#define noERASER_VERBOSE

#include "config.h"

#include <gtk/gtk.h>

#include <gdk/gdkkeysyms.h>

#include <glibmm/i18n.h>

#include <string>

#include <cstring>

#include <numeric>

#include "svg/svg.h"

#include "display/sp-canvas.h"

#include "display/canvas-bpath.h"

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

#include <glib.h>

#include "macros.h"

#include "document.h"

#include "selection.h"

#include "desktop.h"

#include "desktop-events.h"

#include "desktop-handles.h"

#include "desktop-style.h"

#include "message-context.h"

#include "preferences.h"

#include "pixmaps/cursor-eraser.xpm"

#include "xml/repr.h"

#include "context-fns.h"

#include "sp-item.h"

#include "color.h"

#include "rubberband.h"

#include "splivarot.h"

#include "sp-item-group.h"

#include "sp-shape.h"

#include "sp-path.h"

#include "sp-text.h"

#include "display/canvas-bpath.h"

#include "display/canvas-arena.h"

#include "livarot/Shape.h"

#include "document-undo.h"

#include "verbs.h"

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

#include <2geom/pathvector.h>

#include "eraser-context.h"

using Inkscape::DocumentUndo;

#define ERC_RED_RGBA 0xff0000ff

#define TOLERANCE_ERASER 0.1

#define ERASER_EPSILON 0.5e-6

#define ERASER_EPSILON_START 0.5e-2

#define ERASER_VEL_START 1e-5

#define DRAG_MIN 0.0

#define DRAG_DEFAULT 1.0

#define DRAG_MAX 1.0

static void sp_eraser_context_dispose(GObject *object);

static void sp_eraser_context_setup(SPEventContext *ec);

static void sp_eraser_context_set(SPEventContext *ec, Inkscape::Preferences::Entry *val);

static gint sp_eraser_context_root_handler(SPEventContext *ec, GdkEvent *event);

static void clear_current(SPEraserContext *dc);

static void set_to_accumulated(SPEraserContext *dc);

static void add_cap(SPCurve *curve, Geom::Point const &pre, Geom::Point const &from, Geom::Point const &to, Geom::Point const &post, double rounding);

static void accumulate_eraser(SPEraserContext *dc);

static void fit_and_split(SPEraserContext *erc, gboolean release);

static void sp_eraser_reset(SPEraserContext *erc, Geom::Point p);

static Geom::Point sp_eraser_get_npoint(SPEraserContext const *erc, Geom::Point v);

static Geom::Point sp_eraser_get_vpoint(SPEraserContext const *erc, Geom::Point n);

static void draw_temporary_box(SPEraserContext *dc);

#include "sp-factory.h"

namespace {

SPEventContext* createEraserContext() {

return new SPEraserContext();

}

bool eraserContextRegistered = ToolFactory::instance().registerObject("/tools/eraser", createEraserContext);

}

const std::string& CEraserContext::getPrefsPath() {

return SPEraserContext::prefsPath;

}

const std::string SPEraserContext::prefsPath = "/tools/eraser";

G_DEFINE_TYPE(SPEraserContext, sp_eraser_context, SP_TYPE_COMMON_CONTEXT);

static void

sp_eraser_context_class_init(SPEraserContextClass *klass)

{

GObjectClass *object_class = G_OBJECT_CLASS(klass);

SPEventContextClass *event_context_class = SP_EVENT_CONTEXT_CLASS(klass);

object_class->dispose = sp_eraser_context_dispose;

}

CEraserContext::CEraserContext(SPEraserContext* erasercontext) : CCommonContext(erasercontext) {

this->sperasercontext = erasercontext;

}

SPEraserContext::SPEraserContext() : SPCommonContext() {

SPEraserContext* erc = this;

erc->cerasercontext = new CEraserContext(erc);

delete erc->ccommoncontext;

erc->ccommoncontext = erc->cerasercontext;

erc->ceventcontext = erc->cerasercontext;

types.insert(typeid(SPEraserContext));

erc->cursor_shape = cursor_eraser_xpm;

erc->hot_x = 4;

erc->hot_y = 4;

}

static void

sp_eraser_context_init(SPEraserContext *erc)

{

new (erc) SPEraserContext();

}

static void

sp_eraser_context_dispose(GObject *object)

{

G_OBJECT_CLASS(sp_eraser_context_parent_class)->dispose(object);

}

static void

sp_eraser_context_setup(SPEventContext *ec)

{

ec->ceventcontext->setup();

}

void CEraserContext::setup() {

SPEventContext* ec = this->sperasercontext;

SPEraserContext *erc = SP_ERASER_CONTEXT(ec);

SPDesktop *desktop = ec->desktop;

CCommonContext::setup();

erc->accumulated = new SPCurve();

erc->currentcurve = new SPCurve();

erc->cal1 = new SPCurve();

erc->cal2 = new SPCurve();

erc->currentshape = sp_canvas_item_new(sp_desktop_sketch(desktop), SP_TYPE_CANVAS_BPATH, NULL);

sp_canvas_bpath_set_fill(SP_CANVAS_BPATH(erc->currentshape), ERC_RED_RGBA, SP_WIND_RULE_EVENODD);

sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(erc->currentshape), 0x00000000, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);

/* fixme: Cannot we cascade it to root more clearly? */

g_signal_connect(G_OBJECT(erc->currentshape), "event", G_CALLBACK(sp_desktop_root_handler), desktop);

sp_event_context_read(ec, "mass");

sp_event_context_read(ec, "wiggle");

sp_event_context_read(ec, "angle");

sp_event_context_read(ec, "width");

sp_event_context_read(ec, "thinning");

sp_event_context_read(ec, "tremor");

sp_event_context_read(ec, "flatness");

sp_event_context_read(ec, "tracebackground");

sp_event_context_read(ec, "usepressure");

sp_event_context_read(ec, "usetilt");

sp_event_context_read(ec, "abs_width");

sp_event_context_read(ec, "cap_rounding");

erc->is_drawing = false;

erc->_message_context = new Inkscape::MessageContext(desktop->messageStack());

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

if (prefs->getBool("/tools/eraser/selcue", 0) != 0) {

ec->enableSelectionCue();

}

ec->enableSelectionCue();

}

static void

sp_eraser_context_set(SPEventContext *ec, Inkscape::Preferences::Entry *val)

{

ec->ceventcontext->set(val);

}

void CEraserContext::set(Inkscape::Preferences::Entry* val) {

SPEventContext* ec = this->sperasercontext;

//pass on up to parent class to handle common attributes.

CCommonContext::set(val);

}

static double

flerp(double f0, double f1, double p)

{

return f0 + ( f1 - f0 ) * p;

}

static Geom::Point

sp_eraser_get_npoint(SPEraserContext const *dc, Geom::Point v)

{

Geom::Rect drect = SP_EVENT_CONTEXT(dc)->desktop->get_display_area();

double const max = MAX ( drect.dimensions()[Geom::X], drect.dimensions()[Geom::Y] );

return Geom::Point(( v[Geom::X] - drect.min()[Geom::X] ) / max, ( v[Geom::Y] - drect.min()[Geom::Y] ) / max);

}

static Geom::Point

sp_eraser_get_vpoint(SPEraserContext const *dc, Geom::Point n)

{

Geom::Rect drect = SP_EVENT_CONTEXT(dc)->desktop->get_display_area();

double const max = MAX ( drect.dimensions()[Geom::X], drect.dimensions()[Geom::Y] );

return Geom::Point(n[Geom::X] * max + drect.min()[Geom::X], n[Geom::Y] * max + drect.min()[Geom::Y]);

}

static void

sp_eraser_reset(SPEraserContext *dc, Geom::Point p)

{

dc->last = dc->cur = sp_eraser_get_npoint(dc, p);

dc->vel = Geom::Point(0,0);

dc->vel_max = 0;

dc->acc = Geom::Point(0,0);

dc->ang = Geom::Point(0,0);

dc->del = Geom::Point(0,0);

}

static void

sp_eraser_extinput(SPEraserContext *dc, GdkEvent *event)

{

if (gdk_event_get_axis (event, GDK_AXIS_PRESSURE, &dc->pressure))

dc->pressure = CLAMP (dc->pressure, ERC_MIN_PRESSURE, ERC_MAX_PRESSURE);

else

dc->pressure = ERC_DEFAULT_PRESSURE;

if (gdk_event_get_axis (event, GDK_AXIS_XTILT, &dc->xtilt))

dc->xtilt = CLAMP (dc->xtilt, ERC_MIN_TILT, ERC_MAX_TILT);

else

dc->xtilt = ERC_DEFAULT_TILT;

if (gdk_event_get_axis (event, GDK_AXIS_YTILT, &dc->ytilt))

dc->ytilt = CLAMP (dc->ytilt, ERC_MIN_TILT, ERC_MAX_TILT);

else

dc->ytilt = ERC_DEFAULT_TILT;

}

static gboolean

sp_eraser_apply(SPEraserContext *dc, Geom::Point p)

{

Geom::Point n = sp_eraser_get_npoint(dc, p);

/* Calculate mass and drag */

double const mass = flerp(1.0, 160.0, dc->mass);

double const drag = flerp(0.0, 0.5, dc->drag * dc->drag);

/* Calculate force and acceleration */

Geom::Point force = n - dc->cur;

// If force is below the absolute threshold ERASER_EPSILON,

// or we haven't yet reached ERASER_VEL_START (i.e. at the beginning of stroke)

// _and_ the force is below the (higher) ERASER_EPSILON_START threshold,

// discard this move.

// This prevents flips, blobs, and jerks caused by microscopic tremor of the tablet pen,

// especially bothersome at the start of the stroke where we don't yet have the inertia to

// smooth them out.

if ( Geom::L2(force) < ERASER_EPSILON || (dc->vel_max < ERASER_VEL_START && Geom::L2(force) < ERASER_EPSILON_START)) {

return FALSE;

}

dc->acc = force / mass;

/* Calculate new velocity */

dc->vel += dc->acc;

if (Geom::L2(dc->vel) > dc->vel_max)

dc->vel_max = Geom::L2(dc->vel);

/* Calculate angle of drawing tool */

double a1;

if (dc->usetilt) {

// 1a. calculate nib angle from input device tilt:

gdouble length = std::sqrt(dc->xtilt*dc->xtilt + dc->ytilt*dc->ytilt);;

if (length > 0) {

Geom::Point ang1 = Geom::Point(dc->ytilt/length, dc->xtilt/length);

a1 = atan2(ang1);

}

else

a1 = 0.0;

}

else {

// 1b. fixed dc->angle (absolutely flat nib):

double const radians = ( (dc->angle - 90) / 180.0 ) * M_PI;

Geom::Point ang1 = Geom::Point(-sin(radians), cos(radians));

a1 = atan2(ang1);

}

// 2. perpendicular to dc->vel (absolutely non-flat nib):

gdouble const mag_vel = Geom::L2(dc->vel);

if ( mag_vel < ERASER_EPSILON ) {

return FALSE;

}

Geom::Point ang2 = Geom::rot90(dc->vel) / mag_vel;

// 3. Average them using flatness parameter:

// calculate angles

double a2 = atan2(ang2);

// flip a2 to force it to be in the same half-circle as a1

bool flipped = false;

if (fabs (a2-a1) > 0.5*M_PI) {

a2 += M_PI;

flipped = true;

}

// normalize a2

if (a2 > M_PI)

a2 -= 2*M_PI;

if (a2 < -M_PI)

a2 += 2*M_PI;

// find the flatness-weighted bisector angle, unflip if a2 was flipped

// FIXME: when dc->vel is oscillating around the fixed angle, the new_ang flips back and forth. How to avoid this?

double new_ang = a1 + (1 - dc->flatness) * (a2 - a1) - (flipped? M_PI : 0);

// Try to detect a sudden flip when the new angle differs too much from the previous for the

// current velocity; in that case discard this move

double angle_delta = Geom::L2(Geom::Point (cos (new_ang), sin (new_ang)) - dc->ang);

if ( angle_delta / Geom::L2(dc->vel) > 4000 ) {

return FALSE;

}

// convert to point

dc->ang = Geom::Point (cos (new_ang), sin (new_ang));

/* Apply drag */

dc->vel *= 1.0 - drag;

/* Update position */

dc->last = dc->cur;

dc->cur += dc->vel;

return TRUE;

}

static void

sp_eraser_brush(SPEraserContext *dc)

{

g_assert( dc->npoints >= 0 && dc->npoints < SAMPLING_SIZE );

// How much velocity thins strokestyle

double vel_thin = flerp (0, 160, dc->vel_thin);

// Influence of pressure on thickness

double pressure_thick = (dc->usepressure ? dc->pressure : 1.0);

// get the real brush point, not the same as pointer (affected by hatch tracking and/or mass

// drag)

Geom::Point brush = sp_eraser_get_vpoint(dc, dc->cur);

//Geom::Point brush_w = SP_EVENT_CONTEXT(dc)->desktop->d2w(brush);

double trace_thick = 1;

double width = (pressure_thick * trace_thick - vel_thin * Geom::L2(dc->vel)) * dc->width;

double tremble_left = 0, tremble_right = 0;

if (dc->tremor > 0) {

// obtain two normally distributed random variables, using polar Box-Muller transform

double x1, x2, w, y1, y2;

do {

x1 = 2.0 * g_random_double_range(0,1) - 1.0;

x2 = 2.0 * g_random_double_range(0,1) - 1.0;

w = x1 * x1 + x2 * x2;

} while ( w >= 1.0 );

w = sqrt( (-2.0 * log( w ) ) / w );

y1 = x1 * w;

y2 = x2 * w;

// deflect both left and right edges randomly and independently, so that:

// (1) dc->tremor=1 corresponds to sigma=1, decreasing dc->tremor narrows the bell curve;

// (2) deflection depends on width, but is upped for small widths for better visual uniformity across widths;

// (3) deflection somewhat depends on speed, to prevent fast strokes looking

// comparatively smooth and slow ones excessively jittery

tremble_left = (y1)*dc->tremor * (0.15 + 0.8*width) * (0.35 + 14*Geom::L2(dc->vel));

tremble_right = (y2)*dc->tremor * (0.15 + 0.8*width) * (0.35 + 14*Geom::L2(dc->vel));

}

if ( width < 0.02 * dc->width ) {

width = 0.02 * dc->width;

}

double dezoomify_factor = 0.05 * 1000;

if (!dc->abs_width) {

dezoomify_factor /= SP_EVENT_CONTEXT(dc)->desktop->current_zoom();

}

Geom::Point del_left = dezoomify_factor * (width + tremble_left) * dc->ang;

Geom::Point del_right = dezoomify_factor * (width + tremble_right) * dc->ang;

dc->point1[dc->npoints] = brush + del_left;

dc->point2[dc->npoints] = brush - del_right;

dc->del = 0.5*(del_left + del_right);

dc->npoints++;

}

static void

sp_erc_update_toolbox (SPDesktop *desktop, const gchar *id, double value)

{

desktop->setToolboxAdjustmentValue (id, value);

}

static void

eraser_cancel(SPEraserContext *dc)

{

SPDesktop *desktop = SP_EVENT_CONTEXT(dc)->desktop;

dc->dragging = FALSE;

dc->is_drawing = false;

sp_canvas_item_ungrab(SP_CANVAS_ITEM(desktop->acetate), 0);

/* Remove all temporary line segments */

while (dc->segments) {

sp_canvas_item_destroy(SP_CANVAS_ITEM(dc->segments->data));

dc->segments = g_slist_remove(dc->segments, dc->segments->data);

}

/* reset accumulated curve */

dc->accumulated->reset();

clear_current(dc);

if (dc->repr) {

dc->repr = NULL;

}

}

sp_eraser_context_root_handler(SPEventContext *event_context,

GdkEvent *event)

{

return event_context->ceventcontext->root_handler(event);

}

gint CEraserContext::root_handler(GdkEvent* event) {

SPEventContext* event_context = this->sperasercontext;

SPEraserContext *dc = SP_ERASER_CONTEXT(event_context);

SPDesktop *desktop = event_context->desktop;

gint ret = FALSE;

switch (event->type) {

case GDK_BUTTON_PRESS:

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

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

return TRUE;

}

Geom::Point const button_w(event->button.x,

event->button.y);

Geom::Point const button_dt(desktop->w2d(button_w));

sp_eraser_reset(dc, button_dt);

sp_eraser_extinput(dc, event);

sp_eraser_apply(dc, button_dt);

dc->accumulated->reset();

if (dc->repr) {

dc->repr = NULL;

}

Inkscape::Rubberband::get(desktop)->start(desktop, button_dt);

Inkscape::Rubberband::get(desktop)->setMode(RUBBERBAND_MODE_TOUCHPATH);

/* initialize first point */

dc->npoints = 0;

sp_canvas_item_grab(SP_CANVAS_ITEM(desktop->acetate),

( GDK_KEY_PRESS_MASK |

GDK_BUTTON_RELEASE_MASK |

GDK_POINTER_MOTION_MASK |

GDK_BUTTON_PRESS_MASK ),

NULL,

event->button.time);

ret = TRUE;

desktop->canvas->forceFullRedrawAfterInterruptions(3);

dc->is_drawing = true;

}

break;

case GDK_MOTION_NOTIFY:

{

Geom::Point const motion_w(event->motion.x,

event->motion.y);

Geom::Point motion_dt(desktop->w2d(motion_w));

sp_eraser_extinput(dc, event);

dc->_message_context->clear();

if ( dc->is_drawing && (event->motion.state & GDK_BUTTON1_MASK) && !event_context->space_panning) {

dc->dragging = TRUE;

dc->_message_context->set(Inkscape::NORMAL_MESSAGE, _("<b>Drawing</b> an eraser stroke"));

if (!sp_eraser_apply(dc, motion_dt)) {

ret = TRUE;

break;

}

if ( dc->cur != dc->last ) {

sp_eraser_brush(dc);

g_assert( dc->npoints > 0 );

fit_and_split(dc, FALSE);

}

ret = TRUE;

}

Inkscape::Rubberband::get(desktop)->move(motion_dt);

}

break;

case GDK_BUTTON_RELEASE:

{

Geom::Point const motion_w(event->button.x, event->button.y);

Geom::Point const motion_dt(desktop->w2d(motion_w));

sp_canvas_item_ungrab(SP_CANVAS_ITEM(desktop->acetate), event->button.time);

desktop->canvas->endForcedFullRedraws();

dc->is_drawing = false;

if (dc->dragging && event->button.button == 1 && !event_context->space_panning) {

dc->dragging = FALSE;

sp_eraser_apply(dc, motion_dt);

/* Remove all temporary line segments */

while (dc->segments) {

sp_canvas_item_destroy(SP_CANVAS_ITEM(dc->segments->data));

dc->segments = g_slist_remove(dc->segments, dc->segments->data);

}

/* Create object */

fit_and_split(dc, TRUE);

accumulate_eraser(dc);

set_to_accumulated(dc); // performs document_done

/* reset accumulated curve */

dc->accumulated->reset();

clear_current(dc);

if (dc->repr) {

dc->repr = NULL;

}

dc->_message_context->clear();

ret = TRUE;

}

if (Inkscape::Rubberband::get(desktop)->is_started()) {

Inkscape::Rubberband::get(desktop)->stop();

}

break;

}

case GDK_KEY_PRESS:

switch (get_group0_keyval (&event->key)) {

case GDK_KEY_Up:

case GDK_KEY_KP_Up:

if (!MOD__CTRL_ONLY) {

dc->angle += 5.0;

if (dc->angle > 90.0)

dc->angle = 90.0;

sp_erc_update_toolbox (desktop, "eraser-angle", dc->angle);

ret = TRUE;

}

break;

case GDK_KEY_Down:

case GDK_KEY_KP_Down:

if (!MOD__CTRL_ONLY) {

dc->angle -= 5.0;

if (dc->angle < -90.0)

dc->angle = -90.0;

sp_erc_update_toolbox (desktop, "eraser-angle", dc->angle);

ret = TRUE;

}

break;

case GDK_KEY_Right:

case GDK_KEY_KP_Right:

if (!MOD__CTRL_ONLY) {

dc->width += 0.01;

if (dc->width > 1.0)

dc->width = 1.0;

sp_erc_update_toolbox (desktop, "altx-eraser", dc->width * 100); // the same spinbutton is for alt+x

ret = TRUE;

}

break;

case GDK_KEY_Left:

case GDK_KEY_KP_Left:

if (!MOD__CTRL_ONLY) {

dc->width -= 0.01;

if (dc->width < 0.01)

dc->width = 0.01;

sp_erc_update_toolbox (desktop, "altx-eraser", dc->width * 100);

ret = TRUE;

}

break;

case GDK_KEY_Home:

case GDK_KEY_KP_Home:

dc->width = 0.01;

sp_erc_update_toolbox (desktop, "altx-eraser", dc->width * 100);

ret = TRUE;

break;

case GDK_KEY_End:

case GDK_KEY_KP_End:

dc->width = 1.0;

sp_erc_update_toolbox (desktop, "altx-eraser", dc->width * 100);

ret = TRUE;

break;

case GDK_KEY_x:

case GDK_KEY_X:

if (MOD__ALT_ONLY) {

desktop->setToolboxFocusTo ("altx-eraser");

ret = TRUE;

}

break;

case GDK_KEY_Escape:

Inkscape::Rubberband::get(desktop)->stop();

if (dc->is_drawing) {

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

eraser_cancel (dc);

ret = TRUE;

}

break;

case GDK_KEY_z:

case GDK_KEY_Z:

if (MOD__CTRL_ONLY && dc->is_drawing) {

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

eraser_cancel (dc);

ret = TRUE;

}

break;

default:

break;

}

break;

case GDK_KEY_RELEASE:

switch (get_group0_keyval(&event->key)) {

case GDK_KEY_Control_L:

case GDK_KEY_Control_R:

dc->_message_context->clear();

break;

default:

break;

}

default:

break;

}

if (!ret) {

ret = CCommonContext::root_handler(event);

}

return ret;

}

static void

clear_current(SPEraserContext *dc)

{

// reset bpath

sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(dc->currentshape), NULL);

// reset curve

dc->currentcurve->reset();

dc->cal1->reset();

dc->cal2->reset();

// reset points

dc->npoints = 0;

}

static void

set_to_accumulated(SPEraserContext *dc)

{

SPDesktop *desktop = SP_EVENT_CONTEXT(dc)->desktop;

bool workDone = false;

if (!dc->accumulated->is_empty()) {

if (!dc->repr) {

/* Create object */

Inkscape::XML::Document *xml_doc = desktop->doc()->getReprDoc();

Inkscape::XML::Node *repr = xml_doc->createElement("svg:path");

/* Set style */

sp_desktop_apply_style_tool (desktop, repr, "/tools/eraser", false);

dc->repr = repr;

SPItem *item=SP_ITEM(desktop->currentLayer()->appendChildRepr(dc->repr));

Inkscape::GC::release(dc->repr);

item->transform = SP_ITEM(desktop->currentLayer())->i2doc_affine().inverse();

item->updateRepr();

}

Geom::PathVector pathv = dc->accumulated->get_pathvector() * desktop->dt2doc();

gchar *str = sp_svg_write_path(pathv);

g_assert( str != NULL );

dc->repr->setAttribute("d", str);

g_free(str);

if ( dc->repr ) {

bool wasSelection = false;

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

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

gint eraserMode = prefs->getBool("/tools/eraser/mode") ? 1 : 0;

Inkscape::XML::Document *xml_doc = desktop->doc()->getReprDoc();

SPItem* acid = SP_ITEM(desktop->doc()->getObjectByRepr(dc->repr));

Geom::OptRect eraserBbox = acid->visualBounds();

Geom::Rect bounds = (*eraserBbox) * desktop->doc2dt();

std::vector<SPItem*> remainingItems;

GSList* toWorkOn = 0;

if (selection->isEmpty()) {

if ( eraserMode ) {

toWorkOn = sp_desktop_document(desktop)->getItemsPartiallyInBox(desktop->dkey, bounds);

} else {

Inkscape::Rubberband *r = Inkscape::Rubberband::get(desktop);

toWorkOn = sp_desktop_document(desktop)->getItemsAtPoints(desktop->dkey, r->getPoints());

}

toWorkOn = g_slist_remove( toWorkOn, acid );

} else {

toWorkOn = g_slist_copy(const_cast<GSList*>(selection->itemList()));

wasSelection = true;

}

if ( g_slist_length(toWorkOn) > 0 ) {

if ( eraserMode ) {

for (GSList *i = toWorkOn ; i ; i = i->next ) {

SPItem *item = SP_ITEM(i->data);

if ( eraserMode ) {

Geom::OptRect bbox = item->visualBounds();

if (bbox && bbox->intersects(*eraserBbox)) {

Inkscape::XML::Node* dup = dc->repr->duplicate(xml_doc);

dc->repr->parent()->appendChild(dup);

Inkscape::GC::release(dup); // parent takes over

selection->set(item);

selection->add(dup);

sp_selected_path_diff_skip_undo(desktop);

workDone = true; // TODO set this only if something was cut.

if ( !selection->isEmpty() ) {

// If the item was not completely erased, track the new remainder.

GSList *nowSel = g_slist_copy(const_cast<GSList *>(selection->itemList()));

for (GSList const *i2 = nowSel ; i2 ; i2 = i2->next ) {

remainingItems.push_back(SP_ITEM(i2->data));

}

g_slist_free(nowSel);

}

} else {

remainingItems.push_back(item);

}

}

}

} else {

for (GSList *i = toWorkOn ; i ; i = i->next ) {

sp_object_ref( SP_ITEM(i->data), 0 );

}

for (GSList *i = toWorkOn ; i ; i = i->next ) {

SPItem *item = SP_ITEM(i->data);

item->deleteObject(true);

sp_object_unref(item);

workDone = true;

}

}

g_slist_free(toWorkOn);

if ( !eraserMode ) {

//sp_selection_delete(desktop);

remainingItems.clear();

}

selection->clear();

if ( wasSelection ) {

if ( !remainingItems.empty() ) {

selection->add(remainingItems.begin(), remainingItems.end());

}

}

}

// Remove the eraser stroke itself:

sp_repr_unparent( dc->repr );

dc->repr = 0;

}

} else {

if (dc->repr) {

sp_repr_unparent(dc->repr);

dc->repr = 0;

}

}

if ( workDone ) {

DocumentUndo::done(sp_desktop_document(desktop), SP_VERB_CONTEXT_ERASER,

_("Draw eraser stroke"));

} else {

DocumentUndo::cancel(sp_desktop_document(desktop));

}

}

static void

add_cap(SPCurve *curve,

Geom::Point const &pre, Geom::Point const &from,

Geom::Point const &to, Geom::Point const &post,

double rounding)

{

Geom::Point vel = rounding * Geom::rot90( to - from ) / sqrt(2.0);

double mag = Geom::L2(vel);

Geom::Point v_in = from - pre;

double mag_in = Geom::L2(v_in);

if ( mag_in > ERASER_EPSILON ) {

v_in = mag * v_in / mag_in;

} else {

v_in = Geom::Point(0, 0);

}

Geom::Point v_out = to - post;

double mag_out = Geom::L2(v_out);

if ( mag_out > ERASER_EPSILON ) {

v_out = mag * v_out / mag_out;

} else {

v_out = Geom::Point(0, 0);

}

if ( Geom::L2(v_in) > ERASER_EPSILON || Geom::L2(v_out) > ERASER_EPSILON ) {

curve->curveto(from + v_in, to + v_out, to);

}

}

static void

accumulate_eraser(SPEraserContext *dc)

{

if ( !dc->cal1->is_empty() && !dc->cal2->is_empty() ) {

dc->accumulated->reset(); /* Is this required ?? */

SPCurve *rev_cal2 = dc->cal2->create_reverse();

g_assert(dc->cal1->get_segment_count() > 0);

g_assert(rev_cal2->get_segment_count() > 0);

g_assert( ! dc->cal1->first_path()->closed() );

g_assert( ! rev_cal2->first_path()->closed() );

Geom::CubicBezier const * dc_cal1_firstseg = dynamic_cast<Geom::CubicBezier const *>( dc->cal1->first_segment() );

Geom::CubicBezier const * rev_cal2_firstseg = dynamic_cast<Geom::CubicBezier const *>( rev_cal2->first_segment() );

Geom::CubicBezier const * dc_cal1_lastseg = dynamic_cast<Geom::CubicBezier const *>( dc->cal1->last_segment() );

Geom::CubicBezier const * rev_cal2_lastseg = dynamic_cast<Geom::CubicBezier const *>( rev_cal2->last_segment() );

g_assert( dc_cal1_firstseg );

g_assert( rev_cal2_firstseg );

g_assert( dc_cal1_lastseg );

g_assert( rev_cal2_lastseg );

dc->accumulated->append(dc->cal1, FALSE);

add_cap(dc->accumulated, (*dc_cal1_lastseg)[2], (*dc_cal1_lastseg)[3], (*rev_cal2_firstseg)[0], (*rev_cal2_firstseg)[1], dc->cap_rounding);

dc->accumulated->append(rev_cal2, TRUE);

add_cap(dc->accumulated, (*rev_cal2_lastseg)[2], (*rev_cal2_lastseg)[3], (*dc_cal1_firstseg)[0], (*dc_cal1_firstseg)[1], dc->cap_rounding);

dc->accumulated->closepath();

rev_cal2->unref();

dc->cal1->reset();

dc->cal2->reset();

}

}

static double square(double const x)

{

return x * x;

}

static void

fit_and_split(SPEraserContext *dc, gboolean release)

{

SPDesktop *desktop = SP_EVENT_CONTEXT(dc)->desktop;

double const tolerance_sq = square( desktop->w2d().descrim() * TOLERANCE_ERASER );

#ifdef ERASER_VERBOSE

g_print("[F&S:R=%c]", release?'T':'F');

#endif

if (!( dc->npoints > 0 && dc->npoints < SAMPLING_SIZE ))

return; // just clicked

if ( dc->npoints == SAMPLING_SIZE - 1 || release ) {

#define BEZIER_SIZE 4

#define BEZIER_MAX_BEZIERS 8

#define BEZIER_MAX_LENGTH ( BEZIER_SIZE * BEZIER_MAX_BEZIERS )

#ifdef ERASER_VERBOSE

g_print("[F&S:#] dc->npoints:%d, release:%s\n",

dc->npoints, release ? "TRUE" : "FALSE");

#endif

/* Current eraser */

if ( dc->cal1->is_empty() || dc->cal2->is_empty() ) {

/* dc->npoints > 0 */

/* g_print("erasers(1|2) reset\n"); */

dc->cal1->reset();

dc->cal2->reset();

dc->cal1->moveto(dc->point1[0]);

dc->cal2->moveto(dc->point2[0]);

}

Geom::Point b1[BEZIER_MAX_LENGTH];

gint const nb1 = Geom::bezier_fit_cubic_r(b1, dc->point1, dc->npoints,

tolerance_sq, BEZIER_MAX_BEZIERS);

g_assert( nb1 * BEZIER_SIZE <= gint(G_N_ELEMENTS(b1)) );

Geom::Point b2[BEZIER_MAX_LENGTH];

gint const nb2 = Geom::bezier_fit_cubic_r(b2, dc->point2, dc->npoints,

tolerance_sq, BEZIER_MAX_BEZIERS);

g_assert( nb2 * BEZIER_SIZE <= gint(G_N_ELEMENTS(b2)) );

if ( nb1 != -1 && nb2 != -1 ) {

/* Fit and draw and reset state */

#ifdef ERASER_VERBOSE

g_print("nb1:%d nb2:%d\n", nb1, nb2);

#endif

/* CanvasShape */

if (! release) {

dc->currentcurve->reset();

dc->currentcurve->moveto(b1[0]);

for (Geom::Point *bp1 = b1; bp1 < b1 + BEZIER_SIZE * nb1; bp1 += BEZIER_SIZE) {

dc->currentcurve->curveto(bp1[1],

bp1[2], bp1[3]);

}

dc->currentcurve->lineto(b2[BEZIER_SIZE*(nb2-1) + 3]);

for (Geom::Point *bp2 = b2 + BEZIER_SIZE * ( nb2 - 1 ); bp2 >= b2; bp2 -= BEZIER_SIZE) {

dc->currentcurve->curveto(bp2[2], bp2[1], bp2[0]);

}

// FIXME: dc->segments is always NULL at this point??

if (!dc->segments) { // first segment

add_cap(dc->currentcurve, b2[1], b2[0], b1[0], b1[1], dc->cap_rounding);

}

dc->currentcurve->closepath();

sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(dc->currentshape), dc->currentcurve);

}

/* Current eraser */

for (Geom::Point *bp1 = b1; bp1 < b1 + BEZIER_SIZE * nb1; bp1 += BEZIER_SIZE) {

dc->cal1->curveto(bp1[1], bp1[2], bp1[3]);

}

for (Geom::Point *bp2 = b2; bp2 < b2 + BEZIER_SIZE * nb2; bp2 += BEZIER_SIZE) {

dc->cal2->curveto(bp2[1], bp2[2], bp2[3]);

}

} else {

/* fixme: ??? */

#ifdef ERASER_VERBOSE

g_print("[fit_and_split] failed to fit-cubic.\n");

#endif

draw_temporary_box(dc);

for (gint i = 1; i < dc->npoints; i++) {

dc->cal1->lineto(dc->point1[i]);

}

for (gint i = 1; i < dc->npoints; i++) {

dc->cal2->lineto(dc->point2[i]);

}

}

/* Fit and draw and copy last point */

#ifdef ERASER_VERBOSE

g_print("[%d]Yup\n", dc->npoints);

#endif

if (!release) {

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

gint eraserMode = prefs->getBool("/tools/eraser/mode") ? 1 : 0;

g_assert(!dc->currentcurve->is_empty());

SPCanvasItem *cbp = sp_canvas_item_new(sp_desktop_sketch(desktop),

SP_TYPE_CANVAS_BPATH,

NULL);

SPCurve *curve = dc->currentcurve->copy();

sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH (cbp), curve);

curve->unref();

guint32 fillColor = sp_desktop_get_color_tool (desktop, "/tools/eraser", true);

//guint32 strokeColor = sp_desktop_get_color_tool (desktop, "/tools/eraser", false);

double opacity = sp_desktop_get_master_opacity_tool (desktop, "/tools/eraser");

double fillOpacity = sp_desktop_get_opacity_tool (desktop, "/tools/eraser", true);

//double strokeOpacity = sp_desktop_get_opacity_tool (desktop, "/tools/eraser", false);

sp_canvas_bpath_set_fill(SP_CANVAS_BPATH(cbp), ((fillColor & 0xffffff00) | SP_COLOR_F_TO_U(opacity*fillOpacity)), SP_WIND_RULE_EVENODD);

//on second thougtht don't do stroke yet because we don't have stoke-width yet and because stoke appears between segments while drawing

//sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(cbp), ((strokeColor & 0xffffff00) | SP_COLOR_F_TO_U(opacity*strokeOpacity)), 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);

sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(cbp), 0x00000000, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);

/* fixme: Cannot we cascade it to root more clearly? */

g_signal_connect(G_OBJECT(cbp), "event", G_CALLBACK(sp_desktop_root_handler), desktop);

dc->segments = g_slist_prepend(dc->segments, cbp);

if ( !eraserMode ) {

sp_canvas_item_hide(cbp);

sp_canvas_item_hide(dc->currentshape);

}

}

dc->point1[0] = dc->point1[dc->npoints - 1];

dc->point2[0] = dc->point2[dc->npoints - 1];

dc->npoints = 1;

} else {

draw_temporary_box(dc);

}

}

static void

draw_temporary_box(SPEraserContext *dc)

{

dc->currentcurve->reset();

dc->currentcurve->moveto(dc->point1[dc->npoints-1]);

for (gint i = dc->npoints-2; i >= 0; i--) {

dc->currentcurve->lineto(dc->point1[i]);

}

for (gint i = 0; i < dc->npoints; i++) {

dc->currentcurve->lineto(dc->point2[i]);

}

if (dc->npoints >= 2) {

add_cap(dc->currentcurve, dc->point2[dc->npoints-2], dc->point2[dc->npoints-1], dc->point1[dc->npoints-1], dc->point1[dc->npoints-2], dc->cap_rounding);

}

dc->currentcurve->closepath();

sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(dc->currentshape), dc->currentcurve);

}