (!MOD__CTRL_ONLY) {
 596                 dc->angle -= 5.0;
 597                 if (dc->angle < -90.0)
 598                     dc->angle = -90.0;
 599                 sp_ddc_update_toolbox (desktop, "calligraphy-angle", dc->angle);
 600                 ret = TRUE;
 601             }
 602             break;
 603         case GDK_Right:
 604         case GDK_KP_Right:
 605             if (!MOD__CTRL_ONLY) {
 606                 dc->width += 0.01;
 607                 if (dc->width > 1.0)
 608                     dc->width = 1.0;
 609                 sp_ddc_update_toolbox (desktop, "altx-calligraphy", dc->width); // the same spinbutton is for alt+x
 610                 ret = TRUE;
 611             }
 612             break;
 613         case GDK_Left:
 614         case GDK_KP_Left:
 615             if (!MOD__CTRL_ONLY) {
 616                 dc->width -= 0.01;
 617                 if (dc->width < 0.01)
 618                     dc->width = 0.01;
 619                 sp_ddc_update_toolbox (desktop, "altx-calligraphy", dc->width);
 620                 ret = TRUE;
 621             }
 622             break;
 623         case GDK_x:
 624         case GDK_X:
 625             if (MOD__ALT_ONLY) {
 626                 desktop->setToolboxFocusTo ("altx-calligraphy");
 627                 ret = TRUE;
 628             }
 629             break;
 630         case GDK_Escape:
 631             sp_desktop_selection(desktop)->clear();
 632             break;
 633
 634         default:
 635             break;
 636         }
 637     default:
 638         break;
 639     }
 640
 641     if (!ret) {
 642         if (((SPEventContextClass *) parent_class)->root_handler) {
 643             ret = ((SPEventContextClass *) parent_class)->root_handler(event_context, event);
 644         }
 645     }
 646
 647     return ret;
 648 }
 649
 650
 651 static void
 652 clear_current(SPDynaDrawContext *dc)
 653 {
 654     /* reset bpath */
 655     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(dc->currentshape), NULL);
 656     /* reset curve */
 657     sp_curve_reset(dc->currentcurve);
 658     sp_curve_reset(dc->cal1);
 659     sp_curve_reset(dc->cal2);
 660     /* reset points */
 661     dc->npoints = 0;
 662 }
 663
 664 static void
 665 set_to_accumulated(SPDynaDrawContext *dc)
 666 {
 667     SPDesktop *desktop = SP_EVENT_CONTEXT(dc)->desktop;
 668
 669     if (!sp_curve_empty(dc->accumulated)) {
 670         NArtBpath *abp;
 671         gchar *str;
 672
 673         if (!dc->repr) {
 674             /* Create object */
 675             Inkscape::XML::Node *repr = sp_repr_new("svg:path");
 676
 677             /* Set style */
 678             sp_desktop_apply_style_tool (desktop, repr, "tools.calligraphic", false);
 679
 680             dc->repr = repr;
 681
 682             SPItem *item=SP_ITEM(desktop->currentLayer()->appendChildRepr(dc->repr));
 683             Inkscape::GC::release(dc->repr);
 684             item->transform = SP_ITEM(desktop->currentRoot())->getRelativeTransform(desktop->currentLayer());
 685             item->updateRepr();
 686             sp_desktop_selection(desktop)->set(dc->repr);
 687         }
 688         abp = nr_artpath_affine(sp_curve_first_bpath(dc->accumulated), sp_desktop_dt2root_affine(desktop));
 689         str = sp_svg_write_path(abp);
 690         g_assert( str != NULL );
 691         nr_free(abp);
 692         dc->repr->setAttribute("d", str);
 693         g_free(str);
 694     } else {
 695         if (dc->repr) {
 696             sp_repr_unparent(dc->repr);
 697         }
 698         dc->repr = NULL;
 699     }
 700
 701     sp_document_done(sp_desktop_document(desktop));
 702 }
 703
 704 static void
 705 accumulate_calligraphic(SPDynaDrawContext *dc)
 706 {
 707     if ( !sp_curve_empty(dc->cal1) && !sp_curve_empty(dc->cal2) ) {
 708         sp_curve_reset(dc->accumulated); /*  Is this required ?? */
 709         SPCurve *rev_cal2 = sp_curve_reverse(dc->cal2);
 710         sp_curve_append(dc->accumulated, dc->cal1, FALSE);
 711         sp_curve_append(dc->accumulated, rev_cal2, TRUE);
 712         sp_curve_closepath(dc->accumulated);
 713
 714         sp_curve_unref(rev_cal2);
 715
 716         sp_curve_reset(dc->cal1);
 717         sp_curve_reset(dc->cal2);
 718     }
 719 }
 720
 721 static void
 722 fit_and_split(SPDynaDrawContext *dc,
 723               gboolean release)
 724 {
 725     fit_and_split_calligraphics(dc, release);
 726 }
 727
 728 static double square(double const x)
 729 {
 730     return x * x;
 731 }
 732
 733 static void
 734 fit_and_split_calligraphics(SPDynaDrawContext *dc, gboolean release)
 735 {
 736     double const tolerance_sq = square( NR::expansion(SP_EVENT_CONTEXT(dc)->desktop->w2d()) * TOLERANCE_CALLIGRAPHIC );
 737
 738 #ifdef DYNA_DRAW_VERBOSE
 739     g_print("[F&S:R=%c]", release?'T':'F');
 740 #endif
 741
 742     if (!( dc->npoints > 0 && dc->npoints < SAMPLING_SIZE ))
 743         return; // just clicked
 744
 745     if ( dc->npoints == SAMPLING_SIZE - 1 || release ) {
 746 #define BEZIER_SIZE       4
 747 #define BEZIER_MAX_BEZIERS  8
 748 #define BEZIER_MAX_LENGTH ( BEZIER_SIZE * BEZIER_MAX_BEZIERS )
 749
 750 #ifdef DYNA_DRAW_VERBOSE
 751         g_print("[F&S:#] dc->npoints:%d, release:%s\n",
 752                 dc->npoints, release ? "TRUE" : "FALSE");
 753 #endif
 754
 755         /* Current calligraphic */
 756         if ( dc->cal1->end == 0 || dc->cal2->end == 0 ) {
 757             /* dc->npoints > 0 */
 758             /* g_print("calligraphics(1|2) reset\n"); */
 759             sp_curve_reset(dc->cal1);
 760             sp_curve_reset(dc->cal2);
 761
 762             sp_curve_moveto(dc->cal1, dc->point1[0]);
 763             sp_curve_moveto(dc->cal2, dc->point2[0]);
 764         }
 765
 766         NR::Point b1[BEZIER_MAX_LENGTH];
 767         gint const nb1 = sp_bezier_fit_cubic_r(b1, dc->point1, dc->npoints,
 768                                                tolerance_sq, BEZIER_MAX_BEZIERS);
 769         g_assert( nb1 * BEZIER_SIZE <= gint(G_N_ELEMENTS(b1)) );
 770
 771         NR::Point b2[BEZIER_MAX_LENGTH];
 772         gint const nb2 = sp_bezier_fit_cubic_r(b2, dc->point2, dc->npoints,
 773                                                tolerance_sq, BEZIER_MAX_BEZIERS);
 774         g_assert( nb2 * BEZIER_SIZE <= gint(G_N_ELEMENTS(b2)) );
 775
 776         if ( nb1 != -1 && nb2 != -1 ) {
 777             /* Fit and draw and reset state */
 778 #ifdef DYNA_DRAW_VERBOSE
 779             g_print("nb1:%d nb2:%d\n", nb1, nb2);
 780 #endif
 781             /* CanvasShape */
 782             if (! release) {
 783                 sp_curve_reset(dc->currentcurve);
 784                 sp_curve_moveto(dc->currentcurve, b1[0]);
 785                 for (NR::Point *bp1 = b1; bp1 < b1 + BEZIER_SIZE * nb1; bp1 += BEZIER_SIZE) {
 786                     sp_curve_curveto(dc->currentcurve, bp1[1],
 787                                      bp1[2], bp1[3]);
 788                 }
 789                 sp_curve_lineto(dc->currentcurve,
 790                                 b2[BEZIER_SIZE*(nb2-1) + 3]);
 791                 for (NR::Point *bp2 = b2 + BEZIER_SIZE * ( nb2 - 1 ); bp2 >= b2; bp2 -= BEZIER_SIZE) {
 792                     sp_curve_curveto(dc->currentcurve, bp2[2], bp2[1], bp2[0]);
 793                 }
 794                 sp_curve_closepath(dc->currentcurve);
 795                 sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(dc->currentshape), dc->currentcurve);
 796             }
 797
 798             /* Current calligraphic */
 799             for (NR::Point *bp1 = b1; bp1 < b1 + BEZIER_SIZE * nb1; bp1 += BEZIER_SIZE) {
 800                 sp_curve_curveto(dc->cal1, bp1[1], bp1[2], bp1[3]);
 801             }
 802             for (NR::Point *bp2 = b2; bp2 < b2 + BEZIER_SIZE * nb2; bp2 += BEZIER_SIZE) {
 803                 sp_curve_curveto(dc->cal2, bp2[1], bp2[2], bp2[3]);
 804             }
 805         } else {
 806             /* fixme: ??? */
 807 #ifdef DYNA_DRAW_VERBOSE
 808             g_print("[fit_and_split_calligraphics] failed to fit-cubic.\n");
 809 #endif
 810             draw_temporary_box(dc);
 811
 812             for (gint i = 1; i < dc->npoints; i++) {
 813                 sp_curve_lineto(dc->cal1, dc->point1[i]);
 814             }
 815             for (gint i = 1; i < dc->npoints; i++) {
 816                 sp_curve_lineto(dc->cal2, dc->point2[i]);
 817             }
 818         }
 819
 820         /* Fit and draw and copy last point */
 821 #ifdef DYNA_DRAW_VERBOSE
 822         g_print("[%d]Yup\n", dc->npoints);
 823 #endif
 824         if (!release) {
 825             g_assert(!sp_curve_empty(dc->currentcurve));
 826
 827             SPCanvasItem *cbp = sp_canvas_item_new(sp_desktop_sketch(SP_EVENT_CONTEXT(dc)->desktop),
 828                                                    SP_TYPE_CANVAS_BPATH,
 829                                                    NULL);
 830             SPCurve *curve = sp_curve_copy(dc->currentcurve);
 831             sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH (cbp), curve);
 832             sp_curve_unref(curve);
 833             sp_canvas_bpath_set_fill(SP_CANVAS_BPATH(cbp), 0x000000ff, SP_WIND_RULE_EVENODD);
 834             sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(cbp), 0x00000000, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 835             /* fixme: Cannot we cascade it to root more clearly? */
 836             g_signal_connect(G_OBJECT(cbp), "event", G_CALLBACK(sp_desktop_root_handler), SP_EVENT_CONTEXT(dc)->desktop);
 837
 838             dc->segments = g_slist_prepend(dc->segments, cbp);
 839         }
 840
 841         dc->point1[0] = dc->point1[dc->npoints - 1];
 842         dc->point2[0] = dc->point2[dc->npoints - 1];
 843         dc->npoints = 1;
 844     } else {
 845         draw_temporary_box(dc);
 846     }
 847 }
 848
 849 static void
 850 draw_temporary_box(SPDynaDrawContext *dc)
 851 {
 852     sp_curve_reset(dc->currentcurve);
 853     sp_curve_moveto(dc->currentcurve, dc->point1[0]);
 854     for (gint i = 1; i < dc->npoints; i++) {
 855         sp_curve_lineto(dc->currentcurve, dc->point1[i]);
 856     }
 857     for (gint i = dc->npoints-1; i >= 0; i--) {
 858         sp_curve_lineto(dc->currentcurve, dc->point2[i]);
 859     }
 860     sp_curve_closepath(dc->currentcurve);
 861     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(dc->currentshape), dc->currentcurve);
 862 }
 863
 864 /*
 865   Local Variables:
 866   mode:c++
 867   c-file-style:"stroustrup"
 868   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
 869   indent-tabs-mode:nil
 870   fill-column:99
 871   End:
 872 */
 873 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :