src/dyna-draw-context.cpp

   1 #define __SP_DYNA_DRAW_CONTEXT_C__
   2
   3 /*
   4  * Handwriting-like drawing mode
   5  *
   6  * Authors:
   7  *   Mitsuru Oka <oka326@parkcity.ne.jp>
   8  *   Lauris Kaplinski <lauris@kaplinski.com>
   9  *   bulia byak <buliabyak@users.sf.net>
  10  *   MenTaLguY <mental@rydia.net>
  11  *
  12  * The original dynadraw code:
  13  *   Paul Haeberli <paul@sgi.com>
  14  *
  15  * Copyright (C) 1998 The Free Software Foundation
  16  * Copyright (C) 1999-2005 authors
  17  * Copyright (C) 2001-2002 Ximian, Inc.
  18  * Copyright (C) 2005-2006 bulia byak
  19  * Copyright (C) 2006 MenTaLguY
  20  *
  21  * Released under GNU GPL, read the file 'COPYING' for more information
  22  */
  23
  24 #define noDYNA_DRAW_VERBOSE
  25
  26 #include "config.h"
  27
  28 #include <gtk/gtk.h>
  29 #include <gdk/gdkkeysyms.h>
  30 #include <glibmm/i18n.h>
  31
  32 #include "svg/svg.h"
  33 #include "display/canvas-bpath.h"
  34 #include "display/bezier-utils.h"
  35
  36 #include <glib/gmem.h>
  37 #include "macros.h"
  38 #include "document.h"
  39 #include "selection.h"
  40 #include "desktop.h"
  41 #include "desktop-events.h"
  42 #include "desktop-handles.h"
  43 #include "desktop-affine.h"
  44 #include "desktop-style.h"
  45 #include "message-context.h"
  46 #include "pixmaps/cursor-calligraphy.xpm"
  47 #include "dyna-draw-context.h"
  48 #include "libnr/n-art-bpath.h"
  49 #include "libnr/nr-path.h"
  50 #include "xml/repr.h"
  51 #include "context-fns.h"
  52 #include "sp-item.h"
  53 #include "inkscape.h"
  54 #include "color.h"
  55
  56 #define DDC_RED_RGBA 0xff0000ff
  57
  58 #define SAMPLE_TIMEOUT 10
  59 #define TOLERANCE_LINE 1.0
  60 #define TOLERANCE_CALLIGRAPHIC 3.0
  61 #define DYNA_EPSILON 0.5e-2
  62
  63 #define DYNA_MIN_WIDTH 1.0e-6
  64
  65 #define DRAG_MIN 0.0
  66 #define DRAG_DEFAULT 1.0
  67 #define DRAG_MAX 1.0
  68
  69 static void sp_dyna_draw_context_class_init(SPDynaDrawContextClass *klass);
  70 static void sp_dyna_draw_context_init(SPDynaDrawContext *ddc);
  71 static void sp_dyna_draw_context_dispose(GObject *object);
  72
  73 static void sp_dyna_draw_context_setup(SPEventContext *ec);
  74 static void sp_dyna_draw_context_set(SPEventContext *ec, gchar const *key, gchar const *val);
  75 static gint sp_dyna_draw_context_root_handler(SPEventContext *ec, GdkEvent *event);
  76
  77 static void clear_current(SPDynaDrawContext *dc);
  78 static void set_to_accumulated(SPDynaDrawContext *dc);
  79 static void add_cap(SPCurve *curve, NR::Point const &pre, NR::Point const &from, NR::Point const &to, NR::Point const &post, double rounding);
  80 static void accumulate_calligraphic(SPDynaDrawContext *dc);
  81
  82 static void fit_and_split(SPDynaDrawContext *ddc, gboolean release);
  83
  84 static void sp_dyna_draw_reset(SPDynaDrawContext *ddc, NR::Point p);
  85 static NR::Point sp_dyna_draw_get_npoint(SPDynaDrawContext const *ddc, NR::Point v);
  86 static NR::Point sp_dyna_draw_get_vpoint(SPDynaDrawContext const *ddc, NR::Point n);
  87 static void draw_temporary_box(SPDynaDrawContext *dc);
  88
  89
  90 static SPEventContextClass *parent_class;
  91
  92 GtkType
  93 sp_dyna_draw_context_get_type(void)
  94 {
  95     static GType type = 0;
  96     if (!type) {
  97         GTypeInfo info = {
  98             sizeof(SPDynaDrawContextClass),
  99             NULL, NULL,
 100             (GClassInitFunc) sp_dyna_draw_context_class_init,
 101             NULL, NULL,
 102             sizeof(SPDynaDrawContext),
 103             4,
 104             (GInstanceInitFunc) sp_dyna_draw_context_init,
 105             NULL,   /* value_table */
 106         };
 107         type = g_type_register_static(SP_TYPE_EVENT_CONTEXT, "SPDynaDrawContext", &info, (GTypeFlags)0);
 108     }
 109     return type;
 110 }
 111
 112 static void
 113 sp_dyna_draw_context_class_init(SPDynaDrawContextClass *klass)
 114 {
 115     GObjectClass *object_class = (GObjectClass *) klass;
 116     SPEventContextClass *event_context_class = (SPEventContextClass *) klass;
 117
 118     parent_class = (SPEventContextClass*)g_type_class_peek_parent(klass);
 119
 120     object_class->dispose = sp_dyna_draw_context_dispose;
 121
 122     event_context_class->setup = sp_dyna_draw_context_setup;
 123     event_context_class->set = sp_dyna_draw_context_set;
 124     event_context_class->root_handler = sp_dyna_draw_context_root_handler;
 125 }
 126
 127 static void
 128 sp_dyna_draw_context_init(SPDynaDrawContext *ddc)
 129 {
 130     SPEventContext *event_context = SP_EVENT_CONTEXT(ddc);
 131
 132     event_context->cursor_shape = cursor_calligraphy_xpm;
 133     event_context->hot_x = 4;
 134     event_context->hot_y = 4;
 135
 136     ddc->accumulated = NULL;
 137     ddc->segments = NULL;
 138     ddc->currentcurve = NULL;
 139     ddc->currentshape = NULL;
 140     ddc->npoints = 0;
 141     ddc->cal1 = NULL;
 142     ddc->cal2 = NULL;
 143     ddc->repr = NULL;
 144
 145     /* DynaDraw values */
 146     ddc->cur = NR::Point(0,0);
 147     ddc->last = NR::Point(0,0);
 148     ddc->vel = NR::Point(0,0);
 149     ddc->acc = NR::Point(0,0);
 150     ddc->ang = NR::Point(0,0);
 151     ddc->del = NR::Point(0,0);
 152
 153     /* attributes */
 154     ddc->dragging = FALSE;
 155
 156     ddc->mass = 0.3;
 157     ddc->drag = DRAG_DEFAULT;
 158     ddc->angle = 30.0;
 159     ddc->width = 0.2;
 160
 161     ddc->vel_thin = 0.1;
 162     ddc->flatness = 0.9;
 163     ddc->cap_rounding = 0.0;
 164
 165     ddc->abs_width = false;
 166     ddc->keep_selected = true;
 167 }
 168
 169 static void
 170 sp_dyna_draw_context_dispose(GObject *object)
 171 {
 172     SPDynaDrawContext *ddc = SP_DYNA_DRAW_CONTEXT(object);
 173
 174     if (ddc->accumulated) {
 175         ddc->accumulated = sp_curve_unref(ddc->accumulated);
 176     }
 177
 178     while (ddc->segments) {
 179         gtk_object_destroy(GTK_OBJECT(ddc->segments->data));
 180         ddc->segments = g_slist_remove(ddc->segments, ddc->segments->data);
 181     }
 182
 183     if (ddc->currentcurve) ddc->currentcurve = sp_curve_unref(ddc->currentcurve);
 184     if (ddc->cal1) ddc->cal1 = sp_curve_unref(ddc->cal1);
 185     if (ddc->cal2) ddc->cal2 = sp_curve_unref(ddc->cal2);
 186
 187     if (ddc->currentshape) {
 188         gtk_object_destroy(GTK_OBJECT(ddc->currentshape));
 189         ddc->currentshape = NULL;
 190     }
 191
 192     if (ddc->_message_context) {
 193         delete ddc->_message_context;
 194     }
 195
 196     G_OBJECT_CLASS(parent_class)->dispose(object);
 197 }
 198
 199 static void
 200 sp_dyna_draw_context_setup(SPEventContext *ec)
 201 {
 202     SPDynaDrawContext *ddc = SP_DYNA_DRAW_CONTEXT(ec);
 203
 204     if (((SPEventContextClass *) parent_class)->setup)
 205         ((SPEventContextClass *) parent_class)->setup(ec);
 206
 207     ddc->accumulated = sp_curve_new_sized(32);
 208     ddc->currentcurve = sp_curve_new_sized(4);
 209
 210     ddc->cal1 = sp_curve_new_sized(32);
 211     ddc->cal2 = sp_curve_new_sized(32);
 212
 213     ddc->currentshape = sp_canvas_item_new(sp_desktop_sketch(ec->desktop), SP_TYPE_CANVAS_BPATH, NULL);
 214     sp_canvas_bpath_set_fill(SP_CANVAS_BPATH(ddc->currentshape), DDC_RED_RGBA, SP_WIND_RULE_EVENODD);
 215     sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(ddc->currentshape), 0x00000000, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 216     /* fixme: Cannot we cascade it to root more clearly? */
 217     g_signal_connect(G_OBJECT(ddc->currentshape), "event", G_CALLBACK(sp_desktop_root_handler), ec->desktop);
 218
 219     sp_event_context_read(ec, "mass");
 220     sp_event_context_read(ec, "wiggle");
 221     sp_event_context_read(ec, "angle");
 222     sp_event_context_read(ec, "width");
 223     sp_event_context_read(ec, "thinning");
 224     sp_event_context_read(ec, "tremor");
 225     sp_event_context_read(ec, "flatness");
 226     sp_event_context_read(ec, "usepressure");
 227     sp_event_context_read(ec, "usetilt");
 228     sp_event_context_read(ec, "abs_width");
 229     sp_event_context_read(ec, "keep_selected");
 230     sp_event_context_read(ec, "cap_rounding");
 231
 232     ddc->is_drawing = false;
 233
 234     ddc->_message_context = new Inkscape::MessageContext((ec->desktop)->messageStack());
 235 }
 236
 237 static void
 238 sp_dyna_draw_context_set(SPEventContext *ec, gchar const *key, gchar const *val)
 239 {
 240     SPDynaDrawContext *ddc = SP_DYNA_DRAW_CONTEXT(ec);
 241
 242     if (!strcmp(key, "mass")) {
 243         double const dval = ( val ? g_ascii_strtod (val, NULL) : 0.2 );
 244         ddc->mass = CLAMP(dval, -1000.0, 1000.0);
 245     } else if (!strcmp(key, "wiggle")) {
 246         double const dval = ( val ? g_ascii_strtod (val, NULL) : (1 - DRAG_DEFAULT));
 247         ddc->drag = CLAMP((1 - dval), DRAG_MIN, DRAG_MAX); // drag is inverse to wiggle
 248     } else if (!strcmp(key, "angle")) {
 249         double const dval = ( val ? g_ascii_strtod (val, NULL) : 0.0);
 250         ddc->angle = CLAMP (dval, -90, 90);
 251     } else if (!strcmp(key, "width")) {
 252         double const dval = ( val ? g_ascii_strtod (val, NULL) : 0.1 );
 253         ddc->width = CLAMP(dval, -1000.0, 1000.0);
 254     } else if (!strcmp(key, "thinning")) {
 255         double const dval = ( val ? g_ascii_strtod (val, NULL) : 0.1 );
 256         ddc->vel_thin = CLAMP(dval, -1.0, 1.0);
 257     } else if (!strcmp(key, "tremor")) {
 258         double const dval = ( val ? g_ascii_strtod (val, NULL) : 0.0 );
 259         ddc->tremor = CLAMP(dval, 0.0, 1.0);
 260     } else if (!strcmp(key, "flatness")) {
 261         double const dval = ( val ? g_ascii_strtod (val, NULL) : 1.0 );
 262         ddc->flatness = CLAMP(dval, 0, 1.0);
 263     } else if (!strcmp(key, "usepressure")) {
 264         ddc->usepressure = (val && strcmp(val, "0"));
 265     } else if (!strcmp(key, "usetilt")) {
 266         ddc->usetilt = (val && strcmp(val, "0"));
 267     } else if (!strcmp(key, "abs_width")) {
 268         ddc->abs_width = (val && strcmp(val, "0"));
 269     } else if (!strcmp(key, "keep_selected")) {
 270         ddc->keep_selected = (val && strcmp(val, "0"));
 271     } else if (!strcmp(key, "cap_rounding")) {
 272         ddc->cap_rounding = ( val ? g_ascii_strtod (val, NULL) : 0.0 );
 273     }
 274
 275     //g_print("DDC: %g %g %g %g\n", ddc->mass, ddc->drag, ddc->angle, ddc->width);
 276 }
 277
 278 static double
 279 flerp(double f0, double f1, double p)
 280 {
 281     return f0 + ( f1 - f0 ) * p;
 282 }
 283
 284 /* Get normalized point */
 285 static NR::Point
 286 sp_dyna_draw_get_npoint(SPDynaDrawContext const *dc, NR::Point v)
 287 {
 288     NR::Rect drect = SP_EVENT_CONTEXT(dc)->desktop->get_display_area();
 289     double const max = MAX ( drect.dimensions()[NR::X], drect.dimensions()[NR::Y] );
 290     return NR::Point(( v[NR::X] - drect.min()[NR::X] ) / max,  ( v[NR::Y] - drect.min()[NR::Y] ) / max);
 291 }
 292
 293 /* Get view point */
 294 static NR::Point
 295 sp_dyna_draw_get_vpoint(SPDynaDrawContext const *dc, NR::Point n)
 296 {
 297     NR::Rect drect = SP_EVENT_CONTEXT(dc)->desktop->get_display_area();
 298     double const max = MAX ( drect.dimensions()[NR::X], drect.dimensions()[NR::Y] );
 299     return NR::Point(n[NR::X] * max + drect.min()[NR::X], n[NR::Y] * max + drect.min()[NR::Y]);
 300 }
 301
 302 static void
 303 sp_dyna_draw_reset(SPDynaDrawContext *dc, NR::Point p)
 304 {
 305     dc->last = dc->cur = sp_dyna_draw_get_npoint(dc, p);
 306     dc->vel = NR::Point(0,0);
 307     dc->acc = NR::Point(0,0);
 308     dc->ang = NR::Point(0,0);
 309     dc->del = NR::Point(0,0);
 310 }
 311
 312 static void
 313 sp_dyna_draw_extinput(SPDynaDrawContext *dc, GdkEvent *event)
 314 {
 315     if (gdk_event_get_axis (event, GDK_AXIS_PRESSURE, &dc->pressure))
 316         dc->pressure = CLAMP (dc->pressure, DDC_MIN_PRESSURE, DDC_MAX_PRESSURE);
 317     else
 318         dc->pressure = DDC_DEFAULT_PRESSURE;
 319
 320     if (gdk_event_get_axis (event, GDK_AXIS_XTILT, &dc->xtilt))
 321         dc->xtilt = CLAMP (dc->xtilt, DDC_MIN_TILT, DDC_MAX_TILT);
 322     else
 323         dc->xtilt = DDC_DEFAULT_TILT;
 324
 325     if (gdk_event_get_axis (event, GDK_AXIS_YTILT, &dc->ytilt))
 326         dc->ytilt = CLAMP (dc->ytilt, DDC_MIN_TILT, DDC_MAX_TILT);
 327     else
 328         dc->ytilt = DDC_DEFAULT_TILT;
 329 }
 330
 331
 332 static gboolean
 333 sp_dyna_draw_apply(SPDynaDrawContext *dc, NR::Point p)
 334 {
 335     NR::Point n = sp_dyna_draw_get_npoint(dc, p);
 336
 337     /* Calculate mass and drag */
 338     double const mass = flerp(1.0, 160.0, dc->mass);
 339     double const drag = flerp(0.0, 0.5, dc->drag * dc->drag);
 340
 341     /* Calculate force and acceleration */
 342     NR::Point force = n - dc->cur;
 343     if ( NR::L2(force) < DYNA_EPSILON ) {
 344         return FALSE;
 345     }
 346
 347     dc->acc = force / mass;
 348
 349     /* Calculate new velocity */
 350     dc->vel += dc->acc;
 351
 352     /* Calculate angle of drawing tool */
 353
 354     double a1;
 355     if (dc->usetilt) {
 356         // 1a. calculate nib angle from input device tilt:
 357         gdouble length = std::sqrt(dc->xtilt*dc->xtilt + dc->ytilt*dc->ytilt);;
 358
 359         if (length > 0) {
 360             NR::Point ang1 = NR::Point(dc->ytilt/length, dc->xtilt/length);
 361             a1 = atan2(ang1);
 362         }
 363         else
 364             a1 = 0.0;
 365     }
 366     else {
 367         // 1b. fixed dc->angle (absolutely flat nib):
 368         double const radians = ( (dc->angle - 90) / 180.0 ) * M_PI;
 369         NR::Point ang1 = NR::Point(-sin(radians),  cos(radians));
 370         a1 = atan2(ang1);
 371     }
 372
 373     // 2. perpendicular to dc->vel (absolutely non-flat nib):
 374     gdouble const mag_vel = NR::L2(dc->vel);
 375     if ( mag_vel < DYNA_EPSILON ) {
 376         return FALSE;
 377     }
 378     NR::Point ang2 = NR::rot90(dc->vel) / mag_vel;
 379
 380     // 3. Average them using flatness parameter:
 381     // calculate angles
 382     double a2 = atan2(ang2);
 383     // flip a2 to force it to be in the same half-circle as a1
 384     bool flipped = false;
 385     if (fabs (a2-a1) > 0.5*M_PI) {
 386         a2 += M_PI;
 387         flipped = true;
 388     }
 389     // normalize a2
 390     if (a2 > M_PI)
 391         a2 -= 2*M_PI;
 392     if (a2 < -M_PI)
 393         a2 += 2*M_PI;
 394     // find the flatness-weighted bisector angle, unflip if a2 was flipped
 395     // FIXME: when dc->vel is oscillating around the fixed angle, the new_ang flips back and forth. How to avoid this?
 396     double new_ang = a1 + (1 - dc->flatness) * (a2 - a1) - (flipped? M_PI : 0);
 397     // convert to point
 398     dc->ang = NR::Point (cos (new_ang), sin (new_ang));
 399
 400     /* Apply drag */
 401     dc->vel *= 1.0 - drag;
 402
 403     /* Update position */
 404     dc->last = dc->cur;
 405     dc->cur += dc->vel;
 406
 407     return TRUE;
 408 }
 409
 410 static void
 411 sp_dyna_draw_brush(SPDynaDrawContext *dc)
 412 {
 413     g_assert( dc->npoints >= 0 && dc->npoints < SAMPLING_SIZE );
 414
 415     // How much velocity thins strokestyle
 416     double vel_thin = flerp (0, 160, dc->vel_thin);
 417
 418     // Influence of pressure on thickness
 419     double pressure_thick = (dc->usepressure ? dc->pressure : 1.0);
 420
 421     double width = ( pressure_thick - vel_thin * NR::L2(dc->vel) ) * dc->width;
 422
 423     double tremble_left = 0, tremble_right = 0;
 424     if (dc->tremor > 0) {
 425         // obtain two normally distributed random variables, using polar Box-Muller transform
 426         double x1, x2, w, y1, y2;
 427         do {
 428             x1 = 2.0 * g_random_double_range(0,1) - 1.0;
 429             x2 = 2.0 * g_random_double_range(0,1) - 1.0;
 430             w = x1 * x1 + x2 * x2;
 431         } while ( w >= 1.0 );
 432         w = sqrt( (-2.0 * log( w ) ) / w );
 433         y1 = x1 * w;
 434         y2 = x2 * w;
 435
 436         // deflect both left and right edges randomly and independently, so that:
 437         // (1) dc->tremor=1 corresponds to sigma=1, decreasing dc->tremor narrows the bell curve;
 438         // (2) deflection depends on width, but is upped for small widths for better visual uniformity across widths;
 439         // (3) deflection somewhat depends on speed, to prevent fast strokes looking
 440         // comparatively smooth and slow ones excessively jittery
 441         tremble_left  = (y1)*dc->tremor * (0.15 + 0.8*width) * (0.35 + 14*NR::L2(dc->vel));
 442         tremble_right = (y2)*dc->tremor * (0.15 + 0.8*width) * (0.35 + 14*NR::L2(dc->vel));
 443     }
 444
 445     if ( width < 0.02 * dc->width ) {
 446         width = 0.02 * dc->width;
 447     }
 448
 449     double dezoomify_factor = 0.05 * 1000;
 450     if (!dc->abs_width) {
 451         dezoomify_factor /= SP_EVENT_CONTEXT(dc)->desktop->current_zoom();
 452     }
 453
 454     NR::Point del_left = dezoomify_factor * (width + tremble_left) * dc->ang;
 455     NR::Point del_right = dezoomify_factor * (width + tremble_right) * dc->ang;
 456
 457     NR::Point abs_middle = sp_dyna_draw_get_vpoint(dc, dc->cur);
 458
 459     dc->point1[dc->npoints] = abs_middle + del_left;
 460     dc->point2[dc->npoints] = abs_middle - del_right;
 461
 462     dc->del = 0.5*(del_left + del_right);
 463
 464     dc->npoints++;
 465 }
 466
 467 void
 468 sp_ddc_update_toolbox (SPDesktop *desktop, const gchar *id, double value)
 469 {
 470     desktop->setToolboxAdjustmentValue (id, value);
 471 }
 472
 473 gint
 474 sp_dyna_draw_context_root_handler(SPEventContext *event_context,
 475                                   GdkEvent *event)
 476 {
 477     SPDynaDrawContext *dc = SP_DYNA_DRAW_CONTEXT(event_context);
 478     SPDesktop *desktop = event_context->desktop;
 479
 480     gint ret = FALSE;
 481
 482     switch (event->type) {
 483     case GDK_BUTTON_PRESS:
 484         if ( event->button.button == 1 ) {
 485
 486             SPDesktop *desktop = SP_EVENT_CONTEXT_DESKTOP(dc);
 487
 488             if (Inkscape::have_viable_layer(desktop, dc->_message_context) == false) {
 489                 return TRUE;
 490             }
 491
 492             NR::Point const button_w(event->button.x,
 493                                      event->button.y);
 494             NR::Point const button_dt(desktop->w2d(button_w));
 495             sp_dyna_draw_reset(dc, button_dt);
 496             sp_dyna_draw_extinput(dc, event);
 497             sp_dyna_draw_apply(dc, button_dt);
 498             sp_curve_reset(dc->accumulated);
 499             if (dc->repr) {
 500                 dc->repr = NULL;
 501             }
 502
 503             /* initialize first point */
 504             dc->npoints = 0;
 505
 506             sp_canvas_item_grab(SP_CANVAS_ITEM(desktop->acetate),
 507                                 ( GDK_KEY_PRESS_MASK |
 508                                   GDK_BUTTON_RELEASE_MASK |
 509                                   GDK_POINTER_MOTION_MASK |
 510                                   GDK_BUTTON_PRESS_MASK ),
 511                                 NULL,
 512                                 event->button.time);
 513
 514             ret = TRUE;
 515
 516             dc->is_drawing = true;
 517         }
 518         break;
 519     case GDK_MOTION_NOTIFY:
 520         if ( dc->is_drawing && ( event->motion.state & GDK_BUTTON1_MASK ) ) {
 521             dc->dragging = TRUE;
 522
 523             NR::Point const motion_w(event->motion.x,
 524                                      event->motion.y);
 525             NR::Point const motion_dt(desktop->w2d(motion_w));
 526
 527             sp_dyna_draw_extinput(dc, event);
 528             if (!sp_dyna_draw_apply(dc, motion_dt)) {
 529                 ret = TRUE;
 530                 break;
 531             }
 532
 533             if ( dc->cur != dc->last ) {
 534                 sp_dyna_draw_brush(dc);
 535                 g_assert( dc->npoints > 0 );
 536                 fit_and_split(dc, FALSE);
 537             }
 538             ret = TRUE;
 539         }
 540         break;
 541
 542     case GDK_BUTTON_RELEASE:
 543         sp_canvas_item_ungrab(SP_CANVAS_ITEM(desktop->acetate), event->button.time);
 544         dc->is_drawing = false;
 545
 546         if ( dc->dragging && event->button.button == 1 ) {
 547             dc->dragging = FALSE;
 548
 549             NR::Point const motion_w(event->button.x, event->button.y);
 550             NR::Point const motion_dt(desktop->w2d(motion_w));
 551             sp_dyna_draw_apply(dc, motion_dt);
 552
 553             /* Remove all temporary line segments */
 554             while (dc->segments) {
 555                 gtk_object_destroy(GTK_OBJECT(dc->segments->data));
 556                 dc->segments = g_slist_remove(dc->segments, dc->segments->data);
 557             }
 558             /* Create object */
 559             fit_and_split(dc, TRUE);
 560             accumulate_calligraphic(dc);
 561             set_to_accumulated(dc); /* temporal implementation */
 562             /* reset accumulated curve */
 563             sp_curve_reset(dc->accumulated);
 564             clear_current(dc);
 565             if (dc->repr) {
 566                 dc->repr = NULL;
 567             }
 568             ret = TRUE;
 569         }
 570         break;
 571     case GDK_KEY_PRESS:
 572         switch (get_group0_keyval (&event->key)) {
 573         case GDK_Up:
 574         case GDK_KP_Up:
 575             if (!MOD__CTRL_ONLY) {
 576                 dc->angle += 5.0;
 577                 if (dc->angle > 90.0)
 578                     dc->angle = 90.0;
 579                 sp_ddc_update_toolbox (desktop, "calligraphy-angle", dc->angle);
 580                 ret = TRUE;
 581             }
 582             break;
 583         case GDK_Down:
 584         case GDK_KP_Down:
 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_Right:
 594         case GDK_KP_Right:
 595             if (!MOD__CTRL_ONLY) {
 596                 dc->width += 0.01;
 597                 if (dc->width > 1.0)
 598                     dc->width = 1.0;
 599                 sp_ddc_update_toolbox (desktop, "altx-calligraphy", dc->width * 100); // the same spinbutton is for alt+x
 600                 ret = TRUE;
 601             }
 602             break;
 603         case GDK_Left:
 604         case GDK_KP_Left:
 605             if (!MOD__CTRL_ONLY) {
 606                 dc->width -= 0.01;
 607                 if (dc->width < 0.01)
 608                     dc->width = 0.01;
 609                 sp_ddc_update_toolbox (desktop, "altx-calligraphy", dc->width * 100);
 610                 ret = TRUE;
 611             }
 612             break;
 613         case GDK_x:
 614         case GDK_X:
 615             if (MOD__ALT_ONLY) {
 616                 desktop->setToolboxFocusTo ("altx-calligraphy");
 617                 ret = TRUE;
 618             }
 619             break;
 620         case GDK_Escape:
 621             sp_desktop_selection(desktop)->clear();
 622             break;
 623
 624         default:
 625             break;
 626         }
 627     default:
 628         break;
 629     }
 630
 631     if (!ret) {
 632         if (((SPEventContextClass *) parent_class)->root_handler) {
 633             ret = ((SPEventContextClass *) parent_class)->root_handler(event_context, event);
 634         }
 635     }
 636
 637     return ret;
 638 }
 639
 640
 641 static void
 642 clear_current(SPDynaDrawContext *dc)
 643 {
 644     /* reset bpath */
 645     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(dc->currentshape), NULL);
 646     /* reset curve */
 647     sp_curve_reset(dc->currentcurve);
 648     sp_curve_reset(dc->cal1);
 649     sp_curve_reset(dc->cal2);
 650     /* reset points */
 651     dc->npoints = 0;
 652 }
 653
 654 static void
 655 set_to_accumulated(SPDynaDrawContext *dc)
 656 {
 657     SPDesktop *desktop = SP_EVENT_CONTEXT(dc)->desktop;
 658
 659     if (!sp_curve_empty(dc->accumulated)) {
 660         NArtBpath *abp;
 661         gchar *str;
 662
 663         if (!dc->repr) {
 664             /* Create object */
 665             Inkscape::XML::Node *repr = sp_repr_new("svg:path");
 666
 667             /* Set style */
 668             sp_desktop_apply_style_tool (desktop, repr, "tools.calligraphic", false);
 669
 670             dc->repr = repr;
 671
 672             SPItem *item=SP_ITEM(desktop->currentLayer()->appendChildRepr(dc->repr));
 673             Inkscape::GC::release(dc->repr);
 674             item->transform = SP_ITEM(desktop->currentRoot())->getRelativeTransform(desktop->currentLayer());
 675             item->updateRepr();
 676             if (dc->keep_selected) {
 677                 sp_desktop_selection(desktop)->set(dc->repr);
 678             } else {
 679                 sp_desktop_selection(desktop)->clear();
 680             }
 681         }
 682         abp = nr_artpath_affine(sp_curve_first_bpath(dc->accumulated), sp_desktop_dt2root_affine(desktop));
 683         str = sp_svg_write_path(abp);
 684         g_assert( str != NULL );
 685         g_free(abp);
 686         dc->repr->setAttribute("d", str);
 687         g_free(str);
 688     } else {
 689         if (dc->repr) {
 690             sp_repr_unparent(dc->repr);
 691         }
 692         dc->repr = NULL;
 693     }
 694
 695     sp_document_done(sp_desktop_document(desktop), SP_VERB_CONTEXT_CALLIGRAPHIC,
 696                      _("Create calligraphic stroke"));
 697 }
 698
 699 static void
 700 add_cap(SPCurve *curve,
 701         NR::Point const &pre, NR::Point const &from,
 702         NR::Point const &to, NR::Point const &post,
 703         double rounding)
 704 {
 705     NR::Point vel = rounding * NR::rot90( to - from ) / sqrt(2.0);
 706     double mag = NR::L2(vel);
 707
 708     NR::Point v_in = from - pre;
 709     double mag_in = NR::L2(v_in);
 710     if ( mag_in > DYNA_EPSILON ) {
 711         v_in = mag * v_in / mag_in;
 712     } else {
 713         v_in = NR::Point(0, 0);
 714     }
 715
 716     NR::Point v_out = to - post;
 717     double mag_out = NR::L2(v_out);
 718     if ( mag_out > DYNA_EPSILON ) {
 719         v_out = mag * v_out / mag_out;
 720     } else {
 721         v_out = NR::Point(0, 0);
 722     }
 723
 724     if ( NR::L2(v_in) > DYNA_EPSILON || NR::L2(v_out) > DYNA_EPSILON ) {
 725         sp_curve_curveto(curve, from + v_in, to + v_out, to);
 726     }
 727 }
 728
 729 static void
 730 accumulate_calligraphic(SPDynaDrawContext *dc)
 731 {
 732     if ( !sp_curve_empty(dc->cal1) && !sp_curve_empty(dc->cal2) ) {
 733         sp_curve_reset(dc->accumulated); /*  Is this required ?? */
 734         SPCurve *rev_cal2 = sp_curve_reverse(dc->cal2);
 735
 736         g_assert(dc->cal1->end > 1);
 737         g_assert(rev_cal2->end > 1);
 738         g_assert(SP_CURVE_SEGMENT(dc->cal1, 0)->code == NR_MOVETO_OPEN);
 739         g_assert(SP_CURVE_SEGMENT(rev_cal2, 0)->code == NR_MOVETO_OPEN);
 740         g_assert(SP_CURVE_SEGMENT(dc->cal1, 1)->code == NR_CURVETO);
 741         g_assert(SP_CURVE_SEGMENT(rev_cal2, 1)->code == NR_CURVETO);
 742         g_assert(SP_CURVE_SEGMENT(dc->cal1, dc->cal1->end-1)->code == NR_CURVETO);
 743         g_assert(SP_CURVE_SEGMENT(rev_cal2, rev_cal2->end-1)->code == NR_CURVETO);
 744
 745         sp_curve_append(dc->accumulated, dc->cal1, FALSE);
 746
 747         add_cap(dc->accumulated, SP_CURVE_SEGMENT(dc->cal1, dc->cal1->end-1)->c(2), SP_CURVE_SEGMENT(dc->cal1, dc->cal1->end-1)->c(3), SP_CURVE_SEGMENT(rev_cal2, 0)->c(3), SP_CURVE_SEGMENT(rev_cal2, 1)->c(1), dc->cap_rounding);
 748
 749         sp_curve_append(dc->accumulated, rev_cal2, TRUE);
 750
 751         add_cap(dc->accumulated, SP_CURVE_SEGMENT(rev_cal2, rev_cal2->end-1)->c(2), SP_CURVE_SEGMENT(rev_cal2, rev_cal2->end-1)->c(3), SP_CURVE_SEGMENT(dc->cal1, 0)->c(3), SP_CURVE_SEGMENT(dc->cal1, 1)->c(1), dc->cap_rounding);
 752
 753         sp_curve_closepath(dc->accumulated);
 754
 755         sp_curve_unref(rev_cal2);
 756
 757         sp_curve_reset(dc->cal1);
 758         sp_curve_reset(dc->cal2);
 759     }
 760 }
 761
 762 static double square(double const x)
 763 {
 764     return x * x;
 765 }
 766
 767 static void
 768 fit_and_split(SPDynaDrawContext *dc, gboolean release)
 769 {
 770     double const tolerance_sq = square( NR::expansion(SP_EVENT_CONTEXT(dc)->desktop->w2d()) * TOLERANCE_CALLIGRAPHIC );
 771
 772 #ifdef DYNA_DRAW_VERBOSE
 773     g_print("[F&S:R=%c]", release?'T':'F');
 774 #endif
 775
 776     if (!( dc->npoints > 0 && dc->npoints < SAMPLING_SIZE ))
 777         return; // just clicked
 778
 779     if ( dc->npoints == SAMPLING_SIZE - 1 || release ) {
 780 #define BEZIER_SIZE       4
 781 #define BEZIER_MAX_BEZIERS  8
 782 #define BEZIER_MAX_LENGTH ( BEZIER_SIZE * BEZIER_MAX_BEZIERS )
 783
 784 #ifdef DYNA_DRAW_VERBOSE
 785         g_print("[F&S:#] dc->npoints:%d, release:%s\n",
 786                 dc->npoints, release ? "TRUE" : "FALSE");
 787 #endif
 788
 789         /* Current calligraphic */
 790         if ( dc->cal1->end == 0 || dc->cal2->end == 0 ) {
 791             /* dc->npoints > 0 */
 792             /* g_print("calligraphics(1|2) reset\n"); */
 793             sp_curve_reset(dc->cal1);
 794             sp_curve_reset(dc->cal2);
 795
 796             sp_curve_moveto(dc->cal1, dc->point1[0]);
 797             sp_curve_moveto(dc->cal2, dc->point2[0]);
 798         }
 799
 800         NR::Point b1[BEZIER_MAX_LENGTH];
 801         gint const nb1 = sp_bezier_fit_cubic_r(b1, dc->point1, dc->npoints,
 802                                                tolerance_sq, BEZIER_MAX_BEZIERS);
 803         g_assert( nb1 * BEZIER_SIZE <= gint(G_N_ELEMENTS(b1)) );
 804
 805         NR::Point b2[BEZIER_MAX_LENGTH];
 806         gint const nb2 = sp_bezier_fit_cubic_r(b2, dc->point2, dc->npoints,
 807                                                tolerance_sq, BEZIER_MAX_BEZIERS);
 808         g_assert( nb2 * BEZIER_SIZE <= gint(G_N_ELEMENTS(b2)) );
 809
 810         if ( nb1 != -1 && nb2 != -1 ) {
 811             /* Fit and draw and reset state */
 812 #ifdef DYNA_DRAW_VERBOSE
 813             g_print("nb1:%d nb2:%d\n", nb1, nb2);
 814 #endif
 815             /* CanvasShape */
 816             if (! release) {
 817                 sp_curve_reset(dc->currentcurve);
 818                 sp_curve_moveto(dc->currentcurve, b1[0]);
 819                 for (NR::Point *bp1 = b1; bp1 < b1 + BEZIER_SIZE * nb1; bp1 += BEZIER_SIZE) {
 820                     sp_curve_curveto(dc->currentcurve, bp1[1],
 821                                      bp1[2], bp1[3]);
 822                 }
 823                 sp_curve_lineto(dc->currentcurve,
 824                                 b2[BEZIER_SIZE*(nb2-1) + 3]);
 825                 for (NR::Point *bp2 = b2 + BEZIER_SIZE * ( nb2 - 1 ); bp2 >= b2; bp2 -= BEZIER_SIZE) {
 826                     sp_curve_curveto(dc->currentcurve, bp2[2], bp2[1], bp2[0]);
 827                 }
 828                 // FIXME: dc->segments is always NULL at this point??
 829                 if (!dc->segments) { // first segment
 830                     add_cap(dc->currentcurve, b2[1], b2[0], b1[0], b1[1], dc->cap_rounding);
 831                 }
 832                 sp_curve_closepath(dc->currentcurve);
 833                 sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(dc->currentshape), dc->currentcurve);
 834             }
 835
 836             /* Current calligraphic */
 837             for (NR::Point *bp1 = b1; bp1 < b1 + BEZIER_SIZE * nb1; bp1 += BEZIER_SIZE) {
 838                 sp_curve_curveto(dc->cal1, bp1[1], bp1[2], bp1[3]);
 839             }
 840             for (NR::Point *bp2 = b2; bp2 < b2 + BEZIER_SIZE * nb2; bp2 += BEZIER_SIZE) {
 841                 sp_curve_curveto(dc->cal2, bp2[1], bp2[2], bp2[3]);
 842             }
 843         } else {
 844             /* fixme: ??? */
 845 #ifdef DYNA_DRAW_VERBOSE
 846             g_print("[fit_and_split] failed to fit-cubic.\n");
 847 #endif
 848             draw_temporary_box(dc);
 849
 850             for (gint i = 1; i < dc->npoints; i++) {
 851                 sp_curve_lineto(dc->cal1, dc->point1[i]);
 852             }
 853             for (gint i = 1; i < dc->npoints; i++) {
 854                 sp_curve_lineto(dc->cal2, dc->point2[i]);
 855             }
 856         }
 857
 858         /* Fit and draw and copy last point */
 859 #ifdef DYNA_DRAW_VERBOSE
 860         g_print("[%d]Yup\n", dc->npoints);
 861 #endif
 862         if (!release) {
 863             g_assert(!sp_curve_empty(dc->currentcurve));
 864
 865             SPCanvasItem *cbp = sp_canvas_item_new(sp_desktop_sketch(SP_EVENT_CONTEXT(dc)->desktop),
 866                                                    SP_TYPE_CANVAS_BPATH,
 867                                                    NULL);
 868             SPCurve *curve = sp_curve_copy(dc->currentcurve);
 869             sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH (cbp), curve);
 870             sp_curve_unref(curve);
 871
 872             guint32 fillColor = sp_desktop_get_color_tool (SP_ACTIVE_DESKTOP, "tools.calligraphic", true);
 873             //guint32 strokeColor = sp_desktop_get_color_tool (SP_ACTIVE_DESKTOP, "tools.calligraphic", false);
 874             double opacity = sp_desktop_get_master_opacity_tool (SP_ACTIVE_DESKTOP, "tools.calligraphic");
 875             double fillOpacity = sp_desktop_get_opacity_tool (SP_ACTIVE_DESKTOP, "tools.calligraphic", true);
 876             //double strokeOpacity = sp_desktop_get_opacity_tool (SP_ACTIVE_DESKTOP, "tools.calligraphic", false);
 877             sp_canvas_bpath_set_fill(SP_CANVAS_BPATH(cbp), ((fillColor & 0xffffff00) | SP_COLOR_F_TO_U(opacity*fillOpacity)), SP_WIND_RULE_EVENODD);
 878             //on second thougtht don't do stroke yet because we don't have stoke-width yet and because stoke appears between segments while drawing
 879             //sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(cbp), ((strokeColor & 0xffffff00) | SP_COLOR_F_TO_U(opacity*strokeOpacity)), 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 880             sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(cbp), 0x00000000, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 881             /* fixme: Cannot we cascade it to root more clearly? */
 882             g_signal_connect(G_OBJECT(cbp), "event", G_CALLBACK(sp_desktop_root_handler), SP_EVENT_CONTEXT(dc)->desktop);
 883
 884             dc->segments = g_slist_prepend(dc->segments, cbp);
 885         }
 886
 887         dc->point1[0] = dc->point1[dc->npoints - 1];
 888         dc->point2[0] = dc->point2[dc->npoints - 1];
 889         dc->npoints = 1;
 890     } else {
 891         draw_temporary_box(dc);
 892     }
 893 }
 894
 895 static void
 896 draw_temporary_box(SPDynaDrawContext *dc)
 897 {
 898     sp_curve_reset(dc->currentcurve);
 899
 900     sp_curve_moveto(dc->currentcurve, dc->point1[dc->npoints-1]);
 901     for (gint i = dc->npoints-2; i >= 0; i--) {
 902         sp_curve_lineto(dc->currentcurve, dc->point1[i]);
 903     }
 904     for (gint i = 0; i < dc->npoints; i++) {
 905         sp_curve_lineto(dc->currentcurve, dc->point2[i]);
 906     }
 907     if (dc->npoints >= 2) {
 908         add_cap(dc->currentcurve, dc->point2[dc->npoints-2], dc->point2[dc->npoints-1], dc->point1[dc->npoints-1], dc->point1[dc->npoints-2], dc->cap_rounding);
 909     }
 910
 911     sp_curve_closepath(dc->currentcurve);
 912     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(dc->currentshape), dc->currentcurve);
 913 }
 914
 915 /*
 916   Local Variables:
 917   mode:c++
 918   c-file-style:"stroustrup"
 919   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
 920   indent-tabs-mode:nil
 921   fill-column:99
 922   End:
 923 */
 924 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :