#include <gdk/gdkkeysyms.h>

#include "pencil-context.h"

#include "desktop.h"

#include "desktop-handles.h"

#include "selection.h"

#include "selection-chemistry.h"

#include "draw-anchor.h"

#include "message-stack.h"

#include "message-context.h"

#include "modifier-fns.h"

#include "sp-path.h"

#include "preferences.h"

#include "snap.h"

#include "pixmaps/cursor-pencil.xpm"

#include <2geom/bezier-utils.h>

#include "display/canvas-bpath.h"

#include <glibmm/i18n.h>

#include "libnr/in-svg-plane.h"

#include "context-fns.h"

#include "sp-namedview.h"

#include "xml/repr.h"

#include "document.h"

#include "desktop-style.h"

#include "macros.h"

#include "display/curve.h"

static void sp_pencil_context_class_init(SPPencilContextClass *klass);

static void sp_pencil_context_init(SPPencilContext *pc);

static void sp_pencil_context_setup(SPEventContext *ec);

static void sp_pencil_context_dispose(GObject *object);

static gint sp_pencil_context_root_handler(SPEventContext *event_context, GdkEvent *event);

static gint pencil_handle_button_press(SPPencilContext *const pc, GdkEventButton const &bevent);

static gint pencil_handle_motion_notify(SPPencilContext *const pc, GdkEventMotion const &mevent);

static gint pencil_handle_button_release(SPPencilContext *const pc, GdkEventButton const &revent);

static gint pencil_handle_key_press(SPPencilContext *const pc, guint const keyval, guint const state);

static gint pencil_handle_key_release(SPPencilContext *const pc, guint const keyval, guint const state);

static void spdc_set_startpoint(SPPencilContext *pc, Geom::Point const p);

static void spdc_set_endpoint(SPPencilContext *pc, Geom::Point const p);

static void spdc_finish_endpoint(SPPencilContext *pc);

static void spdc_add_freehand_point(SPPencilContext *pc, Geom::Point p, guint state);

static void fit_and_split(SPPencilContext *pc);

static void interpolate(SPPencilContext *pc);

static void sketch_interpolate(SPPencilContext *pc);

static SPDrawContextClass *pencil_parent_class;

static Geom::Point pencil_drag_origin_w(0, 0);

static bool pencil_within_tolerance = false;

sp_pencil_context_get_type()

{

static GType type = 0;

if (!type) {

GTypeInfo info = {

sizeof(SPPencilContextClass),

NULL, NULL,

(GClassInitFunc) sp_pencil_context_class_init,

NULL, NULL,

sizeof(SPPencilContext),

4,

(GInstanceInitFunc) sp_pencil_context_init,

NULL, /* value_table */

};

type = g_type_register_static(SP_TYPE_DRAW_CONTEXT, "SPPencilContext", &info, (GTypeFlags)0);

}

return type;

}

static void

sp_pencil_context_class_init(SPPencilContextClass *klass)

{

GObjectClass *object_class;

SPEventContextClass *event_context_class;

object_class = (GObjectClass *) klass;

event_context_class = (SPEventContextClass *) klass;

pencil_parent_class = (SPDrawContextClass*)g_type_class_peek_parent(klass);

object_class->dispose = sp_pencil_context_dispose;

event_context_class->setup = sp_pencil_context_setup;

event_context_class->root_handler = sp_pencil_context_root_handler;

}

static void

sp_pencil_context_init(SPPencilContext *pc)

{

SPEventContext *event_context = SP_EVENT_CONTEXT(pc);

event_context->cursor_shape = cursor_pencil_xpm;

event_context->hot_x = 4;

event_context->hot_y = 4;

pc->npoints = 0;

pc->state = SP_PENCIL_CONTEXT_IDLE;

pc->req_tangent = Geom::Point(0, 0);

// since SPPencilContext is not properly constructed...

pc->sketch_interpolation = Geom::Path();

pc->sketch_n = 0;

}

static void

sp_pencil_context_setup(SPEventContext *ec)

{

Inkscape::Preferences *prefs = Inkscape::Preferences::get();

if (prefs->getBool("/tools/freehand/pencil/selcue")) {

ec->enableSelectionCue();

}

if (((SPEventContextClass *) pencil_parent_class)->setup) {

((SPEventContextClass *) pencil_parent_class)->setup(ec);

}

SPPencilContext *const pc = SP_PENCIL_CONTEXT(ec);

pc->is_drawing = false;

pc->anchor_statusbar = false;

}

static void

sp_pencil_context_dispose(GObject *object)

{

G_OBJECT_CLASS(pencil_parent_class)->dispose(object);

}

static void

spdc_endpoint_snap(SPPencilContext const *pc, Geom::Point &p, guint const state)

{

if ((state & GDK_CONTROL_MASK)) { //CTRL enables constrained snapping

spdc_endpoint_snap_rotation(pc, p, pc->p[0], state);

} else {

if (!(state & GDK_SHIFT_MASK)) { //SHIFT disables all snapping, except the angular snapping above

//After all, the user explicitely asked for angular snapping by

//pressing CTRL

spdc_endpoint_snap_free(pc, p, state);

}

}

}

sp_pencil_context_root_handler(SPEventContext *const ec, GdkEvent *event)

{

SPPencilContext *const pc = SP_PENCIL_CONTEXT(ec);

gint ret = FALSE;

switch (event->type) {

case GDK_BUTTON_PRESS:

ret = pencil_handle_button_press(pc, event->button);

break;

case GDK_MOTION_NOTIFY:

ret = pencil_handle_motion_notify(pc, event->motion);

break;

case GDK_BUTTON_RELEASE:

ret = pencil_handle_button_release(pc, event->button);

break;

case GDK_KEY_PRESS:

ret = pencil_handle_key_press(pc, get_group0_keyval (&event->key), event->key.state);

break;

case GDK_KEY_RELEASE:

ret = pencil_handle_key_release(pc, get_group0_keyval (&event->key), event->key.state);

break;

default:

break;

}

if (!ret) {

gint (*const parent_root_handler)(SPEventContext *, GdkEvent *)

= ((SPEventContextClass *) pencil_parent_class)->root_handler;

if (parent_root_handler) {

ret = parent_root_handler(ec, event);

}

}

return ret;

}

static gint

pencil_handle_button_press(SPPencilContext *const pc, GdkEventButton const &bevent)

{

gint ret = FALSE;

SPEventContext *event_context = SP_EVENT_CONTEXT(pc);

if ( bevent.button == 1 && !event_context->space_panning) {

SPDrawContext *dc = SP_DRAW_CONTEXT (pc);

SPDesktop *desktop = SP_EVENT_CONTEXT_DESKTOP(dc);

Inkscape::Selection *selection = sp_desktop_selection(desktop);

if (Inkscape::have_viable_layer(desktop, dc->_message_context) == false) {

return TRUE;

}

Geom::Point const button_w(bevent.x, bevent.y);

/* Find desktop coordinates */

Geom::Point p = pc->desktop->w2d(button_w);

/* Test whether we hit any anchor. */

SPDrawAnchor *anchor = spdc_test_inside(pc, button_w);

pencil_drag_origin_w = Geom::Point(bevent.x,bevent.y);

pencil_within_tolerance = true;

switch (pc->state) {

case SP_PENCIL_CONTEXT_ADDLINE:

/* Current segment will be finished with release */

ret = TRUE;

break;

default:

/* Set first point of sequence */

if (bevent.state & GDK_CONTROL_MASK) {

spdc_create_single_dot(event_context, from_2geom(p), "/tools/freehand/pencil", bevent.state);

ret = true;

break;

}

if (anchor) {

p = to_2geom(anchor->dp);

desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Continuing selected path"));

} else {

if (!(bevent.state & GDK_SHIFT_MASK)) {

// This is the first click of a new curve; deselect item so that

// this curve is not combined with it (unless it is drawn from its

// anchor, which is handled by the sibling branch above)

selection->clear();

desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Creating new path"));

SnapManager &m = desktop->namedview->snap_manager;

m.setup(desktop);

Inkscape::SnappedPoint const s = m.freeSnap(Inkscape::SnapPreferences::SNAPPOINT_NODE, p);

if (s.getSnapped()) {

s.getPoint(p);

pc->prev_snap_was_succesful = true;

} else {

pc->prev_snap_was_succesful = false;

}

} else if (selection->singleItem() && SP_IS_PATH(selection->singleItem())) {

desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Appending to selected path"));

}

}

pc->sa = anchor;

spdc_set_startpoint(pc, from_2geom(p));

ret = TRUE;

break;

}

pc->is_drawing = true;

}

return ret;

}

static gint

pencil_handle_motion_notify(SPPencilContext *const pc, GdkEventMotion const &mevent)

{

if ((mevent.state & GDK_CONTROL_MASK) && (mevent.state & GDK_BUTTON1_MASK)) {

// mouse was accidentally moved during Ctrl+click;

// ignore the motion and create a single point

pc->is_drawing = false;

return TRUE;

}

gint ret = FALSE;

SPDesktop *const dt = pc->desktop;

SPEventContext *event_context = SP_EVENT_CONTEXT(pc);

if (event_context->space_panning || mevent.state & GDK_BUTTON2_MASK || mevent.state & GDK_BUTTON3_MASK) {

// allow scrolling

return FALSE;

}

if ( ( mevent.state & GDK_BUTTON1_MASK ) && !pc->grab && pc->is_drawing) {

/* Grab mouse, so release will not pass unnoticed */

pc->grab = SP_CANVAS_ITEM(dt->acetate);

sp_canvas_item_grab(pc->grab, ( GDK_KEY_PRESS_MASK | GDK_BUTTON_PRESS_MASK |

GDK_BUTTON_RELEASE_MASK |

GDK_POINTER_MOTION_MASK ),

NULL, mevent.time);

}

/* Find desktop coordinates */

Geom::Point p = to_2geom(dt->w2d(Geom::Point(mevent.x, mevent.y)));

/* Test whether we hit any anchor. */

SPDrawAnchor *anchor = spdc_test_inside(pc, Geom::Point(mevent.x, mevent.y));

if (pencil_within_tolerance) {

Inkscape::Preferences *prefs = Inkscape::Preferences::get();

gint const tolerance = prefs->getIntLimited("/options/dragtolerance/value", 0, 0, 100);

if ( Geom::LInfty( Geom::Point(mevent.x,mevent.y) - pencil_drag_origin_w ) < tolerance ) {

return FALSE; // Do not drag if we're within tolerance from origin.

}

}

// Once the user has moved farther than tolerance from the original location

// (indicating they intend to move the object, not click), then always process the

// motion notify coordinates as given (no snapping back to origin)

pencil_within_tolerance = false;

switch (pc->state) {

case SP_PENCIL_CONTEXT_ADDLINE:

/* Set red endpoint */

if (anchor) {

p = to_2geom(anchor->dp);

} else {

Geom::Point ptnr = from_2geom(p);

spdc_endpoint_snap(pc, ptnr, mevent.state);

p = to_2geom(ptnr);

}

spdc_set_endpoint(pc, from_2geom(p));

ret = TRUE;

break;

default:

/* We may be idle or already freehand */

if ( mevent.state & GDK_BUTTON1_MASK && pc->is_drawing ) {

pc->state = SP_PENCIL_CONTEXT_FREEHAND;

if ( !pc->sa && !pc->green_anchor ) {

/* Create green anchor */

pc->green_anchor = sp_draw_anchor_new(pc, pc->green_curve, TRUE, pc->p[0]);

}

/** \todo

SnapManager &m = dt->namedview->snap_manager;

if (anchor) {

p = to_2geom(anchor->dp);

} else if ((mevent.state & GDK_SHIFT_MASK) == 0) {

m.setup(dt);

Inkscape::SnappedPoint const s = m.freeSnap(Inkscape::SnapPreferences::SNAPPOINT_NODE, p);

if (s.getSnapped()) {

s.getPoint(p);

pc->prev_snap_was_succesful = true;

} else {

pc->prev_snap_was_succesful = false;

}

}

if ( pc->npoints != 0) { // buttonpress may have happened before we entered draw context!

if (!(pc->prev_snap_was_succesful && m.snapprefs.getSnapPostponedGlobally())) {

// When snapping is enabled but temporarily on hold because the mouse is moving

// fast, then we don't want to add nodes off-grid

spdc_add_freehand_point(pc, from_2geom(p), mevent.state);

ret = TRUE;

}

}

if (anchor && !pc->anchor_statusbar) {

pc->_message_context->set(Inkscape::NORMAL_MESSAGE, _("<b>Release</b> here to close and finish the path."));

pc->anchor_statusbar = true;

} else if (!anchor && pc->anchor_statusbar) {

pc->_message_context->clear();

pc->anchor_statusbar = false;

} else if (!anchor) {

pc->_message_context->set(Inkscape::NORMAL_MESSAGE, _("Drawing a freehand path"));

}

} else {

if (anchor && !pc->anchor_statusbar) {

pc->_message_context->set(Inkscape::NORMAL_MESSAGE, _("<b>Drag</b> to continue the path from this point."));

pc->anchor_statusbar = true;

} else if (!anchor && pc->anchor_statusbar) {

pc->_message_context->clear();

pc->anchor_statusbar = false;

}

}

break;

}

return ret;

}

static gint

pencil_handle_button_release(SPPencilContext *const pc, GdkEventButton const &revent)

{

gint ret = FALSE;

SPEventContext *event_context = SP_EVENT_CONTEXT(pc);

if ( revent.button == 1 && pc->is_drawing && !event_context->space_panning) {

SPDesktop *const dt = pc->desktop;

pc->is_drawing = false;

/* Find desktop coordinates */

Geom::Point p = dt->w2d(Geom::Point(revent.x, revent.y));

/* Test whether we hit any anchor. */

SPDrawAnchor *anchor = spdc_test_inside(pc, Geom::Point(revent.x,

revent.y));

switch (pc->state) {

case SP_PENCIL_CONTEXT_IDLE:

/* Releasing button in idle mode means single click */

/* We have already set up start point/anchor in button_press */

if (!(revent.state & GDK_CONTROL_MASK)) {

// Ctrl+click creates a single point so only set context in ADDLINE mode when Ctrl isn't pressed

pc->state = SP_PENCIL_CONTEXT_ADDLINE;

}

ret = TRUE;

break;

case SP_PENCIL_CONTEXT_ADDLINE:

/* Finish segment now */

if (anchor) {

p = anchor->dp;

} else {

spdc_endpoint_snap(pc, p, revent.state);

}

pc->ea = anchor;

spdc_set_endpoint(pc, p);

spdc_finish_endpoint(pc);

pc->state = SP_PENCIL_CONTEXT_IDLE;

ret = TRUE;

break;

case SP_PENCIL_CONTEXT_FREEHAND:

if (revent.state & GDK_MOD1_MASK) {

/* sketch mode: interpolate the sketched path and improve the current output path with the new interpolation. don't finish sketch */

if (anchor) {

p = anchor->dp;

}

pc->ea = anchor;

dt->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Sketching: release <b>Alt</b> to finalize current curve"));

sketch_interpolate(pc);

pc->state = SP_PENCIL_CONTEXT_SKETCH;

} else {

/* Finish segment now */

/// \todo fixme: Clean up what follows (Lauris)

if (anchor) {

p = anchor->dp;

}

pc->ea = anchor;

/* Write curves to object */

dt->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Finishing freehand"));

interpolate(pc);

spdc_concat_colors_and_flush(pc, FALSE);

pc->sa = NULL;

pc->ea = NULL;

if (pc->green_anchor) {

pc->green_anchor = sp_draw_anchor_destroy(pc->green_anchor);

}

pc->state = SP_PENCIL_CONTEXT_IDLE;

}

ret = TRUE;

break;

case SP_PENCIL_CONTEXT_SKETCH:

default:

break;

}

if (pc->grab) {

/* Release grab now */

sp_canvas_item_ungrab(pc->grab, revent.time);

pc->grab = NULL;

}

ret = TRUE;

}

return ret;

}

static void

pencil_cancel (SPPencilContext *const pc)

{

if (pc->grab) {

/* Release grab now */

sp_canvas_item_ungrab(pc->grab, 0);

pc->grab = NULL;

}

pc->is_drawing = false;

pc->state = SP_PENCIL_CONTEXT_IDLE;

pc->red_curve->reset();

sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), NULL);

while (pc->green_bpaths) {

gtk_object_destroy(GTK_OBJECT(pc->green_bpaths->data));

pc->green_bpaths = g_slist_remove(pc->green_bpaths, pc->green_bpaths->data);

}

pc->green_curve->reset();

if (pc->green_anchor) {

pc->green_anchor = sp_draw_anchor_destroy(pc->green_anchor);

}

pc->_message_context->clear();

pc->_message_context->flash(Inkscape::NORMAL_MESSAGE, _("Drawing cancelled"));

sp_canvas_end_forced_full_redraws(pc->desktop->canvas);

}

static gint

pencil_handle_key_press(SPPencilContext *const pc, guint const keyval, guint const state)

{

gint ret = FALSE;

switch (keyval) {

case GDK_Up:

case GDK_Down:

case GDK_KP_Up:

case GDK_KP_Down:

// Prevent the zoom field from activation.

if (!mod_ctrl_only(state)) {

ret = TRUE;

}

break;

case GDK_Escape:

if (pc->npoints != 0) {

// if drawing, cancel, otherwise pass it up for deselecting

if (pc->state != SP_PENCIL_CONTEXT_IDLE) {

pencil_cancel (pc);

ret = TRUE;

}

}

break;

case GDK_z:

case GDK_Z:

if (mod_ctrl_only(state) && pc->npoints != 0) {

// if drawing, cancel, otherwise pass it up for undo

if (pc->state != SP_PENCIL_CONTEXT_IDLE) {

pencil_cancel (pc);

ret = TRUE;

}

}

break;

case GDK_g:

case GDK_G:

if (mod_shift_only(state)) {

sp_selection_to_guides(SP_EVENT_CONTEXT(pc)->desktop);

ret = true;

}

break;

default:

break;

}

return ret;

}

static gint

pencil_handle_key_release(SPPencilContext *const pc, guint const keyval, guint const /*state*/)

{

gint ret = FALSE;

switch (keyval) {

case GDK_Alt_L:

case GDK_Alt_R:

case GDK_Meta_L:

case GDK_Meta_R:

if (pc->state == SP_PENCIL_CONTEXT_SKETCH) {

spdc_concat_colors_and_flush(pc, FALSE);

pc->sketch_interpolation = Geom::Path();

pc->sketch_n = 0;

pc->sa = NULL;

pc->ea = NULL;

if (pc->green_anchor) {

pc->green_anchor = sp_draw_anchor_destroy(pc->green_anchor);

}

pc->state = SP_PENCIL_CONTEXT_IDLE;

ret = TRUE;

}

break;

default:

break;

}

return ret;

}

static void

spdc_set_startpoint(SPPencilContext *const pc, Geom::Point const p)

{

pc->npoints = 0;

pc->red_curve_is_valid = false;

if (in_svg_plane(p)) {

pc->p[pc->npoints++] = p;

}

}

static void

spdc_set_endpoint(SPPencilContext *const pc, Geom::Point const p)

{

if (pc->npoints == 0) {

return;

/* May occur if first point wasn't in SVG plane (e.g. weird w2d transform, perhaps from bad

}

g_return_if_fail( pc->npoints > 0 );

pc->red_curve->reset();

if ( ( p == pc->p[0] )

|| !in_svg_plane(p) )

{

pc->npoints = 1;

} else {

pc->p[1] = p;

pc->npoints = 2;

pc->red_curve->moveto(pc->p[0]);

pc->red_curve->lineto(pc->p[1]);

pc->red_curve_is_valid = true;

sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), pc->red_curve);

}

}

static void

spdc_finish_endpoint(SPPencilContext *const pc)

{

if ( ( pc->red_curve->is_empty() )

|| ( *(pc->red_curve->first_point()) == *(pc->red_curve->second_point()) ) )

{

pc->red_curve->reset();

sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), NULL);

} else {

/* Write curves to object. */

spdc_concat_colors_and_flush(pc, FALSE);

pc->sa = NULL;

pc->ea = NULL;

}

}

static void

spdc_add_freehand_point(SPPencilContext *pc, Geom::Point p, guint /*state*/)

{

g_assert( pc->npoints > 0 );

g_return_if_fail(unsigned(pc->npoints) < G_N_ELEMENTS(pc->p));

if ( ( p != pc->p[ pc->npoints - 1 ] )

&& in_svg_plane(p) )

{

pc->ps.push_back(p);

pc->p[pc->npoints++] = p;

fit_and_split(pc);

}

}

static inline double

square(double const x)

{

return x * x;

}

static void

interpolate(SPPencilContext *pc)

{

g_assert( pc->ps.size() > 1 );

Inkscape::Preferences *prefs = Inkscape::Preferences::get();

double const tol = prefs->getDoubleLimited("/tools/freehand/pencil/tolerance", 10.0, 1.0, 100.0) * 0.4;

double const tolerance_sq = 0.02 * square( pc->desktop->w2d().descrim() *

tol) * exp(0.2*tol - 2);

g_assert(is_zero(pc->req_tangent)

|| is_unit_vector(pc->req_tangent));

Geom::Point const tHatEnd(0, 0);

guint n_points = pc->ps.size();

pc->green_curve->reset();

pc->red_curve->reset();

pc->red_curve_is_valid = false;

Geom::Point * b = g_new(Geom::Point, 4*n_points);

Geom::Point * points = g_new(Geom::Point, 4*n_points);

for (int i = 0; i < pc->ps.size(); i++) {

points[i] = pc->ps[i];

}

// worst case gives us a segment per point

int max_segs = 4*n_points;

int const n_segs = Geom::bezier_fit_cubic_r(b, points, n_points,

tolerance_sq, max_segs);

if ( n_segs > 0)

{

/* Fit and draw and reset state */

pc->green_curve->moveto(b[0]);

for (int c = 0; c < n_segs; c++) {

pc->green_curve->curveto(b[4*c+1], b[4*c+2], b[4*c+3]);

}

sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), pc->green_curve);

/* Fit and draw and copy last point */

g_assert(!pc->green_curve->is_empty());

/* Set up direction of next curve. */

{

Geom::CubicBezier const * last_seg = dynamic_cast<Geom::CubicBezier const *>(pc->green_curve->last_segment());

g_assert( last_seg ); // Relevance: validity of (*last_seg)[2]

pc->p[0] = last_seg->finalPoint();

pc->npoints = 1;

Geom::Point const req_vec( pc->p[0] - (*last_seg)[2] );

pc->req_tangent = ( ( Geom::is_zero(req_vec) || !in_svg_plane(req_vec) )

? Geom::Point(0, 0)

: Geom::unit_vector(req_vec) );

}

}

g_free(b);

g_free(points);

pc->ps.clear();

}

static void

sketch_interpolate(SPPencilContext *pc)

{

g_assert( pc->ps.size() > 1 );

Inkscape::Preferences *prefs = Inkscape::Preferences::get();

double const tol = 100.0 * 0.4; //prefs->getDoubleLimited("/tools/freehand/pencil/tolerance", 10.0, 1.0, 100.0) * 0.4;

double const tolerance_sq = 0.02 * square( pc->desktop->w2d().descrim() *

tol) * exp(0.2*tol - 2);

bool average_all_sketches = prefs->getBool("/tools/freehand/pencil/average_all_sketches", true);

g_assert(is_zero(pc->req_tangent)

|| is_unit_vector(pc->req_tangent));

Geom::Point const tHatEnd(0, 0);

guint n_points = pc->ps.size();

pc->red_curve->reset();

pc->red_curve_is_valid = false;

Geom::Point * b = g_new(Geom::Point, 4*n_points);

Geom::Point * points = g_new(Geom::Point, 4*n_points);

for (unsigned i = 0; i < pc->ps.size(); i++) {

points[i] = pc->ps[i];

}

// worst case gives us a segment per point

int max_segs = 4*n_points;

int const n_segs = Geom::bezier_fit_cubic_r(b, points, n_points,

tolerance_sq, max_segs);

if ( n_segs > 0)

{

// only take first cubic and average its coefficients with the old ones

Geom::Point coeffs[4];

if ( pc->sketch_n > 0 ) {

Geom::CubicBezier const * oldcubic = dynamic_cast<Geom::CubicBezier const *>( &pc->sketch_interpolation.front() );

g_assert(oldcubic);

for (unsigned i = 0; i < 4; i++){

if (average_all_sketches) {

// Average = (sum of all) / n

// = (sum of all + new one) / n+1

// = ((old average)*n + new one) / n+1

coeffs[i] = ((*oldcubic)[i] * pc->sketch_n + b[i]) / (pc->sketch_n + 1);

} else {

coeffs[i] = 0.5 * (b[i] + (*oldcubic)[i]);

}

}

} else {

for (unsigned i = 0; i < 4; i++){

coeffs[i] = b[i];

}

}

pc->sketch_n++;

pc->sketch_interpolation.start(coeffs[0]);

pc->sketch_interpolation.appendNew<Geom::CubicBezier>(coeffs[1], coeffs[2], coeffs[3]);

Geom::PathVector temp;

temp.push_back(pc->sketch_interpolation);

pc->green_curve->reset();

pc->green_curve->set_pathvector(temp);

sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), pc->green_curve);

/* Fit and draw and copy last point */

g_assert(!pc->green_curve->is_empty());

/* Set up direction of next curve. */

{

Geom::CubicBezier const * last_seg = dynamic_cast<Geom::CubicBezier const *>(pc->green_curve->last_segment());

g_assert( last_seg ); // Relevance: validity of (*last_seg)[2]

pc->p[0] = last_seg->finalPoint();

pc->npoints = 1;

Geom::Point const req_vec( pc->p[0] - (*last_seg)[2] );

pc->req_tangent = ( ( Geom::is_zero(req_vec) || !in_svg_plane(req_vec) )

? Geom::Point(0, 0)

: Geom::unit_vector(req_vec) );

}

}

g_free(b);

g_free(points);

pc->ps.clear();

}

static void

fit_and_split(SPPencilContext *pc)

{

g_assert( pc->npoints > 1 );

double const tolerance_sq = 0;

Geom::Point b[4];

g_assert(is_zero(pc->req_tangent)

|| is_unit_vector(pc->req_tangent));

Geom::Point const tHatEnd(0, 0);

int const n_segs = Geom::bezier_fit_cubic_full(b, NULL, pc->p, pc->npoints,

pc->req_tangent, tHatEnd,

tolerance_sq, 1);

if ( n_segs > 0

&& unsigned(pc->npoints) < G_N_ELEMENTS(pc->p) )

{

/* Fit and draw and reset state */

pc->red_curve->reset();

pc->red_curve->moveto(b[0]);

pc->red_curve->curveto(b[1], b[2], b[3]);

sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), pc->red_curve);

pc->red_curve_is_valid = true;

} else {

/* Fit and draw and copy last point */

g_assert(!pc->red_curve->is_empty());

/* Set up direction of next curve. */

{

Geom::CubicBezier const * last_seg = dynamic_cast<Geom::CubicBezier const *>(pc->red_curve->last_segment());

g_assert( last_seg ); // Relevance: validity of (*last_seg)[2]

pc->p[0] = last_seg->finalPoint();

pc->npoints = 1;

Geom::Point const req_vec( pc->p[0] - (*last_seg)[2] );

pc->req_tangent = ( ( Geom::is_zero(req_vec) || !in_svg_plane(req_vec) )

? Geom::Point(0, 0)

: Geom::unit_vector(req_vec) );

}

pc->green_curve->append_continuous(pc->red_curve, 0.0625);

SPCurve *curve = pc->red_curve->copy();

/// \todo fixme:

SPCanvasItem *cshape = sp_canvas_bpath_new(sp_desktop_sketch(pc->desktop), curve);

curve->unref();

sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(cshape), pc->green_color, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);

pc->green_bpaths = g_slist_prepend(pc->green_bpaths, cshape);

pc->red_curve_is_valid = false;

}

}