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
  62 #define DYNA_EPSILON 0.5e-6
  63 #define DYNA_EPSILON_START 0.5e-2
  64 #define DYNA_VEL_START 1e-5
  65
  66 #define DYNA_MIN_WIDTH 1.0e-6
  67
  68 #define DRAG_MIN 0.0
  69 #define DRAG_DEFAULT 1.0
  70 #define DRAG_MAX 1.0
  71
  72 static void sp_dyna_draw_context_class_init(SPDynaDrawContextClass *klass);
  73 static void sp_dyna_draw_context_init(SPDynaDrawContext *ddc);
  74 static void sp_dyna_draw_context_dispose(GObject *object);
  75
  76 static void sp_dyna_draw_context_setup(SPEventContext *ec);
  77 static void sp_dyna_draw_context_set(SPEventContext *ec, gchar const *key, gchar const *val);
  78 static gint sp_dyna_draw_context_root_handler(SPEventContext *ec, GdkEvent *event);
  79
  80 static void clear_current(SPDynaDrawContext *dc);
  81 static void set_to_accumulated(SPDynaDrawContext *dc);
  82 static void add_cap(SPCurve *curve, NR::Point const &pre, NR::Point const &from, NR::Point const &to, NR::Point const &post, double rounding);
  83 static void accumulate_calligraphic(SPDynaDrawContext *dc);
  84
  85 static void fit_and_split(SPDynaDrawContext *ddc, gboolean release);
  86
  87 static void sp_dyna_draw_reset(SPDynaDrawContext *ddc, NR::Point p);
  88 static NR::Point sp_dyna_draw_get_npoint(SPDynaDrawContext const *ddc, NR::Point v);
  89 static NR::Point sp_dyna_draw_get_vpoint(SPDynaDrawContext const *ddc, NR::Point n);
  90 static void draw_temporary_box(SPDynaDrawContext *dc);
  91
  92
  93 static SPEventContextClass *parent_class;
  94
  95 GtkType
  96 sp_dyna_draw_context_get_type(void)
  97 {
  98     static GType type = 0;
  99     if (!type) {
 100         GTypeInfo info = {
 101             sizeof(SPDynaDrawContextClass),
 102             NULL, NULL,
 103             (GClassInitFunc) sp_dyna_draw_context_class_init,
 104             NULL, NULL,
 105             sizeof(SPDynaDrawContext),
 106             4,
 107             (GInstanceInitFunc) sp_dyna_draw_context_init,
 108             NULL,   /* value_table */
 109         };
 110         type = g_type_register_static(SP_TYPE_EVENT_CONTEXT, "SPDynaDrawContext", &info, (GTypeFlags)0);
 111     }
 112     return type;
 113 }
 114
 115 static void
 116 sp_dyna_draw_context_class_init(SPDynaDrawContextClass *klass)
 117 {
 118     GObjectClass *object_class = (GObjectClass *) klass;
 119     SPEventContextClass *event_context_class = (SPEventContextClass *) klass;
 120
 121     parent_class = (SPEventContextClass*)g_type_class_peek_parent(klass);
 122
 123     object_class->dispose = sp_dyna_draw_context_dispose;
 124
 125     event_context_class->setup = sp_dyna_draw_context_setup;
 126     event_context_class->set = sp_dyna_draw_context_set;
 127     event_context_class->root_handler = sp_dyna_draw_context_root_handler;
 128 }
 129
 130 static void
 131 sp_dyna_draw_context_init(SPDynaDrawContext *ddc)
 132 {
 133     SPEventContext *event_context = SP_EVENT_CONTEXT(ddc);
 134
 135     event_context->cursor_shape = cursor_calligraphy_xpm;
 136     event_context->hot_x = 4;
 137     event_context->hot_y = 4;
 138
 139     ddc->accumulated = NULL;
 140     ddc->segments = NULL;
 141     ddc->currentcurve = NULL;
 142     ddc->currentshape = NULL;
 143     ddc->npoints = 0;
 144     ddc->cal1 = NULL;
 145     ddc->cal2 = NULL;
 146     ddc->repr = NULL;
 147
 148     /* DynaDraw values */
 149     ddc->cur = NR::Point(0,0);
 150     ddc->last = NR::Point(0,0);
 151     ddc->vel = NR::Point(0,0);
 152     ddc->vel_max = 0;
 153     ddc->acc = NR::Point(0,0);
 154     ddc->ang = NR::Point(0,0);
 155     ddc->del = NR::Point(0,0);
 156
 157     /* attributes */
 158     ddc->dragging = FALSE;
 159
 160     ddc->mass = 0.3;
 161     ddc->drag = DRAG_DEFAULT;
 162     ddc->angle = 30.0;
 163     ddc->width = 0.2;
 164
 165     ddc->vel_thin = 0.1;
 166     ddc->flatness = 0.9;
 167     ddc->cap_rounding = 0.0;
 168
 169     ddc->abs_width = false;
 170     ddc->keep_selected = true;
 171 }
 172
 173 static void
 174 sp_dyna_draw_context_dispose(GObject *object)
 175 {
 176     SPDynaDrawContext *ddc = SP_DYNA_DRAW_CONTEXT(object);
 177
 178     if (ddc->accumulated) {
 179         ddc->accumulated = sp_curve_unref(ddc->accumulated);
 180     }
 181
 182     while (ddc->segments) {
 183         gtk_object_destroy(GTK_OBJECT(ddc->segments->data));
 184         ddc->segments = g_slist_remove(ddc->segments, ddc->segments->data);
 185     }
 186
 187     if (ddc->currentcurve) ddc->currentcurve = sp_curve_unref(ddc->currentcurve);
 188     if (ddc->cal1) ddc->cal1 = sp_curve_unref(ddc->cal1);
 189     if (ddc->cal2) ddc->cal2 = sp_curve_unref(ddc->cal2);
 190
 191     if (ddc->currentshape) {
 192         gtk_object_destroy(GTK_OBJECT(ddc->currentshape));
 193         ddc->currentshape = NULL;
 194     }
 195
 196     if (ddc->_message_context) {
 197         delete ddc->_message_context;
 198     }
 199
 200     G_OBJECT_CLASS(parent_class)->dispose(object);
 201 }
 202
 203 static void
 204 sp_dyna_draw_context_setup(SPEventContext *ec)
 205 {
 206     SPDynaDrawContext *ddc = SP_DYNA_DRAW_CONTEXT(ec);
 207
 208     if (((SPEventContextClass *) parent_class)->setup)
 209         ((SPEventContextClass *) parent_class)->setup(ec);
 210
 211     ddc->accumulated = sp_curve_new_sized(32);
 212     ddc->currentcurve = sp_curve_new_sized(4);
 213
 214     ddc->cal1 = sp_curve_new_sized(32);
 215     ddc->cal2 = sp_curve_new_sized(32);
 216
 217     ddc->currentshape = sp_canvas_item_new(sp_desktop_sketch(ec->desktop), SP_TYPE_CANVAS_BPATH, NULL);
 218     sp_canvas_bpath_set_fill(SP_CANVAS_BPATH(ddc->currentshape), DDC_RED_RGBA, SP_WIND_RULE_EVENODD);
 219     sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(ddc->currentshape), 0x00000000, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 220     /* fixme: Cannot we cascade it to root more clearly? */
 221     g_signal_connect(G_OBJECT(ddc->currentshape), "event", G_CALLBACK(sp_desktop_root_handler), ec->desktop);
 222
 223     sp_event_context_read(ec, "mass");
 224     sp_event_context_read(ec, "wiggle");
 225     sp_event_context_read(ec, "angle");
 226     sp_event_context_read(ec, "width");
 227     sp_event_context_read(ec, "thinning");
 228     sp_event_context_read(ec, "tremor");
 229     sp_event_context_read(ec, "flatness");
 230     sp_event_context_read(ec, "usepressure");
 231     sp_event_context_read(ec, "usetilt");
 232     sp_event_context_read(ec, "abs_width");
 233     sp_event_context_read(ec, "keep_selected");
 234     sp_event_context_read(ec, "cap_rounding");
 235
 236     ddc->is_drawing = false;
 237
 238     ddc->_message_context = new Inkscape::MessageContext((ec->desktop)->messageStack());
 239 }
 240
 241 static void
 242 sp_dyna_draw_context_set(SPEventContext *ec, gchar const *key, gchar const *val)
 243 {
 244     SPDynaDrawContext *ddc = SP_DYNA_DRAW_CONTEXT(ec);
 245
 246     if (!strcmp(key, "mass")) {
 247         double const dval = ( val ? g_ascii_strtod (val, NULL) : 0.2 );
 248         ddc->mass = CLAMP(dval, -1000.0, 1000.0);
 249     } else if (!strcmp(key, "wiggle")) {
 250         double const dval = ( val ? g_ascii_strtod (val, NULL) : (1 - DRAG_DEFAULT));
 251         ddc->drag = CLAMP((1 - dval), DRAG_MIN, DRAG_MAX); // drag is inverse to wiggle
 252     } else if (!strcmp(key, "angle")) {
 253         double const dval = ( val ? g_ascii_strtod (val, NULL) : 0.0);
 254         ddc->angle = CLAMP (dval, -90, 90);
 255     } else if (!strcmp(key, "width")) {
 256         double const dval = ( val ? g_ascii_strtod (val, NULL) : 0.1 );
 257         ddc->width = CLAMP(dval, -1000.0, 1000.0);
 258     } else if (!strcmp(key, "thinning")) {
 259         double const dval = ( val ? g_ascii_strtod (val, NULL) : 0.1 );
 260         ddc->vel_thin = CLAMP(dval, -1.0, 1.0);
 261     } else if (!strcmp(key, "tremor")) {
 262         double const dval = ( val ? g_ascii_strtod (val, NULL) : 0.0 );
 263         ddc->tremor = CLAMP(dval, 0.0, 1.0);
 264     } else if (!strcmp(key, "flatness")) {
 265         double const dval = ( val ? g_ascii_strtod (val, NULL) : 1.0 );
 266         ddc->flatness = CLAMP(dval, 0, 1.0);
 267     } else if (!strcmp(key, "usepressure")) {
 268         ddc->usepressure = (val && strcmp(val, "0"));
 269     } else if (!strcmp(key, "usetilt")) {
 270         ddc->usetilt = (val && strcmp(val, "0"));
 271     } else if (!strcmp(key, "abs_width")) {
 272         ddc->abs_width = (val && strcmp(val, "0"));
 273     } else if (!strcmp(key, "keep_selected")) {
 274         ddc->keep_selected = (val && strcmp(val, "0"));
 275     } else if (!strcmp(key, "cap_rounding")) {
 276         ddc->cap_rounding = ( val ? g_ascii_strtod (val, NULL) : 0.0 );
 277     }
 278
 279     //g_print("DDC: %g %g %g %g\n", ddc->mass, ddc->drag, ddc->angle, ddc->width);
 280 }
 281
 282 static double
 283 flerp(double f0, double f1, double p)
 284 {
 285     return f0 + ( f1 - f0 ) * p;
 286 }
 287
 288 /* Get normalized point */
 289 static NR::Point
 290 sp_dyna_draw_get_npoint(SPDynaDrawContext const *dc, NR::Point v)
 291 {
 292     NR::Rect drect = SP_EVENT_CONTEXT(dc)->desktop->get_display_area();
 293     double const max = MAX ( drect.dimensions()[NR::X], drect.dimensions()[NR::Y] );
 294     return NR::Point(( v[NR::X] - drect.min()[NR::X] ) / max,  ( v[NR::Y] - drect.min()[NR::Y] ) / max);
 295 }
 296
 297 /* Get view point */
 298 static NR::Point
 299 sp_dyna_draw_get_vpoint(SPDynaDrawContext const *dc, NR::Point n)
 300 {
 301     NR::Rect drect = SP_EVENT_CONTEXT(dc)->desktop->get_display_area();
 302     double const max = MAX ( drect.dimensions()[NR::X], drect.dimensions()[NR::Y] );
 303     return NR::Point(n[NR::X] * max + drect.min()[NR::X], n[NR::Y] * max + drect.min()[NR::Y]);
 304 }
 305
 306 static void
 307 sp_dyna_draw_reset(SPDynaDrawContext *dc, NR::Point p)
 308 {
 309     dc->last = dc->cur = sp_dyna_draw_get_npoint(dc, p);
 310     dc->vel = NR::Point(0,0);
 311     dc->vel_max = 0;
 312     dc->acc = NR::Point(0,0);
 313     dc->ang = NR::Point(0,0);
 314     dc->del = NR::Point(0,0);
 315 }
 316
 317 static void
 318 sp_dyna_draw_extinput(SPDynaDrawContext *dc, GdkEvent *event)
 319 {
 320     if (gdk_event_get_axis (event, GDK_AXIS_PRESSURE, &dc->pressure))
 321         dc->pressure = CLAMP (dc->pressure, DDC_MIN_PRESSURE, DDC_MAX_PRESSURE);
 322     else
 323         dc->pressure = DDC_DEFAULT_PRESSURE;
 324
 325     if (gdk_event_get_axis (event, GDK_AXIS_XTILT, &dc->xtilt))
 326         dc->xtilt = CLAMP (dc->xtilt, DDC_MIN_TILT, DDC_MAX_TILT);
 327     else
 328         dc->xtilt = DDC_DEFAULT_TILT;
 329
 330     if (gdk_event_get_axis (event, GDK_AXIS_YTILT, &dc->ytilt))
 331         dc->ytilt = CLAMP (dc->ytilt, DDC_MIN_TILT, DDC_MAX_TILT);
 332     else
 333         dc->ytilt = DDC_DEFAULT_TILT;
 334 }
 335
 336
 337 static gboolean
 338 sp_dyna_draw_apply(SPDynaDrawContext *dc, NR::Point p)
 339 {
 340     NR::Point n = sp_dyna_draw_get_npoint(dc, p);
 341
 342     /* Calculate mass and drag */
 343     double const mass = flerp(1.0, 160.0, dc->mass);
 344     double const drag = flerp(0.0, 0.5, dc->drag * dc->drag);
 345
 346     /* Calculate force and acceleration */
 347     NR::Point force = n - dc->cur;
 348     if ( NR::L2(force) < DYNA_EPSILON || (dc->vel_max < DYNA_VEL_START && NR::L2(force) < DYNA_EPSILON_START)) {
 349         return FALSE;
 350     }
 351
 352     dc->acc = force / mass;
 353
 354     /* Calculate new velocity */
 355     dc->vel += dc->acc;
 356
 357     if (NR::L2(dc->vel) > dc->vel_max)
 358         dc->vel_max = NR::L2(dc->vel);
 359
 360     /* Calculate angle of drawing tool */
 361
 362     double a1;
 363     if (dc->usetilt) {
 364         // 1a. calculate nib angle from input device tilt:
 365         gdouble length = std::sqrt(dc->xtilt*dc->xtilt + dc->ytilt*dc->ytilt);;
 366
 367         if (length > 0) {
 368             NR::Point ang1 = NR::Point(dc->ytilt/length, dc->xtilt/length);
 369             a1 = atan2(ang1);
 370         }
 371         else
 372             a1 = 0.0;
 373     }
 374     else {
 375         // 1b. fixed dc->angle (absolutely flat nib):
 376         double const radians = ( (dc->angle - 90) / 180.0 ) * M_PI;
 377         NR::Point ang1 = NR::Point(-sin(radians),  cos(radians));
 378         a1 = atan2(ang1);
 379     }
 380
 381     // 2. perpendicular to dc->vel (absolutely non-flat nib):
 382     gdouble const mag_vel = NR::L2(dc->vel);
 383     if ( mag_vel < DYNA_EPSILON ) {
 384         return FALSE;
 385     }
 386     NR::Point ang2 = NR::rot90(dc->vel) / mag_vel;
 387
 388     // 3. Average them using flatness parameter:
 389     // calculate angles
 390     double a2 = atan2(ang2);
 391     // flip a2 to force it to be in the same half-circle as a1
 392     bool flipped = false;
 393     if (fabs (a2-a1) > 0.5*M_PI) {
 394         a2 += M_PI;
 395         flipped = true;
 396     }
 397     // normalize a2
 398     if (a2 > M_PI)
 399         a2 -= 2*M_PI;
 400     if (a2 < -M_PI)
 401         a2 += 2*M_PI;
 402     // find the flatness-weighted bisector angle, unflip if a2 was flipped
 403     // FIXME: when dc->vel is oscillating around the fixed angle, the new_ang flips back and forth. How to avoid this?
 404     double new_ang = a1 + (1 - dc->flatness) * (a2 - a1) - (flipped? M_PI : 0);
 405
 406     double angle_delta = NR::L2(NR::Point (cos (new_ang), sin (new_ang)) - dc->ang);
 407
 408     if ( angle_delta / NR::L2(dc->vel) > 4000 ) {
 409         return FALSE;
 410     }
 411
 412     // convert to point
 413     dc->ang = NR::Point (cos (new_ang), sin (new_ang));
 414
 415 //    g_print ("force %g  acc %g  vel_max %g  vel %g  a1 %g  a2 %g  new_ang %g\n", NR::L2(force), NR::L2(dc->acc), dc->vel_max, NR::L2(dc->vel), a1, a2, new_ang);
 416
 417     /* Apply drag */
 418     dc->vel *= 1.0 - drag;
 419
 420     /* Update position */
 421     dc->last = dc->cur;
 422     dc->cur += dc->vel;
 423
 424     return TRUE;
 425 }
 426
 427 static void
 428 sp_dyna_draw_brush(SPDynaDrawContext *dc)
 429 {
 430     g_assert( dc->npoints >= 0 && dc->npoints < SAMPLING_SIZE );
 431
 432     // How much velocity thins strokestyle
 433     double vel_thin = flerp (0, 160, dc->vel_thin);
 434
 435     // Influence of pressure on thickness
 436     double pressure_thick = (dc->usepressure ? dc->pressure : 1.0);
 437
 438     double width = ( pressure_thick - vel_thin * NR::L2(dc->vel) ) * dc->width;
 439
 440     double tremble_left = 0, tremble_right = 0;
 441     if (dc->tremor > 0) {
 442         // obtain two normally distributed random variables, using polar Box-Muller transform
 443         double x1, x2, w, y1, y2;
 444         do {
 445             x1 = 2.0 * g_random_double_range(0,1) - 1.0;
 446             x2 = 2.0 * g_random_double_range(0,1) - 1.0;
 447             w = x1 * x1 + x2 * x2;
 448         } while ( w >= 1.0 );
 449         w = sqrt( (-2.0 * log( w ) ) / w );
 450         y1 = x1 * w;
 451         y2 = x2 * w;
 452
 453         // deflect both left and right edges randomly and independently, so that:
 454         // (1) dc->tremor=1 corresponds to sigma=1, decreasing dc->tremor narrows the bell curve;
 455         // (2) deflection depends on width, but is upped for small widths for better visual uniformity across widths;
 456         // (3) deflection somewhat depends on speed, to prevent fast strokes looking
 457         // comparatively smooth and slow ones excessively jittery
 458         tremble_left  = (y1)*dc->tremor * (0.15 + 0.8*width) * (0.35 + 14*NR::L2(dc->vel));
 459         tremble_right = (y2)*dc->tremor * (0.15 + 0.8*width) * (0.35 + 14*NR::L2(dc->vel));
 460     }
 461
 462     if ( width < 0.02 * dc->width ) {
 463         width = 0.02 * dc->width;
 464     }
 465
 466     double dezoomify_factor = 0.05 * 1000;
 467     if (!dc->abs_width) {
 468         dezoomify_factor /= SP_EVENT_CONTEXT(dc)->desktop->current_zoom();
 469     }
 470
 471     NR::Point del_left = dezoomify_factor * (width + tremble_left) * dc->ang;
 472     NR::Point del_right = dezoomify_factor * (width + tremble_right) * dc->ang;
 473
 474     NR::Point abs_middle = sp_dyna_draw_get_vpoint(dc, dc->cur);
 475
 476     dc->point1[dc->npoints] = abs_middle + del_left;
 477     dc->point2[dc->npoints] = abs_middle - del_right;
 478
 479     dc->del = 0.5*(del_left + del_right);
 480
 481     dc->npoints++;
 482 }
 483
 484 void
 485 sp_ddc_update_toolbox (SPDesktop *desktop, const gchar *id, double value)
 486 {
 487     desktop->setToolboxAdjustmentValue (id, value);
 488 }
 489
 490 static void
 491 calligraphic_cancel(SPDynaDrawContext *dc)
 492 {
 493     SPDesktop *desktop = SP_EVENT_CONTEXT(dc)->desktop;
 494     dc->dragging = FALSE;
 495     dc->is_drawing = false;
 496     sp_canvas_item_ungrab(SP_CANVAS_ITEM(desktop->acetate), 0);
 497             /* Remove all temporary line segments */
 498             while (dc->segments) {
 499                 gtk_object_destroy(GTK_OBJECT(dc->segments->data));
 500                 dc->segments = g_slist_remove(dc->segments, dc->segments->data);
 501             }
 502             /* reset accumulated curve */
 503             sp_curve_reset(dc->accumulated);
 504             clear_current(dc);
 505             if (dc->repr) {
 506                 dc->repr = NULL;
 507             }
 508 }
 509
 510
 511 gint
 512 sp_dyna_draw_context_root_handler(SPEventContext *event_context,
 513                                   GdkEvent *event)
 514 {
 515     SPDynaDrawContext *dc = SP_DYNA_DRAW_CONTEXT(event_context);
 516     SPDesktop *desktop = event_context->desktop;
 517
 518     gint ret = FALSE;
 519
 520     switch (event->type) {
 521     case GDK_BUTTON_PRESS:
 522         if ( event->button.button == 1 ) {
 523
 524             SPDesktop *desktop = SP_EVENT_CONTEXT_DESKTOP(dc);
 525
 526             if (Inkscape::have_viable_layer(desktop, dc->_message_context) == false) {
 527                 return TRUE;
 528             }
 529
 530             NR::Point const button_w(event->button.x,
 531                                      event->button.y);
 532             NR::Point const button_dt(desktop->w2d(button_w));
 533             sp_dyna_draw_reset(dc, button_dt);
 534             sp_dyna_draw_extinput(dc, event);
 535             sp_dyna_draw_apply(dc, button_dt);
 536             sp_curve_reset(dc->accumulated);
 537             if (dc->repr) {
 538                 dc->repr = NULL;
 539             }
 540
 541             /* initialize first point */
 542             dc->npoints = 0;
 543
 544             sp_canvas_item_grab(SP_CANVAS_ITEM(desktop->acetate),
 545                                 ( GDK_KEY_PRESS_MASK |
 546                                   GDK_BUTTON_RELEASE_MASK |
 547                                   GDK_POINTER_MOTION_MASK |
 548                                   GDK_BUTTON_PRESS_MASK ),
 549                                 NULL,
 550                                 event->button.time);
 551
 552             ret = TRUE;
 553
 554             dc->is_drawing = true;
 555         }
 556         break;
 557     case GDK_MOTION_NOTIFY:
 558         if ( dc->is_drawing && ( event->motion.state & GDK_BUTTON1_MASK ) ) {
 559             dc->dragging = TRUE;
 560
 561             NR::Point const motion_w(event->motion.x,
 562                                      event->motion.y);
 563             NR::Point const motion_dt(desktop->w2d(motion_w));
 564
 565             sp_dyna_draw_extinput(dc, event);
 566             if (!sp_dyna_draw_apply(dc, motion_dt)) {
 567                 ret = TRUE;
 568                 break;
 569             }
 570
 571             if ( dc->cur != dc->last ) {
 572                 sp_dyna_draw_brush(dc);
 573                 g_assert( dc->npoints > 0 );
 574                 fit_and_split(dc, FALSE);
 575             }
 576             ret = TRUE;
 577         }
 578         break;
 579
 580     case GDK_BUTTON_RELEASE:
 581         sp_canvas_item_ungrab(SP_CANVAS_ITEM(desktop->acetate), event->button.time);
 582         dc->is_drawing = false;
 583
 584         if ( dc->dragging && event->button.button == 1 ) {
 585             dc->dragging = FALSE;
 586
 587             NR::Point const motion_w(event->button.x, event->button.y);
 588             NR::Point const motion_dt(desktop->w2d(motion_w));
 589             sp_dyna_draw_apply(dc, motion_dt);
 590
 591             /* Remove all temporary line segments */
 592             while (dc->segments) {
 593                 gtk_object_destroy(GTK_OBJECT(dc->segments->data));
 594                 dc->segments = g_slist_remove(dc->segments, dc->segments->data);
 595             }
 596             /* Create object */
 597             fit_and_split(dc, TRUE);
 598             accumulate_calligraphic(dc);
 599             set_to_accumulated(dc); /* temporal implementation */
 600             /* reset accumulated curve */
 601             sp_curve_reset(dc->accumulated);
 602             clear_current(dc);
 603             if (dc->repr) {
 604                 dc->repr = NULL;
 605             }
 606             ret = TRUE;
 607         }
 608         break;
 609     case GDK_KEY_PRESS:
 610         switch (get_group0_keyval (&event->key)) {
 611         case GDK_Up:
 612         case GDK_KP_Up:
 613             if (!MOD__CTRL_ONLY) {
 614                 dc->angle += 5.0;
 615                 if (dc->angle > 90.0)
 616                     dc->angle = 90.0;
 617                 sp_ddc_update_toolbox (desktop, "calligraphy-angle", dc->angle);
 618                 ret = TRUE;
 619             }
 620             break;
 621         case GDK_Down:
 622         case GDK_KP_Down:
 623             if (!MOD__CTRL_ONLY) {
 624                 dc->angle -= 5.0;
 625                 if (dc->angle < -90.0)
 626                     dc->angle = -90.0;
 627                 sp_ddc_update_toolbox (desktop, "calligraphy-angle", dc->angle);
 628                 ret = TRUE;
 629             }
 630             break;
 631         case GDK_Right:
 632         case GDK_KP_Right:
 633             if (!MOD__CTRL_ONLY) {
 634                 dc->width += 0.01;
 635                 if (dc->width > 1.0)
 636                     dc->width = 1.0;
 637                 sp_ddc_update_toolbox (desktop, "altx-calligraphy", dc->width * 100); // the same spinbutton is for alt+x
 638                 ret = TRUE;
 639             }
 640             break;
 641         case GDK_Left:
 642         case GDK_KP_Left:
 643             if (!MOD__CTRL_ONLY) {
 644                 dc->width -= 0.01;
 645                 if (dc->width < 0.01)
 646                     dc->width = 0.01;
 647                 sp_ddc_update_toolbox (desktop, "altx-calligraphy", dc->width * 100);
 648                 ret = TRUE;
 649             }
 650             break;
 651         case GDK_x:
 652         case GDK_X:
 653             if (MOD__ALT_ONLY) {
 654                 desktop->setToolboxFocusTo ("altx-calligraphy");
 655                 ret = TRUE;
 656             }
 657             break;
 658         case GDK_Escape:
 659             if (dc->is_drawing) {
 660                 // if drawing, cancel, otherwise pass it up for deselecting
 661                 calligraphic_cancel (dc);
 662                 ret = TRUE;
 663             }
 664             break;
 665         case GDK_z:
 666         case GDK_Z:
 667             if (MOD__CTRL_ONLY && dc->is_drawing) {
 668                 // if drawing, cancel, otherwise pass it up for undo
 669                 calligraphic_cancel (dc);
 670                 ret = TRUE;
 671             }
 672             break;
 673         default:
 674             break;
 675         }
 676     default:
 677         break;
 678     }
 679
 680     if (!ret) {
 681         if (((SPEventContextClass *) parent_class)->root_handler) {
 682             ret = ((SPEventContextClass *) parent_class)->root_handler(event_context, event);
 683         }
 684     }
 685
 686     return ret;
 687 }
 688
 689
 690 static void
 691 clear_current(SPDynaDrawContext *dc)
 692 {
 693     /* reset bpath */
 694     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(dc->currentshape), NULL);
 695     /* reset curve */
 696     sp_curve_reset(dc->currentcurve);
 697     sp_curve_reset(dc->cal1);
 698     sp_curve_reset(dc->cal2);
 699     /* reset points */
 700     dc->npoints = 0;
 701 }
 702
 703 static void
 704 set_to_accumulated(SPDynaDrawContext *dc)
 705 {
 706     SPDesktop *desktop = SP_EVENT_CONTEXT(dc)->desktop;
 707
 708     if (!sp_curve_empty(dc->accumulated)) {
 709         NArtBpath *abp;
 710         gchar *str;
 711
 712         if (!dc->repr) {
 713             /* Create object */
 714             Inkscape::XML::Document *xml_doc = sp_document_repr_doc(desktop->doc());
 715             Inkscape::XML::Node *repr = xml_doc->createElement("svg:path");
 716
 717             /* Set style */
 718             sp_desktop_apply_style_tool (desktop, repr, "tools.calligraphic", false);
 719
 720             dc->repr = repr;
 721
 722             SPItem *item=SP_ITEM(desktop->currentLayer()->appendChildRepr(dc->repr));
 723             Inkscape::GC::release(dc->repr);
 724             item->transform = SP_ITEM(desktop->currentRoot())->getRelativeTransform(desktop->currentLayer());
 725             item->updateRepr();
 726             if (dc->keep_selected) {
 727                 sp_desktop_selection(desktop)->set(dc->repr);
 728             } else {
 729                 sp_desktop_selection(desktop)->clear();
 730             }
 731         }
 732         abp = nr_artpath_affine(sp_curve_first_bpath(dc->accumulated), sp_desktop_dt2root_affine(desktop));
 733         str = sp_svg_write_path(abp);
 734         g_assert( str != NULL );
 735         g_free(abp);
 736         dc->repr->setAttribute("d", str);
 737         g_free(str);
 738     } else {
 739         if (dc->repr) {
 740             sp_repr_unparent(dc->repr);
 741         }
 742         dc->repr = NULL;
 743     }
 744
 745     sp_document_done(sp_desktop_document(desktop), SP_VERB_CONTEXT_CALLIGRAPHIC,
 746                      _("Create calligraphic stroke"));
 747 }
 748
 749 static void
 750 add_cap(SPCurve *curve,
 751         NR::Point const &pre, NR::Point const &from,
 752         NR::Point const &to, NR::Point const &post,
 753         double rounding)
 754 {
 755     NR::Point vel = rounding * NR::rot90( to - from ) / sqrt(2.0);
 756     double mag = NR::L2(vel);
 757
 758     NR::Point v_in = from - pre;
 759     double mag_in = NR::L2(v_in);
 760     if ( mag_in > DYNA_EPSILON ) {
 761         v_in = mag * v_in / mag_in;
 762     } else {
 763         v_in = NR::Point(0, 0);
 764     }
 765
 766     NR::Point v_out = to - post;
 767     double mag_out = NR::L2(v_out);
 768     if ( mag_out > DYNA_EPSILON ) {
 769         v_out = mag * v_out / mag_out;
 770     } else {
 771         v_out = NR::Point(0, 0);
 772     }
 773
 774     if ( NR::L2(v_in) > DYNA_EPSILON || NR::L2(v_out) > DYNA_EPSILON ) {
 775         sp_curve_curveto(curve, from + v_in, to + v_out, to);
 776     }
 777 }
 778
 779 static void
 780 accumulate_calligraphic(SPDynaDrawContext *dc)
 781 {
 782     if ( !sp_curve_empty(dc->cal1) && !sp_curve_empty(dc->cal2) ) {
 783         sp_curve_reset(dc->accumulated); /*  Is this required ?? */
 784         SPCurve *rev_cal2 = sp_curve_reverse(dc->cal2);
 785
 786         g_assert(dc->cal1->end > 1);
 787         g_assert(rev_cal2->end > 1);
 788         g_assert(SP_CURVE_SEGMENT(dc->cal1, 0)->code == NR_MOVETO_OPEN);
 789         g_assert(SP_CURVE_SEGMENT(rev_cal2, 0)->code == NR_MOVETO_OPEN);
 790         g_assert(SP_CURVE_SEGMENT(dc->cal1, 1)->code == NR_CURVETO);
 791         g_assert(SP_CURVE_SEGMENT(rev_cal2, 1)->code == NR_CURVETO);
 792         g_assert(SP_CURVE_SEGMENT(dc->cal1, dc->cal1->end-1)->code == NR_CURVETO);
 793         g_assert(SP_CURVE_SEGMENT(rev_cal2, rev_cal2->end-1)->code == NR_CURVETO);
 794
 795         sp_curve_append(dc->accumulated, dc->cal1, FALSE);
 796
 797         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);
 798
 799         sp_curve_append(dc->accumulated, rev_cal2, TRUE);
 800
 801         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);
 802
 803         sp_curve_closepath(dc->accumulated);
 804
 805         sp_curve_unref(rev_cal2);
 806
 807         sp_curve_reset(dc->cal1);
 808         sp_curve_reset(dc->cal2);
 809     }
 810 }
 811
 812 static double square(double const x)
 813 {
 814     return x * x;
 815 }
 816
 817 static void
 818 fit_and_split(SPDynaDrawContext *dc, gboolean release)
 819 {
 820     double const tolerance_sq = square( NR::expansion(SP_EVENT_CONTEXT(dc)->desktop->w2d()) * TOLERANCE_CALLIGRAPHIC );
 821
 822 #ifdef DYNA_DRAW_VERBOSE
 823     g_print("[F&S:R=%c]", release?'T':'F');
 824 #endif
 825
 826     if (!( dc->npoints > 0 && dc->npoints < SAMPLING_SIZE ))
 827         return; // just clicked
 828
 829     if ( dc->npoints == SAMPLING_SIZE - 1 || release ) {
 830 #define BEZIER_SIZE       4
 831 #define BEZIER_MAX_BEZIERS  8
 832 #define BEZIER_MAX_LENGTH ( BEZIER_SIZE * BEZIER_MAX_BEZIERS )
 833
 834 #ifdef DYNA_DRAW_VERBOSE
 835         g_print("[F&S:#] dc->npoints:%d, release:%s\n",
 836                 dc->npoints, release ? "TRUE" : "FALSE");
 837 #endif
 838
 839         /* Current calligraphic */
 840         if ( dc->cal1->end == 0 || dc->cal2->end == 0 ) {
 841             /* dc->npoints > 0 */
 842             /* g_print("calligraphics(1|2) reset\n"); */
 843             sp_curve_reset(dc->cal1);
 844             sp_curve_reset(dc->cal2);
 845
 846             sp_curve_moveto(dc->cal1, dc->point1[0]);
 847             sp_curve_moveto(dc->cal2, dc->point2[0]);
 848         }
 849
 850         NR::Point b1[BEZIER_MAX_LENGTH];
 851         gint const nb1 = sp_bezier_fit_cubic_r(b1, dc->point1, dc->npoints,
 852                                                tolerance_sq, BEZIER_MAX_BEZIERS);
 853         g_assert( nb1 * BEZIER_SIZE <= gint(G_N_ELEMENTS(b1)) );
 854
 855         NR::Point b2[BEZIER_MAX_LENGTH];
 856         gint const nb2 = sp_bezier_fit_cubic_r(b2, dc->point2, dc->npoints,
 857                                                tolerance_sq, BEZIER_MAX_BEZIERS);
 858         g_assert( nb2 * BEZIER_SIZE <= gint(G_N_ELEMENTS(b2)) );
 859
 860         if ( nb1 != -1 && nb2 != -1 ) {
 861             /* Fit and draw and reset state */
 862 #ifdef DYNA_DRAW_VERBOSE
 863             g_print("nb1:%d nb2:%d\n", nb1, nb2);
 864 #endif
 865             /* CanvasShape */
 866             if (! release) {
 867                 sp_curve_reset(dc->currentcurve);
 868                 sp_curve_moveto(dc->currentcurve, b1[0]);
 869                 for (NR::Point *bp1 = b1; bp1 < b1 + BEZIER_SIZE * nb1; bp1 += BEZIER_SIZE) {
 870                     sp_curve_curveto(dc->currentcurve, bp1[1],
 871                                      bp1[2], bp1[3]);
 872                 }
 873                 sp_curve_lineto(dc->currentcurve,
 874                                 b2[BEZIER_SIZE*(nb2-1) + 3]);
 875                 for (NR::Point *bp2 = b2 + BEZIER_SIZE * ( nb2 - 1 ); bp2 >= b2; bp2 -= BEZIER_SIZE) {
 876                     sp_curve_curveto(dc->currentcurve, bp2[2], bp2[1], bp2[0]);
 877                 }
 878                 // FIXME: dc->segments is always NULL at this point??
 879                 if (!dc->segments) { // first segment
 880                     add_cap(dc->currentcurve, b2[1], b2[0], b1[0], b1[1], dc->cap_rounding);
 881                 }
 882                 sp_curve_closepath(dc->currentcurve);
 883                 sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(dc->currentshape), dc->currentcurve);
 884             }
 885
 886             /* Current calligraphic */
 887             for (NR::Point *bp1 = b1; bp1 < b1 + BEZIER_SIZE * nb1; bp1 += BEZIER_SIZE) {
 888                 sp_curve_curveto(dc->cal1, bp1[1], bp1[2], bp1[3]);
 889             }
 890             for (NR::Point *bp2 = b2; bp2 < b2 + BEZIER_SIZE * nb2; bp2 += BEZIER_SIZE) {
 891                 sp_curve_curveto(dc->cal2, bp2[1], bp2[2], bp2[3]);
 892             }
 893         } else {
 894             /* fixme: ??? */
 895 #ifdef DYNA_DRAW_VERBOSE
 896             g_print("[fit_and_split] failed to fit-cubic.\n");
 897 #endif
 898             draw_temporary_box(dc);
 899
 900             for (gint i = 1; i < dc->npoints; i++) {
 901                 sp_curve_lineto(dc->cal1, dc->point1[i]);
 902             }
 903             for (gint i = 1; i < dc->npoints; i++) {
 904                 sp_curve_lineto(dc->cal2, dc->point2[i]);
 905             }
 906         }
 907
 908         /* Fit and draw and copy last point */
 909 #ifdef DYNA_DRAW_VERBOSE
 910         g_print("[%d]Yup\n", dc->npoints);
 911 #endif
 912         if (!release) {
 913             g_assert(!sp_curve_empty(dc->currentcurve));
 914
 915             SPCanvasItem *cbp = sp_canvas_item_new(sp_desktop_sketch(SP_EVENT_CONTEXT(dc)->desktop),
 916                                                    SP_TYPE_CANVAS_BPATH,
 917                                                    NULL);
 918             SPCurve *curve = sp_curve_copy(dc->currentcurve);
 919             sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH (cbp), curve);
 920             sp_curve_unref(curve);
 921
 922             guint32 fillColor = sp_desktop_get_color_tool (SP_ACTIVE_DESKTOP, "tools.calligraphic", true);
 923             //guint32 strokeColor = sp_desktop_get_color_tool (SP_ACTIVE_DESKTOP, "tools.calligraphic", false);
 924             double opacity = sp_desktop_get_master_opacity_tool (SP_ACTIVE_DESKTOP, "tools.calligraphic");
 925             double fillOpacity = sp_desktop_get_opacity_tool (SP_ACTIVE_DESKTOP, "tools.calligraphic", true);
 926             //double strokeOpacity = sp_desktop_get_opacity_tool (SP_ACTIVE_DESKTOP, "tools.calligraphic", false);
 927             sp_canvas_bpath_set_fill(SP_CANVAS_BPATH(cbp), ((fillColor & 0xffffff00) | SP_COLOR_F_TO_U(opacity*fillOpacity)), SP_WIND_RULE_EVENODD);
 928             //on second thougtht don't do stroke yet because we don't have stoke-width yet and because stoke appears between segments while drawing
 929             //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);
 930             sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(cbp), 0x00000000, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 931             /* fixme: Cannot we cascade it to root more clearly? */
 932             g_signal_connect(G_OBJECT(cbp), "event", G_CALLBACK(sp_desktop_root_handler), SP_EVENT_CONTEXT(dc)->desktop);
 933
 934             dc->segments = g_slist_prepend(dc->segments, cbp);
 935         }
 936
 937         dc->point1[0] = dc->point1[dc->npoints - 1];
 938         dc->point2[0] = dc->point2[dc->npoints - 1];
 939         dc->npoints = 1;
 940     } else {
 941         draw_temporary_box(dc);
 942     }
 943 }
 944
 945 static void
 946 draw_temporary_box(SPDynaDrawContext *dc)
 947 {
 948     sp_curve_reset(dc->currentcurve);
 949
 950     sp_curve_moveto(dc->currentcurve, dc->point1[dc->npoints-1]);
 951     for (gint i = dc->npoints-2; i >= 0; i--) {
 952         sp_curve_lineto(dc->currentcurve, dc->point1[i]);
 953     }
 954     for (gint i = 0; i < dc->npoints; i++) {
 955         sp_curve_lineto(dc->currentcurve, dc->point2[i]);
 956     }
 957     if (dc->npoints >= 2) {
 958         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);
 959     }
 960
 961     sp_curve_closepath(dc->currentcurve);
 962     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(dc->currentshape), dc->currentcurve);
 963 }
 964
 965 /*
 966   Local Variables:
 967   mode:c++
 968   c-file-style:"stroustrup"
 969   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
 970   indent-tabs-mode:nil
 971   fill-column:99
 972   End:
 973 */
 974 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :