src/dyna-draw-context.cpp

   1 #define __SP_DYNA_DRAW_CONTEXT_C__
   2
   3 /*
   4  * Handwriting-like drawing mode
   5  *
   6  * Authors:
   7  *   Mitsuru Oka <oka326@parkcity.ne.jp>
   8  *   Lauris Kaplinski <lauris@kaplinski.com>
   9  *   bulia byak <buliabyak@users.sf.net>
  10  *
  11  * The original dynadraw code:
  12  *   Paul Haeberli <paul@sgi.com>
  13  *
  14  * Copyright (C) 1998 The Free Software Foundation
  15  * Copyright (C) 1999-2005 authors
  16  * Copyright (C) 2001-2002 Ximian, Inc.
  17  *
  18  * Released under GNU GPL, read the file 'COPYING' for more information
  19  */
  20
  21 #define noDYNA_DRAW_VERBOSE
  22
  23 #include "config.h"
  24
  25 #include <gtk/gtk.h>
  26 #include <gdk/gdkkeysyms.h>
  27
  28 #include "svg/svg.h"
  29 #include "display/canvas-bpath.h"
  30 #include "display/bezier-utils.h"
  31
  32 #include "macros.h"
  33 #include "document.h"
  34 #include "selection.h"
  35 #include "desktop.h"
  36 #include "desktop-events.h"
  37 #include "desktop-handles.h"
  38 #include "desktop-affine.h"
  39 #include "desktop-style.h"
  40 #include "message-context.h"
  41 #include "pixmaps/cursor-calligraphy.xpm"
  42 #include "dyna-draw-context.h"
  43 #include "libnr/n-art-bpath.h"
  44 #include "libnr/nr-path.h"
  45 #include "xml/repr.h"
  46 #include "context-fns.h"
  47 #include "sp-item.h"
  48 #include "inkscape.h"
  49
  50 #define DDC_RED_RGBA 0xff0000ff
  51
  52 #define SAMPLE_TIMEOUT 10
  53 #define TOLERANCE_LINE 1.0
  54 #define TOLERANCE_CALLIGRAPHIC 3.0
  55 #define DYNA_EPSILON 1.0e-6
  56
  57 #define DYNA_MIN_WIDTH 1.0e-6
  58
  59 #define DRAG_MIN 0.0
  60 #define DRAG_DEFAULT 1.0
  61 #define DRAG_MAX 1.0
  62
  63 static void sp_dyna_draw_context_class_init(SPDynaDrawContextClass *klass);
  64 static void sp_dyna_draw_context_init(SPDynaDrawContext *ddc);
  65 static void sp_dyna_draw_context_dispose(GObject *object);
  66
  67 static void sp_dyna_draw_context_setup(SPEventContext *ec);
  68 static void sp_dyna_draw_context_set(SPEventContext *ec, gchar const *key, gchar const *val);
  69 static gint sp_dyna_draw_context_root_handler(SPEventContext *ec, GdkEvent *event);
  70
  71 static void clear_current(SPDynaDrawContext *dc);
  72 static void set_to_accumulated(SPDynaDrawContext *dc);
  73 static void accumulate_calligraphic(SPDynaDrawContext *dc);
  74
  75 static void fit_and_split(SPDynaDrawContext *ddc, gboolean release);
  76 static void fit_and_split_calligraphics(SPDynaDrawContext *ddc, gboolean release);
  77
  78 static void sp_dyna_draw_reset(SPDynaDrawContext *ddc, NR::Point p);
  79 static NR::Point sp_dyna_draw_get_npoint(SPDynaDrawContext const *ddc, NR::Point v);
  80 static NR::Point sp_dyna_draw_get_vpoint(SPDynaDrawContext const *ddc, NR::Point n);
  81 static void draw_temporary_box(SPDynaDrawContext *dc);
  82
  83
  84 static SPEventContextClass *parent_class;
  85
  86 GtkType
  87 sp_dyna_draw_context_get_type(void)
  88 {
  89     static GType type = 0;
  90     if (!type) {
  91         GTypeInfo info = {
  92             sizeof(SPDynaDrawContextClass),
  93             NULL, NULL,
  94             (GClassInitFunc) sp_dyna_draw_context_class_init,
  95             NULL, NULL,
  96             sizeof(SPDynaDrawContext),
  97             4,
  98             (GInstanceInitFunc) sp_dyna_draw_context_init,
  99             NULL,   /* value_table */
 100         };
 101         type = g_type_register_static(SP_TYPE_EVENT_CONTEXT, "SPDynaDrawContext", &info, (GTypeFlags)0);
 102     }
 103     return type;
 104 }
 105
 106 static void
 107 sp_dyna_draw_context_class_init(SPDynaDrawContextClass *klass)
 108 {
 109     GObjectClass *object_class = (GObjectClass *) klass;
 110     SPEventContextClass *event_context_class = (SPEventContextClass *) klass;
 111
 112     parent_class = (SPEventContextClass*)g_type_class_peek_parent(klass);
 113
 114     object_class->dispose = sp_dyna_draw_context_dispose;
 115
 116     event_context_class->setup = sp_dyna_draw_context_setup;
 117     event_context_class->set = sp_dyna_draw_context_set;
 118     event_context_class->root_handler = sp_dyna_draw_context_root_handler;
 119 }
 120
 121 static void
 122 sp_dyna_draw_context_init(SPDynaDrawContext *ddc)
 123 {
 124     SPEventContext *event_context = SP_EVENT_CONTEXT(ddc);
 125
 126     event_context->cursor_shape = cursor_calligraphy_xpm;
 127     event_context->hot_x = 4;
 128     event_context->hot_y = 4;
 129
 130     ddc->accumulated = NULL;
 131     ddc->segments = NULL;
 132     ddc->currentcurve = NULL;
 133     ddc->currentshape = NULL;
 134     ddc->npoints = 0;
 135     ddc->cal1 = NULL;
 136     ddc->cal2 = NULL;
 137     ddc->repr = NULL;
 138
 139     /* DynaDraw values */
 140     ddc->cur = NR::Point(0,0);
 141     ddc->last = NR::Point(0,0);
 142     ddc->vel = NR::Point(0,0);
 143     ddc->acc = NR::Point(0,0);
 144     ddc->ang = NR::Point(0,0);
 145     ddc->del = NR::Point(0,0);
 146
 147     /* attributes */
 148     ddc->dragging = FALSE;
 149
 150     ddc->mass = 0.3;
 151     ddc->drag = DRAG_DEFAULT;
 152     ddc->angle = 30.0;
 153     ddc->width = 0.2;
 154
 155     ddc->vel_thin = 0.1;
 156     ddc->flatness = 0.9;
 157
 158     ddc->abs_width = false;
 159     ddc->keep_selected = true;
 160 }
 161
 162 static void
 163 sp_dyna_draw_context_dispose(GObject *object)
 164 {
 165     SPDynaDrawContext *ddc = SP_DYNA_DRAW_CONTEXT(object);
 166
 167     if (ddc->accumulated) {
 168         ddc->accumulated = sp_curve_unref(ddc->accumulated);
 169     }
 170
 171     while (ddc->segments) {
 172         gtk_object_destroy(GTK_OBJECT(ddc->segments->data));
 173         ddc->segments = g_slist_remove(ddc->segments, ddc->segments->data);
 174     }
 175
 176     if (ddc->currentcurve) ddc->currentcurve = sp_curve_unref(ddc->currentcurve);
 177     if (ddc->cal1) ddc->cal1 = sp_curve_unref(ddc->cal1);
 178     if (ddc->cal2) ddc->cal2 = sp_curve_unref(ddc->cal2);
 179
 180     if (ddc->currentshape) {
 181         gtk_object_destroy(GTK_OBJECT(ddc->currentshape));
 182         ddc->currentshape = NULL;
 183     }
 184
 185     if (ddc->_message_context) {
 186         delete ddc->_message_context;
 187     }
 188
 189     G_OBJECT_CLASS(parent_class)->dispose(object);
 190 }
 191
 192 static void
 193 sp_dyna_draw_context_setup(SPEventContext *ec)
 194 {
 195     SPDynaDrawContext *ddc = SP_DYNA_DRAW_CONTEXT(ec);
 196
 197     if (((SPEventContextClass *) parent_class)->setup)
 198         ((SPEventContextClass *) parent_class)->setup(ec);
 199
 200     ddc->accumulated = sp_curve_new_sized(32);
 201     ddc->currentcurve = sp_curve_new_sized(4);
 202
 203     ddc->cal1 = sp_curve_new_sized(32);
 204     ddc->cal2 = sp_curve_new_sized(32);
 205
 206     ddc->currentshape = sp_canvas_item_new(sp_desktop_sketch(ec->desktop), SP_TYPE_CANVAS_BPATH, NULL);
 207     sp_canvas_bpath_set_fill(SP_CANVAS_BPATH(ddc->currentshape), DDC_RED_RGBA, SP_WIND_RULE_EVENODD);
 208     sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(ddc->currentshape), 0x00000000, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 209     /* fixme: Cannot we cascade it to root more clearly? */
 210     g_signal_connect(G_OBJECT(ddc->currentshape), "event", G_CALLBACK(sp_desktop_root_handler), ec->desktop);
 211
 212     sp_event_context_read(ec, "mass");
 213     sp_event_context_read(ec, "drag");
 214     sp_event_context_read(ec, "angle");
 215     sp_event_context_read(ec, "width");
 216     sp_event_context_read(ec, "thinning");
 217     sp_event_context_read(ec, "tremor");
 218     sp_event_context_read(ec, "flatness");
 219     sp_event_context_read(ec, "usepressure");
 220     sp_event_context_read(ec, "usetilt");
 221     sp_event_context_read(ec, "abs_width");
 222     sp_event_context_read(ec, "keep_selected");
 223
 224     ddc->is_drawing = false;
 225
 226     ddc->_message_context = new Inkscape::MessageContext((ec->desktop)->messageStack());
 227 }
 228
 229 static void
 230 sp_dyna_draw_context_set(SPEventContext *ec, gchar const *key, gchar const *val)
 231 {
 232     SPDynaDrawContext *ddc = SP_DYNA_DRAW_CONTEXT(ec);
 233
 234     if (!strcmp(key, "mass")) {
 235         double const dval = ( val ? g_ascii_strtod (val, NULL) : 0.2 );
 236         ddc->mass = CLAMP(dval, -1000.0, 1000.0);
 237     } else if (!strcmp(key, "drag")) {
 238         double const dval = ( val ? g_ascii_strtod (val, NULL) : DRAG_DEFAULT );
 239         ddc->drag = CLAMP(dval, DRAG_MIN, DRAG_MAX);
 240     } else if (!strcmp(key, "angle")) {
 241         double const dval = ( val ? g_ascii_strtod (val, NULL) : 0.0);
 242         ddc->angle = CLAMP (dval, -90, 90);
 243     } else if (!strcmp(key, "width")) {
 244         double const dval = ( val ? g_ascii_strtod (val, NULL) : 0.1 );
 245         ddc->width = CLAMP(dval, -1000.0, 1000.0);
 246     } else if (!strcmp(key, "thinning")) {
 247         double const dval = ( val ? g_ascii_strtod (val, NULL) : 0.1 );
 248         ddc->vel_thin = CLAMP(dval, -1.0, 1.0);
 249     } else if (!strcmp(key, "tremor")) {
 250         double const dval = ( val ? g_ascii_strtod (val, NULL) : 0.0 );
 251         ddc->tremor = CLAMP(dval, 0.0, 1.0);
 252     } else if (!strcmp(key, "flatness")) {
 253         double const dval = ( val ? g_ascii_strtod (val, NULL) : 1.0 );
 254         ddc->flatness = CLAMP(dval, 0, 1.0);
 255     } else if (!strcmp(key, "usepressure")) {
 256         ddc->usepressure = (val && strcmp(val, "0"));
 257     } else if (!strcmp(key, "usetilt")) {
 258         ddc->usetilt = (val && strcmp(val, "0"));
 259     } else if (!strcmp(key, "abs_width")) {
 260         ddc->abs_width = (val && strcmp(val, "0"));
 261     } else if (!strcmp(key, "keep_selected")) {
 262         ddc->keep_selected = (val && strcmp(val, "0"));
 263     }
 264
 265     //g_print("DDC: %g %g %g %g\n", ddc->mass, ddc->drag, ddc->angle, ddc->width);
 266 }
 267
 268 static double
 269 flerp(double f0, double f1, double p)
 270 {
 271     return f0 + ( f1 - f0 ) * p;
 272 }
 273
 274 /* Get normalized point */
 275 static NR::Point
 276 sp_dyna_draw_get_npoint(SPDynaDrawContext const *dc, NR::Point v)
 277 {
 278     NR::Rect drect = SP_EVENT_CONTEXT(dc)->desktop->get_display_area();
 279     double const max = MAX ( drect.dimensions()[NR::X], drect.dimensions()[NR::Y] );
 280     return NR::Point(( v[NR::X] - drect.min()[NR::X] ) / max,  ( v[NR::Y] - drect.min()[NR::Y] ) / max);
 281 }
 282
 283 /* Get view point */
 284 static NR::Point
 285 sp_dyna_draw_get_vpoint(SPDynaDrawContext const *dc, NR::Point n)
 286 {
 287     NR::Rect drect = SP_EVENT_CONTEXT(dc)->desktop->get_display_area();
 288     double const max = MAX ( drect.dimensions()[NR::X], drect.dimensions()[NR::Y] );
 289     return NR::Point(n[NR::X] * max + drect.min()[NR::X], n[NR::Y] * max + drect.min()[NR::Y]);
 290 }
 291
 292 static void
 293 sp_dyna_draw_reset(SPDynaDrawContext *dc, NR::Point p)
 294 {
 295     dc->last = dc->cur = sp_dyna_draw_get_npoint(dc, p);
 296     dc->vel = NR::Point(0,0);
 297     dc->acc = NR::Point(0,0);
 298     dc->ang = NR::Point(0,0);
 299     dc->del = NR::Point(0,0);
 300 }
 301
 302 static void
 303 sp_dyna_draw_extinput(SPDynaDrawContext *dc, GdkEvent *event)
 304 {
 305     if (gdk_event_get_axis (event, GDK_AXIS_PRESSURE, &dc->pressure))
 306         dc->pressure = CLAMP (dc->pressure, DDC_MIN_PRESSURE, DDC_MAX_PRESSURE);
 307     else
 308         dc->pressure = DDC_DEFAULT_PRESSURE;
 309
 310     if (gdk_event_get_axis (event, GDK_AXIS_XTILT, &dc->xtilt))
 311         dc->xtilt = CLAMP (dc->xtilt, DDC_MIN_TILT, DDC_MAX_TILT);
 312     else
 313         dc->xtilt = DDC_DEFAULT_TILT;
 314
 315     if (gdk_event_get_axis (event, GDK_AXIS_YTILT, &dc->ytilt))
 316         dc->ytilt = CLAMP (dc->ytilt, DDC_MIN_TILT, DDC_MAX_TILT);
 317     else
 318         dc->ytilt = DDC_DEFAULT_TILT;
 319 }
 320
 321
 322 static gboolean
 323 sp_dyna_draw_apply(SPDynaDrawContext *dc, NR::Point p)
 324 {
 325     NR::Point n = sp_dyna_draw_get_npoint(dc, p);
 326
 327     /* Calculate mass and drag */
 328     double const mass = flerp(1.0, 160.0, dc->mass);
 329     double const drag = flerp(0.0, 0.5, dc->drag * dc->drag);
 330
 331     /* Calculate force and acceleration */
 332     NR::Point force = n - dc->cur;
 333     if ( NR::L2(force) < DYNA_EPSILON ) {
 334         return FALSE;
 335     }
 336
 337     dc->acc = force / mass;
 338
 339     /* Calculate new velocity */
 340     dc->vel += dc->acc;
 341
 342     /* Calculate angle of drawing tool */
 343
 344     double a1;
 345     if (dc->usetilt) {
 346         // 1a. calculate nib angle from input device tilt:
 347         gdouble length = std::sqrt(dc->xtilt*dc->xtilt + dc->ytilt*dc->ytilt);;
 348
 349         if (length > 0) {
 350             NR::Point ang1 = NR::Point(dc->ytilt/length, dc->xtilt/length);
 351             a1 = atan2(ang1);
 352         }
 353         else
 354             a1 = 0.0;
 355     }
 356     else {
 357         // 1b. fixed dc->angle (absolutely flat nib):
 358         double const radians = ( (dc->angle - 90) / 180.0 ) * M_PI;
 359         NR::Point ang1 = NR::Point(-sin(radians),  cos(radians));
 360         a1 = atan2(ang1);
 361     }
 362
 363     // 2. perpendicular to dc->vel (absolutely non-flat nib):
 364     gdouble const mag_vel = NR::L2(dc->vel);
 365     if ( mag_vel < DYNA_EPSILON ) {
 366         return FALSE;
 367     }
 368     NR::Point ang2 = NR::rot90(dc->vel) / mag_vel;
 369
 370     // 3. Average them using flatness parameter:
 371     // calculate angles
 372     double a2 = atan2(ang2);
 373     // flip a2 to force it to be in the same half-circle as a1
 374     bool flipped = false;
 375     if (fabs (a2-a1) > 0.5*M_PI) {
 376         a2 += M_PI;
 377         flipped = true;
 378     }
 379     // normalize a2
 380     if (a2 > M_PI)
 381         a2 -= 2*M_PI;
 382     if (a2 < -M_PI)
 383         a2 += 2*M_PI;
 384     // find the flatness-weighted bisector angle, unflip if a2 was flipped
 385     // FIXME: when dc->vel is oscillating around the fixed angle, the new_ang flips back and forth. How to avoid this?
 386     double new_ang = a1 + (1 - dc->flatness) * (a2 - a1) - (flipped? M_PI : 0);
 387     // convert to point
 388     dc->ang = NR::Point (cos (new_ang), sin (new_ang));
 389
 390     /* Apply drag */
 391     dc->vel *= 1.0 - drag;
 392
 393     /* Update position */
 394     dc->last = dc->cur;
 395     dc->cur += dc->vel;
 396
 397     return TRUE;
 398 }
 399
 400 static void
 401 sp_dyna_draw_brush(SPDynaDrawContext *dc)
 402 {
 403     g_assert( dc->npoints >= 0 && dc->npoints < SAMPLING_SIZE );
 404
 405     // How much velocity thins strokestyle
 406     double vel_thin = flerp (0, 160, dc->vel_thin);
 407
 408     // Influence of pressure on thickness
 409     double pressure_thick = (dc->usepressure ? dc->pressure : 1.0);
 410
 411     double width = ( pressure_thick - vel_thin * NR::L2(dc->vel) ) * dc->width;
 412
 413     double tremble_left = 0, tremble_right = 0;
 414     if (dc->tremor > 0) {
 415         // obtain two normally distributed random variables, using polar Box-Muller transform
 416         double x1, x2, w, y1, y2;
 417         do {
 418             x1 = 2.0 * g_random_double_range(0,1) - 1.0;
 419             x2 = 2.0 * g_random_double_range(0,1) - 1.0;
 420             w = x1 * x1 + x2 * x2;
 421         } while ( w >= 1.0 );
 422         w = sqrt( (-2.0 * log( w ) ) / w );
 423         y1 = x1 * w;
 424         y2 = x2 * w;
 425
 426         // deflect both left and right edges randomly and independently, so that:
 427         // (1) dc->tremor=1 corresponds to sigma=1, decreasing dc->tremor narrows the bell curve;
 428         // (2) deflection depends on width, but is upped for small widths for better visual uniformity across widths;
 429         // (3) deflection somewhat depends on speed, to prevent fast strokes looking
 430         // comparatively smooth and slow ones excessively jittery
 431         tremble_left  = (y1)*dc->tremor * (0.15 + 0.8*width) * (0.35 + 14*NR::L2(dc->vel));
 432         tremble_right = (y2)*dc->tremor * (0.15 + 0.8*width) * (0.35 + 14*NR::L2(dc->vel));
 433     }
 434
 435     if ( width < 0.02 * dc->width ) {
 436         width = 0.02 * dc->width;
 437     }
 438
 439     double dezoomify_factor = 0.05 * 1000;
 440     if (!dc->abs_width) {
 441         dezoomify_factor /= SP_EVENT_CONTEXT(dc)->desktop->current_zoom();
 442     }
 443
 444     NR::Point del_left = dezoomify_factor * (width + tremble_left) * dc->ang;
 445     NR::Point del_right = dezoomify_factor * (width + tremble_right) * dc->ang;
 446
 447     NR::Point abs_middle = sp_dyna_draw_get_vpoint(dc, dc->cur);
 448
 449     dc->point1[dc->npoints] = abs_middle + del_left;
 450     dc->point2[dc->npoints] = abs_middle - del_right;
 451
 452     dc->del = 0.5*(del_left + del_right);
 453
 454     dc->npoints++;
 455 }
 456
 457 void
 458 sp_ddc_update_toolbox (SPDesktop *desktop, const gchar *id, double value)
 459 {
 460     desktop->setToolboxAdjustmentValue (id, value);
 461 }
 462
 463 gint
 464 sp_dyna_draw_context_root_handler(SPEventContext *event_context,
 465                                   GdkEvent *event)
 466 {
 467     SPDynaDrawContext *dc = SP_DYNA_DRAW_CONTEXT(event_context);
 468     SPDesktop *desktop = event_context->desktop;
 469
 470     gint ret = FALSE;
 471
 472     switch (event->type) {
 473     case GDK_BUTTON_PRESS:
 474         if ( event->button.button == 1 ) {
 475
 476             SPDesktop *desktop = SP_EVENT_CONTEXT_DESKTOP(dc);
 477
 478             if (Inkscape::have_viable_layer(desktop, dc->_message_context) == false) {
 479                 return TRUE;
 480             }
 481
 482             NR::Point const button_w(event->button.x,
 483                                      event->button.y);
 484             NR::Point const button_dt(desktop->w2d(button_w));
 485             sp_dyna_draw_reset(dc, button_dt);
 486             sp_dyna_draw_extinput(dc, event);
 487             sp_dyna_draw_apply(dc, button_dt);
 488             sp_curve_reset(dc->accumulated);
 489             if (dc->repr) {
 490                 dc->repr = NULL;
 491             }
 492
 493             /* initialize first point */
 494             dc->npoints = 0;
 495
 496             sp_canvas_item_grab(SP_CANVAS_ITEM(desktop->acetate),
 497                                 ( GDK_KEY_PRESS_MASK |
 498                                   GDK_BUTTON_RELEASE_MASK |
 499                                   GDK_POINTER_MOTION_MASK |
 500                                   GDK_BUTTON_PRESS_MASK ),
 501                                 NULL,
 502                                 event->button.time);
 503
 504             ret = TRUE;
 505
 506             dc->is_drawing = true;
 507         }
 508         break;
 509     case GDK_MOTION_NOTIFY:
 510         if ( dc->is_drawing && ( event->motion.state & GDK_BUTTON1_MASK ) ) {
 511             dc->dragging = TRUE;
 512
 513             NR::Point const motion_w(event->motion.x,
 514                                      event->motion.y);
 515             NR::Point const motion_dt(desktop->w2d(motion_w));
 516
 517             sp_dyna_draw_extinput(dc, event);
 518             if (!sp_dyna_draw_apply(dc, motion_dt)) {
 519                 ret = TRUE;
 520                 break;
 521             }
 522
 523             if ( dc->cur != dc->last ) {
 524                 sp_dyna_draw_brush(dc);
 525                 g_assert( dc->npoints > 0 );
 526                 fit_and_split(dc, FALSE);
 527             }
 528             ret = TRUE;
 529         }
 530         break;
 531
 532     case GDK_BUTTON_RELEASE:
 533         sp_canvas_item_ungrab(SP_CANVAS_ITEM(desktop->acetate), event->button.time);
 534         dc->is_drawing = false;
 535         if ( dc->dragging && event->button.button == 1 ) {
 536             dc->dragging = FALSE;
 537
 538             /* Remove all temporary line segments */
 539             while (dc->segments) {
 540                 gtk_object_destroy(GTK_OBJECT(dc->segments->data));
 541                 dc->segments = g_slist_remove(dc->segments, dc->segments->data);
 542             }
 543             /* Create object */
 544             fit_and_split(dc, TRUE);
 545             accumulate_calligraphic(dc);
 546             set_to_accumulated(dc); /* temporal implementation */
 547             /* reset accumulated curve */
 548             sp_curve_reset(dc->accumulated);
 549             clear_current(dc);
 550             if (dc->repr) {
 551                 dc->repr = NULL;
 552             }
 553             ret = TRUE;
 554         }
 555         break;
 556     case GDK_KEY_PRESS:
 557         switch (get_group0_keyval (&event->key)) {
 558         case GDK_Up:
 559         case GDK_KP_Up:
 560             if (!MOD__CTRL_ONLY) {
 561                 dc->angle += 5.0;
 562                 if (dc->angle > 90.0)
 563                     dc->angle = 90.0;
 564                 sp_ddc_update_toolbox (desktop, "calligraphy-angle", dc->angle);
 565                 ret = TRUE;
 566             }
 567             break;
 568         case GDK_Down:
 569         case GDK_KP_Down:
 570             if (!MOD__CTRL_ONLY) {
 571                 dc->angle -= 5.0;
 572                 if (dc->angle < -90.0)
 573                     dc->angle = -90.0;
 574                 sp_ddc_update_toolbox (desktop, "calligraphy-angle", dc->angle);
 575                 ret = TRUE;
 576             }
 577             break;
 578         case GDK_Right:
 579         case GDK_KP_Right:
 580             if (!MOD__CTRL_ONLY) {
 581                 dc->width += 0.01;
 582                 if (dc->width > 1.0)
 583                     dc->width = 1.0;
 584                 sp_ddc_update_toolbox (desktop, "altx-calligraphy", dc->width * 100); // the same spinbutton is for alt+x
 585                 ret = TRUE;
 586             }
 587             break;
 588         case GDK_Left:
 589         case GDK_KP_Left:
 590             if (!MOD__CTRL_ONLY) {
 591                 dc->width -= 0.01;
 592                 if (dc->width < 0.01)
 593                     dc->width = 0.01;
 594                 sp_ddc_update_toolbox (desktop, "altx-calligraphy", dc->width * 100);
 595                 ret = TRUE;
 596             }
 597             break;
 598         case GDK_x:
 599         case GDK_X:
 600             if (MOD__ALT_ONLY) {
 601                 desktop->setToolboxFocusTo ("altx-calligraphy");
 602                 ret = TRUE;
 603             }
 604             break;
 605         case GDK_Escape:
 606             sp_desktop_selection(desktop)->clear();
 607             break;
 608
 609         default:
 610             break;
 611         }
 612     default:
 613         break;
 614     }
 615
 616     if (!ret) {
 617         if (((SPEventContextClass *) parent_class)->root_handler) {
 618             ret = ((SPEventContextClass *) parent_class)->root_handler(event_context, event);
 619         }
 620     }
 621
 622     return ret;
 623 }
 624
 625
 626 static void
 627 clear_current(SPDynaDrawContext *dc)
 628 {
 629     /* reset bpath */
 630     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(dc->currentshape), NULL);
 631     /* reset curve */
 632     sp_curve_reset(dc->currentcurve);
 633     sp_curve_reset(dc->cal1);
 634     sp_curve_reset(dc->cal2);
 635     /* reset points */
 636     dc->npoints = 0;
 637 }
 638
 639 static void
 640 set_to_accumulated(SPDynaDrawContext *dc)
 641 {
 642     SPDesktop *desktop = SP_EVENT_CONTEXT(dc)->desktop;
 643
 644     if (!sp_curve_empty(dc->accumulated)) {
 645         NArtBpath *abp;
 646         gchar *str;
 647
 648         if (!dc->repr) {
 649             /* Create object */
 650             Inkscape::XML::Node *repr = sp_repr_new("svg:path");
 651
 652             /* Set style */
 653             sp_desktop_apply_style_tool (desktop, repr, "tools.calligraphic", false);
 654
 655             dc->repr = repr;
 656
 657             SPItem *item=SP_ITEM(desktop->currentLayer()->appendChildRepr(dc->repr));
 658             Inkscape::GC::release(dc->repr);
 659             item->transform = SP_ITEM(desktop->currentRoot())->getRelativeTransform(desktop->currentLayer());
 660             item->updateRepr();
 661             if (dc->keep_selected)
 662                 sp_desktop_selection(desktop)->set(dc->repr);
 663         }
 664         abp = nr_artpath_affine(sp_curve_first_bpath(dc->accumulated), sp_desktop_dt2root_affine(desktop));
 665         str = sp_svg_write_path(abp);
 666         g_assert( str != NULL );
 667         nr_free(abp);
 668         dc->repr->setAttribute("d", str);
 669         g_free(str);
 670     } else {
 671         if (dc->repr) {
 672             sp_repr_unparent(dc->repr);
 673         }
 674         dc->repr = NULL;
 675     }
 676
 677     sp_document_done(sp_desktop_document(desktop));
 678 }
 679
 680 static void
 681 accumulate_calligraphic(SPDynaDrawContext *dc)
 682 {
 683     if ( !sp_curve_empty(dc->cal1) && !sp_curve_empty(dc->cal2) ) {
 684         sp_curve_reset(dc->accumulated); /*  Is this required ?? */
 685         SPCurve *rev_cal2 = sp_curve_reverse(dc->cal2);
 686         sp_curve_append(dc->accumulated, dc->cal1, FALSE);
 687         sp_curve_append(dc->accumulated, rev_cal2, TRUE);
 688         sp_curve_closepath(dc->accumulated);
 689
 690         sp_curve_unref(rev_cal2);
 691
 692         sp_curve_reset(dc->cal1);
 693         sp_curve_reset(dc->cal2);
 694     }
 695 }
 696
 697 static void
 698 fit_and_split(SPDynaDrawContext *dc,
 699               gboolean release)
 700 {
 701     fit_and_split_calligraphics(dc, release);
 702 }
 703
 704 static double square(double const x)
 705 {
 706     return x * x;
 707 }
 708
 709 static void
 710 fit_and_split_calligraphics(SPDynaDrawContext *dc, gboolean release)
 711 {
 712     double const tolerance_sq = square( NR::expansion(SP_EVENT_CONTEXT(dc)->desktop->w2d()) * TOLERANCE_CALLIGRAPHIC );
 713
 714 #ifdef DYNA_DRAW_VERBOSE
 715     g_print("[F&S:R=%c]", release?'T':'F');
 716 #endif
 717
 718     if (!( dc->npoints > 0 && dc->npoints < SAMPLING_SIZE ))
 719         return; // just clicked
 720
 721     if ( dc->npoints == SAMPLING_SIZE - 1 || release ) {
 722 #define BEZIER_SIZE       4
 723 #define BEZIER_MAX_BEZIERS  8
 724 #define BEZIER_MAX_LENGTH ( BEZIER_SIZE * BEZIER_MAX_BEZIERS )
 725
 726 #ifdef DYNA_DRAW_VERBOSE
 727         g_print("[F&S:#] dc->npoints:%d, release:%s\n",
 728                 dc->npoints, release ? "TRUE" : "FALSE");
 729 #endif
 730
 731         /* Current calligraphic */
 732         if ( dc->cal1->end == 0 || dc->cal2->end == 0 ) {
 733             /* dc->npoints > 0 */
 734             /* g_print("calligraphics(1|2) reset\n"); */
 735             sp_curve_reset(dc->cal1);
 736             sp_curve_reset(dc->cal2);
 737
 738             sp_curve_moveto(dc->cal1, dc->point1[0]);
 739             sp_curve_moveto(dc->cal2, dc->point2[0]);
 740         }
 741
 742         NR::Point b1[BEZIER_MAX_LENGTH];
 743         gint const nb1 = sp_bezier_fit_cubic_r(b1, dc->point1, dc->npoints,
 744                                                tolerance_sq, BEZIER_MAX_BEZIERS);
 745         g_assert( nb1 * BEZIER_SIZE <= gint(G_N_ELEMENTS(b1)) );
 746
 747         NR::Point b2[BEZIER_MAX_LENGTH];
 748         gint const nb2 = sp_bezier_fit_cubic_r(b2, dc->point2, dc->npoints,
 749                                                tolerance_sq, BEZIER_MAX_BEZIERS);
 750         g_assert( nb2 * BEZIER_SIZE <= gint(G_N_ELEMENTS(b2)) );
 751
 752         if ( nb1 != -1 && nb2 != -1 ) {
 753             /* Fit and draw and reset state */
 754 #ifdef DYNA_DRAW_VERBOSE
 755             g_print("nb1:%d nb2:%d\n", nb1, nb2);
 756 #endif
 757             /* CanvasShape */
 758             if (! release) {
 759                 sp_curve_reset(dc->currentcurve);
 760                 sp_curve_moveto(dc->currentcurve, b1[0]);
 761                 for (NR::Point *bp1 = b1; bp1 < b1 + BEZIER_SIZE * nb1; bp1 += BEZIER_SIZE) {
 762                     sp_curve_curveto(dc->currentcurve, bp1[1],
 763                                      bp1[2], bp1[3]);
 764                 }
 765                 sp_curve_lineto(dc->currentcurve,
 766                                 b2[BEZIER_SIZE*(nb2-1) + 3]);
 767                 for (NR::Point *bp2 = b2 + BEZIER_SIZE * ( nb2 - 1 ); bp2 >= b2; bp2 -= BEZIER_SIZE) {
 768                     sp_curve_curveto(dc->currentcurve, bp2[2], bp2[1], bp2[0]);
 769                 }
 770                 sp_curve_closepath(dc->currentcurve);
 771                 sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(dc->currentshape), dc->currentcurve);
 772             }
 773
 774             /* Current calligraphic */
 775             for (NR::Point *bp1 = b1; bp1 < b1 + BEZIER_SIZE * nb1; bp1 += BEZIER_SIZE) {
 776                 sp_curve_curveto(dc->cal1, bp1[1], bp1[2], bp1[3]);
 777             }
 778             for (NR::Point *bp2 = b2; bp2 < b2 + BEZIER_SIZE * nb2; bp2 += BEZIER_SIZE) {
 779                 sp_curve_curveto(dc->cal2, bp2[1], bp2[2], bp2[3]);
 780             }
 781         } else {
 782             /* fixme: ??? */
 783 #ifdef DYNA_DRAW_VERBOSE
 784             g_print("[fit_and_split_calligraphics] failed to fit-cubic.\n");
 785 #endif
 786             draw_temporary_box(dc);
 787
 788             for (gint i = 1; i < dc->npoints; i++) {
 789                 sp_curve_lineto(dc->cal1, dc->point1[i]);
 790             }
 791             for (gint i = 1; i < dc->npoints; i++) {
 792                 sp_curve_lineto(dc->cal2, dc->point2[i]);
 793             }
 794         }
 795
 796         /* Fit and draw and copy last point */
 797 #ifdef DYNA_DRAW_VERBOSE
 798         g_print("[%d]Yup\n", dc->npoints);
 799 #endif
 800         if (!release) {
 801             g_assert(!sp_curve_empty(dc->currentcurve));
 802
 803             SPCanvasItem *cbp = sp_canvas_item_new(sp_desktop_sketch(SP_EVENT_CONTEXT(dc)->desktop),
 804                                                    SP_TYPE_CANVAS_BPATH,
 805                                                    NULL);
 806             SPCurve *curve = sp_curve_copy(dc->currentcurve);
 807             sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH (cbp), curve);
 808             sp_curve_unref(curve);
 809             guint32 fillColor = sp_desktop_get_color_tool(SP_ACTIVE_DESKTOP, "tools.calligraphic", true);
 810             sp_canvas_bpath_set_fill(SP_CANVAS_BPATH(cbp), fillColor , SP_WIND_RULE_EVENODD);
 811
 812             sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(cbp), 0x00000000, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 813             /* fixme: Cannot we cascade it to root more clearly? */
 814             g_signal_connect(G_OBJECT(cbp), "event", G_CALLBACK(sp_desktop_root_handler), SP_EVENT_CONTEXT(dc)->desktop);
 815
 816             dc->segments = g_slist_prepend(dc->segments, cbp);
 817         }
 818
 819         dc->point1[0] = dc->point1[dc->npoints - 1];
 820         dc->point2[0] = dc->point2[dc->npoints - 1];
 821         dc->npoints = 1;
 822     } else {
 823         draw_temporary_box(dc);
 824     }
 825 }
 826
 827 static void
 828 draw_temporary_box(SPDynaDrawContext *dc)
 829 {
 830     sp_curve_reset(dc->currentcurve);
 831     sp_curve_moveto(dc->currentcurve, dc->point1[0]);
 832     for (gint i = 1; i < dc->npoints; i++) {
 833         sp_curve_lineto(dc->currentcurve, dc->point1[i]);
 834     }
 835     for (gint i = dc->npoints-1; i >= 0; i--) {
 836         sp_curve_lineto(dc->currentcurve, dc->point2[i]);
 837     }
 838     sp_curve_closepath(dc->currentcurve);
 839     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(dc->currentshape), dc->currentcurve);
 840 }
 841
 842 /*
 843   Local Variables:
 844   mode:c++
 845   c-file-style:"stroustrup"
 846   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
 847   indent-tabs-mode:nil
 848   fill-column:99
 849   End:
 850 */
 851 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :