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 /*
  22  * TODO: Tue Oct  2 22:57:15 2001
  23  *  - Decide control point behavior when use_calligraphic==1.
  24  *  - Decide to use NORMALIZED_COORDINATE or not.
  25  *  - Bug fix.
  26  */
  27
  28 #define noDYNA_DRAW_VERBOSE
  29
  30 #include "config.h"
  31
  32 #include <gtk/gtk.h>
  33 #include <gdk/gdkkeysyms.h>
  34
  35 #include "svg/svg.h"
  36 #include "display/canvas-bpath.h"
  37 #include "display/bezier-utils.h"
  38
  39 #include "macros.h"
  40 #include "document.h"
  41 #include "selection.h"
  42 #include "desktop.h"
  43 #include "desktop-events.h"
  44 #include "desktop-handles.h"
  45 #include "desktop-affine.h"
  46 #include "desktop-style.h"
  47 #include "message-context.h"
  48 #include "pixmaps/cursor-calligraphy.xpm"
  49 #include "dyna-draw-context.h"
  50 #include "libnr/n-art-bpath.h"
  51 #include "libnr/nr-path.h"
  52 #include "xml/repr.h"
  53 #include "context-fns.h"
  54 #include "sp-item.h"
  55
  56 #define DDC_RED_RGBA 0xff0000ff
  57 #define DDC_GREEN_RGBA 0x000000ff
  58
  59 #define SAMPLE_TIMEOUT 10
  60 #define TOLERANCE_LINE 1.0
  61 #define TOLERANCE_CALLIGRAPHIC 3.0
  62 #define DYNA_EPSILON 1.0e-6
  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 concat_current_line(SPDynaDrawContext *dc);
  81 static void accumulate_calligraphic(SPDynaDrawContext *dc);
  82
  83 static void fit_and_split(SPDynaDrawContext *ddc, gboolean release);
  84 static void fit_and_split_line(SPDynaDrawContext *ddc, gboolean release);
  85 static void fit_and_split_calligraphics(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 NR::Point sp_dyna_draw_get_curr_vpoint(SPDynaDrawContext const *ddc);
  91 static void draw_temporary_box(SPDynaDrawContext *dc);
  92
  93
  94 static SPEventContextClass *parent_class;
  95
  96 GtkType
  97 sp_dyna_draw_context_get_type(void)
  98 {
  99     static GType type = 0;
 100     if (!type) {
 101         GTypeInfo info = {
 102             sizeof(SPDynaDrawContextClass),
 103             NULL, NULL,
 104             (GClassInitFunc) sp_dyna_draw_context_class_init,
 105             NULL, NULL,
 106             sizeof(SPDynaDrawContext),
 107             4,
 108             (GInstanceInitFunc) sp_dyna_draw_context_init,
 109             NULL,   /* value_table */
 110         };
 111         type = g_type_register_static(SP_TYPE_EVENT_CONTEXT, "SPDynaDrawContext", &info, (GTypeFlags)0);
 112     }
 113     return type;
 114 }
 115
 116 static void
 117 sp_dyna_draw_context_class_init(SPDynaDrawContextClass *klass)
 118 {
 119     GObjectClass *object_class = (GObjectClass *) klass;
 120     SPEventContextClass *event_context_class = (SPEventContextClass *) klass;
 121
 122     parent_class = (SPEventContextClass*)g_type_class_peek_parent(klass);
 123
 124     object_class->dispose = sp_dyna_draw_context_dispose;
 125
 126     event_context_class->setup = sp_dyna_draw_context_setup;
 127     event_context_class->set = sp_dyna_draw_context_set;
 128     event_context_class->root_handler = sp_dyna_draw_context_root_handler;
 129 }
 130
 131 static void
 132 sp_dyna_draw_context_init(SPDynaDrawContext *ddc)
 133 {
 134     SPEventContext *event_context = SP_EVENT_CONTEXT(ddc);
 135
 136     event_context->cursor_shape = cursor_calligraphy_xpm;
 137     event_context->hot_x = 4;
 138     event_context->hot_y = 4;
 139
 140     ddc->accumulated = NULL;
 141     ddc->segments = NULL;
 142     ddc->currentcurve = NULL;
 143     ddc->currentshape = NULL;
 144     ddc->npoints = 0;
 145     ddc->cal1 = NULL;
 146     ddc->cal2 = NULL;
 147     ddc->repr = NULL;
 148
 149     /* DynaDraw values */
 150     ddc->cur = NR::Point(0,0);
 151     ddc->last = NR::Point(0,0);
 152     ddc->vel = NR::Point(0,0);
 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->use_timeout = FALSE;
 159     ddc->use_calligraphic = TRUE;
 160     ddc->timer_id = 0;
 161     ddc->dragging = FALSE;
 162     ddc->dynahand = FALSE;
 163
 164     ddc->mass = 0.3;
 165     ddc->drag = DRAG_DEFAULT;
 166     ddc->angle = 30.0;
 167     ddc->width = 0.2;
 168
 169     ddc->vel_thin = 0.1;
 170     ddc->flatness = 0.9;
 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     /* style should be changed when dc->use_calligraphc is touched */
 218     ddc->currentshape = sp_canvas_item_new(SP_DT_SKETCH(ec->desktop), SP_TYPE_CANVAS_BPATH, NULL);
 219     sp_canvas_bpath_set_fill(SP_CANVAS_BPATH(ddc->currentshape), DDC_RED_RGBA, SP_WIND_RULE_EVENODD);
 220     sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(ddc->currentshape), 0x00000000, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 221     /* fixme: Cannot we cascade it to root more clearly? */
 222     g_signal_connect(G_OBJECT(ddc->currentshape), "event", G_CALLBACK(sp_desktop_root_handler), ec->desktop);
 223
 224     sp_event_context_read(ec, "mass");
 225     sp_event_context_read(ec, "drag");
 226     sp_event_context_read(ec, "angle");
 227     sp_event_context_read(ec, "width");
 228     sp_event_context_read(ec, "thinning");
 229     sp_event_context_read(ec, "flatness");
 230     sp_event_context_read(ec, "usepressure");
 231     sp_event_context_read(ec, "usetilt");
 232
 233     ddc->is_drawing = false;
 234
 235     ddc->_message_context = new Inkscape::MessageContext((ec->desktop)->messageStack());
 236 }
 237
 238 static void
 239 sp_dyna_draw_context_set(SPEventContext *ec, gchar const *key, gchar const *val)
 240 {
 241     SPDynaDrawContext *ddc = SP_DYNA_DRAW_CONTEXT(ec);
 242
 243     if (!strcmp(key, "mass")) {
 244         double const dval = ( val ? g_ascii_strtod (val, NULL) : 0.2 );
 245         ddc->mass = CLAMP(dval, -1000.0, 1000.0);
 246     } else if (!strcmp(key, "drag")) {
 247         double const dval = ( val ? g_ascii_strtod (val, NULL) : DRAG_DEFAULT );
 248         ddc->drag = CLAMP(dval, DRAG_MIN, DRAG_MAX);
 249     } else if (!strcmp(key, "angle")) {
 250         double const dval = ( val ? g_ascii_strtod (val, NULL) : 0.0);
 251         ddc->angle = CLAMP (dval, -90, 90);
 252     } else if (!strcmp(key, "width")) {
 253         double const dval = ( val ? g_ascii_strtod (val, NULL) : 0.1 );
 254         ddc->width = CLAMP(dval, -1000.0, 1000.0);
 255     } else if (!strcmp(key, "thinning")) {
 256         double const dval = ( val ? g_ascii_strtod (val, NULL) : 0.1 );
 257         ddc->vel_thin = CLAMP(dval, -1.0, 1.0);
 258     } else if (!strcmp(key, "flatness")) {
 259         double const dval = ( val ? g_ascii_strtod (val, NULL) : 1.0 );
 260         ddc->flatness = CLAMP(dval, 0, 1.0);
 261     } else if (!strcmp(key, "usepressure")) {
 262         ddc->usepressure = (val && strcmp(val, "0"));
 263     } else if (!strcmp(key, "usetilt")) {
 264         ddc->usetilt = (val && strcmp(val, "0"));
 265     }
 266
 267     //g_print("DDC: %g %g %g %g\n", ddc->mass, ddc->drag, ddc->angle, ddc->width);
 268 }
 269
 270 static double
 271 flerp(double f0, double f1, double p)
 272 {
 273     return f0 + ( f1 - f0 ) * p;
 274 }
 275
 276 /* Get normalized point */
 277 static NR::Point
 278 sp_dyna_draw_get_npoint(SPDynaDrawContext const *dc, NR::Point v)
 279 {
 280     NR::Rect drect = SP_EVENT_CONTEXT(dc)->desktop->get_display_area();
 281     double const max = MAX ( drect.dimensions()[NR::X], drect.dimensions()[NR::Y] );
 282     return NR::Point(( v[NR::X] - drect.min()[NR::X] ) / max,  ( v[NR::Y] - drect.min()[NR::Y] ) / max);
 283 }
 284
 285 /* Get view point */
 286 static NR::Point
 287 sp_dyna_draw_get_vpoint(SPDynaDrawContext const *dc, NR::Point n)
 288 {
 289     NR::Rect drect = SP_EVENT_CONTEXT(dc)->desktop->get_display_area();
 290     double const max = MAX ( drect.dimensions()[NR::X], drect.dimensions()[NR::Y] );
 291     return NR::Point(n[NR::X] * max + drect.min()[NR::X], n[NR::Y] * max + drect.min()[NR::Y]);
 292 }
 293
 294 /* Get current view point */
 295 static NR::Point sp_dyna_draw_get_curr_vpoint(SPDynaDrawContext const *dc)
 296 {
 297     NR::Rect drect = SP_EVENT_CONTEXT(dc)->desktop->get_display_area();
 298     double const max = MAX ( drect.dimensions()[NR::X], drect.dimensions()[NR::Y] );
 299     return NR::Point(dc->cur[NR::X] * max + drect.min()[NR::X], dc->cur[NR::Y] * max + drect.min()[NR::Y]);
 300 }
 301
 302 static void
 303 sp_dyna_draw_reset(SPDynaDrawContext *dc, NR::Point p)
 304 {
 305     dc->last = dc->cur = sp_dyna_draw_get_npoint(dc, p);
 306     dc->vel = NR::Point(0,0);
 307     dc->acc = NR::Point(0,0);
 308     dc->ang = NR::Point(0,0);
 309     dc->del = NR::Point(0,0);
 310 }
 311
 312 static void
 313 sp_dyna_draw_extinput(SPDynaDrawContext *dc, GdkEvent *event)
 314 {
 315     if (gdk_event_get_axis (event, GDK_AXIS_PRESSURE, &dc->pressure))
 316         dc->pressure = CLAMP (dc->pressure, DDC_MIN_PRESSURE, DDC_MAX_PRESSURE);
 317     else
 318         dc->pressure = DDC_DEFAULT_PRESSURE;
 319
 320     if (gdk_event_get_axis (event, GDK_AXIS_XTILT, &dc->xtilt))
 321         dc->xtilt = CLAMP (dc->xtilt, DDC_MIN_TILT, DDC_MAX_TILT);
 322     else
 323         dc->xtilt = DDC_DEFAULT_TILT;
 324
 325     if (gdk_event_get_axis (event, GDK_AXIS_YTILT, &dc->ytilt))
 326         dc->ytilt = CLAMP (dc->ytilt, DDC_MIN_TILT, DDC_MAX_TILT);
 327     else
 328         dc->ytilt = DDC_DEFAULT_TILT;
 329 }
 330
 331
 332 static gboolean
 333 sp_dyna_draw_apply(SPDynaDrawContext *dc, NR::Point p)
 334 {
 335     NR::Point n = sp_dyna_draw_get_npoint(dc, p);
 336
 337     /* Calculate mass and drag */
 338     double const mass = flerp(1.0, 160.0, dc->mass);
 339     double const drag = flerp(0.0, 0.5, dc->drag * dc->drag);
 340
 341     /* Calculate force and acceleration */
 342     NR::Point force = n - dc->cur;
 343     if ( NR::L2(force) < DYNA_EPSILON ) {
 344         return FALSE;
 345     }
 346
 347     dc->acc = force / mass;
 348
 349     /* Calculate new velocity */
 350     dc->vel += dc->acc;
 351
 352     /* Calculate angle of drawing tool */
 353
 354     double a1;
 355     if (dc->usetilt) {
 356         // 1a. calculate nib angle from input device tilt:
 357         gdouble length = std::sqrt(dc->xtilt*dc->xtilt + dc->ytilt*dc->ytilt);;
 358
 359         if (length > 0) {
 360             NR::Point ang1 = NR::Point(dc->ytilt/length, dc->xtilt/length);
 361             a1 = atan2(ang1);
 362         }
 363         else
 364             a1 = 0.0;
 365     }
 366     else {
 367         // 1b. fixed dc->angle (absolutely flat nib):
 368         double const radians = ( (dc->angle - 90) / 180.0 ) * M_PI;
 369         NR::Point ang1 = NR::Point(-sin(radians),  cos(radians));
 370         a1 = atan2(ang1);
 371     }
 372
 373     // 2. perpendicular to dc->vel (absolutely non-flat nib):
 374     gdouble const mag_vel = NR::L2(dc->vel);
 375     if ( mag_vel < DYNA_EPSILON ) {
 376         return FALSE;
 377     }
 378     NR::Point ang2 = NR::rot90(dc->vel) / mag_vel;
 379
 380     // 3. Average them using flatness parameter:
 381     // calculate angles
 382     double a2 = atan2(ang2);
 383     // flip a2 to force it to be in the same half-circle as a1
 384     bool flipped = false;
 385     if (fabs (a2-a1) > 0.5*M_PI) {
 386         a2 += M_PI;
 387         flipped = true;
 388     }
 389     // normalize a2
 390     if (a2 > M_PI)
 391         a2 -= 2*M_PI;
 392     if (a2 < -M_PI)
 393         a2 += 2*M_PI;
 394     // find the flatness-weighted bisector angle, unflip if a2 was flipped
 395     // FIXME: when dc->vel is oscillating around the fixed angle, the new_ang flips back and forth. How to avoid this?
 396     double new_ang = a1 + (1 - dc->flatness) * (a2 - a1) - (flipped? M_PI : 0);
 397     // convert to point
 398     dc->ang = NR::Point (cos (new_ang), sin (new_ang));
 399
 400     /* Apply drag */
 401     dc->vel *= 1.0 - drag;
 402
 403     /* Update position */
 404     dc->last = dc->cur;
 405     dc->cur += dc->vel;
 406
 407     return TRUE;
 408 }
 409
 410 static void
 411 sp_dyna_draw_brush(SPDynaDrawContext *dc)
 412 {
 413     g_assert( dc->npoints >= 0 && dc->npoints < SAMPLING_SIZE );
 414
 415     if (dc->use_calligraphic) {
 416         /* calligraphics */
 417
 418         // How much velocity thins strokestyle
 419         double vel_thin = flerp (0, 160, dc->vel_thin);
 420
 421         // Influence of pressure on thickness
 422         double pressure_thick = (dc->usepressure ? dc->pressure : 1.0);
 423
 424         double width = ( pressure_thick - vel_thin * NR::L2(dc->vel) ) * dc->width;
 425         if ( width < 0.02 * dc->width ) {
 426             width = 0.02 * dc->width;
 427         }
 428
 429         NR::Point del = 0.05 * width * dc->ang;
 430
 431         dc->point1[dc->npoints] = sp_dyna_draw_get_vpoint(dc, dc->cur + del);
 432         dc->point2[dc->npoints] = sp_dyna_draw_get_vpoint(dc, dc->cur - del);
 433
 434         dc->del = del;
 435     } else {
 436         dc->point1[dc->npoints] = sp_dyna_draw_get_curr_vpoint(dc);
 437     }
 438
 439     dc->npoints++;
 440 }
 441
 442 static gint
 443 sp_dyna_draw_timeout_handler(gpointer data)
 444 {
 445     SPDynaDrawContext *dc = SP_DYNA_DRAW_CONTEXT(data);
 446     SPDesktop *desktop = SP_EVENT_CONTEXT(dc)->desktop;
 447     SPCanvas *canvas = SP_CANVAS(SP_DT_CANVAS(desktop));
 448
 449     dc->dragging = TRUE;
 450     dc->dynahand = TRUE;
 451
 452     int x, y;
 453     gtk_widget_get_pointer(GTK_WIDGET(canvas), &x, &y);
 454     NR::Point p = sp_canvas_window_to_world(canvas, NR::Point(x, y));
 455     p = desktop->w2d(p);
 456     if (! sp_dyna_draw_apply(dc, p)) {
 457         return TRUE;
 458     }
 459
 460     if ( dc->cur != dc->last ) {
 461         sp_dyna_draw_brush(dc);
 462         g_assert( dc->npoints > 0 );
 463         fit_and_split(dc, FALSE);
 464     }
 465
 466     return TRUE;
 467 }
 468
 469 void
 470 sp_ddc_update_toolbox (SPDesktop *desktop, const gchar *id, double value)
 471 {
 472     desktop->setToolboxAdjustmentValue (id, value);
 473 }
 474
 475 gint
 476 sp_dyna_draw_context_root_handler(SPEventContext *event_context,
 477                                   GdkEvent *event)
 478 {
 479     SPDynaDrawContext *dc = SP_DYNA_DRAW_CONTEXT(event_context);
 480     SPDesktop *desktop = event_context->desktop;
 481
 482     gint ret = FALSE;
 483
 484     switch (event->type) {
 485     case GDK_BUTTON_PRESS:
 486         if ( event->button.button == 1 ) {
 487
 488             SPDesktop *desktop = SP_EVENT_CONTEXT_DESKTOP(dc);
 489
 490             if (Inkscape::have_viable_layer(desktop, dc->_message_context) == false) {
 491                 return TRUE;
 492             }
 493
 494             NR::Point const button_w(event->button.x,
 495                                      event->button.y);
 496             NR::Point const button_dt(desktop->w2d(button_w));
 497             sp_dyna_draw_reset(dc, button_dt);
 498             sp_dyna_draw_extinput(dc, event);
 499             sp_dyna_draw_apply(dc, button_dt);
 500             sp_curve_reset(dc->accumulated);
 501             if (dc->repr) {
 502                 dc->repr = NULL;
 503             }
 504
 505             /* initialize first point */
 506             dc->npoints = 0;
 507
 508             sp_canvas_item_grab(SP_CANVAS_ITEM(desktop->acetate),
 509                                 ( dc->use_timeout
 510                                   ? ( GDK_KEY_PRESS_MASK |
 511                                       GDK_BUTTON_RELEASE_MASK |
 512                                       GDK_BUTTON_PRESS_MASK    )
 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             if ( dc->use_timeout && !dc->timer_id ) {
 521                 dc->timer_id = gtk_timeout_add(SAMPLE_TIMEOUT, sp_dyna_draw_timeout_handler, dc);
 522             }
 523             ret = TRUE;
 524
 525             dc->is_drawing = true;
 526         }
 527         break;
 528     case GDK_MOTION_NOTIFY:
 529         if ( dc->is_drawing && !dc->use_timeout && ( event->motion.state & GDK_BUTTON1_MASK ) ) {
 530             dc->dragging = TRUE;
 531             dc->dynahand = TRUE;
 532
 533             NR::Point const motion_w(event->motion.x,
 534                                      event->motion.y);
 535             NR::Point const motion_dt(desktop->w2d(motion_w));
 536
 537             sp_dyna_draw_extinput(dc, event);
 538             if (!sp_dyna_draw_apply(dc, motion_dt)) {
 539                 ret = TRUE;
 540                 break;
 541             }
 542
 543             if ( dc->cur != dc->last ) {
 544                 sp_dyna_draw_brush(dc);
 545                 g_assert( dc->npoints > 0 );
 546                 fit_and_split(dc, FALSE);
 547             }
 548             ret = TRUE;
 549         }
 550         break;
 551
 552     case GDK_BUTTON_RELEASE:
 553         sp_canvas_item_ungrab(SP_CANVAS_ITEM(desktop->acetate), event->button.time);
 554         dc->is_drawing = false;
 555         if ( event->button.button == 1
 556              && dc->use_timeout
 557              && dc->timer_id != 0 )
 558         {
 559             gtk_timeout_remove(dc->timer_id);
 560             dc->timer_id = 0;
 561         }
 562         if ( dc->dragging && event->button.button == 1 ) {
 563             dc->dragging = FALSE;
 564
 565             /* release */
 566             if (dc->dynahand) {
 567                 dc->dynahand = FALSE;
 568                 /* Remove all temporary line segments */
 569                 while (dc->segments) {
 570                     gtk_object_destroy(GTK_OBJECT(dc->segments->data));
 571                     dc->segments = g_slist_remove(dc->segments, dc->segments->data);
 572                 }
 573                 /* Create object */
 574                 fit_and_split(dc, TRUE);
 575                 if (dc->use_calligraphic) {
 576                     accumulate_calligraphic(dc);
 577                 } else {
 578                     concat_current_line(dc);
 579                 }
 580                 set_to_accumulated(dc); /* temporal implementation */
 581                 if (dc->use_calligraphic /* || dc->cinside*/) {
 582                     /* reset accumulated curve */
 583                     sp_curve_reset(dc->accumulated);
 584                     clear_current(dc);
 585                     if (dc->repr) {
 586                         dc->repr = NULL;
 587                     }
 588                 }
 589             }
 590             ret = TRUE;
 591         }
 592         break;
 593     case GDK_KEY_PRESS:
 594         switch (get_group0_keyval (&event->key)) {
 595         case GDK_Up:
 596         case GDK_KP_Up:
 597             if (!MOD__CTRL_ONLY) {
 598                 dc->angle += 5.0;
 599                 if (dc->angle > 90.0)
 600                     dc->angle = 90.0;
 601                 sp_ddc_update_toolbox (desktop, "calligraphy-angle", dc->angle);
 602                 ret = TRUE;
 603             }
 604             break;
 605         case GDK_Down:
 606         case GDK_KP_Down:
 607             if (!MOD__CTRL_ONLY) {
 608                 dc->angle -= 5.0;
 609                 if (dc->angle < -90.0)
 610                     dc->angle = -90.0;
 611                 sp_ddc_update_toolbox (desktop, "calligraphy-angle", dc->angle);
 612                 ret = TRUE;
 613             }
 614             break;
 615         case GDK_Right:
 616         case GDK_KP_Right:
 617             if (!MOD__CTRL_ONLY) {
 618                 dc->width += 0.01;
 619                 if (dc->width > 1.0)
 620                     dc->width = 1.0;
 621                 sp_ddc_update_toolbox (desktop, "altx-calligraphy", dc->width); // the same spinbutton is for alt+x
 622                 ret = TRUE;
 623             }
 624             break;
 625         case GDK_Left:
 626         case GDK_KP_Left:
 627             if (!MOD__CTRL_ONLY) {
 628                 dc->width -= 0.01;
 629                 if (dc->width < 0.01)
 630                     dc->width = 0.01;
 631                 sp_ddc_update_toolbox (desktop, "altx-calligraphy", dc->width);
 632                 ret = TRUE;
 633             }
 634             break;
 635         case GDK_x:
 636         case GDK_X:
 637             if (MOD__ALT_ONLY) {
 638                 desktop->setToolboxFocusTo ("altx-calligraphy");
 639                 ret = TRUE;
 640             }
 641             break;
 642         case GDK_Escape:
 643             SP_DT_SELECTION(desktop)->clear();
 644             break;
 645
 646         default:
 647             break;
 648         }
 649     default:
 650         break;
 651     }
 652
 653     if (!ret) {
 654         if (((SPEventContextClass *) parent_class)->root_handler) {
 655             ret = ((SPEventContextClass *) parent_class)->root_handler(event_context, event);
 656         }
 657     }
 658
 659     return ret;
 660 }
 661
 662
 663 static void
 664 clear_current(SPDynaDrawContext *dc)
 665 {
 666     /* reset bpath */
 667     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(dc->currentshape), NULL);
 668     /* reset curve */
 669     sp_curve_reset(dc->currentcurve);
 670     sp_curve_reset(dc->cal1);
 671     sp_curve_reset(dc->cal2);
 672     /* reset points */
 673     dc->npoints = 0;
 674 }
 675
 676 static void
 677 set_to_accumulated(SPDynaDrawContext *dc)
 678 {
 679     SPDesktop *desktop = SP_EVENT_CONTEXT(dc)->desktop;
 680
 681     if (!sp_curve_empty(dc->accumulated)) {
 682         NArtBpath *abp;
 683         gchar *str;
 684
 685         if (!dc->repr) {
 686             /* Create object */
 687             Inkscape::XML::Node *repr = sp_repr_new("svg:path");
 688
 689             /* Set style */
 690             sp_desktop_apply_style_tool (desktop, repr, "tools.calligraphic", false);
 691
 692             dc->repr = repr;
 693
 694             SPItem *item=SP_ITEM(desktop->currentLayer()->appendChildRepr(dc->repr));
 695             Inkscape::GC::release(dc->repr);
 696             item->transform = SP_ITEM(desktop->currentRoot())->getRelativeTransform(desktop->currentLayer());
 697             item->updateRepr();
 698             SP_DT_SELECTION(desktop)->set(dc->repr);
 699         }
 700         abp = nr_artpath_affine(sp_curve_first_bpath(dc->accumulated), sp_desktop_dt2root_affine(desktop));
 701         str = sp_svg_write_path(abp);
 702         g_assert( str != NULL );
 703         nr_free(abp);
 704         dc->repr->setAttribute("d", str);
 705         g_free(str);
 706     } else {
 707         if (dc->repr) {
 708             sp_repr_unparent(dc->repr);
 709         }
 710         dc->repr = NULL;
 711     }
 712
 713     sp_document_done(SP_DT_DOCUMENT(desktop));
 714 }
 715
 716 static void
 717 concat_current_line(SPDynaDrawContext *dc)
 718 {
 719     if (!sp_curve_empty(dc->currentcurve)) {
 720         NArtBpath *bpath;
 721         if (sp_curve_empty(dc->accumulated)) {
 722             bpath = sp_curve_first_bpath(dc->currentcurve);
 723             g_assert( bpath->code == NR_MOVETO_OPEN );
 724             sp_curve_moveto(dc->accumulated, bpath->x3, bpath->y3);
 725         }
 726         bpath = sp_curve_last_bpath(dc->currentcurve);
 727         if ( bpath->code == NR_CURVETO ) {
 728             sp_curve_curveto(dc->accumulated,
 729                              bpath->x1, bpath->y1,
 730                              bpath->x2, bpath->y2,
 731                              bpath->x3, bpath->y3);
 732         } else if ( bpath->code == NR_LINETO ) {
 733             sp_curve_lineto(dc->accumulated, bpath->x3, bpath->y3);
 734         } else {
 735             g_assert_not_reached();
 736         }
 737     }
 738 }
 739
 740 static void
 741 accumulate_calligraphic(SPDynaDrawContext *dc)
 742 {
 743     if ( !sp_curve_empty(dc->cal1) && !sp_curve_empty(dc->cal2) ) {
 744         sp_curve_reset(dc->accumulated); /*  Is this required ?? */
 745         SPCurve *rev_cal2 = sp_curve_reverse(dc->cal2);
 746         sp_curve_append(dc->accumulated, dc->cal1, FALSE);
 747         sp_curve_append(dc->accumulated, rev_cal2, TRUE);
 748         sp_curve_closepath(dc->accumulated);
 749
 750         sp_curve_unref(rev_cal2);
 751
 752         sp_curve_reset(dc->cal1);
 753         sp_curve_reset(dc->cal2);
 754     }
 755 }
 756
 757 static void
 758 fit_and_split(SPDynaDrawContext *dc,
 759               gboolean release)
 760 {
 761     if (dc->use_calligraphic) {
 762         fit_and_split_calligraphics(dc, release);
 763     } else {
 764         fit_and_split_line(dc, release);
 765     }
 766 }
 767
 768 static double square(double const x)
 769 {
 770     return x * x;
 771 }
 772
 773 static void
 774 fit_and_split_line(SPDynaDrawContext *dc,
 775                    gboolean release)
 776 {
 777     double const tolerance_sq = square( NR::expansion(SP_EVENT_CONTEXT(dc)->desktop->w2d()) * TOLERANCE_LINE );
 778
 779     NR::Point b[4];
 780     double const n_segs = sp_bezier_fit_cubic(b, dc->point1, dc->npoints, tolerance_sq);
 781     if ( n_segs > 0
 782          && dc->npoints < SAMPLING_SIZE )
 783     {
 784         /* Fit and draw and reset state */
 785 #ifdef DYNA_DRAW_VERBOSE
 786         g_print("%d", dc->npoints);
 787 #endif
 788         sp_curve_reset(dc->currentcurve);
 789         sp_curve_moveto(dc->currentcurve, b[0]);
 790         sp_curve_curveto(dc->currentcurve, b[1], b[2], b[3]);
 791         sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(dc->currentshape), dc->currentcurve);
 792     } else {
 793         /* Fit and draw and copy last point */
 794 #ifdef DYNA_DRAW_VERBOSE
 795         g_print("[%d]Yup\n", dc->npoints);
 796 #endif
 797         g_assert(!sp_curve_empty(dc->currentcurve));
 798         concat_current_line(dc);
 799
 800         SPCanvasItem *cbp = sp_canvas_item_new(SP_DT_SKETCH(SP_EVENT_CONTEXT(dc)->desktop),
 801                                                SP_TYPE_CANVAS_BPATH,
 802                                                NULL);
 803         SPCurve *curve = sp_curve_copy(dc->currentcurve);
 804         sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(cbp), curve);
 805         sp_curve_unref(curve);
 806         /* fixme: We have to parse style color somehow */
 807         sp_canvas_bpath_set_fill(SP_CANVAS_BPATH(cbp), DDC_GREEN_RGBA, SP_WIND_RULE_EVENODD);
 808         sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(cbp), 0x000000ff, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 809         /* fixme: Cannot we cascade it to root more clearly? */
 810         g_signal_connect(G_OBJECT(cbp), "event", G_CALLBACK(sp_desktop_root_handler), SP_EVENT_CONTEXT(dc)->desktop);
 811
 812         dc->segments = g_slist_prepend(dc->segments, cbp);
 813         dc->point1[0] = dc->point1[dc->npoints - 2];
 814         dc->npoints = 1;
 815     }
 816 }
 817
 818 static void
 819 fit_and_split_calligraphics(SPDynaDrawContext *dc, gboolean release)
 820 {
 821     double const tolerance_sq = square( NR::expansion(SP_EVENT_CONTEXT(dc)->desktop->w2d()) * TOLERANCE_CALLIGRAPHIC );
 822
 823 #ifdef DYNA_DRAW_VERBOSE
 824     g_print("[F&S:R=%c]", release?'T':'F');
 825 #endif
 826
 827     if (!( dc->npoints > 0 && dc->npoints < SAMPLING_SIZE ))
 828         return; // just clicked
 829
 830     if ( dc->npoints == SAMPLING_SIZE - 1 || release ) {
 831 #define BEZIER_SIZE       4
 832 #define BEZIER_MAX_BEZIERS  8
 833 #define BEZIER_MAX_LENGTH ( BEZIER_SIZE * BEZIER_MAX_BEZIERS )
 834
 835 #ifdef DYNA_DRAW_VERBOSE
 836         g_print("[F&S:#] dc->npoints:%d, release:%s\n",
 837                 dc->npoints, release ? "TRUE" : "FALSE");
 838 #endif
 839
 840         /* Current calligraphic */
 841         if ( dc->cal1->end == 0 || dc->cal2->end == 0 ) {
 842             /* dc->npoints > 0 */
 843             /* g_print("calligraphics(1|2) reset\n"); */
 844             sp_curve_reset(dc->cal1);
 845             sp_curve_reset(dc->cal2);
 846
 847             sp_curve_moveto(dc->cal1, dc->point1[0]);
 848             sp_curve_moveto(dc->cal2, dc->point2[0]);
 849         }
 850
 851         NR::Point b1[BEZIER_MAX_LENGTH];
 852         gint const nb1 = sp_bezier_fit_cubic_r(b1, dc->point1, dc->npoints,
 853                                                tolerance_sq, BEZIER_MAX_BEZIERS);
 854         g_assert( nb1 * BEZIER_SIZE <= gint(G_N_ELEMENTS(b1)) );
 855
 856         NR::Point b2[BEZIER_MAX_LENGTH];
 857         gint const nb2 = sp_bezier_fit_cubic_r(b2, dc->point2, dc->npoints,
 858                                                tolerance_sq, BEZIER_MAX_BEZIERS);
 859         g_assert( nb2 * BEZIER_SIZE <= gint(G_N_ELEMENTS(b2)) );
 860
 861         if ( nb1 != -1 && nb2 != -1 ) {
 862             /* Fit and draw and reset state */
 863 #ifdef DYNA_DRAW_VERBOSE
 864             g_print("nb1:%d nb2:%d\n", nb1, nb2);
 865 #endif
 866             /* CanvasShape */
 867             if (! release) {
 868                 sp_curve_reset(dc->currentcurve);
 869                 sp_curve_moveto(dc->currentcurve, b1[0]);
 870                 for (NR::Point *bp1 = b1; bp1 < b1 + BEZIER_SIZE * nb1; bp1 += BEZIER_SIZE) {
 871                     sp_curve_curveto(dc->currentcurve, bp1[1],
 872                                      bp1[2], bp1[3]);
 873                 }
 874                 sp_curve_lineto(dc->currentcurve,
 875                                 b2[BEZIER_SIZE*(nb2-1) + 3]);
 876                 for (NR::Point *bp2 = b2 + BEZIER_SIZE * ( nb2 - 1 ); bp2 >= b2; bp2 -= BEZIER_SIZE) {
 877                     sp_curve_curveto(dc->currentcurve, bp2[2], bp2[1], bp2[0]);
 878                 }
 879                 sp_curve_closepath(dc->currentcurve);
 880                 sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(dc->currentshape), dc->currentcurve);
 881             }
 882
 883             /* Current calligraphic */
 884             for (NR::Point *bp1 = b1; bp1 < b1 + BEZIER_SIZE * nb1; bp1 += BEZIER_SIZE) {
 885                 sp_curve_curveto(dc->cal1, bp1[1], bp1[2], bp1[3]);
 886             }
 887             for (NR::Point *bp2 = b2; bp2 < b2 + BEZIER_SIZE * nb2; bp2 += BEZIER_SIZE) {
 888                 sp_curve_curveto(dc->cal2, bp2[1], bp2[2], bp2[3]);
 889             }
 890         } else {
 891             /* fixme: ??? */
 892 #ifdef DYNA_DRAW_VERBOSE
 893             g_print("[fit_and_split_calligraphics] failed to fit-cubic.\n");
 894 #endif
 895             draw_temporary_box(dc);
 896
 897             for (gint i = 1; i < dc->npoints; i++) {
 898                 sp_curve_lineto(dc->cal1, dc->point1[i]);
 899             }
 900             for (gint i = 1; i < dc->npoints; i++) {
 901                 sp_curve_lineto(dc->cal2, dc->point2[i]);
 902             }
 903         }
 904
 905         /* Fit and draw and copy last point */
 906 #ifdef DYNA_DRAW_VERBOSE
 907         g_print("[%d]Yup\n", dc->npoints);
 908 #endif
 909         if (!release) {
 910             g_assert(!sp_curve_empty(dc->currentcurve));
 911
 912             SPCanvasItem *cbp = sp_canvas_item_new(SP_DT_SKETCH(SP_EVENT_CONTEXT(dc)->desktop),
 913                                                    SP_TYPE_CANVAS_BPATH,
 914                                                    NULL);
 915             SPCurve *curve = sp_curve_copy(dc->currentcurve);
 916             sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH (cbp), curve);
 917             sp_curve_unref(curve);
 918             sp_canvas_bpath_set_fill(SP_CANVAS_BPATH(cbp), 0x000000ff, SP_WIND_RULE_EVENODD);
 919             sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(cbp), 0x00000000, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 920             /* fixme: Cannot we cascade it to root more clearly? */
 921             g_signal_connect(G_OBJECT(cbp), "event", G_CALLBACK(sp_desktop_root_handler), SP_EVENT_CONTEXT(dc)->desktop);
 922
 923             dc->segments = g_slist_prepend(dc->segments, cbp);
 924         }
 925
 926         dc->point1[0] = dc->point1[dc->npoints - 1];
 927         dc->point2[0] = dc->point2[dc->npoints - 1];
 928         dc->npoints = 1;
 929     } else {
 930         draw_temporary_box(dc);
 931     }
 932 }
 933
 934 static void
 935 draw_temporary_box(SPDynaDrawContext *dc)
 936 {
 937     sp_curve_reset(dc->currentcurve);
 938     sp_curve_moveto(dc->currentcurve, dc->point1[0]);
 939     for (gint i = 1; i < dc->npoints; i++) {
 940         sp_curve_lineto(dc->currentcurve, dc->point1[i]);
 941     }
 942     for (gint i = dc->npoints-1; i >= 0; i--) {
 943         sp_curve_lineto(dc->currentcurve, dc->point2[i]);
 944     }
 945     sp_curve_closepath(dc->currentcurve);
 946     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(dc->currentshape), dc->currentcurve);
 947 }
 948
 949 /*
 950   Local Variables:
 951   mode:c++
 952   c-file-style:"stroustrup"
 953   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
 954   indent-tabs-mode:nil
 955   fill-column:99
 956   End:
 957 */
 958 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :