1 /** \file
2 * Pencil event context implementation.
3 */
5 /*
6 * Authors:
7 * Lauris Kaplinski <lauris@kaplinski.com>
8 * bulia byak <buliabyak@users.sf.net>
9 *
10 * Copyright (C) 2000 Lauris Kaplinski
11 * Copyright (C) 2000-2001 Ximian, Inc.
12 * Copyright (C) 2002 Lauris Kaplinski
13 * Copyright (C) 2004 Monash University
14 *
15 * Released under GNU GPL, read the file 'COPYING' for more information
16 */
18 #include <gdk/gdkkeysyms.h>
20 #include "pencil-context.h"
21 #include "desktop.h"
22 #include "desktop-handles.h"
23 #include "selection.h"
24 #include "selection-chemistry.h"
25 #include "draw-anchor.h"
26 #include "message-stack.h"
27 #include "message-context.h"
28 #include "modifier-fns.h"
29 #include "sp-path.h"
30 #include "preferences.h"
31 #include "snap.h"
32 #include "pixmaps/cursor-pencil.xpm"
33 #include <2geom/sbasis-to-bezier.h>
34 #include <2geom/bezier-utils.h>
35 #include "display/canvas-bpath.h"
36 #include <glibmm/i18n.h>
37 #include "libnr/in-svg-plane.h"
38 #include "context-fns.h"
39 #include "sp-namedview.h"
40 #include "xml/repr.h"
41 #include "document.h"
42 #include "desktop-style.h"
43 #include "macros.h"
44 #include "display/curve.h"
45 #include "livarot/Path.h"
47 static void sp_pencil_context_class_init(SPPencilContextClass *klass);
48 static void sp_pencil_context_init(SPPencilContext *pc);
49 static void sp_pencil_context_setup(SPEventContext *ec);
50 static void sp_pencil_context_dispose(GObject *object);
52 static gint sp_pencil_context_root_handler(SPEventContext *event_context, GdkEvent *event);
53 static gint pencil_handle_button_press(SPPencilContext *const pc, GdkEventButton const &bevent);
54 static gint pencil_handle_motion_notify(SPPencilContext *const pc, GdkEventMotion const &mevent);
55 static gint pencil_handle_button_release(SPPencilContext *const pc, GdkEventButton const &revent);
56 static gint pencil_handle_key_press(SPPencilContext *const pc, guint const keyval, guint const state);
57 static gint pencil_handle_key_release(SPPencilContext *const pc, guint const keyval, guint const state);
59 static void spdc_set_startpoint(SPPencilContext *pc, Geom::Point const p);
60 static void spdc_set_endpoint(SPPencilContext *pc, Geom::Point const p);
61 static void spdc_finish_endpoint(SPPencilContext *pc);
62 static void spdc_add_freehand_point(SPPencilContext *pc, Geom::Point p, guint state);
63 static void fit_and_split(SPPencilContext *pc);
64 static void interpolate(SPPencilContext *pc);
65 static void sketch_interpolate(SPPencilContext *pc);
67 static SPDrawContextClass *pencil_parent_class;
68 static Geom::Point pencil_drag_origin_w(0, 0);
69 static bool pencil_within_tolerance = false;
71 /**
72 * Register SPPencilContext class with Gdk and return its type number.
73 */
74 GType
75 sp_pencil_context_get_type()
76 {
77 static GType type = 0;
78 if (!type) {
79 GTypeInfo info = {
80 sizeof(SPPencilContextClass),
81 NULL, NULL,
82 (GClassInitFunc) sp_pencil_context_class_init,
83 NULL, NULL,
84 sizeof(SPPencilContext),
85 4,
86 (GInstanceInitFunc) sp_pencil_context_init,
87 NULL, /* value_table */
88 };
89 type = g_type_register_static(SP_TYPE_DRAW_CONTEXT, "SPPencilContext", &info, (GTypeFlags)0);
90 }
91 return type;
92 }
94 /**
95 * Initialize SPPencilContext vtable.
96 */
97 static void
98 sp_pencil_context_class_init(SPPencilContextClass *klass)
99 {
100 GObjectClass *object_class;
101 SPEventContextClass *event_context_class;
103 object_class = (GObjectClass *) klass;
104 event_context_class = (SPEventContextClass *) klass;
106 pencil_parent_class = (SPDrawContextClass*)g_type_class_peek_parent(klass);
108 object_class->dispose = sp_pencil_context_dispose;
110 event_context_class->setup = sp_pencil_context_setup;
111 event_context_class->root_handler = sp_pencil_context_root_handler;
112 }
114 /**
115 * Callback to initialize SPPencilContext object.
116 */
117 static void
118 sp_pencil_context_init(SPPencilContext *pc)
119 {
120 SPEventContext *event_context = SP_EVENT_CONTEXT(pc);
122 event_context->cursor_shape = cursor_pencil_xpm;
123 event_context->hot_x = 4;
124 event_context->hot_y = 4;
126 pc->npoints = 0;
127 pc->state = SP_PENCIL_CONTEXT_IDLE;
128 pc->req_tangent = Geom::Point(0, 0);
130 // since SPPencilContext is not properly constructed...
131 pc->sketch_interpolation = Geom::Piecewise<Geom::D2<Geom::SBasis> >();
132 pc->sketch_n = 0;
133 }
135 /**
136 * Callback to setup SPPencilContext object.
137 */
138 static void
139 sp_pencil_context_setup(SPEventContext *ec)
140 {
141 Inkscape::Preferences *prefs = Inkscape::Preferences::get();
142 if (prefs->getBool("/tools/freehand/pencil/selcue")) {
143 ec->enableSelectionCue();
144 }
146 if (((SPEventContextClass *) pencil_parent_class)->setup) {
147 ((SPEventContextClass *) pencil_parent_class)->setup(ec);
148 }
150 SPPencilContext *const pc = SP_PENCIL_CONTEXT(ec);
151 pc->is_drawing = false;
153 pc->anchor_statusbar = false;
154 }
156 static void
157 sp_pencil_context_dispose(GObject *object)
158 {
159 G_OBJECT_CLASS(pencil_parent_class)->dispose(object);
160 }
162 /** Snaps new node relative to the previous node. */
163 static void
164 spdc_endpoint_snap(SPPencilContext const *pc, Geom::Point &p, guint const state)
165 {
166 if ((state & GDK_CONTROL_MASK)) { //CTRL enables constrained snapping
167 spdc_endpoint_snap_rotation(pc, p, pc->p[0], state);
168 } else {
169 if (!(state & GDK_SHIFT_MASK)) { //SHIFT disables all snapping, except the angular snapping above
170 //After all, the user explicitely asked for angular snapping by
171 //pressing CTRL
172 spdc_endpoint_snap_free(pc, p, state);
173 }
174 }
175 }
177 /**
178 * Callback for handling all pencil context events.
179 */
180 gint
181 sp_pencil_context_root_handler(SPEventContext *const ec, GdkEvent *event)
182 {
183 SPPencilContext *const pc = SP_PENCIL_CONTEXT(ec);
185 gint ret = FALSE;
187 switch (event->type) {
188 case GDK_BUTTON_PRESS:
189 ret = pencil_handle_button_press(pc, event->button);
190 break;
192 case GDK_MOTION_NOTIFY:
193 ret = pencil_handle_motion_notify(pc, event->motion);
194 break;
196 case GDK_BUTTON_RELEASE:
197 ret = pencil_handle_button_release(pc, event->button);
198 break;
200 case GDK_KEY_PRESS:
201 ret = pencil_handle_key_press(pc, get_group0_keyval (&event->key), event->key.state);
202 break;
204 case GDK_KEY_RELEASE:
205 ret = pencil_handle_key_release(pc, get_group0_keyval (&event->key), event->key.state);
206 break;
208 default:
209 break;
210 }
212 if (!ret) {
213 gint (*const parent_root_handler)(SPEventContext *, GdkEvent *)
214 = ((SPEventContextClass *) pencil_parent_class)->root_handler;
215 if (parent_root_handler) {
216 ret = parent_root_handler(ec, event);
217 }
218 }
220 return ret;
221 }
223 static gint
224 pencil_handle_button_press(SPPencilContext *const pc, GdkEventButton const &bevent)
225 {
226 gint ret = FALSE;
227 SPEventContext *event_context = SP_EVENT_CONTEXT(pc);
228 if ( bevent.button == 1 && !event_context->space_panning) {
230 SPDrawContext *dc = SP_DRAW_CONTEXT (pc);
231 SPDesktop *desktop = SP_EVENT_CONTEXT_DESKTOP(dc);
232 Inkscape::Selection *selection = sp_desktop_selection(desktop);
234 if (Inkscape::have_viable_layer(desktop, dc->_message_context) == false) {
235 return TRUE;
236 }
238 if (!pc->grab) {
239 /* Grab mouse, so release will not pass unnoticed */
240 pc->grab = SP_CANVAS_ITEM(desktop->acetate);
241 sp_canvas_item_grab(pc->grab, ( GDK_KEY_PRESS_MASK | GDK_BUTTON_PRESS_MASK |
242 GDK_BUTTON_RELEASE_MASK |
243 GDK_POINTER_MOTION_MASK ),
244 NULL, bevent.time);
245 }
247 Geom::Point const button_w(bevent.x, bevent.y);
249 /* Find desktop coordinates */
250 Geom::Point p = pc->desktop->w2d(button_w);
252 /* Test whether we hit any anchor. */
253 SPDrawAnchor *anchor = spdc_test_inside(pc, button_w);
255 pencil_drag_origin_w = Geom::Point(bevent.x,bevent.y);
256 pencil_within_tolerance = true;
258 switch (pc->state) {
259 case SP_PENCIL_CONTEXT_ADDLINE:
260 /* Current segment will be finished with release */
261 ret = TRUE;
262 break;
263 default:
264 /* Set first point of sequence */
265 SnapManager &m = desktop->namedview->snap_manager;
267 if (bevent.state & GDK_CONTROL_MASK) {
268 m.setup(desktop);
269 if (!(bevent.state & GDK_SHIFT_MASK)) {
270 m.freeSnapReturnByRef(p, Inkscape::SNAPSOURCE_NODE_HANDLE);
271 }
272 spdc_create_single_dot(event_context, p, "/tools/freehand/pencil", bevent.state);
273 m.unSetup();
274 ret = true;
275 break;
276 }
277 if (anchor) {
278 p = anchor->dp;
279 desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Continuing selected path"));
280 } else {
281 m.setup(desktop);
282 if (!(bevent.state & GDK_SHIFT_MASK)) {
283 // This is the first click of a new curve; deselect item so that
284 // this curve is not combined with it (unless it is drawn from its
285 // anchor, which is handled by the sibling branch above)
286 selection->clear();
287 desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Creating new path"));
288 m.freeSnapReturnByRef(p, Inkscape::SNAPSOURCE_NODE_HANDLE);
289 } else if (selection->singleItem() && SP_IS_PATH(selection->singleItem())) {
290 desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Appending to selected path"));
291 m.freeSnapReturnByRef(p, Inkscape::SNAPSOURCE_NODE_HANDLE);
292 }
293 m.unSetup();
294 }
295 pc->sa = anchor;
296 spdc_set_startpoint(pc, p);
297 ret = TRUE;
298 break;
299 }
301 pc->is_drawing = true;
302 }
303 return ret;
304 }
306 static gint
307 pencil_handle_motion_notify(SPPencilContext *const pc, GdkEventMotion const &mevent)
308 {
309 SPDesktop *const dt = pc->desktop;
311 if ((mevent.state & GDK_CONTROL_MASK) && (mevent.state & GDK_BUTTON1_MASK)) {
312 // mouse was accidentally moved during Ctrl+click;
313 // ignore the motion and create a single point
314 pc->is_drawing = false;
315 return TRUE;
316 }
317 gint ret = FALSE;
319 SPEventContext *event_context = SP_EVENT_CONTEXT(pc);
320 if (event_context->space_panning || mevent.state & GDK_BUTTON2_MASK || mevent.state & GDK_BUTTON3_MASK) {
321 // allow scrolling
322 return FALSE;
323 }
325 if ( ( mevent.state & GDK_BUTTON1_MASK ) && !pc->grab && pc->is_drawing) {
326 /* Grab mouse, so release will not pass unnoticed */
327 pc->grab = SP_CANVAS_ITEM(dt->acetate);
328 sp_canvas_item_grab(pc->grab, ( GDK_KEY_PRESS_MASK | GDK_BUTTON_PRESS_MASK |
329 GDK_BUTTON_RELEASE_MASK |
330 GDK_POINTER_MOTION_MASK ),
331 NULL, mevent.time);
332 }
334 /* Find desktop coordinates */
335 Geom::Point p = dt->w2d(Geom::Point(mevent.x, mevent.y));
337 /* Test whether we hit any anchor. */
338 SPDrawAnchor *anchor = spdc_test_inside(pc, Geom::Point(mevent.x, mevent.y));
340 if (pencil_within_tolerance) {
341 Inkscape::Preferences *prefs = Inkscape::Preferences::get();
342 gint const tolerance = prefs->getIntLimited("/options/dragtolerance/value", 0, 0, 100);
343 if ( Geom::LInfty( Geom::Point(mevent.x,mevent.y) - pencil_drag_origin_w ) < tolerance ) {
344 return FALSE; // Do not drag if we're within tolerance from origin.
345 }
346 }
348 // Once the user has moved farther than tolerance from the original location
349 // (indicating they intend to move the object, not click), then always process the
350 // motion notify coordinates as given (no snapping back to origin)
351 pencil_within_tolerance = false;
353 switch (pc->state) {
354 case SP_PENCIL_CONTEXT_ADDLINE:
355 /* Set red endpoint */
356 if (anchor) {
357 p = anchor->dp;
358 } else {
359 Geom::Point ptnr(p);
360 spdc_endpoint_snap(pc, ptnr, mevent.state);
361 p = ptnr;
362 }
363 spdc_set_endpoint(pc, p);
364 ret = TRUE;
365 break;
366 default:
367 /* We may be idle or already freehand */
368 if ( mevent.state & GDK_BUTTON1_MASK && pc->is_drawing ) {
369 if (pc->state == SP_PENCIL_CONTEXT_IDLE) {
370 sp_event_context_discard_delayed_snap_event(event_context);
371 }
372 pc->state = SP_PENCIL_CONTEXT_FREEHAND;
374 if ( !pc->sa && !pc->green_anchor ) {
375 /* Create green anchor */
376 pc->green_anchor = sp_draw_anchor_new(pc, pc->green_curve, TRUE, pc->p[0]);
377 }
378 if (anchor) {
379 p = anchor->dp;
380 }
382 if ( pc->npoints != 0) { // buttonpress may have happened before we entered draw context!
383 if (pc->ps.size() == 0) {
384 // Only in freehand mode we have to add the first point also to pc->ps (apparently)
385 // - We cannot add this point in spdc_set_startpoint, because we only need it for freehand
386 // - We cannot do this in the button press handler because at that point we don't know yet
387 // wheter we're going into freehand mode or not
388 pc->ps.push_back(pc->p[0]);
389 }
390 spdc_add_freehand_point(pc, p, mevent.state);
391 ret = TRUE;
392 }
394 if (anchor && !pc->anchor_statusbar) {
395 pc->_message_context->set(Inkscape::NORMAL_MESSAGE, _("<b>Release</b> here to close and finish the path."));
396 pc->anchor_statusbar = true;
397 } else if (!anchor && pc->anchor_statusbar) {
398 pc->_message_context->clear();
399 pc->anchor_statusbar = false;
400 } else if (!anchor) {
401 pc->_message_context->set(Inkscape::NORMAL_MESSAGE, _("Drawing a freehand path"));
402 }
404 } else {
405 if (anchor && !pc->anchor_statusbar) {
406 pc->_message_context->set(Inkscape::NORMAL_MESSAGE, _("<b>Drag</b> to continue the path from this point."));
407 pc->anchor_statusbar = true;
408 } else if (!anchor && pc->anchor_statusbar) {
409 pc->_message_context->clear();
410 pc->anchor_statusbar = false;
411 }
412 }
414 // Show the pre-snap indicator to communicate to the user where we would snap to if he/she were to
415 // a) press the mousebutton to start a freehand drawing, or
416 // b) release the mousebutton to finish a freehand drawing
417 if (!sp_event_context_knot_mouseover(pc)) {
418 SnapManager &m = dt->namedview->snap_manager;
419 m.setup(dt);
420 m.preSnap(Inkscape::SnapCandidatePoint(p, Inkscape::SNAPSOURCE_NODE_HANDLE));
421 m.unSetup();
422 }
423 break;
424 }
425 return ret;
426 }
428 static gint
429 pencil_handle_button_release(SPPencilContext *const pc, GdkEventButton const &revent)
430 {
431 gint ret = FALSE;
433 SPEventContext *event_context = SP_EVENT_CONTEXT(pc);
434 if ( revent.button == 1 && pc->is_drawing && !event_context->space_panning) {
435 SPDesktop *const dt = pc->desktop;
437 pc->is_drawing = false;
439 /* Find desktop coordinates */
440 Geom::Point p = dt->w2d(Geom::Point(revent.x, revent.y));
442 /* Test whether we hit any anchor. */
443 SPDrawAnchor *anchor = spdc_test_inside(pc, Geom::Point(revent.x,
444 revent.y));
446 switch (pc->state) {
447 case SP_PENCIL_CONTEXT_IDLE:
448 /* Releasing button in idle mode means single click */
449 /* We have already set up start point/anchor in button_press */
450 if (!(revent.state & GDK_CONTROL_MASK)) {
451 // Ctrl+click creates a single point so only set context in ADDLINE mode when Ctrl isn't pressed
452 pc->state = SP_PENCIL_CONTEXT_ADDLINE;
453 }
454 ret = TRUE;
455 break;
456 case SP_PENCIL_CONTEXT_ADDLINE:
457 /* Finish segment now */
458 if (anchor) {
459 p = anchor->dp;
460 } else {
461 spdc_endpoint_snap(pc, p, revent.state);
462 }
463 pc->ea = anchor;
464 spdc_set_endpoint(pc, p);
465 spdc_finish_endpoint(pc);
466 pc->state = SP_PENCIL_CONTEXT_IDLE;
467 sp_event_context_discard_delayed_snap_event(event_context);
468 ret = TRUE;
469 break;
470 case SP_PENCIL_CONTEXT_FREEHAND:
471 if (revent.state & GDK_MOD1_MASK) {
472 /* sketch mode: interpolate the sketched path and improve the current output path with the new interpolation. don't finish sketch */
474 sketch_interpolate(pc);
476 if (pc->green_anchor) {
477 pc->green_anchor = sp_draw_anchor_destroy(pc->green_anchor);
478 }
480 pc->state = SP_PENCIL_CONTEXT_SKETCH;
481 } else {
482 /* Finish segment now */
483 /// \todo fixme: Clean up what follows (Lauris)
484 if (anchor) {
485 p = anchor->dp;
486 } else {
487 Geom::Point p_end = p;
488 spdc_endpoint_snap(pc, p_end, revent.state);
489 if (p_end != p) {
490 // then we must have snapped!
491 spdc_add_freehand_point(pc, p_end, revent.state);
492 }
493 }
495 pc->ea = anchor;
496 /* Write curves to object */
498 dt->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Finishing freehand"));
500 interpolate(pc);
501 spdc_concat_colors_and_flush(pc, FALSE);
502 pc->sa = NULL;
503 pc->ea = NULL;
504 if (pc->green_anchor) {
505 pc->green_anchor = sp_draw_anchor_destroy(pc->green_anchor);
506 }
507 pc->state = SP_PENCIL_CONTEXT_IDLE;
508 // reset sketch mode too
509 pc->sketch_n = 0;
510 }
511 ret = TRUE;
512 break;
513 case SP_PENCIL_CONTEXT_SKETCH:
514 default:
515 break;
516 }
518 if (pc->grab) {
519 /* Release grab now */
520 sp_canvas_item_ungrab(pc->grab, revent.time);
521 pc->grab = NULL;
522 }
524 ret = TRUE;
525 }
526 return ret;
527 }
529 static void
530 pencil_cancel (SPPencilContext *const pc)
531 {
532 if (pc->grab) {
533 /* Release grab now */
534 sp_canvas_item_ungrab(pc->grab, 0);
535 pc->grab = NULL;
536 }
538 pc->is_drawing = false;
539 pc->state = SP_PENCIL_CONTEXT_IDLE;
540 sp_event_context_discard_delayed_snap_event(SP_EVENT_CONTEXT(pc));
542 pc->red_curve->reset();
543 sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), NULL);
544 while (pc->green_bpaths) {
545 gtk_object_destroy(GTK_OBJECT(pc->green_bpaths->data));
546 pc->green_bpaths = g_slist_remove(pc->green_bpaths, pc->green_bpaths->data);
547 }
548 pc->green_curve->reset();
549 if (pc->green_anchor) {
550 pc->green_anchor = sp_draw_anchor_destroy(pc->green_anchor);
551 }
553 pc->_message_context->clear();
554 pc->_message_context->flash(Inkscape::NORMAL_MESSAGE, _("Drawing cancelled"));
556 sp_canvas_end_forced_full_redraws(pc->desktop->canvas);
557 }
559 static gint
560 pencil_handle_key_press(SPPencilContext *const pc, guint const keyval, guint const state)
561 {
562 gint ret = FALSE;
563 switch (keyval) {
564 case GDK_Up:
565 case GDK_Down:
566 case GDK_KP_Up:
567 case GDK_KP_Down:
568 // Prevent the zoom field from activation.
569 if (!mod_ctrl_only(state)) {
570 ret = TRUE;
571 }
572 break;
573 case GDK_Escape:
574 if (pc->npoints != 0) {
575 // if drawing, cancel, otherwise pass it up for deselecting
576 if (pc->state != SP_PENCIL_CONTEXT_IDLE) {
577 pencil_cancel (pc);
578 ret = TRUE;
579 }
580 }
581 break;
582 case GDK_z:
583 case GDK_Z:
584 if (mod_ctrl_only(state) && pc->npoints != 0) {
585 // if drawing, cancel, otherwise pass it up for undo
586 if (pc->state != SP_PENCIL_CONTEXT_IDLE) {
587 pencil_cancel (pc);
588 ret = TRUE;
589 }
590 }
591 break;
592 case GDK_g:
593 case GDK_G:
594 if (mod_shift_only(state)) {
595 sp_selection_to_guides(SP_EVENT_CONTEXT(pc)->desktop);
596 ret = true;
597 }
598 break;
599 case GDK_Alt_L:
600 case GDK_Alt_R:
601 case GDK_Meta_L:
602 case GDK_Meta_R:
603 if (pc->state == SP_PENCIL_CONTEXT_IDLE) {
604 pc->desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("<b>Sketch mode</b>: holding <b>Alt</b> interpolates between sketched paths. Release <b>Alt</b> to finalize."));
605 }
606 break;
607 default:
608 break;
609 }
610 return ret;
611 }
613 static gint
614 pencil_handle_key_release(SPPencilContext *const pc, guint const keyval, guint const /*state*/)
615 {
616 gint ret = FALSE;
617 switch (keyval) {
618 case GDK_Alt_L:
619 case GDK_Alt_R:
620 case GDK_Meta_L:
621 case GDK_Meta_R:
622 if (pc->state == SP_PENCIL_CONTEXT_SKETCH) {
623 spdc_concat_colors_and_flush(pc, FALSE);
624 pc->sketch_n = 0;
625 pc->sa = NULL;
626 pc->ea = NULL;
627 if (pc->green_anchor) {
628 pc->green_anchor = sp_draw_anchor_destroy(pc->green_anchor);
629 }
630 pc->state = SP_PENCIL_CONTEXT_IDLE;
631 sp_event_context_discard_delayed_snap_event(SP_EVENT_CONTEXT(pc));
632 pc->desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Finishing freehand sketch"));
633 ret = TRUE;
634 }
635 break;
636 default:
637 break;
638 }
639 return ret;
640 }
642 /**
643 * Reset points and set new starting point.
644 */
645 static void
646 spdc_set_startpoint(SPPencilContext *const pc, Geom::Point const p)
647 {
648 pc->npoints = 0;
649 pc->red_curve_is_valid = false;
650 if (in_svg_plane(p)) {
651 pc->p[pc->npoints++] = p;
652 }
653 }
655 /**
656 * Change moving endpoint position.
657 * <ul>
658 * <li>Ctrl constrains to moving to H/V direction, snapping in given direction.
659 * <li>Otherwise we snap freely to whatever attractors are available.
660 * </ul>
661 *
662 * Number of points is (re)set to 2 always, 2nd point is modified.
663 * We change RED curve.
664 */
665 static void
666 spdc_set_endpoint(SPPencilContext *const pc, Geom::Point const p)
667 {
668 if (pc->npoints == 0) {
669 return;
670 /* May occur if first point wasn't in SVG plane (e.g. weird w2d transform, perhaps from bad
671 * zoom setting).
672 */
673 }
674 g_return_if_fail( pc->npoints > 0 );
676 pc->red_curve->reset();
677 if ( ( p == pc->p[0] )
678 || !in_svg_plane(p) )
679 {
680 pc->npoints = 1;
681 } else {
682 pc->p[1] = p;
683 pc->npoints = 2;
685 pc->red_curve->moveto(pc->p[0]);
686 pc->red_curve->lineto(pc->p[1]);
687 pc->red_curve_is_valid = true;
689 sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), pc->red_curve);
690 }
691 }
693 /**
694 * Finalize addline.
695 *
696 * \todo
697 * fixme: I'd like remove red reset from concat colors (lauris).
698 * Still not sure, how it will make most sense.
699 */
700 static void
701 spdc_finish_endpoint(SPPencilContext *const pc)
702 {
703 if ( ( pc->red_curve->is_empty() )
704 || ( *(pc->red_curve->first_point()) == *(pc->red_curve->second_point()) ) )
705 {
706 pc->red_curve->reset();
707 sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), NULL);
708 } else {
709 /* Write curves to object. */
710 spdc_concat_colors_and_flush(pc, FALSE);
711 pc->sa = NULL;
712 pc->ea = NULL;
713 }
714 }
717 static void
718 spdc_add_freehand_point(SPPencilContext *pc, Geom::Point p, guint /*state*/)
719 {
720 g_assert( pc->npoints > 0 );
721 g_return_if_fail(unsigned(pc->npoints) < G_N_ELEMENTS(pc->p));
723 if ( ( p != pc->p[ pc->npoints - 1 ] )
724 && in_svg_plane(p) )
725 {
726 pc->ps.push_back(p);
727 pc->p[pc->npoints++] = p;
728 fit_and_split(pc);
729 }
730 }
732 static inline double
733 square(double const x)
734 {
735 return x * x;
736 }
738 static void
739 interpolate(SPPencilContext *pc)
740 {
741 if ( pc->ps.size() <= 1 ) {
742 return;
743 }
745 Inkscape::Preferences *prefs = Inkscape::Preferences::get();
746 double const tol = prefs->getDoubleLimited("/tools/freehand/pencil/tolerance", 10.0, 1.0, 100.0) * 0.4;
747 double const tolerance_sq = 0.02 * square( pc->desktop->w2d().descrim() *
748 tol) * exp(0.2*tol - 2);
750 g_assert(is_zero(pc->req_tangent)
751 || is_unit_vector(pc->req_tangent));
752 Geom::Point const tHatEnd(0, 0);
754 guint n_points = pc->ps.size();
755 pc->green_curve->reset();
756 pc->red_curve->reset();
757 pc->red_curve_is_valid = false;
759 Geom::Point * b = g_new(Geom::Point, 4*n_points);
760 Geom::Point * points = g_new(Geom::Point, 4*n_points);
761 for (unsigned int i = 0; i < pc->ps.size(); i++) {
762 points[i] = pc->ps[i];
763 }
765 // worst case gives us a segment per point
766 int max_segs = 4*n_points;
768 int const n_segs = Geom::bezier_fit_cubic_r(b, points, n_points,
769 tolerance_sq, max_segs);
771 if ( n_segs > 0)
772 {
773 /* Fit and draw and reset state */
774 pc->green_curve->moveto(b[0]);
775 for (int c = 0; c < n_segs; c++) {
776 pc->green_curve->curveto(b[4*c+1], b[4*c+2], b[4*c+3]);
777 }
778 sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), pc->green_curve);
780 /* Fit and draw and copy last point */
781 g_assert(!pc->green_curve->is_empty());
783 /* Set up direction of next curve. */
784 {
785 Geom::CubicBezier const * last_seg = dynamic_cast<Geom::CubicBezier const *>(pc->green_curve->last_segment());
786 g_assert( last_seg ); // Relevance: validity of (*last_seg)[2]
787 pc->p[0] = last_seg->finalPoint();
788 pc->npoints = 1;
789 Geom::Point const req_vec( pc->p[0] - (*last_seg)[2] );
790 pc->req_tangent = ( ( Geom::is_zero(req_vec) || !in_svg_plane(req_vec) )
791 ? Geom::Point(0, 0)
792 : Geom::unit_vector(req_vec) );
793 }
794 }
795 g_free(b);
796 g_free(points);
797 pc->ps.clear();
798 }
801 /* interpolates the sketched curve and tweaks the current sketch interpolation*/
802 static void
803 sketch_interpolate(SPPencilContext *pc)
804 {
805 if ( pc->ps.size() <= 1 ) {
806 return;
807 }
809 Inkscape::Preferences *prefs = Inkscape::Preferences::get();
810 double const tol = prefs->getDoubleLimited("/tools/freehand/pencil/tolerance", 10.0, 1.0, 100.0) * 0.4;
811 double const tolerance_sq = 0.02 * square( pc->desktop->w2d().descrim() *
812 tol) * exp(0.2*tol - 2);
814 bool average_all_sketches = prefs->getBool("/tools/freehand/pencil/average_all_sketches", true);
816 g_assert(is_zero(pc->req_tangent)
817 || is_unit_vector(pc->req_tangent));
818 Geom::Point const tHatEnd(0, 0);
820 guint n_points = pc->ps.size();
821 pc->red_curve->reset();
822 pc->red_curve_is_valid = false;
824 Geom::Point * b = g_new(Geom::Point, 4*n_points);
825 Geom::Point * points = g_new(Geom::Point, 4*n_points);
826 for (unsigned i = 0; i < pc->ps.size(); i++) {
827 points[i] = pc->ps[i];
828 }
830 // worst case gives us a segment per point
831 int max_segs = 4*n_points;
833 int const n_segs = Geom::bezier_fit_cubic_r(b, points, n_points,
834 tolerance_sq, max_segs);
836 if ( n_segs > 0)
837 {
838 Geom::Path fit(b[0]);
839 for (int c = 0; c < n_segs; c++) {
840 fit.appendNew<Geom::CubicBezier>(b[4*c+1], b[4*c+2], b[4*c+3]);
841 }
842 Geom::Piecewise<Geom::D2<Geom::SBasis> > fit_pwd2 = fit.toPwSb();
844 double t =0.;
845 if ( pc->sketch_n > 0 ) {
846 if (average_all_sketches) {
847 // Average = (sum of all) / n
848 // = (sum of all + new one) / n+1
849 // = ((old average)*n + new one) / n+1
850 t = pc->sketch_n / (pc->sketch_n + 1.);
851 } else {
852 t = 0.5;
853 }
854 pc->sketch_interpolation = Geom::lerp(t, fit_pwd2, pc->sketch_interpolation);
855 // simplify path, to eliminate small segments
856 Path *path = new Path;
857 path->LoadPathVector(Geom::path_from_piecewise(pc->sketch_interpolation, 0.01));
858 path->Simplify(0.5);
859 Geom::PathVector *pathv = path->MakePathVector();
860 pc->sketch_interpolation = (*pathv)[0].toPwSb();
861 delete path;
862 delete pathv;
863 } else {
864 pc->sketch_interpolation = fit_pwd2;
865 }
866 pc->sketch_n++;
868 pc->green_curve->reset();
869 pc->green_curve->set_pathvector(Geom::path_from_piecewise(pc->sketch_interpolation, 0.01));
870 sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), pc->green_curve);
872 /* Fit and draw and copy last point */
873 g_assert(!pc->green_curve->is_empty());
875 /* Set up direction of next curve. */
876 {
877 Geom::CubicBezier const * last_seg = dynamic_cast<Geom::CubicBezier const *>(pc->green_curve->last_segment());
878 g_assert( last_seg ); // Relevance: validity of (*last_seg)[2]
879 pc->p[0] = last_seg->finalPoint();
880 pc->npoints = 1;
881 Geom::Point const req_vec( pc->p[0] - (*last_seg)[2] );
882 pc->req_tangent = ( ( Geom::is_zero(req_vec) || !in_svg_plane(req_vec) )
883 ? Geom::Point(0, 0)
884 : Geom::unit_vector(req_vec) );
885 }
886 }
887 g_free(b);
888 g_free(points);
889 pc->ps.clear();
890 }
892 static void
893 fit_and_split(SPPencilContext *pc)
894 {
895 g_assert( pc->npoints > 1 );
897 double const tolerance_sq = 0;
899 Geom::Point b[4];
900 g_assert(is_zero(pc->req_tangent)
901 || is_unit_vector(pc->req_tangent));
902 Geom::Point const tHatEnd(0, 0);
903 int const n_segs = Geom::bezier_fit_cubic_full(b, NULL, pc->p, pc->npoints,
904 pc->req_tangent, tHatEnd,
905 tolerance_sq, 1);
906 if ( n_segs > 0
907 && unsigned(pc->npoints) < G_N_ELEMENTS(pc->p) )
908 {
909 /* Fit and draw and reset state */
910 pc->red_curve->reset();
911 pc->red_curve->moveto(b[0]);
912 pc->red_curve->curveto(b[1], b[2], b[3]);
913 sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), pc->red_curve);
914 pc->red_curve_is_valid = true;
915 } else {
916 /* Fit and draw and copy last point */
918 g_assert(!pc->red_curve->is_empty());
920 /* Set up direction of next curve. */
921 {
922 Geom::CubicBezier const * last_seg = dynamic_cast<Geom::CubicBezier const *>(pc->red_curve->last_segment());
923 g_assert( last_seg ); // Relevance: validity of (*last_seg)[2]
924 pc->p[0] = last_seg->finalPoint();
925 pc->npoints = 1;
926 Geom::Point const req_vec( pc->p[0] - (*last_seg)[2] );
927 pc->req_tangent = ( ( Geom::is_zero(req_vec) || !in_svg_plane(req_vec) )
928 ? Geom::Point(0, 0)
929 : Geom::unit_vector(req_vec) );
930 }
932 pc->green_curve->append_continuous(pc->red_curve, 0.0625);
933 SPCurve *curve = pc->red_curve->copy();
935 /// \todo fixme:
936 SPCanvasItem *cshape = sp_canvas_bpath_new(sp_desktop_sketch(pc->desktop), curve);
937 curve->unref();
938 sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(cshape), pc->green_color, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
940 pc->green_bpaths = g_slist_prepend(pc->green_bpaths, cshape);
942 pc->red_curve_is_valid = false;
943 }
944 }
947 /*
948 Local Variables:
949 mode:c++
950 c-file-style:"stroustrup"
951 c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
952 indent-tabs-mode:nil
953 fill-column:99
954 End:
955 */
956 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :