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 #include "color.h"
  50
  51 #define DDC_RED_RGBA 0xff0000ff
  52
  53 #define SAMPLE_TIMEOUT 10
  54 #define TOLERANCE_LINE 1.0
  55 #define TOLERANCE_CALLIGRAPHIC 3.0
  56 #define DYNA_EPSILON 1.0e-6
  57
  58 #define DYNA_MIN_WIDTH 1.0e-6
  59
  60 #define DRAG_MIN 0.0
  61 #define DRAG_DEFAULT 1.0
  62 #define DRAG_MAX 1.0
  63
  64 static void sp_dyna_draw_context_class_init(SPDynaDrawContextClass *klass);
  65 static void sp_dyna_draw_context_init(SPDynaDrawContext *ddc);
  66 static void sp_dyna_draw_context_dispose(GObject *object);
  67
  68 static void sp_dyna_draw_context_setup(SPEventContext *ec);
  69 static void sp_dyna_draw_context_set(SPEventContext *ec, gchar const *key, gchar const *val);
  70 static gint sp_dyna_draw_context_root_handler(SPEventContext *ec, GdkEvent *event);
  71
  72 static void clear_current(SPDynaDrawContext *dc);
  73 static void set_to_accumulated(SPDynaDrawContext *dc);
  74 static void accumulate_calligraphic(SPDynaDrawContext *dc);
  75
  76 static void fit_and_split(SPDynaDrawContext *ddc, gboolean release);
  77 static void fit_and_split_calligraphics(SPDynaDrawContext *ddc, gboolean release);
  78
  79 static void sp_dyna_draw_reset(SPDynaDrawContext *ddc, NR::Point p);
  80 static NR::Point sp_dyna_draw_get_npoint(SPDynaDrawContext const *ddc, NR::Point v);
  81 static NR::Point sp_dyna_draw_get_vpoint(SPDynaDrawContext const *ddc, NR::Point n);
  82 static void draw_temporary_box(SPDynaDrawContext *dc);
  83
  84
  85 static SPEventContextClass *parent_class;
  86
  87 GtkType
  88 sp_dyna_draw_context_get_type(void)
  89 {
  90     static GType type = 0;
  91     if (!type) {
  92         GTypeInfo info = {
  93             sizeof(SPDynaDrawContextClass),
  94             NULL, NULL,
  95             (GClassInitFunc) sp_dyna_draw_context_class_init,
  96             NULL, NULL,
  97             sizeof(SPDynaDrawContext),
  98             4,
  99             (GInstanceInitFunc) sp_dyna_draw_context_init,
 100             NULL,   /* value_table */
 101         };
 102         type = g_type_register_static(SP_TYPE_EVENT_CONTEXT, "SPDynaDrawContext", &info, (GTypeFlags)0);
 103     }
 104     return type;
 105 }
 106
 107 static void
 108 sp_dyna_draw_context_class_init(SPDynaDrawContextClass *klass)
 109 {
 110     GObjectClass *object_class = (GObjectClass *) klass;
 111     SPEventContextClass *event_context_class = (SPEventContextClass *) klass;
 112
 113     parent_class = (SPEventContextClass*)g_type_class_peek_parent(klass);
 114
 115     object_class->dispose = sp_dyna_draw_context_dispose;
 116
 117     event_context_class->setup = sp_dyna_draw_context_setup;
 118     event_context_class->set = sp_dyna_draw_context_set;
 119     event_context_class->root_handler = sp_dyna_draw_context_root_handler;
 120 }
 121
 122 static void
 123 sp_dyna_draw_context_init(SPDynaDrawContext *ddc)
 124 {
 125     SPEventContext *event_context = SP_EVENT_CONTEXT(ddc);
 126
 127     event_context->cursor_shape = cursor_calligraphy_xpm;
 128     event_context->hot_x = 4;
 129     event_context->hot_y = 4;
 130
 131     ddc->accumulated = NULL;
 132     ddc->segments = NULL;
 133     ddc->currentcurve = NULL;
 134     ddc->currentshape = NULL;
 135     ddc->npoints = 0;
 136     ddc->cal1 = NULL;
 137     ddc->cal2 = NULL;
 138     ddc->repr = NULL;
 139
 140     /* DynaDraw values */
 141     ddc->cur = NR::Point(0,0);
 142     ddc->last = NR::Point(0,0);
 143     ddc->vel = NR::Point(0,0);
 144     ddc->acc = NR::Point(0,0);
 145     ddc->ang = NR::Point(0,0);
 146     ddc->del = NR::Point(0,0);
 147
 148     /* attributes */
 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     ddc->abs_width = false;
 160     ddc->keep_selected = true;
 161 }
 162
 163 static void
 164 sp_dyna_draw_context_dispose(GObject *object)
 165 {
 166     SPDynaDrawContext *ddc = SP_DYNA_DRAW_CONTEXT(object);
 167
 168     if (ddc->accumulated) {
 169         ddc->accumulated = sp_curve_unref(ddc->accumulated);
 170     }
 171
 172     while (ddc->segments) {
 173         gtk_object_destroy(GTK_OBJECT(ddc->segments->data));
 174         ddc->segments = g_slist_remove(ddc->segments, ddc->segments->data);
 175     }
 176
 177     if (ddc->currentcurve) ddc->currentcurve = sp_curve_unref(ddc->currentcurve);
 178     if (ddc->cal1) ddc->cal1 = sp_curve_unref(ddc->cal1);
 179     if (ddc->cal2) ddc->cal2 = sp_curve_unref(ddc->cal2);
 180
 181     if (ddc->currentshape) {
 182         gtk_object_destroy(GTK_OBJECT(ddc->currentshape));
 183         ddc->currentshape = NULL;
 184     }
 185
 186     if (ddc->_message_context) {
 187         delete ddc->_message_context;
 188     }
 189
 190     G_OBJECT_CLASS(parent_class)->dispose(object);
 191 }
 192
 193 static void
 194 sp_dyna_draw_context_setup(SPEventContext *ec)
 195 {
 196     SPDynaDrawContext *ddc = SP_DYNA_DRAW_CONTEXT(ec);
 197
 198     if (((SPEventContextClass *) parent_class)->setup)
 199         ((SPEventContextClass *) parent_class)->setup(ec);
 200
 201     ddc->accumulated = sp_curve_new_sized(32);
 202     ddc->currentcurve = sp_curve_new_sized(4);
 203
 204     ddc->cal1 = sp_curve_new_sized(32);
 205     ddc->cal2 = sp_curve_new_sized(32);
 206
 207     ddc->currentshape = sp_canvas_item_new(sp_desktop_sketch(ec->desktop), SP_TYPE_CANVAS_BPATH, NULL);
 208     sp_canvas_bpath_set_fill(SP_CANVAS_BPATH(ddc->currentshape), DDC_RED_RGBA, SP_WIND_RULE_EVENODD);
 209     sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(ddc->currentshape), 0x00000000, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 210     /* fixme: Cannot we cascade it to root more clearly? */
 211     g_signal_connect(G_OBJECT(ddc->currentshape), "event", G_CALLBACK(sp_desktop_root_handler), ec->desktop);
 212
 213     sp_event_context_read(ec, "mass");
 214     sp_event_context_read(ec, "drag");
 215     sp_event_context_read(ec, "angle");
 216     sp_event_context_read(ec, "width");
 217     sp_event_context_read(ec, "thinning");
 218     sp_event_context_read(ec, "tremor");
 219     sp_event_context_read(ec, "flatness");
 220     sp_event_context_read(ec, "usepressure");
 221     sp_event_context_read(ec, "usetilt");
 222     sp_event_context_read(ec, "abs_width");
 223     sp_event_context_read(ec, "keep_selected");
 224
 225     ddc->is_drawing = false;
 226
 227     ddc->_message_context = new Inkscape::MessageContext((ec->desktop)->messageStack());
 228 }
 229
 230 static void
 231 sp_dyna_draw_context_set(SPEventContext *ec, gchar const *key, gchar const *val)
 232 {
 233     SPDynaDrawContext *ddc = SP_DYNA_DRAW_CONTEXT(ec);
 234
 235     if (!strcmp(key, "mass")) {
 236         double const dval = ( val ? g_ascii_strtod (val, NULL) : 0.2 );
 237         ddc->mass = CLAMP(dval, -1000.0, 1000.0);
 238     } else if (!strcmp(key, "drag")) {
 239         double const dval = ( val ? g_ascii_strtod (val, NULL) : DRAG_DEFAULT );
 240         ddc->drag = CLAMP(dval, DRAG_MIN, DRAG_MAX);
 241     } else if (!strcmp(key, "angle")) {
 242         double const dval = ( val ? g_ascii_strtod (val, NULL) : 0.0);
 243         ddc->angle = CLAMP (dval, -90, 90);
 244     } else if (!strcmp(key, "width")) {
 245         double const dval = ( val ? g_ascii_strtod (val, NULL) : 0.1 );
 246         ddc->width = CLAMP(dval, -1000.0, 1000.0);
 247     } else if (!strcmp(key, "thinning")) {
 248         double const dval = ( val ? g_ascii_strtod (val, NULL) : 0.1 );
 249         ddc->vel_thin = CLAMP(dval, -1.0, 1.0);
 250     } else if (!strcmp(key, "tremor")) {
 251         double const dval = ( val ? g_ascii_strtod (val, NULL) : 0.0 );
 252         ddc->tremor = CLAMP(dval, 0.0, 1.0);
 253     } else if (!strcmp(key, "flatness")) {
 254         double const dval = ( val ? g_ascii_strtod (val, NULL) : 1.0 );
 255         ddc->flatness = CLAMP(dval, 0, 1.0);
 256     } else if (!strcmp(key, "usepressure")) {
 257         ddc->usepressure = (val && strcmp(val, "0"));
 258     } else if (!strcmp(key, "usetilt")) {
 259         ddc->usetilt = (val && strcmp(val, "0"));
 260     } else if (!strcmp(key, "abs_width")) {
 261         ddc->abs_width = (val && strcmp(val, "0"));
 262     } else if (!strcmp(key, "keep_selected")) {
 263         ddc->keep_selected = (val && strcmp(val, "0"));
 264     }
 265
 266     //g_print("DDC: %g %g %g %g\n", ddc->mass, ddc->drag, ddc->angle, ddc->width);
 267 }
 268
 269 static double
 270 flerp(double f0, double f1, double p)
 271 {
 272     return f0 + ( f1 - f0 ) * p;
 273 }
 274
 275 /* Get normalized point */
 276 static NR::Point
 277 sp_dyna_draw_get_npoint(SPDynaDrawContext const *dc, NR::Point v)
 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(( v[NR::X] - drect.min()[NR::X] ) / max,  ( v[NR::Y] - drect.min()[NR::Y] ) / max);
 282 }
 283
 284 /* Get view point */
 285 static NR::Point
 286 sp_dyna_draw_get_vpoint(SPDynaDrawContext const *dc, NR::Point n)
 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(n[NR::X] * max + drect.min()[NR::X], n[NR::Y] * max + drect.min()[NR::Y]);
 291 }
 292
 293 static void
 294 sp_dyna_draw_reset(SPDynaDrawContext *dc, NR::Point p)
 295 {
 296     dc->last = dc->cur = sp_dyna_draw_get_npoint(dc, p);
 297     dc->vel = NR::Point(0,0);
 298     dc->acc = NR::Point(0,0);
 299     dc->ang = NR::Point(0,0);
 300     dc->del = NR::Point(0,0);
 301 }
 302
 303 static void
 304 sp_dyna_draw_extinput(SPDynaDrawContext *dc, GdkEvent *event)
 305 {
 306     if (gdk_event_get_axis (event, GDK_AXIS_PRESSURE, &dc->pressure))
 307         dc->pressure = CLAMP (dc->pressure, DDC_MIN_PRESSURE, DDC_MAX_PRESSURE);
 308     else
 309         dc->pressure = DDC_DEFAULT_PRESSURE;
 310
 311     if (gdk_event_get_axis (event, GDK_AXIS_XTILT, &dc->xtilt))
 312         dc->xtilt = CLAMP (dc->xtilt, DDC_MIN_TILT, DDC_MAX_TILT);
 313     else
 314         dc->xtilt = DDC_DEFAULT_TILT;
 315
 316     if (gdk_event_get_axis (event, GDK_AXIS_YTILT, &dc->ytilt))
 317         dc->ytilt = CLAMP (dc->ytilt, DDC_MIN_TILT, DDC_MAX_TILT);
 318     else
 319         dc->ytilt = DDC_DEFAULT_TILT;
 320 }
 321
 322
 323 static gboolean
 324 sp_dyna_draw_apply(SPDynaDrawContext *dc, NR::Point p)
 325 {
 326     NR::Point n = sp_dyna_draw_get_npoint(dc, p);
 327
 328     /* Calculate mass and drag */
 329     double const mass = flerp(1.0, 160.0, dc->mass);
 330     double const drag = flerp(0.0, 0.5, dc->drag * dc->drag);
 331
 332     /* Calculate force and acceleration */
 333     NR::Point force = n - dc->cur;
 334     if ( NR::L2(force) < DYNA_EPSILON ) {
 335         return FALSE;
 336     }
 337
 338     dc->acc = force / mass;
 339
 340     /* Calculate new velocity */
 341     dc->vel += dc->acc;
 342
 343     /* Calculate angle of drawing tool */
 344
 345     double a1;
 346     if (dc->usetilt) {
 347         // 1a. calculate nib angle from input device tilt:
 348         gdouble length = std::sqrt(dc->xtilt*dc->xtilt + dc->ytilt*dc->ytilt);;
 349
 350         if (length > 0) {
 351             NR::Point ang1 = NR::Point(dc->ytilt/length, dc->xtilt/length);
 352             a1 = atan2(ang1);
 353         }
 354         else
 355             a1 = 0.0;
 356     }
 357     else {
 358         // 1b. fixed dc->angle (absolutely flat nib):
 359         double const radians = ( (dc->angle - 90) / 180.0 ) * M_PI;
 360         NR::Point ang1 = NR::Point(-sin(radians),  cos(radians));
 361         a1 = atan2(ang1);
 362     }
 363
 364     // 2. perpendicular to dc->vel (absolutely non-flat nib):
 365     gdouble const mag_vel = NR::L2(dc->vel);
 366     if ( mag_vel < DYNA_EPSILON ) {
 367         return FALSE;
 368     }
 369     NR::Point ang2 = NR::rot90(dc->vel) / mag_vel;
 370
 371     // 3. Average them using flatness parameter:
 372     // calculate angles
 373     double a2 = atan2(ang2);
 374     // flip a2 to force it to be in the same half-circle as a1
 375     bool flipped = false;
 376     if (fabs (a2-a1) > 0.5*M_PI) {
 377         a2 += M_PI;
 378         flipped = true;
 379     }
 380     // normalize a2
 381     if (a2 > M_PI)
 382         a2 -= 2*M_PI;
 383     if (a2 < -M_PI)
 384         a2 += 2*M_PI;
 385     // find the flatness-weighted bisector angle, unflip if a2 was flipped
 386     // FIXME: when dc->vel is oscillating around the fixed angle, the new_ang flips back and forth. How to avoid this?
 387     double new_ang = a1 + (1 - dc->flatness) * (a2 - a1) - (flipped? M_PI : 0);
 388     // convert to point
 389     dc->ang = NR::Point (cos (new_ang), sin (new_ang));
 390
 391     /* Apply drag */
 392     dc->vel *= 1.0 - drag;
 393
 394     /* Update position */
 395     dc->last = dc->cur;
 396     dc->cur += dc->vel;
 397
 398     return TRUE;
 399 }
 400
 401 static void
 402 sp_dyna_draw_brush(SPDynaDrawContext *dc)
 403 {
 404     g_assert( dc->npoints >= 0 && dc->npoints < SAMPLING_SIZE );
 405
 406     // How much velocity thins strokestyle
 407     double vel_thin = flerp (0, 160, dc->vel_thin);
 408
 409     // Influence of pressure on thickness
 410     double pressure_thick = (dc->usepressure ? dc->pressure : 1.0);
 411
 412     double width = ( pressure_thick - vel_thin * NR::L2(dc->vel) ) * dc->width;
 413
 414     double tremble_left = 0, tremble_right = 0;
 415     if (dc->tremor > 0) {
 416         // obtain two normally distributed random variables, using polar Box-Muller transform
 417         double x1, x2, w, y1, y2;
 418         do {
 419             x1 = 2.0 * g_random_double_range(0,1) - 1.0;
 420             x2 = 2.0 * g_random_double_range(0,1) - 1.0;
 421             w = x1 * x1 + x2 * x2;
 422         } while ( w >= 1.0 );
 423         w = sqrt( (-2.0 * log( w ) ) / w );
 424         y1 = x1 * w;
 425         y2 = x2 * w;
 426
 427         // deflect both left and right edges randomly and independently, so that:
 428         // (1) dc->tremor=1 corresponds to sigma=1, decreasing dc->tremor narrows the bell curve;
 429         // (2) deflection depends on width, but is upped for small widths for better visual uniformity across widths;
 430         // (3) deflection somewhat depends on speed, to prevent fast strokes looking
 431         // comparatively smooth and slow ones excessively jittery
 432         tremble_left  = (y1)*dc->tremor * (0.15 + 0.8*width) * (0.35 + 14*NR::L2(dc->vel));
 433         tremble_right = (y2)*dc->tremor * (0.15 + 0.8*width) * (0.35 + 14*NR::L2(dc->vel));
 434     }
 435
 436     if ( width < 0.02 * dc->width ) {
 437         width = 0.02 * dc->width;
 438     }
 439
 440     double dezoomify_factor = 0.05 * 1000;
 441     if (!dc->abs_width) {
 442         dezoomify_factor /= SP_EVENT_CONTEXT(dc)->desktop->current_zoom();
 443     }
 444
 445     NR::Point del_left = dezoomify_factor * (width + tremble_left) * dc->ang;
 446     NR::Point del_right = dezoomify_factor * (width + tremble_right) * dc->ang;
 447
 448     NR::Point abs_middle = sp_dyna_draw_get_vpoint(dc, dc->cur);
 449
 450     dc->point1[dc->npoints] = abs_middle + del_left;
 451     dc->point2[dc->npoints] = abs_middle - del_right;
 452
 453     dc->del = 0.5*(del_left + del_right);
 454
 455     dc->npoints++;
 456 }
 457
 458 void
 459 sp_ddc_update_toolbox (SPDesktop *desktop, const gchar *id, double value)
 460 {
 461     desktop->setToolboxAdjustmentValue (id, value);
 462 }
 463
 464 gint
 465 sp_dyna_draw_context_root_handler(SPEventContext *event_context,
 466                                   GdkEvent *event)
 467 {
 468     SPDynaDrawContext *dc = SP_DYNA_DRAW_CONTEXT(event_context);
 469     SPDesktop *desktop = event_context->desktop;
 470
 471     gint ret = FALSE;
 472
 473     switch (event->type) {
 474     case GDK_BUTTON_PRESS:
 475         if ( event->button.button == 1 ) {
 476
 477             SPDesktop *desktop = SP_EVENT_CONTEXT_DESKTOP(dc);
 478
 479             if (Inkscape::have_viable_layer(desktop, dc->_message_context) == false) {
 480                 return TRUE;
 481             }
 482
 483             NR::Point const button_w(event->button.x,
 484                                      event->button.y);
 485             NR::Point const button_dt(desktop->w2d(button_w));
 486             sp_dyna_draw_reset(dc, button_dt);
 487             sp_dyna_draw_extinput(dc, event);
 488             sp_dyna_draw_apply(dc, button_dt);
 489             sp_curve_reset(dc->accumulated);
 490             if (dc->repr) {
 491                 dc->repr = NULL;
 492             }
 493
 494             /* initialize first point */
 495             dc->npoints = 0;
 496
 497             sp_canvas_item_grab(SP_CANVAS_ITEM(desktop->acetate),
 498                                 ( GDK_KEY_PRESS_MASK |
 499                                   GDK_BUTTON_RELEASE_MASK |
 500                                   GDK_POINTER_MOTION_MASK |
 501                                   GDK_BUTTON_PRESS_MASK ),
 502                                 NULL,
 503                                 event->button.time);
 504
 505             ret = TRUE;
 506
 507             dc->is_drawing = true;
 508         }
 509         break;
 510     case GDK_MOTION_NOTIFY:
 511         if ( dc->is_drawing && ( event->motion.state & GDK_BUTTON1_MASK ) ) {
 512             dc->dragging = TRUE;
 513
 514             NR::Point const motion_w(event->motion.x,
 515                                      event->motion.y);
 516             NR::Point const motion_dt(desktop->w2d(motion_w));
 517
 518             sp_dyna_draw_extinput(dc, event);
 519             if (!sp_dyna_draw_apply(dc, motion_dt)) {
 520                 ret = TRUE;
 521                 break;
 522             }
 523
 524             if ( dc->cur != dc->last ) {
 525                 sp_dyna_draw_brush(dc);
 526                 g_assert( dc->npoints > 0 );
 527                 fit_and_split(dc, FALSE);
 528             }
 529             ret = TRUE;
 530         }
 531         break;
 532
 533     case GDK_BUTTON_RELEASE:
 534         sp_canvas_item_ungrab(SP_CANVAS_ITEM(desktop->acetate), event->button.time);
 535         dc->is_drawing = false;
 536         if ( dc->dragging && event->button.button == 1 ) {
 537             dc->dragging = FALSE;
 538
 539             /* Remove all temporary line segments */
 540             while (dc->segments) {
 541                 gtk_object_destroy(GTK_OBJECT(dc->segments->data));
 542                 dc->segments = g_slist_remove(dc->segments, dc->segments->data);
 543             }
 544             /* Create object */
 545             fit_and_split(dc, TRUE);
 546             accumulate_calligraphic(dc);
 547             set_to_accumulated(dc); /* temporal implementation */
 548             /* reset accumulated curve */
 549             sp_curve_reset(dc->accumulated);
 550             clear_current(dc);
 551             if (dc->repr) {
 552                 dc->repr = NULL;
 553             }
 554             ret = TRUE;
 555         }
 556         break;
 557     case GDK_KEY_PRESS:
 558         switch (get_group0_keyval (&event->key)) {
 559         case GDK_Up:
 560         case GDK_KP_Up:
 561             if (!MOD__CTRL_ONLY) {
 562                 dc->angle += 5.0;
 563                 if (dc->angle > 90.0)
 564                     dc->angle = 90.0;
 565                 sp_ddc_update_toolbox (desktop, "calligraphy-angle", dc->angle);
 566                 ret = TRUE;
 567             }
 568             break;
 569         case GDK_Down:
 570         case GDK_KP_Down:
 571             if (!MOD__CTRL_ONLY) {
 572                 dc->angle -= 5.0;
 573                 if (dc->angle < -90.0)
 574                     dc->angle = -90.0;
 575                 sp_ddc_update_toolbox (desktop, "calligraphy-angle", dc->angle);
 576                 ret = TRUE;
 577             }
 578             break;
 579         case GDK_Right:
 580         case GDK_KP_Right:
 581             if (!MOD__CTRL_ONLY) {
 582                 dc->width += 0.01;
 583                 if (dc->width > 1.0)
 584                     dc->width = 1.0;
 585                 sp_ddc_update_toolbox (desktop, "altx-calligraphy", dc->width * 100); // the same spinbutton is for alt+x
 586                 ret = TRUE;
 587             }
 588             break;
 589         case GDK_Left:
 590         case GDK_KP_Left:
 591             if (!MOD__CTRL_ONLY) {
 592                 dc->width -= 0.01;
 593                 if (dc->width < 0.01)
 594                     dc->width = 0.01;
 595                 sp_ddc_update_toolbox (desktop, "altx-calligraphy", dc->width * 100);
 596                 ret = TRUE;
 597             }
 598             break;
 599         case GDK_x:
 600         case GDK_X:
 601             if (MOD__ALT_ONLY) {
 602                 desktop->setToolboxFocusTo ("altx-calligraphy");
 603                 ret = TRUE;
 604             }
 605             break;
 606         case GDK_Escape:
 607             sp_desktop_selection(desktop)->clear();
 608             break;
 609
 610         default:
 611             break;
 612         }
 613     default:
 614         break;
 615     }
 616
 617     if (!ret) {
 618         if (((SPEventContextClass *) parent_class)->root_handler) {
 619             ret = ((SPEventContextClass *) parent_class)->root_handler(event_context, event);
 620         }
 621     }
 622
 623     return ret;
 624 }
 625
 626
 627 static void
 628 clear_current(SPDynaDrawContext *dc)
 629 {
 630     /* reset bpath */
 631     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(dc->currentshape), NULL);
 632     /* reset curve */
 633     sp_curve_reset(dc->currentcurve);
 634     sp_curve_reset(dc->cal1);
 635     sp_curve_reset(dc->cal2);
 636     /* reset points */
 637     dc->npoints = 0;
 638 }
 639
 640 static void
 641 set_to_accumulated(SPDynaDrawContext *dc)
 642 {
 643     SPDesktop *desktop = SP_EVENT_CONTEXT(dc)->desktop;
 644
 645     if (!sp_curve_empty(dc->accumulated)) {
 646         NArtBpath *abp;
 647         gchar *str;
 648
 649         if (!dc->repr) {
 650             /* Create object */
 651             Inkscape::XML::Node *repr = sp_repr_new("svg:path");
 652
 653             /* Set style */
 654             sp_desktop_apply_style_tool (desktop, repr, "tools.calligraphic", false);
 655
 656             dc->repr = repr;
 657
 658             SPItem *item=SP_ITEM(desktop->currentLayer()->appendChildRepr(dc->repr));
 659             Inkscape::GC::release(dc->repr);
 660             item->transform = SP_ITEM(desktop->currentRoot())->getRelativeTransform(desktop->currentLayer());
 661             item->updateRepr();
 662             if (dc->keep_selected)
 663                 sp_desktop_selection(desktop)->set(dc->repr);
 664         }
 665         abp = nr_artpath_affine(sp_curve_first_bpath(dc->accumulated), sp_desktop_dt2root_affine(desktop));
 666         str = sp_svg_write_path(abp);
 667         g_assert( str != NULL );
 668         nr_free(abp);
 669         dc->repr->setAttribute("d", str);
 670         g_free(str);
 671     } else {
 672         if (dc->repr) {
 673             sp_repr_unparent(dc->repr);
 674         }
 675         dc->repr = NULL;
 676     }
 677
 678     sp_document_done(sp_desktop_document(desktop));
 679 }
 680
 681 static void
 682 accumulate_calligraphic(SPDynaDrawContext *dc)
 683 {
 684     if ( !sp_curve_empty(dc->cal1) && !sp_curve_empty(dc->cal2) ) {
 685         sp_curve_reset(dc->accumulated); /*  Is this required ?? */
 686         SPCurve *rev_cal2 = sp_curve_reverse(dc->cal2);
 687         sp_curve_append(dc->accumulated, dc->cal1, FALSE);
 688         sp_curve_append(dc->accumulated, rev_cal2, TRUE);
 689         sp_curve_closepath(dc->accumulated);
 690
 691         sp_curve_unref(rev_cal2);
 692
 693         sp_curve_reset(dc->cal1);
 694         sp_curve_reset(dc->cal2);
 695     }
 696 }
 697
 698 static void
 699 fit_and_split(SPDynaDrawContext *dc,
 700               gboolean release)
 701 {
 702     fit_and_split_calligraphics(dc, release);
 703 }
 704
 705 static double square(double const x)
 706 {
 707     return x * x;
 708 }
 709
 710 static void
 711 fit_and_split_calligraphics(SPDynaDrawContext *dc, gboolean release)
 712 {
 713     double const tolerance_sq = square( NR::expansion(SP_EVENT_CONTEXT(dc)->desktop->w2d()) * TOLERANCE_CALLIGRAPHIC );
 714
 715 #ifdef DYNA_DRAW_VERBOSE
 716     g_print("[F&S:R=%c]", release?'T':'F');
 717 #endif
 718
 719     if (!( dc->npoints > 0 && dc->npoints < SAMPLING_SIZE ))
 720         return; // just clicked
 721
 722     if ( dc->npoints == SAMPLING_SIZE - 1 || release ) {
 723 #define BEZIER_SIZE       4
 724 #define BEZIER_MAX_BEZIERS  8
 725 #define BEZIER_MAX_LENGTH ( BEZIER_SIZE * BEZIER_MAX_BEZIERS )
 726
 727 #ifdef DYNA_DRAW_VERBOSE
 728         g_print("[F&S:#] dc->npoints:%d, release:%s\n",
 729                 dc->npoints, release ? "TRUE" : "FALSE");
 730 #endif
 731
 732         /* Current calligraphic */
 733         if ( dc->cal1->end == 0 || dc->cal2->end == 0 ) {
 734             /* dc->npoints > 0 */
 735             /* g_print("calligraphics(1|2) reset\n"); */
 736             sp_curve_reset(dc->cal1);
 737             sp_curve_reset(dc->cal2);
 738
 739             sp_curve_moveto(dc->cal1, dc->point1[0]);
 740             sp_curve_moveto(dc->cal2, dc->point2[0]);
 741         }
 742
 743         NR::Point b1[BEZIER_MAX_LENGTH];
 744         gint const nb1 = sp_bezier_fit_cubic_r(b1, dc->point1, dc->npoints,
 745                                                tolerance_sq, BEZIER_MAX_BEZIERS);
 746         g_assert( nb1 * BEZIER_SIZE <= gint(G_N_ELEMENTS(b1)) );
 747
 748         NR::Point b2[BEZIER_MAX_LENGTH];
 749         gint const nb2 = sp_bezier_fit_cubic_r(b2, dc->point2, dc->npoints,
 750                                                tolerance_sq, BEZIER_MAX_BEZIERS);
 751         g_assert( nb2 * BEZIER_SIZE <= gint(G_N_ELEMENTS(b2)) );
 752
 753         if ( nb1 != -1 && nb2 != -1 ) {
 754             /* Fit and draw and reset state */
 755 #ifdef DYNA_DRAW_VERBOSE
 756             g_print("nb1:%d nb2:%d\n", nb1, nb2);
 757 #endif
 758             /* CanvasShape */
 759             if (! release) {
 760                 sp_curve_reset(dc->currentcurve);
 761                 sp_curve_moveto(dc->currentcurve, b1[0]);
 762                 for (NR::Point *bp1 = b1; bp1 < b1 + BEZIER_SIZE * nb1; bp1 += BEZIER_SIZE) {
 763                     sp_curve_curveto(dc->currentcurve, bp1[1],
 764                                      bp1[2], bp1[3]);
 765                 }
 766                 sp_curve_lineto(dc->currentcurve,
 767                                 b2[BEZIER_SIZE*(nb2-1) + 3]);
 768                 for (NR::Point *bp2 = b2 + BEZIER_SIZE * ( nb2 - 1 ); bp2 >= b2; bp2 -= BEZIER_SIZE) {
 769                     sp_curve_curveto(dc->currentcurve, bp2[2], bp2[1], bp2[0]);
 770                 }
 771                 sp_curve_closepath(dc->currentcurve);
 772                 sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(dc->currentshape), dc->currentcurve);
 773             }
 774
 775             /* Current calligraphic */
 776             for (NR::Point *bp1 = b1; bp1 < b1 + BEZIER_SIZE * nb1; bp1 += BEZIER_SIZE) {
 777                 sp_curve_curveto(dc->cal1, bp1[1], bp1[2], bp1[3]);
 778             }
 779             for (NR::Point *bp2 = b2; bp2 < b2 + BEZIER_SIZE * nb2; bp2 += BEZIER_SIZE) {
 780                 sp_curve_curveto(dc->cal2, bp2[1], bp2[2], bp2[3]);
 781             }
 782         } else {
 783             /* fixme: ??? */
 784 #ifdef DYNA_DRAW_VERBOSE
 785             g_print("[fit_and_split_calligraphics] failed to fit-cubic.\n");
 786 #endif
 787             draw_temporary_box(dc);
 788
 789             for (gint i = 1; i < dc->npoints; i++) {
 790                 sp_curve_lineto(dc->cal1, dc->point1[i]);
 791             }
 792             for (gint i = 1; i < dc->npoints; i++) {
 793                 sp_curve_lineto(dc->cal2, dc->point2[i]);
 794             }
 795         }
 796
 797         /* Fit and draw and copy last point */
 798 #ifdef DYNA_DRAW_VERBOSE
 799         g_print("[%d]Yup\n", dc->npoints);
 800 #endif
 801         if (!release) {
 802             g_assert(!sp_curve_empty(dc->currentcurve));
 803
 804             SPCanvasItem *cbp = sp_canvas_item_new(sp_desktop_sketch(SP_EVENT_CONTEXT(dc)->desktop),
 805                                                    SP_TYPE_CANVAS_BPATH,
 806                                                    NULL);
 807             SPCurve *curve = sp_curve_copy(dc->currentcurve);
 808             sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH (cbp), curve);
 809             sp_curve_unref(curve);
 810
 811             guint32 fillColor = sp_desktop_get_color_tool (SP_ACTIVE_DESKTOP, "tools.calligraphic", true);
 812             double opacity = sp_desktop_get_opacity_tool (SP_ACTIVE_DESKTOP, "tools.calligraphic");
 813             sp_canvas_bpath_set_fill(SP_CANVAS_BPATH(cbp), ((fillColor & 0xffffff00) | SP_COLOR_F_TO_U(opacity)), SP_WIND_RULE_EVENODD);
 814             sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(cbp), 0x00000000, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 815             /* fixme: Cannot we cascade it to root more clearly? */
 816             g_signal_connect(G_OBJECT(cbp), "event", G_CALLBACK(sp_desktop_root_handler), SP_EVENT_CONTEXT(dc)->desktop);
 817
 818             dc->segments = g_slist_prepend(dc->segments, cbp);
 819         }
 820
 821         dc->point1[0] = dc->point1[dc->npoints - 1];
 822         dc->point2[0] = dc->point2[dc->npoints - 1];
 823         dc->npoints = 1;
 824     } else {
 825         draw_temporary_box(dc);
 826     }
 827 }
 828
 829 static void
 830 draw_temporary_box(SPDynaDrawContext *dc)
 831 {
 832     sp_curve_reset(dc->currentcurve);
 833     sp_curve_moveto(dc->currentcurve, dc->point1[0]);
 834     for (gint i = 1; i < dc->npoints; i++) {
 835         sp_curve_lineto(dc->currentcurve, dc->point1[i]);
 836     }
 837     for (gint i = dc->npoints-1; i >= 0; i--) {
 838         sp_curve_lineto(dc->currentcurve, dc->point2[i]);
 839     }
 840     sp_curve_closepath(dc->currentcurve);
 841     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(dc->currentshape), dc->currentcurve);
 842 }
 843
 844 /*
 845   Local Variables:
 846   mode:c++
 847   c-file-style:"stroustrup"
 848   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
 849   indent-tabs-mode:nil
 850   fill-column:99
 851   End:
 852 */
 853 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :