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 "pixmaps/cursor-calligraphy.pixbuf"
  48 #include "dyna-draw-context.h"
  49 #include "libnr/n-art-bpath.h"
  50 #include "libnr/nr-path.h"
  51 #include "xml/repr.h"
  52 #include "context-fns.h"
  53 #include "sp-item.h"
  54 #include "inkscape.h"
  55 #include "color.h"
  56
  57 #define DDC_RED_RGBA 0xff0000ff
  58
  59 #define SAMPLE_TIMEOUT 10
  60 #define TOLERANCE_LINE 1.0
  61 #define TOLERANCE_CALLIGRAPHIC 3.0
  62 #define DYNA_EPSILON 0.5e-2
  63
  64 #define DYNA_MIN_WIDTH 1.0e-6
  65
  66 #define DRAG_MIN 0.0
  67 #define DRAG_DEFAULT 1.0
  68 #define DRAG_MAX 1.0
  69
  70 static void sp_dyna_draw_context_class_init(SPDynaDrawContextClass *klass);
  71 static void sp_dyna_draw_context_init(SPDynaDrawContext *ddc);
  72 static void sp_dyna_draw_context_dispose(GObject *object);
  73
  74 static void sp_dyna_draw_context_setup(SPEventContext *ec);
  75 static void sp_dyna_draw_context_set(SPEventContext *ec, gchar const *key, gchar const *val);
  76 static gint sp_dyna_draw_context_root_handler(SPEventContext *ec, GdkEvent *event);
  77
  78 static void clear_current(SPDynaDrawContext *dc);
  79 static void set_to_accumulated(SPDynaDrawContext *dc);
  80 static void add_cap(SPCurve *curve, NR::Point const &pre, NR::Point const &from, NR::Point const &to, NR::Point const &post, double rounding);
  81 static void accumulate_calligraphic(SPDynaDrawContext *dc);
  82
  83 static void fit_and_split(SPDynaDrawContext *ddc, gboolean release);
  84
  85 static void sp_dyna_draw_reset(SPDynaDrawContext *ddc, NR::Point p);
  86 static NR::Point sp_dyna_draw_get_npoint(SPDynaDrawContext const *ddc, NR::Point v);
  87 static NR::Point sp_dyna_draw_get_vpoint(SPDynaDrawContext const *ddc, NR::Point n);
  88 static void draw_temporary_box(SPDynaDrawContext *dc);
  89
  90
  91 static SPEventContextClass *parent_class;
  92
  93 GtkType
  94 sp_dyna_draw_context_get_type(void)
  95 {
  96     static GType type = 0;
  97     if (!type) {
  98         GTypeInfo info = {
  99             sizeof(SPDynaDrawContextClass),
 100             NULL, NULL,
 101             (GClassInitFunc) sp_dyna_draw_context_class_init,
 102             NULL, NULL,
 103             sizeof(SPDynaDrawContext),
 104             4,
 105             (GInstanceInitFunc) sp_dyna_draw_context_init,
 106             NULL,   /* value_table */
 107         };
 108         type = g_type_register_static(SP_TYPE_EVENT_CONTEXT, "SPDynaDrawContext", &info, (GTypeFlags)0);
 109     }
 110     return type;
 111 }
 112
 113 static void
 114 sp_dyna_draw_context_class_init(SPDynaDrawContextClass *klass)
 115 {
 116     GObjectClass *object_class = (GObjectClass *) klass;
 117     SPEventContextClass *event_context_class = (SPEventContextClass *) klass;
 118
 119     parent_class = (SPEventContextClass*)g_type_class_peek_parent(klass);
 120
 121     object_class->dispose = sp_dyna_draw_context_dispose;
 122
 123     event_context_class->setup = sp_dyna_draw_context_setup;
 124     event_context_class->set = sp_dyna_draw_context_set;
 125     event_context_class->root_handler = sp_dyna_draw_context_root_handler;
 126 }
 127
 128 static void
 129 sp_dyna_draw_context_init(SPDynaDrawContext *ddc)
 130 {
 131     SPEventContext *event_context = SP_EVENT_CONTEXT(ddc);
 132
 133     event_context->cursor_shape = cursor_calligraphy_xpm;
 134     event_context->cursor_pixbuf = gdk_pixbuf_new_from_inline(
 135             -1,
 136             cursor_calligraphy_pixbuf,
 137             FALSE,
 138             NULL);
 139     event_context->hot_x = 4;
 140     event_context->hot_y = 4;
 141
 142     ddc->accumulated = NULL;
 143     ddc->segments = NULL;
 144     ddc->currentcurve = NULL;
 145     ddc->currentshape = NULL;
 146     ddc->npoints = 0;
 147     ddc->cal1 = NULL;
 148     ddc->cal2 = NULL;
 149     ddc->repr = NULL;
 150
 151     /* DynaDraw values */
 152     ddc->cur = NR::Point(0,0);
 153     ddc->last = NR::Point(0,0);
 154     ddc->vel = NR::Point(0,0);
 155     ddc->acc = NR::Point(0,0);
 156     ddc->ang = NR::Point(0,0);
 157     ddc->del = NR::Point(0,0);
 158
 159     /* attributes */
 160     ddc->dragging = FALSE;
 161
 162     ddc->mass = 0.3;
 163     ddc->drag = DRAG_DEFAULT;
 164     ddc->angle = 30.0;
 165     ddc->width = 0.2;
 166
 167     ddc->vel_thin = 0.1;
 168     ddc->flatness = 0.9;
 169     ddc->cap_rounding = 0.0;
 170
 171     ddc->abs_width = false;
 172     ddc->keep_selected = true;
 173 }
 174
 175 static void
 176 sp_dyna_draw_context_dispose(GObject *object)
 177 {
 178     SPDynaDrawContext *ddc = SP_DYNA_DRAW_CONTEXT(object);
 179
 180     if (ddc->accumulated) {
 181         ddc->accumulated = sp_curve_unref(ddc->accumulated);
 182     }
 183
 184     while (ddc->segments) {
 185         gtk_object_destroy(GTK_OBJECT(ddc->segments->data));
 186         ddc->segments = g_slist_remove(ddc->segments, ddc->segments->data);
 187     }
 188
 189     if (ddc->currentcurve) ddc->currentcurve = sp_curve_unref(ddc->currentcurve);
 190     if (ddc->cal1) ddc->cal1 = sp_curve_unref(ddc->cal1);
 191     if (ddc->cal2) ddc->cal2 = sp_curve_unref(ddc->cal2);
 192
 193     if (ddc->currentshape) {
 194         gtk_object_destroy(GTK_OBJECT(ddc->currentshape));
 195         ddc->currentshape = NULL;
 196     }
 197
 198     if (ddc->_message_context) {
 199         delete ddc->_message_context;
 200     }
 201
 202     G_OBJECT_CLASS(parent_class)->dispose(object);
 203 }
 204
 205 static void
 206 sp_dyna_draw_context_setup(SPEventContext *ec)
 207 {
 208     SPDynaDrawContext *ddc = SP_DYNA_DRAW_CONTEXT(ec);
 209
 210     if (((SPEventContextClass *) parent_class)->setup)
 211         ((SPEventContextClass *) parent_class)->setup(ec);
 212
 213     ddc->accumulated = sp_curve_new_sized(32);
 214     ddc->currentcurve = sp_curve_new_sized(4);
 215
 216     ddc->cal1 = sp_curve_new_sized(32);
 217     ddc->cal2 = sp_curve_new_sized(32);
 218
 219     ddc->currentshape = sp_canvas_item_new(sp_desktop_sketch(ec->desktop), SP_TYPE_CANVAS_BPATH, NULL);
 220     sp_canvas_bpath_set_fill(SP_CANVAS_BPATH(ddc->currentshape), DDC_RED_RGBA, SP_WIND_RULE_EVENODD);
 221     sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(ddc->currentshape), 0x00000000, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 222     /* fixme: Cannot we cascade it to root more clearly? */
 223     g_signal_connect(G_OBJECT(ddc->currentshape), "event", G_CALLBACK(sp_desktop_root_handler), ec->desktop);
 224
 225     sp_event_context_read(ec, "mass");
 226     sp_event_context_read(ec, "wiggle");
 227     sp_event_context_read(ec, "angle");
 228     sp_event_context_read(ec, "width");
 229     sp_event_context_read(ec, "thinning");
 230     sp_event_context_read(ec, "tremor");
 231     sp_event_context_read(ec, "flatness");
 232     sp_event_context_read(ec, "usepressure");
 233     sp_event_context_read(ec, "usetilt");
 234     sp_event_context_read(ec, "abs_width");
 235     sp_event_context_read(ec, "keep_selected");
 236     sp_event_context_read(ec, "cap_rounding");
 237
 238     ddc->is_drawing = false;
 239
 240     ddc->_message_context = new Inkscape::MessageContext((ec->desktop)->messageStack());
 241 }
 242
 243 static void
 244 sp_dyna_draw_context_set(SPEventContext *ec, gchar const *key, gchar const *val)
 245 {
 246     SPDynaDrawContext *ddc = SP_DYNA_DRAW_CONTEXT(ec);
 247
 248     if (!strcmp(key, "mass")) {
 249         double const dval = ( val ? g_ascii_strtod (val, NULL) : 0.2 );
 250         ddc->mass = CLAMP(dval, -1000.0, 1000.0);
 251     } else if (!strcmp(key, "wiggle")) {
 252         double const dval = ( val ? g_ascii_strtod (val, NULL) : (1 - DRAG_DEFAULT));
 253         ddc->drag = CLAMP((1 - dval), DRAG_MIN, DRAG_MAX); // drag is inverse to wiggle
 254     } else if (!strcmp(key, "angle")) {
 255         double const dval = ( val ? g_ascii_strtod (val, NULL) : 0.0);
 256         ddc->angle = CLAMP (dval, -90, 90);
 257     } else if (!strcmp(key, "width")) {
 258         double const dval = ( val ? g_ascii_strtod (val, NULL) : 0.1 );
 259         ddc->width = CLAMP(dval, -1000.0, 1000.0);
 260     } else if (!strcmp(key, "thinning")) {
 261         double const dval = ( val ? g_ascii_strtod (val, NULL) : 0.1 );
 262         ddc->vel_thin = CLAMP(dval, -1.0, 1.0);
 263     } else if (!strcmp(key, "tremor")) {
 264         double const dval = ( val ? g_ascii_strtod (val, NULL) : 0.0 );
 265         ddc->tremor = CLAMP(dval, 0.0, 1.0);
 266     } else if (!strcmp(key, "flatness")) {
 267         double const dval = ( val ? g_ascii_strtod (val, NULL) : 1.0 );
 268         ddc->flatness = CLAMP(dval, 0, 1.0);
 269     } else if (!strcmp(key, "usepressure")) {
 270         ddc->usepressure = (val && strcmp(val, "0"));
 271     } else if (!strcmp(key, "usetilt")) {
 272         ddc->usetilt = (val && strcmp(val, "0"));
 273     } else if (!strcmp(key, "abs_width")) {
 274         ddc->abs_width = (val && strcmp(val, "0"));
 275     } else if (!strcmp(key, "keep_selected")) {
 276         ddc->keep_selected = (val && strcmp(val, "0"));
 277     } else if (!strcmp(key, "cap_rounding")) {
 278         ddc->cap_rounding = ( val ? g_ascii_strtod (val, NULL) : 0.0 );
 279     }
 280
 281     //g_print("DDC: %g %g %g %g\n", ddc->mass, ddc->drag, ddc->angle, ddc->width);
 282 }
 283
 284 static double
 285 flerp(double f0, double f1, double p)
 286 {
 287     return f0 + ( f1 - f0 ) * p;
 288 }
 289
 290 /* Get normalized point */
 291 static NR::Point
 292 sp_dyna_draw_get_npoint(SPDynaDrawContext const *dc, NR::Point v)
 293 {
 294     NR::Rect drect = SP_EVENT_CONTEXT(dc)->desktop->get_display_area();
 295     double const max = MAX ( drect.dimensions()[NR::X], drect.dimensions()[NR::Y] );
 296     return NR::Point(( v[NR::X] - drect.min()[NR::X] ) / max,  ( v[NR::Y] - drect.min()[NR::Y] ) / max);
 297 }
 298
 299 /* Get view point */
 300 static NR::Point
 301 sp_dyna_draw_get_vpoint(SPDynaDrawContext const *dc, NR::Point n)
 302 {
 303     NR::Rect drect = SP_EVENT_CONTEXT(dc)->desktop->get_display_area();
 304     double const max = MAX ( drect.dimensions()[NR::X], drect.dimensions()[NR::Y] );
 305     return NR::Point(n[NR::X] * max + drect.min()[NR::X], n[NR::Y] * max + drect.min()[NR::Y]);
 306 }
 307
 308 static void
 309 sp_dyna_draw_reset(SPDynaDrawContext *dc, NR::Point p)
 310 {
 311     dc->last = dc->cur = sp_dyna_draw_get_npoint(dc, p);
 312     dc->vel = NR::Point(0,0);
 313     dc->acc = NR::Point(0,0);
 314     dc->ang = NR::Point(0,0);
 315     dc->del = NR::Point(0,0);
 316 }
 317
 318 static void
 319 sp_dyna_draw_extinput(SPDynaDrawContext *dc, GdkEvent *event)
 320 {
 321     if (gdk_event_get_axis (event, GDK_AXIS_PRESSURE, &dc->pressure))
 322         dc->pressure = CLAMP (dc->pressure, DDC_MIN_PRESSURE, DDC_MAX_PRESSURE);
 323     else
 324         dc->pressure = DDC_DEFAULT_PRESSURE;
 325
 326     if (gdk_event_get_axis (event, GDK_AXIS_XTILT, &dc->xtilt))
 327         dc->xtilt = CLAMP (dc->xtilt, DDC_MIN_TILT, DDC_MAX_TILT);
 328     else
 329         dc->xtilt = DDC_DEFAULT_TILT;
 330
 331     if (gdk_event_get_axis (event, GDK_AXIS_YTILT, &dc->ytilt))
 332         dc->ytilt = CLAMP (dc->ytilt, DDC_MIN_TILT, DDC_MAX_TILT);
 333     else
 334         dc->ytilt = DDC_DEFAULT_TILT;
 335 }
 336
 337
 338 static gboolean
 339 sp_dyna_draw_apply(SPDynaDrawContext *dc, NR::Point p)
 340 {
 341     NR::Point n = sp_dyna_draw_get_npoint(dc, p);
 342
 343     /* Calculate mass and drag */
 344     double const mass = flerp(1.0, 160.0, dc->mass);
 345     double const drag = flerp(0.0, 0.5, dc->drag * dc->drag);
 346
 347     /* Calculate force and acceleration */
 348     NR::Point force = n - dc->cur;
 349     if ( NR::L2(force) < DYNA_EPSILON ) {
 350         return FALSE;
 351     }
 352
 353     dc->acc = force / mass;
 354
 355     /* Calculate new velocity */
 356     dc->vel += dc->acc;
 357
 358     /* Calculate angle of drawing tool */
 359
 360     double a1;
 361     if (dc->usetilt) {
 362         // 1a. calculate nib angle from input device tilt:
 363         gdouble length = std::sqrt(dc->xtilt*dc->xtilt + dc->ytilt*dc->ytilt);;
 364
 365         if (length > 0) {
 366             NR::Point ang1 = NR::Point(dc->ytilt/length, dc->xtilt/length);
 367             a1 = atan2(ang1);
 368         }
 369         else
 370             a1 = 0.0;
 371     }
 372     else {
 373         // 1b. fixed dc->angle (absolutely flat nib):
 374         double const radians = ( (dc->angle - 90) / 180.0 ) * M_PI;
 375         NR::Point ang1 = NR::Point(-sin(radians),  cos(radians));
 376         a1 = atan2(ang1);
 377     }
 378
 379     // 2. perpendicular to dc->vel (absolutely non-flat nib):
 380     gdouble const mag_vel = NR::L2(dc->vel);
 381     if ( mag_vel < DYNA_EPSILON ) {
 382         return FALSE;
 383     }
 384     NR::Point ang2 = NR::rot90(dc->vel) / mag_vel;
 385
 386     // 3. Average them using flatness parameter:
 387     // calculate angles
 388     double a2 = atan2(ang2);
 389     // flip a2 to force it to be in the same half-circle as a1
 390     bool flipped = false;
 391     if (fabs (a2-a1) > 0.5*M_PI) {
 392         a2 += M_PI;
 393         flipped = true;
 394     }
 395     // normalize a2
 396     if (a2 > M_PI)
 397         a2 -= 2*M_PI;
 398     if (a2 < -M_PI)
 399         a2 += 2*M_PI;
 400     // find the flatness-weighted bisector angle, unflip if a2 was flipped
 401     // FIXME: when dc->vel is oscillating around the fixed angle, the new_ang flips back and forth. How to avoid this?
 402     double new_ang = a1 + (1 - dc->flatness) * (a2 - a1) - (flipped? M_PI : 0);
 403     // convert to point
 404     dc->ang = NR::Point (cos (new_ang), sin (new_ang));
 405
 406     /* Apply drag */
 407     dc->vel *= 1.0 - drag;
 408
 409     /* Update position */
 410     dc->last = dc->cur;
 411     dc->cur += dc->vel;
 412
 413     return TRUE;
 414 }
 415
 416 static void
 417 sp_dyna_draw_brush(SPDynaDrawContext *dc)
 418 {
 419     g_assert( dc->npoints >= 0 && dc->npoints < SAMPLING_SIZE );
 420
 421     // How much velocity thins strokestyle
 422     double vel_thin = flerp (0, 160, dc->vel_thin);
 423
 424     // Influence of pressure on thickness
 425     double pressure_thick = (dc->usepressure ? dc->pressure : 1.0);
 426
 427     double width = ( pressure_thick - vel_thin * NR::L2(dc->vel) ) * dc->width;
 428
 429     double tremble_left = 0, tremble_right = 0;
 430     if (dc->tremor > 0) {
 431         // obtain two normally distributed random variables, using polar Box-Muller transform
 432         double x1, x2, w, y1, y2;
 433         do {
 434             x1 = 2.0 * g_random_double_range(0,1) - 1.0;
 435             x2 = 2.0 * g_random_double_range(0,1) - 1.0;
 436             w = x1 * x1 + x2 * x2;
 437         } while ( w >= 1.0 );
 438         w = sqrt( (-2.0 * log( w ) ) / w );
 439         y1 = x1 * w;
 440         y2 = x2 * w;
 441
 442         // deflect both left and right edges randomly and independently, so that:
 443         // (1) dc->tremor=1 corresponds to sigma=1, decreasing dc->tremor narrows the bell curve;
 444         // (2) deflection depends on width, but is upped for small widths for better visual uniformity across widths;
 445         // (3) deflection somewhat depends on speed, to prevent fast strokes looking
 446         // comparatively smooth and slow ones excessively jittery
 447         tremble_left  = (y1)*dc->tremor * (0.15 + 0.8*width) * (0.35 + 14*NR::L2(dc->vel));
 448         tremble_right = (y2)*dc->tremor * (0.15 + 0.8*width) * (0.35 + 14*NR::L2(dc->vel));
 449     }
 450
 451     if ( width < 0.02 * dc->width ) {
 452         width = 0.02 * dc->width;
 453     }
 454
 455     double dezoomify_factor = 0.05 * 1000;
 456     if (!dc->abs_width) {
 457         dezoomify_factor /= SP_EVENT_CONTEXT(dc)->desktop->current_zoom();
 458     }
 459
 460     NR::Point del_left = dezoomify_factor * (width + tremble_left) * dc->ang;
 461     NR::Point del_right = dezoomify_factor * (width + tremble_right) * dc->ang;
 462
 463     NR::Point abs_middle = sp_dyna_draw_get_vpoint(dc, dc->cur);
 464
 465     dc->point1[dc->npoints] = abs_middle + del_left;
 466     dc->point2[dc->npoints] = abs_middle - del_right;
 467
 468     dc->del = 0.5*(del_left + del_right);
 469
 470     dc->npoints++;
 471 }
 472
 473 void
 474 sp_ddc_update_toolbox (SPDesktop *desktop, const gchar *id, double value)
 475 {
 476     desktop->setToolboxAdjustmentValue (id, value);
 477 }
 478
 479 gint
 480 sp_dyna_draw_context_root_handler(SPEventContext *event_context,
 481                                   GdkEvent *event)
 482 {
 483     SPDynaDrawContext *dc = SP_DYNA_DRAW_CONTEXT(event_context);
 484     SPDesktop *desktop = event_context->desktop;
 485
 486     gint ret = FALSE;
 487
 488     switch (event->type) {
 489     case GDK_BUTTON_PRESS:
 490         if ( event->button.button == 1 ) {
 491
 492             SPDesktop *desktop = SP_EVENT_CONTEXT_DESKTOP(dc);
 493
 494             if (Inkscape::have_viable_layer(desktop, dc->_message_context) == false) {
 495                 return TRUE;
 496             }
 497
 498             NR::Point const button_w(event->button.x,
 499                                      event->button.y);
 500             NR::Point const button_dt(desktop->w2d(button_w));
 501             sp_dyna_draw_reset(dc, button_dt);
 502             sp_dyna_draw_extinput(dc, event);
 503             sp_dyna_draw_apply(dc, button_dt);
 504             sp_curve_reset(dc->accumulated);
 505             if (dc->repr) {
 506                 dc->repr = NULL;
 507             }
 508
 509             /* initialize first point */
 510             dc->npoints = 0;
 511
 512             sp_canvas_item_grab(SP_CANVAS_ITEM(desktop->acetate),
 513                                 ( GDK_KEY_PRESS_MASK |
 514                                   GDK_BUTTON_RELEASE_MASK |
 515                                   GDK_POINTER_MOTION_MASK |
 516                                   GDK_BUTTON_PRESS_MASK ),
 517                                 NULL,
 518                                 event->button.time);
 519
 520             ret = TRUE;
 521
 522             dc->is_drawing = true;
 523         }
 524         break;
 525     case GDK_MOTION_NOTIFY:
 526         if ( dc->is_drawing && ( event->motion.state & GDK_BUTTON1_MASK ) ) {
 527             dc->dragging = TRUE;
 528
 529             NR::Point const motion_w(event->motion.x,
 530                                      event->motion.y);
 531             NR::Point const motion_dt(desktop->w2d(motion_w));
 532
 533             sp_dyna_draw_extinput(dc, event);
 534             if (!sp_dyna_draw_apply(dc, motion_dt)) {
 535                 ret = TRUE;
 536                 break;
 537             }
 538
 539             if ( dc->cur != dc->last ) {
 540                 sp_dyna_draw_brush(dc);
 541                 g_assert( dc->npoints > 0 );
 542                 fit_and_split(dc, FALSE);
 543             }
 544             ret = TRUE;
 545         }
 546         break;
 547
 548     case GDK_BUTTON_RELEASE:
 549         sp_canvas_item_ungrab(SP_CANVAS_ITEM(desktop->acetate), event->button.time);
 550         dc->is_drawing = false;
 551
 552         if ( dc->dragging && event->button.button == 1 ) {
 553             dc->dragging = FALSE;
 554
 555             NR::Point const motion_w(event->button.x, event->button.y);
 556             NR::Point const motion_dt(desktop->w2d(motion_w));
 557             sp_dyna_draw_apply(dc, motion_dt);
 558
 559             /* Remove all temporary line segments */
 560             while (dc->segments) {
 561                 gtk_object_destroy(GTK_OBJECT(dc->segments->data));
 562                 dc->segments = g_slist_remove(dc->segments, dc->segments->data);
 563             }
 564             /* Create object */
 565             fit_and_split(dc, TRUE);
 566             accumulate_calligraphic(dc);
 567             set_to_accumulated(dc); /* temporal implementation */
 568             /* reset accumulated curve */
 569             sp_curve_reset(dc->accumulated);
 570             clear_current(dc);
 571             if (dc->repr) {
 572                 dc->repr = NULL;
 573             }
 574             ret = TRUE;
 575         }
 576         break;
 577     case GDK_KEY_PRESS:
 578         switch (get_group0_keyval (&event->key)) {
 579         case GDK_Up:
 580         case GDK_KP_Up:
 581             if (!MOD__CTRL_ONLY) {
 582                 dc->angle += 5.0;
 583                 if (dc->angle > 90.0)
 584                     dc->angle = 90.0;
 585                 sp_ddc_update_toolbox (desktop, "calligraphy-angle", dc->angle);
 586                 ret = TRUE;
 587             }
 588             break;
 589         case GDK_Down:
 590         case GDK_KP_Down:
 591             if (!MOD__CTRL_ONLY) {
 592                 dc->angle -= 5.0;
 593                 if (dc->angle < -90.0)
 594                     dc->angle = -90.0;
 595                 sp_ddc_update_toolbox (desktop, "calligraphy-angle", dc->angle);
 596                 ret = TRUE;
 597             }
 598             break;
 599         case GDK_Right:
 600         case GDK_KP_Right:
 601             if (!MOD__CTRL_ONLY) {
 602                 dc->width += 0.01;
 603                 if (dc->width > 1.0)
 604                     dc->width = 1.0;
 605                 sp_ddc_update_toolbox (desktop, "altx-calligraphy", dc->width * 100); // the same spinbutton is for alt+x
 606                 ret = TRUE;
 607             }
 608             break;
 609         case GDK_Left:
 610         case GDK_KP_Left:
 611             if (!MOD__CTRL_ONLY) {
 612                 dc->width -= 0.01;
 613                 if (dc->width < 0.01)
 614                     dc->width = 0.01;
 615                 sp_ddc_update_toolbox (desktop, "altx-calligraphy", dc->width * 100);
 616                 ret = TRUE;
 617             }
 618             break;
 619         case GDK_x:
 620         case GDK_X:
 621             if (MOD__ALT_ONLY) {
 622                 desktop->setToolboxFocusTo ("altx-calligraphy");
 623                 ret = TRUE;
 624             }
 625             break;
 626         case GDK_Escape:
 627             sp_desktop_selection(desktop)->clear();
 628             break;
 629
 630         default:
 631             break;
 632         }
 633     default:
 634         break;
 635     }
 636
 637     if (!ret) {
 638         if (((SPEventContextClass *) parent_class)->root_handler) {
 639             ret = ((SPEventContextClass *) parent_class)->root_handler(event_context, event);
 640         }
 641     }
 642
 643     return ret;
 644 }
 645
 646
 647 static void
 648 clear_current(SPDynaDrawContext *dc)
 649 {
 650     /* reset bpath */
 651     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(dc->currentshape), NULL);
 652     /* reset curve */
 653     sp_curve_reset(dc->currentcurve);
 654     sp_curve_reset(dc->cal1);
 655     sp_curve_reset(dc->cal2);
 656     /* reset points */
 657     dc->npoints = 0;
 658 }
 659
 660 static void
 661 set_to_accumulated(SPDynaDrawContext *dc)
 662 {
 663     SPDesktop *desktop = SP_EVENT_CONTEXT(dc)->desktop;
 664
 665     if (!sp_curve_empty(dc->accumulated)) {
 666         NArtBpath *abp;
 667         gchar *str;
 668
 669         if (!dc->repr) {
 670             /* Create object */
 671             Inkscape::XML::Node *repr = sp_repr_new("svg:path");
 672
 673             /* Set style */
 674             sp_desktop_apply_style_tool (desktop, repr, "tools.calligraphic", false);
 675
 676             dc->repr = repr;
 677
 678             SPItem *item=SP_ITEM(desktop->currentLayer()->appendChildRepr(dc->repr));
 679             Inkscape::GC::release(dc->repr);
 680             item->transform = SP_ITEM(desktop->currentRoot())->getRelativeTransform(desktop->currentLayer());
 681             item->updateRepr();
 682             if (dc->keep_selected) {
 683                 sp_desktop_selection(desktop)->set(dc->repr);
 684             } else {
 685                 sp_desktop_selection(desktop)->clear();
 686             }
 687         }
 688         abp = nr_artpath_affine(sp_curve_first_bpath(dc->accumulated), sp_desktop_dt2root_affine(desktop));
 689         str = sp_svg_write_path(abp);
 690         g_assert( str != NULL );
 691         g_free(abp);
 692         dc->repr->setAttribute("d", str);
 693         g_free(str);
 694     } else {
 695         if (dc->repr) {
 696             sp_repr_unparent(dc->repr);
 697         }
 698         dc->repr = NULL;
 699     }
 700
 701     sp_document_done(sp_desktop_document(desktop), SP_VERB_CONTEXT_CALLIGRAPHIC,
 702                      _("Create calligraphic stroke"));
 703 }
 704
 705 static void
 706 add_cap(SPCurve *curve,
 707         NR::Point const &pre, NR::Point const &from,
 708         NR::Point const &to, NR::Point const &post,
 709         double rounding)
 710 {
 711     NR::Point vel = rounding * NR::rot90( to - from ) / sqrt(2.0);
 712     double mag = NR::L2(vel);
 713
 714     NR::Point v_in = from - pre;
 715     double mag_in = NR::L2(v_in);
 716     if ( mag_in > DYNA_EPSILON ) {
 717         v_in = mag * v_in / mag_in;
 718     } else {
 719         v_in = NR::Point(0, 0);
 720     }
 721
 722     NR::Point v_out = to - post;
 723     double mag_out = NR::L2(v_out);
 724     if ( mag_out > DYNA_EPSILON ) {
 725         v_out = mag * v_out / mag_out;
 726     } else {
 727         v_out = NR::Point(0, 0);
 728     }
 729
 730     if ( NR::L2(v_in) > DYNA_EPSILON || NR::L2(v_out) > DYNA_EPSILON ) {
 731         sp_curve_curveto(curve, from + v_in, to + v_out, to);
 732     }
 733 }
 734
 735 static void
 736 accumulate_calligraphic(SPDynaDrawContext *dc)
 737 {
 738     if ( !sp_curve_empty(dc->cal1) && !sp_curve_empty(dc->cal2) ) {
 739         sp_curve_reset(dc->accumulated); /*  Is this required ?? */
 740         SPCurve *rev_cal2 = sp_curve_reverse(dc->cal2);
 741
 742         g_assert(dc->cal1->end > 1);
 743         g_assert(rev_cal2->end > 1);
 744         g_assert(SP_CURVE_SEGMENT(dc->cal1, 0)->code == NR_MOVETO_OPEN);
 745         g_assert(SP_CURVE_SEGMENT(rev_cal2, 0)->code == NR_MOVETO_OPEN);
 746         g_assert(SP_CURVE_SEGMENT(dc->cal1, 1)->code == NR_CURVETO);
 747         g_assert(SP_CURVE_SEGMENT(rev_cal2, 1)->code == NR_CURVETO);
 748         g_assert(SP_CURVE_SEGMENT(dc->cal1, dc->cal1->end-1)->code == NR_CURVETO);
 749         g_assert(SP_CURVE_SEGMENT(rev_cal2, rev_cal2->end-1)->code == NR_CURVETO);
 750
 751         sp_curve_append(dc->accumulated, dc->cal1, FALSE);
 752
 753         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);
 754
 755         sp_curve_append(dc->accumulated, rev_cal2, TRUE);
 756
 757         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);
 758
 759         sp_curve_closepath(dc->accumulated);
 760
 761         sp_curve_unref(rev_cal2);
 762
 763         sp_curve_reset(dc->cal1);
 764         sp_curve_reset(dc->cal2);
 765     }
 766 }
 767
 768 static double square(double const x)
 769 {
 770     return x * x;
 771 }
 772
 773 static void
 774 fit_and_split(SPDynaDrawContext *dc, gboolean release)
 775 {
 776     double const tolerance_sq = square( NR::expansion(SP_EVENT_CONTEXT(dc)->desktop->w2d()) * TOLERANCE_CALLIGRAPHIC );
 777
 778 #ifdef DYNA_DRAW_VERBOSE
 779     g_print("[F&S:R=%c]", release?'T':'F');
 780 #endif
 781
 782     if (!( dc->npoints > 0 && dc->npoints < SAMPLING_SIZE ))
 783         return; // just clicked
 784
 785     if ( dc->npoints == SAMPLING_SIZE - 1 || release ) {
 786 #define BEZIER_SIZE       4
 787 #define BEZIER_MAX_BEZIERS  8
 788 #define BEZIER_MAX_LENGTH ( BEZIER_SIZE * BEZIER_MAX_BEZIERS )
 789
 790 #ifdef DYNA_DRAW_VERBOSE
 791         g_print("[F&S:#] dc->npoints:%d, release:%s\n",
 792                 dc->npoints, release ? "TRUE" : "FALSE");
 793 #endif
 794
 795         /* Current calligraphic */
 796         if ( dc->cal1->end == 0 || dc->cal2->end == 0 ) {
 797             /* dc->npoints > 0 */
 798             /* g_print("calligraphics(1|2) reset\n"); */
 799             sp_curve_reset(dc->cal1);
 800             sp_curve_reset(dc->cal2);
 801
 802             sp_curve_moveto(dc->cal1, dc->point1[0]);
 803             sp_curve_moveto(dc->cal2, dc->point2[0]);
 804         }
 805
 806         NR::Point b1[BEZIER_MAX_LENGTH];
 807         gint const nb1 = sp_bezier_fit_cubic_r(b1, dc->point1, dc->npoints,
 808                                                tolerance_sq, BEZIER_MAX_BEZIERS);
 809         g_assert( nb1 * BEZIER_SIZE <= gint(G_N_ELEMENTS(b1)) );
 810
 811         NR::Point b2[BEZIER_MAX_LENGTH];
 812         gint const nb2 = sp_bezier_fit_cubic_r(b2, dc->point2, dc->npoints,
 813                                                tolerance_sq, BEZIER_MAX_BEZIERS);
 814         g_assert( nb2 * BEZIER_SIZE <= gint(G_N_ELEMENTS(b2)) );
 815
 816         if ( nb1 != -1 && nb2 != -1 ) {
 817             /* Fit and draw and reset state */
 818 #ifdef DYNA_DRAW_VERBOSE
 819             g_print("nb1:%d nb2:%d\n", nb1, nb2);
 820 #endif
 821             /* CanvasShape */
 822             if (! release) {
 823                 sp_curve_reset(dc->currentcurve);
 824                 sp_curve_moveto(dc->currentcurve, b1[0]);
 825                 for (NR::Point *bp1 = b1; bp1 < b1 + BEZIER_SIZE * nb1; bp1 += BEZIER_SIZE) {
 826                     sp_curve_curveto(dc->currentcurve, bp1[1],
 827                                      bp1[2], bp1[3]);
 828                 }
 829                 sp_curve_lineto(dc->currentcurve,
 830                                 b2[BEZIER_SIZE*(nb2-1) + 3]);
 831                 for (NR::Point *bp2 = b2 + BEZIER_SIZE * ( nb2 - 1 ); bp2 >= b2; bp2 -= BEZIER_SIZE) {
 832                     sp_curve_curveto(dc->currentcurve, bp2[2], bp2[1], bp2[0]);
 833                 }
 834                 // FIXME: dc->segments is always NULL at this point??
 835                 if (!dc->segments) { // first segment
 836                     add_cap(dc->currentcurve, b2[1], b2[0], b1[0], b1[1], dc->cap_rounding);
 837                 }
 838                 sp_curve_closepath(dc->currentcurve);
 839                 sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(dc->currentshape), dc->currentcurve);
 840             }
 841
 842             /* Current calligraphic */
 843             for (NR::Point *bp1 = b1; bp1 < b1 + BEZIER_SIZE * nb1; bp1 += BEZIER_SIZE) {
 844                 sp_curve_curveto(dc->cal1, bp1[1], bp1[2], bp1[3]);
 845             }
 846             for (NR::Point *bp2 = b2; bp2 < b2 + BEZIER_SIZE * nb2; bp2 += BEZIER_SIZE) {
 847                 sp_curve_curveto(dc->cal2, bp2[1], bp2[2], bp2[3]);
 848             }
 849         } else {
 850             /* fixme: ??? */
 851 #ifdef DYNA_DRAW_VERBOSE
 852             g_print("[fit_and_split] failed to fit-cubic.\n");
 853 #endif
 854             draw_temporary_box(dc);
 855
 856             for (gint i = 1; i < dc->npoints; i++) {
 857                 sp_curve_lineto(dc->cal1, dc->point1[i]);
 858             }
 859             for (gint i = 1; i < dc->npoints; i++) {
 860                 sp_curve_lineto(dc->cal2, dc->point2[i]);
 861             }
 862         }
 863
 864         /* Fit and draw and copy last point */
 865 #ifdef DYNA_DRAW_VERBOSE
 866         g_print("[%d]Yup\n", dc->npoints);
 867 #endif
 868         if (!release) {
 869             g_assert(!sp_curve_empty(dc->currentcurve));
 870
 871             SPCanvasItem *cbp = sp_canvas_item_new(sp_desktop_sketch(SP_EVENT_CONTEXT(dc)->desktop),
 872                                                    SP_TYPE_CANVAS_BPATH,
 873                                                    NULL);
 874             SPCurve *curve = sp_curve_copy(dc->currentcurve);
 875             sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH (cbp), curve);
 876             sp_curve_unref(curve);
 877
 878             guint32 fillColor = sp_desktop_get_color_tool (SP_ACTIVE_DESKTOP, "tools.calligraphic", true);
 879             //guint32 strokeColor = sp_desktop_get_color_tool (SP_ACTIVE_DESKTOP, "tools.calligraphic", false);
 880             double opacity = sp_desktop_get_master_opacity_tool (SP_ACTIVE_DESKTOP, "tools.calligraphic");
 881             double fillOpacity = sp_desktop_get_opacity_tool (SP_ACTIVE_DESKTOP, "tools.calligraphic", true);
 882             //double strokeOpacity = sp_desktop_get_opacity_tool (SP_ACTIVE_DESKTOP, "tools.calligraphic", false);
 883             sp_canvas_bpath_set_fill(SP_CANVAS_BPATH(cbp), ((fillColor & 0xffffff00) | SP_COLOR_F_TO_U(opacity*fillOpacity)), SP_WIND_RULE_EVENODD);
 884             //on second thougtht don't do stroke yet because we don't have stoke-width yet and because stoke appears between segments while drawing
 885             //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);
 886             sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(cbp), 0x00000000, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 887             /* fixme: Cannot we cascade it to root more clearly? */
 888             g_signal_connect(G_OBJECT(cbp), "event", G_CALLBACK(sp_desktop_root_handler), SP_EVENT_CONTEXT(dc)->desktop);
 889
 890             dc->segments = g_slist_prepend(dc->segments, cbp);
 891         }
 892
 893         dc->point1[0] = dc->point1[dc->npoints - 1];
 894         dc->point2[0] = dc->point2[dc->npoints - 1];
 895         dc->npoints = 1;
 896     } else {
 897         draw_temporary_box(dc);
 898     }
 899 }
 900
 901 static void
 902 draw_temporary_box(SPDynaDrawContext *dc)
 903 {
 904     sp_curve_reset(dc->currentcurve);
 905     sp_curve_moveto(dc->currentcurve, dc->point1[0]);
 906     for (gint i = 1; i < dc->npoints; i++) {
 907         sp_curve_lineto(dc->currentcurve, dc->point1[i]);
 908     }
 909     for (gint i = dc->npoints-1; i >= 0; i--) {
 910         sp_curve_lineto(dc->currentcurve, dc->point2[i]);
 911     }
 912     add_cap(dc->currentcurve, dc->point2[1], dc->point2[0], dc->point1[0], dc->point1[1], dc->cap_rounding);
 913     sp_curve_closepath(dc->currentcurve);
 914     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(dc->currentshape), dc->currentcurve);
 915 }
 916
 917 /*
 918   Local Variables:
 919   mode:c++
 920   c-file-style:"stroustrup"
 921   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
 922   indent-tabs-mode:nil
 923   fill-column:99
 924   End:
 925 */
 926 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :