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, "tremor");
 230     sp_event_context_read(ec, "flatness");
 231     sp_event_context_read(ec, "usepressure");
 232     sp_event_context_read(ec, "usetilt");
 233
 234     ddc->is_drawing = false;
 235
 236     ddc->_message_context = new Inkscape::MessageContext((ec->desktop)->messageStack());
 237 }
 238
 239 static void
 240 sp_dyna_draw_context_set(SPEventContext *ec, gchar const *key, gchar const *val)
 241 {
 242     SPDynaDrawContext *ddc = SP_DYNA_DRAW_CONTEXT(ec);
 243
 244     if (!strcmp(key, "mass")) {
 245         double const dval = ( val ? g_ascii_strtod (val, NULL) : 0.2 );
 246         ddc->mass = CLAMP(dval, -1000.0, 1000.0);
 247     } else if (!strcmp(key, "drag")) {
 248         double const dval = ( val ? g_ascii_strtod (val, NULL) : DRAG_DEFAULT );
 249         ddc->drag = CLAMP(dval, DRAG_MIN, DRAG_MAX);
 250     } else if (!strcmp(key, "angle")) {
 251         double const dval = ( val ? g_ascii_strtod (val, NULL) : 0.0);
 252         ddc->angle = CLAMP (dval, -90, 90);
 253     } else if (!strcmp(key, "width")) {
 254         double const dval = ( val ? g_ascii_strtod (val, NULL) : 0.1 );
 255         ddc->width = CLAMP(dval, -1000.0, 1000.0);
 256     } else if (!strcmp(key, "thinning")) {
 257         double const dval = ( val ? g_ascii_strtod (val, NULL) : 0.1 );
 258         ddc->vel_thin = CLAMP(dval, -1.0, 1.0);
 259     } else if (!strcmp(key, "tremor")) {
 260         double const dval = ( val ? g_ascii_strtod (val, NULL) : 0.0 );
 261         ddc->tremor = CLAMP(dval, 0.0, 1.0);
 262     } else if (!strcmp(key, "flatness")) {
 263         double const dval = ( val ? g_ascii_strtod (val, NULL) : 1.0 );
 264         ddc->flatness = CLAMP(dval, 0, 1.0);
 265     } else if (!strcmp(key, "usepressure")) {
 266         ddc->usepressure = (val && strcmp(val, "0"));
 267     } else if (!strcmp(key, "usetilt")) {
 268         ddc->usetilt = (val && strcmp(val, "0"));
 269     }
 270
 271     //g_print("DDC: %g %g %g %g\n", ddc->mass, ddc->drag, ddc->angle, ddc->width);
 272 }
 273
 274 static double
 275 flerp(double f0, double f1, double p)
 276 {
 277     return f0 + ( f1 - f0 ) * p;
 278 }
 279
 280 /* Get normalized point */
 281 static NR::Point
 282 sp_dyna_draw_get_npoint(SPDynaDrawContext const *dc, NR::Point v)
 283 {
 284     NR::Rect drect = SP_EVENT_CONTEXT(dc)->desktop->get_display_area();
 285     double const max = MAX ( drect.dimensions()[NR::X], drect.dimensions()[NR::Y] );
 286     return NR::Point(( v[NR::X] - drect.min()[NR::X] ) / max,  ( v[NR::Y] - drect.min()[NR::Y] ) / max);
 287 }
 288
 289 /* Get view point */
 290 static NR::Point
 291 sp_dyna_draw_get_vpoint(SPDynaDrawContext const *dc, NR::Point n)
 292 {
 293     NR::Rect drect = SP_EVENT_CONTEXT(dc)->desktop->get_display_area();
 294     double const max = MAX ( drect.dimensions()[NR::X], drect.dimensions()[NR::Y] );
 295     return NR::Point(n[NR::X] * max + drect.min()[NR::X], n[NR::Y] * max + drect.min()[NR::Y]);
 296 }
 297
 298 /* Get current view point */
 299 static NR::Point sp_dyna_draw_get_curr_vpoint(SPDynaDrawContext const *dc)
 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(dc->cur[NR::X] * max + drect.min()[NR::X], dc->cur[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->acc = NR::Point(0,0);
 312     dc->ang = NR::Point(0,0);
 313     dc->del = NR::Point(0,0);
 314 }
 315
 316 static void
 317 sp_dyna_draw_extinput(SPDynaDrawContext *dc, GdkEvent *event)
 318 {
 319     if (gdk_event_get_axis (event, GDK_AXIS_PRESSURE, &dc->pressure))
 320         dc->pressure = CLAMP (dc->pressure, DDC_MIN_PRESSURE, DDC_MAX_PRESSURE);
 321     else
 322         dc->pressure = DDC_DEFAULT_PRESSURE;
 323
 324     if (gdk_event_get_axis (event, GDK_AXIS_XTILT, &dc->xtilt))
 325         dc->xtilt = CLAMP (dc->xtilt, DDC_MIN_TILT, DDC_MAX_TILT);
 326     else
 327         dc->xtilt = DDC_DEFAULT_TILT;
 328
 329     if (gdk_event_get_axis (event, GDK_AXIS_YTILT, &dc->ytilt))
 330         dc->ytilt = CLAMP (dc->ytilt, DDC_MIN_TILT, DDC_MAX_TILT);
 331     else
 332         dc->ytilt = DDC_DEFAULT_TILT;
 333 }
 334
 335
 336 static gboolean
 337 sp_dyna_draw_apply(SPDynaDrawContext *dc, NR::Point p)
 338 {
 339     NR::Point n = sp_dyna_draw_get_npoint(dc, p);
 340
 341     /* Calculate mass and drag */
 342     double const mass = flerp(1.0, 160.0, dc->mass);
 343     double const drag = flerp(0.0, 0.5, dc->drag * dc->drag);
 344
 345     /* Calculate force and acceleration */
 346     NR::Point force = n - dc->cur;
 347     if ( NR::L2(force) < DYNA_EPSILON ) {
 348         return FALSE;
 349     }
 350
 351     dc->acc = force / mass;
 352
 353     /* Calculate new velocity */
 354     dc->vel += dc->acc;
 355
 356     /* Calculate angle of drawing tool */
 357
 358     double a1;
 359     if (dc->usetilt) {
 360         // 1a. calculate nib angle from input device tilt:
 361         gdouble length = std::sqrt(dc->xtilt*dc->xtilt + dc->ytilt*dc->ytilt);;
 362
 363         if (length > 0) {
 364             NR::Point ang1 = NR::Point(dc->ytilt/length, dc->xtilt/length);
 365             a1 = atan2(ang1);
 366         }
 367         else
 368             a1 = 0.0;
 369     }
 370     else {
 371         // 1b. fixed dc->angle (absolutely flat nib):
 372         double const radians = ( (dc->angle - 90) / 180.0 ) * M_PI;
 373         NR::Point ang1 = NR::Point(-sin(radians),  cos(radians));
 374         a1 = atan2(ang1);
 375     }
 376
 377     // 2. perpendicular to dc->vel (absolutely non-flat nib):
 378     gdouble const mag_vel = NR::L2(dc->vel);
 379     if ( mag_vel < DYNA_EPSILON ) {
 380         return FALSE;
 381     }
 382     NR::Point ang2 = NR::rot90(dc->vel) / mag_vel;
 383
 384     // 3. Average them using flatness parameter:
 385     // calculate angles
 386     double a2 = atan2(ang2);
 387     // flip a2 to force it to be in the same half-circle as a1
 388     bool flipped = false;
 389     if (fabs (a2-a1) > 0.5*M_PI) {
 390         a2 += M_PI;
 391         flipped = true;
 392     }
 393     // normalize a2
 394     if (a2 > M_PI)
 395         a2 -= 2*M_PI;
 396     if (a2 < -M_PI)
 397         a2 += 2*M_PI;
 398     // find the flatness-weighted bisector angle, unflip if a2 was flipped
 399     // FIXME: when dc->vel is oscillating around the fixed angle, the new_ang flips back and forth. How to avoid this?
 400     double new_ang = a1 + (1 - dc->flatness) * (a2 - a1) - (flipped? M_PI : 0);
 401     // convert to point
 402     dc->ang = NR::Point (cos (new_ang), sin (new_ang));
 403
 404     /* Apply drag */
 405     dc->vel *= 1.0 - drag;
 406
 407     /* Update position */
 408     dc->last = dc->cur;
 409     dc->cur += dc->vel;
 410
 411     return TRUE;
 412 }
 413
 414 static void
 415 sp_dyna_draw_brush(SPDynaDrawContext *dc)
 416 {
 417     g_assert( dc->npoints >= 0 && dc->npoints < SAMPLING_SIZE );
 418
 419     if (dc->use_calligraphic) {
 420         /* calligraphics */
 421
 422         // How much velocity thins strokestyle
 423         double vel_thin = flerp (0, 160, dc->vel_thin);
 424
 425         // Influence of pressure on thickness
 426         double pressure_thick = (dc->usepressure ? dc->pressure : 1.0);
 427
 428         double width = ( pressure_thick - vel_thin * NR::L2(dc->vel) ) * dc->width;
 429
 430         double tremble_left = 0, tremble_right = 0;
 431         if (dc->tremor > 0) {
 432             // obtain two normally distributed random variables, using polar Box-Muller transform
 433             double x1, x2, w, y1, y2;
 434             do {
 435                  x1 = 2.0 * g_random_double_range(0,1) - 1.0;
 436                  x2 = 2.0 * g_random_double_range(0,1) - 1.0;
 437                  w = x1 * x1 + x2 * x2;
 438             } while ( w >= 1.0 );
 439             w = sqrt( (-2.0 * log( w ) ) / w );
 440             y1 = x1 * w;
 441             y2 = x2 * w;
 442
 443             // deflect both left and right edges randomly and independently, so that:
 444             // (1) dc->tremor=1 corresponds to sigma=1, decreasing dc->tremor narrows the bell curve;
 445             // (2) deflection depends on width, but is upped for small widths for better visual uniformity across widths;
 446             // (3) deflection somewhat depends on speed, to prevent fast strokes looking
 447             // comparatively smooth and slow ones excessively jittery
 448             tremble_left  = (y1)*dc->tremor * (0.15 + 0.8*width) * (0.35 + 14*NR::L2(dc->vel));
 449             tremble_right = (y2)*dc->tremor * (0.15 + 0.8*width) * (0.35 + 14*NR::L2(dc->vel));
 450         }
 451
 452         if ( width < 0.02 * dc->width ) {
 453             width = 0.02 * dc->width;
 454         }
 455
 456         NR::Point del_left = 0.05 * (width + tremble_left) * dc->ang;
 457         NR::Point del_right = 0.05 * (width + tremble_right) * dc->ang;
 458
 459         dc->point1[dc->npoints] = sp_dyna_draw_get_vpoint(dc, dc->cur + del_left);
 460         dc->point2[dc->npoints] = sp_dyna_draw_get_vpoint(dc, dc->cur - del_right);
 461
 462         dc->del = 0.5*(del_left + del_right);
 463     } else {
 464         dc->point1[dc->npoints] = sp_dyna_draw_get_curr_vpoint(dc);
 465     }
 466
 467     dc->npoints++;
 468 }
 469
 470 static gint
 471 sp_dyna_draw_timeout_handler(gpointer data)
 472 {
 473     SPDynaDrawContext *dc = SP_DYNA_DRAW_CONTEXT(data);
 474     SPDesktop *desktop = SP_EVENT_CONTEXT(dc)->desktop;
 475     SPCanvas *canvas = SP_CANVAS(SP_DT_CANVAS(desktop));
 476
 477     dc->dragging = TRUE;
 478     dc->dynahand = TRUE;
 479
 480     int x, y;
 481     gtk_widget_get_pointer(GTK_WIDGET(canvas), &x, &y);
 482     NR::Point p = sp_canvas_window_to_world(canvas, NR::Point(x, y));
 483     p = desktop->w2d(p);
 484     if (! sp_dyna_draw_apply(dc, p)) {
 485         return TRUE;
 486     }
 487
 488     if ( dc->cur != dc->last ) {
 489         sp_dyna_draw_brush(dc);
 490         g_assert( dc->npoints > 0 );
 491         fit_and_split(dc, FALSE);
 492     }
 493
 494     return TRUE;
 495 }
 496
 497 void
 498 sp_ddc_update_toolbox (SPDesktop *desktop, const gchar *id, double value)
 499 {
 500     desktop->setToolboxAdjustmentValue (id, value);
 501 }
 502
 503 gint
 504 sp_dyna_draw_context_root_handler(SPEventContext *event_context,
 505                                   GdkEvent *event)
 506 {
 507     SPDynaDrawContext *dc = SP_DYNA_DRAW_CONTEXT(event_context);
 508     SPDesktop *desktop = event_context->desktop;
 509
 510     gint ret = FALSE;
 511
 512     switch (event->type) {
 513     case GDK_BUTTON_PRESS:
 514         if ( event->button.button == 1 ) {
 515
 516             SPDesktop *desktop = SP_EVENT_CONTEXT_DESKTOP(dc);
 517
 518             if (Inkscape::have_viable_layer(desktop, dc->_message_context) == false) {
 519                 return TRUE;
 520             }
 521
 522             NR::Point const button_w(event->button.x,
 523                                      event->button.y);
 524             NR::Point const button_dt(desktop->w2d(button_w));
 525             sp_dyna_draw_reset(dc, button_dt);
 526             sp_dyna_draw_extinput(dc, event);
 527             sp_dyna_draw_apply(dc, button_dt);
 528             sp_curve_reset(dc->accumulated);
 529             if (dc->repr) {
 530                 dc->repr = NULL;
 531             }
 532
 533             /* initialize first point */
 534             dc->npoints = 0;
 535
 536             sp_canvas_item_grab(SP_CANVAS_ITEM(desktop->acetate),
 537                                 ( dc->use_timeout
 538                                   ? ( GDK_KEY_PRESS_MASK |
 539                                       GDK_BUTTON_RELEASE_MASK |
 540                                       GDK_BUTTON_PRESS_MASK    )
 541                                   : ( GDK_KEY_PRESS_MASK |
 542                                       GDK_BUTTON_RELEASE_MASK |
 543                                       GDK_POINTER_MOTION_MASK |
 544                                       GDK_BUTTON_PRESS_MASK    ) ),
 545                                 NULL,
 546                                 event->button.time);
 547
 548             if ( dc->use_timeout && !dc->timer_id ) {
 549                 dc->timer_id = gtk_timeout_add(SAMPLE_TIMEOUT, sp_dyna_draw_timeout_handler, dc);
 550             }
 551             ret = TRUE;
 552
 553             dc->is_drawing = true;
 554         }
 555         break;
 556     case GDK_MOTION_NOTIFY:
 557         if ( dc->is_drawing && !dc->use_timeout && ( event->motion.state & GDK_BUTTON1_MASK ) ) {
 558             dc->dragging = TRUE;
 559             dc->dynahand = 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         if ( event->button.button == 1
 584              && dc->use_timeout
 585              && dc->timer_id != 0 )
 586         {
 587             gtk_timeout_remove(dc->timer_id);
 588             dc->timer_id = 0;
 589         }
 590         if ( dc->dragging && event->button.button == 1 ) {
 591             dc->dragging = FALSE;
 592
 593             /* release */
 594             if (dc->dynahand) {
 595                 dc->dynahand = FALSE;
 596                 /* Remove all temporary line segments */
 597                 while (dc->segments) {
 598                     gtk_object_destroy(GTK_OBJECT(dc->segments->data));
 599                     dc->segments = g_slist_remove(dc->segments, dc->segments->data);
 600                 }
 601                 /* Create object */
 602                 fit_and_split(dc, TRUE);
 603                 if (dc->use_calligraphic) {
 604                     accumulate_calligraphic(dc);
 605                 } else {
 606                     concat_current_line(dc);
 607                 }
 608                 set_to_accumulated(dc); /* temporal implementation */
 609                 if (dc->use_calligraphic /* || dc->cinside*/) {
 610                     /* reset accumulated curve */
 611                     sp_curve_reset(dc->accumulated);
 612                     clear_current(dc);
 613                     if (dc->repr) {
 614                         dc->repr = NULL;
 615                     }
 616                 }
 617             }
 618             ret = TRUE;
 619         }
 620         break;
 621     case GDK_KEY_PRESS:
 622         switch (get_group0_keyval (&event->key)) {
 623         case GDK_Up:
 624         case GDK_KP_Up:
 625             if (!MOD__CTRL_ONLY) {
 626                 dc->angle += 5.0;
 627                 if (dc->angle > 90.0)
 628                     dc->angle = 90.0;
 629                 sp_ddc_update_toolbox (desktop, "calligraphy-angle", dc->angle);
 630                 ret = TRUE;
 631             }
 632             break;
 633         case GDK_Down:
 634         case GDK_KP_Down:
 635             if (!MOD__CTRL_ONLY) {
 636                 dc->angle -= 5.0;
 637                 if (dc->angle < -90.0)
 638                     dc->angle = -90.0;
 639                 sp_ddc_update_toolbox (desktop, "calligraphy-angle", dc->angle);
 640                 ret = TRUE;
 641             }
 642             break;
 643         case GDK_Right:
 644         case GDK_KP_Right:
 645             if (!MOD__CTRL_ONLY) {
 646                 dc->width += 0.01;
 647                 if (dc->width > 1.0)
 648                     dc->width = 1.0;
 649                 sp_ddc_update_toolbox (desktop, "altx-calligraphy", dc->width); // the same spinbutton is for alt+x
 650                 ret = TRUE;
 651             }
 652             break;
 653         case GDK_Left:
 654         case GDK_KP_Left:
 655             if (!MOD__CTRL_ONLY) {
 656                 dc->width -= 0.01;
 657                 if (dc->width < 0.01)
 658                     dc->width = 0.01;
 659                 sp_ddc_update_toolbox (desktop, "altx-calligraphy", dc->width);
 660                 ret = TRUE;
 661             }
 662             break;
 663         case GDK_x:
 664         case GDK_X:
 665             if (MOD__ALT_ONLY) {
 666                 desktop->setToolboxFocusTo ("altx-calligraphy");
 667                 ret = TRUE;
 668             }
 669             break;
 670         case GDK_Escape:
 671             SP_DT_SELECTION(desktop)->clear();
 672             break;
 673
 674         default:
 675             break;
 676         }
 677     default:
 678         break;
 679     }
 680
 681     if (!ret) {
 682         if (((SPEventContextClass *) parent_class)->root_handler) {
 683             ret = ((SPEventContextClass *) parent_class)->root_handler(event_context, event);
 684         }
 685     }
 686
 687     return ret;
 688 }
 689
 690
 691 static void
 692 clear_current(SPDynaDrawContext *dc)
 693 {
 694     /* reset bpath */
 695     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(dc->currentshape), NULL);
 696     /* reset curve */
 697     sp_curve_reset(dc->currentcurve);
 698     sp_curve_reset(dc->cal1);
 699     sp_curve_reset(dc->cal2);
 700     /* reset points */
 701     dc->npoints = 0;
 702 }
 703
 704 static void
 705 set_to_accumulated(SPDynaDrawContext *dc)
 706 {
 707     SPDesktop *desktop = SP_EVENT_CONTEXT(dc)->desktop;
 708
 709     if (!sp_curve_empty(dc->accumulated)) {
 710         NArtBpath *abp;
 711         gchar *str;
 712
 713         if (!dc->repr) {
 714             /* Create object */
 715             Inkscape::XML::Node *repr = sp_repr_new("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             SP_DT_SELECTION(desktop)->set(dc->repr);
 727         }
 728         abp = nr_artpath_affine(sp_curve_first_bpath(dc->accumulated), sp_desktop_dt2root_affine(desktop));
 729         str = sp_svg_write_path(abp);
 730         g_assert( str != NULL );
 731         nr_free(abp);
 732         dc->repr->setAttribute("d", str);
 733         g_free(str);
 734     } else {
 735         if (dc->repr) {
 736             sp_repr_unparent(dc->repr);
 737         }
 738         dc->repr = NULL;
 739     }
 740
 741     sp_document_done(SP_DT_DOCUMENT(desktop));
 742 }
 743
 744 static void
 745 concat_current_line(SPDynaDrawContext *dc)
 746 {
 747     if (!sp_curve_empty(dc->currentcurve)) {
 748         NArtBpath *bpath;
 749         if (sp_curve_empty(dc->accumulated)) {
 750             bpath = sp_curve_first_bpath(dc->currentcurve);
 751             g_assert( bpath->code == NR_MOVETO_OPEN );
 752             sp_curve_moveto(dc->accumulated, bpath->x3, bpath->y3);
 753         }
 754         bpath = sp_curve_last_bpath(dc->currentcurve);
 755         if ( bpath->code == NR_CURVETO ) {
 756             sp_curve_curveto(dc->accumulated,
 757                              bpath->x1, bpath->y1,
 758                              bpath->x2, bpath->y2,
 759                              bpath->x3, bpath->y3);
 760         } else if ( bpath->code == NR_LINETO ) {
 761             sp_curve_lineto(dc->accumulated, bpath->x3, bpath->y3);
 762         } else {
 763             g_assert_not_reached();
 764         }
 765     }
 766 }
 767
 768 static void
 769 accumulate_calligraphic(SPDynaDrawContext *dc)
 770 {
 771     if ( !sp_curve_empty(dc->cal1) && !sp_curve_empty(dc->cal2) ) {
 772         sp_curve_reset(dc->accumulated); /*  Is this required ?? */
 773         SPCurve *rev_cal2 = sp_curve_reverse(dc->cal2);
 774         sp_curve_append(dc->accumulated, dc->cal1, FALSE);
 775         sp_curve_append(dc->accumulated, rev_cal2, TRUE);
 776         sp_curve_closepath(dc->accumulated);
 777
 778         sp_curve_unref(rev_cal2);
 779
 780         sp_curve_reset(dc->cal1);
 781         sp_curve_reset(dc->cal2);
 782     }
 783 }
 784
 785 static void
 786 fit_and_split(SPDynaDrawContext *dc,
 787               gboolean release)
 788 {
 789     if (dc->use_calligraphic) {
 790         fit_and_split_calligraphics(dc, release);
 791     } else {
 792         fit_and_split_line(dc, release);
 793     }
 794 }
 795
 796 static double square(double const x)
 797 {
 798     return x * x;
 799 }
 800
 801 static void
 802 fit_and_split_line(SPDynaDrawContext *dc,
 803                    gboolean release)
 804 {
 805     double const tolerance_sq = square( NR::expansion(SP_EVENT_CONTEXT(dc)->desktop->w2d()) * TOLERANCE_LINE );
 806
 807     NR::Point b[4];
 808     double const n_segs = sp_bezier_fit_cubic(b, dc->point1, dc->npoints, tolerance_sq);
 809     if ( n_segs > 0
 810          && dc->npoints < SAMPLING_SIZE )
 811     {
 812         /* Fit and draw and reset state */
 813 #ifdef DYNA_DRAW_VERBOSE
 814         g_print("%d", dc->npoints);
 815 #endif
 816         sp_curve_reset(dc->currentcurve);
 817         sp_curve_moveto(dc->currentcurve, b[0]);
 818         sp_curve_curveto(dc->currentcurve, b[1], b[2], b[3]);
 819         sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(dc->currentshape), dc->currentcurve);
 820     } else {
 821         /* Fit and draw and copy last point */
 822 #ifdef DYNA_DRAW_VERBOSE
 823         g_print("[%d]Yup\n", dc->npoints);
 824 #endif
 825         g_assert(!sp_curve_empty(dc->currentcurve));
 826         concat_current_line(dc);
 827
 828         SPCanvasItem *cbp = sp_canvas_item_new(SP_DT_SKETCH(SP_EVENT_CONTEXT(dc)->desktop),
 829                                                SP_TYPE_CANVAS_BPATH,
 830                                                NULL);
 831         SPCurve *curve = sp_curve_copy(dc->currentcurve);
 832         sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(cbp), curve);
 833         sp_curve_unref(curve);
 834         /* fixme: We have to parse style color somehow */
 835         sp_canvas_bpath_set_fill(SP_CANVAS_BPATH(cbp), DDC_GREEN_RGBA, SP_WIND_RULE_EVENODD);
 836         sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(cbp), 0x000000ff, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 837         /* fixme: Cannot we cascade it to root more clearly? */
 838         g_signal_connect(G_OBJECT(cbp), "event", G_CALLBACK(sp_desktop_root_handler), SP_EVENT_CONTEXT(dc)->desktop);
 839
 840         dc->segments = g_slist_prepend(dc->segments, cbp);
 841         dc->point1[0] = dc->point1[dc->npoints - 2];
 842         dc->npoints = 1;
 843     }
 844 }
 845
 846 static void
 847 fit_and_split_calligraphics(SPDynaDrawContext *dc, gboolean release)
 848 {
 849     double const tolerance_sq = square( NR::expansion(SP_EVENT_CONTEXT(dc)->desktop->w2d()) * TOLERANCE_CALLIGRAPHIC );
 850
 851 #ifdef DYNA_DRAW_VERBOSE
 852     g_print("[F&S:R=%c]", release?'T':'F');
 853 #endif
 854
 855     if (!( dc->npoints > 0 && dc->npoints < SAMPLING_SIZE ))
 856         return; // just clicked
 857
 858     if ( dc->npoints == SAMPLING_SIZE - 1 || release ) {
 859 #define BEZIER_SIZE       4
 860 #define BEZIER_MAX_BEZIERS  8
 861 #define BEZIER_MAX_LENGTH ( BEZIER_SIZE * BEZIER_MAX_BEZIERS )
 862
 863 #ifdef DYNA_DRAW_VERBOSE
 864         g_print("[F&S:#] dc->npoints:%d, release:%s\n",
 865                 dc->npoints, release ? "TRUE" : "FALSE");
 866 #endif
 867
 868         /* Current calligraphic */
 869         if ( dc->cal1->end == 0 || dc->cal2->end == 0 ) {
 870             /* dc->npoints > 0 */
 871             /* g_print("calligraphics(1|2) reset\n"); */
 872             sp_curve_reset(dc->cal1);
 873             sp_curve_reset(dc->cal2);
 874
 875             sp_curve_moveto(dc->cal1, dc->point1[0]);
 876             sp_curve_moveto(dc->cal2, dc->point2[0]);
 877         }
 878
 879         NR::Point b1[BEZIER_MAX_LENGTH];
 880         gint const nb1 = sp_bezier_fit_cubic_r(b1, dc->point1, dc->npoints,
 881                                                tolerance_sq, BEZIER_MAX_BEZIERS);
 882         g_assert( nb1 * BEZIER_SIZE <= gint(G_N_ELEMENTS(b1)) );
 883
 884         NR::Point b2[BEZIER_MAX_LENGTH];
 885         gint const nb2 = sp_bezier_fit_cubic_r(b2, dc->point2, dc->npoints,
 886                                                tolerance_sq, BEZIER_MAX_BEZIERS);
 887         g_assert( nb2 * BEZIER_SIZE <= gint(G_N_ELEMENTS(b2)) );
 888
 889         if ( nb1 != -1 && nb2 != -1 ) {
 890             /* Fit and draw and reset state */
 891 #ifdef DYNA_DRAW_VERBOSE
 892             g_print("nb1:%d nb2:%d\n", nb1, nb2);
 893 #endif
 894             /* CanvasShape */
 895             if (! release) {
 896                 sp_curve_reset(dc->currentcurve);
 897                 sp_curve_moveto(dc->currentcurve, b1[0]);
 898                 for (NR::Point *bp1 = b1; bp1 < b1 + BEZIER_SIZE * nb1; bp1 += BEZIER_SIZE) {
 899                     sp_curve_curveto(dc->currentcurve, bp1[1],
 900                                      bp1[2], bp1[3]);
 901                 }
 902                 sp_curve_lineto(dc->currentcurve,
 903                                 b2[BEZIER_SIZE*(nb2-1) + 3]);
 904                 for (NR::Point *bp2 = b2 + BEZIER_SIZE * ( nb2 - 1 ); bp2 >= b2; bp2 -= BEZIER_SIZE) {
 905                     sp_curve_curveto(dc->currentcurve, bp2[2], bp2[1], bp2[0]);
 906                 }
 907                 sp_curve_closepath(dc->currentcurve);
 908                 sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(dc->currentshape), dc->currentcurve);
 909             }
 910
 911             /* Current calligraphic */
 912             for (NR::Point *bp1 = b1; bp1 < b1 + BEZIER_SIZE * nb1; bp1 += BEZIER_SIZE) {
 913                 sp_curve_curveto(dc->cal1, bp1[1], bp1[2], bp1[3]);
 914             }
 915             for (NR::Point *bp2 = b2; bp2 < b2 + BEZIER_SIZE * nb2; bp2 += BEZIER_SIZE) {
 916                 sp_curve_curveto(dc->cal2, bp2[1], bp2[2], bp2[3]);
 917             }
 918         } else {
 919             /* fixme: ??? */
 920 #ifdef DYNA_DRAW_VERBOSE
 921             g_print("[fit_and_split_calligraphics] failed to fit-cubic.\n");
 922 #endif
 923             draw_temporary_box(dc);
 924
 925             for (gint i = 1; i < dc->npoints; i++) {
 926                 sp_curve_lineto(dc->cal1, dc->point1[i]);
 927             }
 928             for (gint i = 1; i < dc->npoints; i++) {
 929                 sp_curve_lineto(dc->cal2, dc->point2[i]);
 930             }
 931         }
 932
 933         /* Fit and draw and copy last point */
 934 #ifdef DYNA_DRAW_VERBOSE
 935         g_print("[%d]Yup\n", dc->npoints);
 936 #endif
 937         if (!release) {
 938             g_assert(!sp_curve_empty(dc->currentcurve));
 939
 940             SPCanvasItem *cbp = sp_canvas_item_new(SP_DT_SKETCH(SP_EVENT_CONTEXT(dc)->desktop),
 941                                                    SP_TYPE_CANVAS_BPATH,
 942                                                    NULL);
 943             SPCurve *curve = sp_curve_copy(dc->currentcurve);
 944             sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH (cbp), curve);
 945             sp_curve_unref(curve);
 946             sp_canvas_bpath_set_fill(SP_CANVAS_BPATH(cbp), 0x000000ff, SP_WIND_RULE_EVENODD);
 947             sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(cbp), 0x00000000, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 948             /* fixme: Cannot we cascade it to root more clearly? */
 949             g_signal_connect(G_OBJECT(cbp), "event", G_CALLBACK(sp_desktop_root_handler), SP_EVENT_CONTEXT(dc)->desktop);
 950
 951             dc->segments = g_slist_prepend(dc->segments, cbp);
 952         }
 953
 954         dc->point1[0] = dc->point1[dc->npoints - 1];
 955         dc->point2[0] = dc->point2[dc->npoints - 1];
 956         dc->npoints = 1;
 957     } else {
 958         draw_temporary_box(dc);
 959     }
 960 }
 961
 962 static void
 963 draw_temporary_box(SPDynaDrawContext *dc)
 964 {
 965     sp_curve_reset(dc->currentcurve);
 966     sp_curve_moveto(dc->currentcurve, dc->point1[0]);
 967     for (gint i = 1; i < dc->npoints; i++) {
 968         sp_curve_lineto(dc->currentcurve, dc->point1[i]);
 969     }
 970     for (gint i = dc->npoints-1; i >= 0; i--) {
 971         sp_curve_lineto(dc->currentcurve, dc->point2[i]);
 972     }
 973     sp_curve_closepath(dc->currentcurve);
 974     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(dc->currentshape), dc->currentcurve);
 975 }
 976
 977 /*
 978   Local Variables:
 979   mode:c++
 980   c-file-style:"stroustrup"
 981   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
 982   indent-tabs-mode:nil
 983   fill-column:99
 984   End:
 985 */
 986 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :