#define __SP_DYNA_DRAW_CONTEXT_C__

#define noDYNA_DRAW_VERBOSE

#include "config.h"

#include <gtk/gtk.h>

#include <gdk/gdkkeysyms.h>

#include <glibmm/i18n.h>

#include "svg/svg.h"

#include "display/canvas-bpath.h"

#include "display/bezier-utils.h"

#include <glib/gmem.h>

#include "macros.h"

#include "document.h"

#include "selection.h"

#include "desktop.h"

#include "desktop-events.h"

#include "desktop-handles.h"

#include "desktop-affine.h"

#include "desktop-style.h"

#include "message-context.h"

#include "pixmaps/cursor-calligraphy.xpm"

#include "dyna-draw-context.h"

#include "libnr/n-art-bpath.h"

#include "libnr/nr-path.h"

#include "xml/repr.h"

#include "context-fns.h"

#include "sp-item.h"

#include "inkscape.h"

#include "color.h"

#define DDC_RED_RGBA 0xff0000ff

#define SAMPLE_TIMEOUT 10

#define TOLERANCE_LINE 1.0

#define TOLERANCE_CALLIGRAPHIC 3.0

#define DYNA_EPSILON 0.5e-2

#define DYNA_MIN_WIDTH 1.0e-6

#define DRAG_MIN 0.0

#define DRAG_DEFAULT 1.0

#define DRAG_MAX 1.0

static void sp_dyna_draw_context_class_init(SPDynaDrawContextClass *klass);

static void sp_dyna_draw_context_init(SPDynaDrawContext *ddc);

static void sp_dyna_draw_context_dispose(GObject *object);

static void sp_dyna_draw_context_setup(SPEventContext *ec);

static void sp_dyna_draw_context_set(SPEventContext *ec, gchar const *key, gchar const *val);

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

static void clear_current(SPDynaDrawContext *dc);

static void set_to_accumulated(SPDynaDrawContext *dc);

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

static void accumulate_calligraphic(SPDynaDrawContext *dc);

static void fit_and_split(SPDynaDrawContext *ddc, gboolean release);

static void sp_dyna_draw_reset(SPDynaDrawContext *ddc, NR::Point p);

static NR::Point sp_dyna_draw_get_npoint(SPDynaDrawContext const *ddc, NR::Point v);

static NR::Point sp_dyna_draw_get_vpoint(SPDynaDrawContext const *ddc, NR::Point n);

static void draw_temporary_box(SPDynaDrawContext *dc);

static SPEventContextClass *parent_class;

sp_dyna_draw_context_get_type(void)

{

static GType type = 0;

if (!type) {

GTypeInfo info = {

sizeof(SPDynaDrawContextClass),

NULL, NULL,

(GClassInitFunc) sp_dyna_draw_context_class_init,

NULL, NULL,

sizeof(SPDynaDrawContext),

4,

(GInstanceInitFunc) sp_dyna_draw_context_init,

NULL, /* value_table */

};

type = g_type_register_static(SP_TYPE_EVENT_CONTEXT, "SPDynaDrawContext", &info, (GTypeFlags)0);

}

return type;

}

static void

sp_dyna_draw_context_class_init(SPDynaDrawContextClass *klass)

{

GObjectClass *object_class = (GObjectClass *) klass;

SPEventContextClass *event_context_class = (SPEventContextClass *) klass;

parent_class = (SPEventContextClass*)g_type_class_peek_parent(klass);

object_class->dispose = sp_dyna_draw_context_dispose;

event_context_class->setup = sp_dyna_draw_context_setup;

event_context_class->set = sp_dyna_draw_context_set;

event_context_class->root_handler = sp_dyna_draw_context_root_handler;

}

static void

sp_dyna_draw_context_init(SPDynaDrawContext *ddc)

{

SPEventContext *event_context = SP_EVENT_CONTEXT(ddc);

event_context->cursor_shape = cursor_calligraphy_xpm;

event_context->hot_x = 4;

event_context->hot_y = 4;

ddc->accumulated = NULL;

ddc->segments = NULL;

ddc->currentcurve = NULL;

ddc->currentshape = NULL;

ddc->npoints = 0;

ddc->cal1 = NULL;

ddc->cal2 = NULL;

ddc->repr = NULL;

/* DynaDraw values */

ddc->cur = NR::Point(0,0);

ddc->last = NR::Point(0,0);

ddc->vel = NR::Point(0,0);

ddc->acc = NR::Point(0,0);

ddc->ang = NR::Point(0,0);

ddc->del = NR::Point(0,0);

/* attributes */

ddc->dragging = FALSE;

ddc->mass = 0.3;

ddc->drag = DRAG_DEFAULT;

ddc->angle = 30.0;

ddc->width = 0.2;

ddc->vel_thin = 0.1;

ddc->flatness = 0.9;

ddc->cap_rounding = 0.0;

ddc->abs_width = false;

ddc->keep_selected = true;

}

static void

sp_dyna_draw_context_dispose(GObject *object)

{

SPDynaDrawContext *ddc = SP_DYNA_DRAW_CONTEXT(object);

if (ddc->accumulated) {

ddc->accumulated = sp_curve_unref(ddc->accumulated);

}

while (ddc->segments) {

gtk_object_destroy(GTK_OBJECT(ddc->segments->data));

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

}

if (ddc->currentcurve) ddc->currentcurve = sp_curve_unref(ddc->currentcurve);

if (ddc->cal1) ddc->cal1 = sp_curve_unref(ddc->cal1);

if (ddc->cal2) ddc->cal2 = sp_curve_unref(ddc->cal2);

if (ddc->currentshape) {

gtk_object_destroy(GTK_OBJECT(ddc->currentshape));

ddc->currentshape = NULL;

}

if (ddc->_message_context) {

delete ddc->_message_context;

}

G_OBJECT_CLASS(parent_class)->dispose(object);

}

static void

sp_dyna_draw_context_setup(SPEventContext *ec)

{

SPDynaDrawContext *ddc = SP_DYNA_DRAW_CONTEXT(ec);

if (((SPEventContextClass *) parent_class)->setup)

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

ddc->accumulated = sp_curve_new_sized(32);

ddc->currentcurve = sp_curve_new_sized(4);

ddc->cal1 = sp_curve_new_sized(32);

ddc->cal2 = sp_curve_new_sized(32);

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

sp_canvas_bpath_set_fill(SP_CANVAS_BPATH(ddc->currentshape), DDC_RED_RGBA, SP_WIND_RULE_EVENODD);

sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(ddc->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(ddc->currentshape), "event", G_CALLBACK(sp_desktop_root_handler), ec->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, "usepressure");

sp_event_context_read(ec, "usetilt");

sp_event_context_read(ec, "abs_width");

sp_event_context_read(ec, "keep_selected");

sp_event_context_read(ec, "cap_rounding");

ddc->is_drawing = false;

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

}

static void

sp_dyna_draw_context_set(SPEventContext *ec, gchar const *key, gchar const *val)

{

SPDynaDrawContext *ddc = SP_DYNA_DRAW_CONTEXT(ec);

if (!strcmp(key, "mass")) {

double const dval = ( val ? g_ascii_strtod (val, NULL) : 0.2 );

ddc->mass = CLAMP(dval, -1000.0, 1000.0);

} else if (!strcmp(key, "wiggle")) {

double const dval = ( val ? g_ascii_strtod (val, NULL) : (1 - DRAG_DEFAULT));

ddc->drag = CLAMP((1 - dval), DRAG_MIN, DRAG_MAX); // drag is inverse to wiggle

} else if (!strcmp(key, "angle")) {

double const dval = ( val ? g_ascii_strtod (val, NULL) : 0.0);

ddc->angle = CLAMP (dval, -90, 90);

} else if (!strcmp(key, "width")) {

double const dval = ( val ? g_ascii_strtod (val, NULL) : 0.1 );

ddc->width = CLAMP(dval, -1000.0, 1000.0);

} else if (!strcmp(key, "thinning")) {

double const dval = ( val ? g_ascii_strtod (val, NULL) : 0.1 );

ddc->vel_thin = CLAMP(dval, -1.0, 1.0);

} else if (!strcmp(key, "tremor")) {

double const dval = ( val ? g_ascii_strtod (val, NULL) : 0.0 );

ddc->tremor = CLAMP(dval, 0.0, 1.0);

} else if (!strcmp(key, "flatness")) {

double const dval = ( val ? g_ascii_strtod (val, NULL) : 1.0 );

ddc->flatness = CLAMP(dval, 0, 1.0);

} else if (!strcmp(key, "usepressure")) {

ddc->usepressure = (val && strcmp(val, "0"));

} else if (!strcmp(key, "usetilt")) {

ddc->usetilt = (val && strcmp(val, "0"));

} else if (!strcmp(key, "abs_width")) {

ddc->abs_width = (val && strcmp(val, "0"));

} else if (!strcmp(key, "keep_selected")) {

ddc->keep_selected = (val && strcmp(val, "0"));

} else if (!strcmp(key, "cap_rounding")) {

ddc->cap_rounding = ( val ? g_ascii_strtod (val, NULL) : 0.0 );

}

//g_print("DDC: %g %g %g %g\n", ddc->mass, ddc->drag, ddc->angle, ddc->width);

}

static double

flerp(double f0, double f1, double p)

{

return f0 + ( f1 - f0 ) * p;

}

static NR::Point

sp_dyna_draw_get_npoint(SPDynaDrawContext const *dc, NR::Point v)

{

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

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

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

}

static NR::Point

sp_dyna_draw_get_vpoint(SPDynaDrawContext const *dc, NR::Point n)

{

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

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

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

}

static void

sp_dyna_draw_reset(SPDynaDrawContext *dc, NR::Point p)

{

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

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

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

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

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

}

static void

sp_dyna_draw_extinput(SPDynaDrawContext *dc, GdkEvent *event)

{

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

dc->pressure = CLAMP (dc->pressure, DDC_MIN_PRESSURE, DDC_MAX_PRESSURE);

else

dc->pressure = DDC_DEFAULT_PRESSURE;

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

dc->xtilt = CLAMP (dc->xtilt, DDC_MIN_TILT, DDC_MAX_TILT);

else

dc->xtilt = DDC_DEFAULT_TILT;

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

dc->ytilt = CLAMP (dc->ytilt, DDC_MIN_TILT, DDC_MAX_TILT);

else

dc->ytilt = DDC_DEFAULT_TILT;

}

static gboolean

sp_dyna_draw_apply(SPDynaDrawContext *dc, NR::Point p)

{

NR::Point n = sp_dyna_draw_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 */

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

if ( NR::L2(force) < DYNA_EPSILON ) {

return FALSE;

}

dc->acc = force / mass;

/* Calculate new velocity */

dc->vel += dc->acc;

/* 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) {

NR::Point ang1 = NR::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;

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

a1 = atan2(ang1);

}

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

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

if ( mag_vel < DYNA_EPSILON ) {

return FALSE;

}

NR::Point ang2 = NR::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);

// convert to point

dc->ang = NR::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_dyna_draw_brush(SPDynaDrawContext *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);

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

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

}

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

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

NR::Point abs_middle = sp_dyna_draw_get_vpoint(dc, dc->cur);

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

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

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

dc->npoints++;

}

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

{

desktop->setToolboxAdjustmentValue (id, value);

}

sp_dyna_draw_context_root_handler(SPEventContext *event_context,

GdkEvent *event)

{

SPDynaDrawContext *dc = SP_DYNA_DRAW_CONTEXT(event_context);

SPDesktop *desktop = event_context->desktop;

gint ret = FALSE;

switch (event->type) {

case GDK_BUTTON_PRESS:

if ( event->button.button == 1 ) {

SPDesktop *desktop = SP_EVENT_CONTEXT_DESKTOP(dc);

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

return TRUE;

}

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

event->button.y);

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

sp_dyna_draw_reset(dc, button_dt);

sp_dyna_draw_extinput(dc, event);

sp_dyna_draw_apply(dc, button_dt);

sp_curve_reset(dc->accumulated);

if (dc->repr) {

dc->repr = NULL;

}

/* 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;

dc->is_drawing = true;

}

break;

case GDK_MOTION_NOTIFY:

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

dc->dragging = TRUE;

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

event->motion.y);

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

sp_dyna_draw_extinput(dc, event);

if (!sp_dyna_draw_apply(dc, motion_dt)) {

ret = TRUE;

break;

}

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

sp_dyna_draw_brush(dc);

g_assert( dc->npoints > 0 );

fit_and_split(dc, FALSE);

}

ret = TRUE;

}

break;

case GDK_BUTTON_RELEASE:

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

dc->is_drawing = false;

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

dc->dragging = FALSE;

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

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

sp_dyna_draw_apply(dc, motion_dt);

/* Remove all temporary line segments */

while (dc->segments) {

gtk_object_destroy(GTK_OBJECT(dc->segments->data));

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

}

/* Create object */

fit_and_split(dc, TRUE);

accumulate_calligraphic(dc);

set_to_accumulated(dc); /* temporal implementation */

/* reset accumulated curve */

sp_curve_reset(dc->accumulated);

clear_current(dc);

if (dc->repr) {

dc->repr = NULL;

}

ret = TRUE;

}

break;

case GDK_KEY_PRESS:

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

case GDK_Up:

case GDK_KP_Up:

if (!MOD__CTRL_ONLY) {

dc->angle += 5.0;

if (dc->angle > 90.0)

dc->angle = 90.0;

sp_ddc_update_toolbox (desktop, "calligraphy-angle", dc->angle);

ret = TRUE;

}

break;

case GDK_Down:

case GDK_KP_Down:

if (!MOD__CTRL_ONLY) {

dc->angle -= 5.0;

if (dc->angle < -90.0)

dc->angle = -90.0;

sp_ddc_update_toolbox (desktop, "calligraphy-angle", dc->angle);

ret = TRUE;

}

break;

case GDK_Right:

case GDK_KP_Right:

if (!MOD__CTRL_ONLY) {

dc->width += 0.01;

if (dc->width > 1.0)

dc->width = 1.0;

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

ret = TRUE;

}

break;

case GDK_Left:

case GDK_KP_Left:

if (!MOD__CTRL_ONLY) {

dc->width -= 0.01;

if (dc->width < 0.01)

dc->width = 0.01;

sp_ddc_update_toolbox (desktop, "altx-calligraphy", dc->width * 100);

ret = TRUE;

}

break;

case GDK_x:

case GDK_X:

if (MOD__ALT_ONLY) {

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

ret = TRUE;

}

break;

case GDK_Escape:

sp_desktop_selection(desktop)->clear();

break;

default:

break;

}

default:

break;

}

if (!ret) {

if (((SPEventContextClass *) parent_class)->root_handler) {

ret = ((SPEventContextClass *) parent_class)->root_handler(event_context, event);

}

}

return ret;

}

static void

clear_current(SPDynaDrawContext *dc)

{

/* reset bpath */

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

/* reset curve */

sp_curve_reset(dc->currentcurve);

sp_curve_reset(dc->cal1);

sp_curve_reset(dc->cal2);

/* reset points */

dc->npoints = 0;

}

static void

set_to_accumulated(SPDynaDrawContext *dc)

{

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

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

NArtBpath *abp;

gchar *str;

if (!dc->repr) {

/* Create object */

Inkscape::XML::Node *repr = sp_repr_new("svg:path");

/* Set style */

sp_desktop_apply_style_tool (desktop, repr, "tools.calligraphic", false);

dc->repr = repr;

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

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

item->transform = SP_ITEM(desktop->currentRoot())->getRelativeTransform(desktop->currentLayer());

item->updateRepr();

if (dc->keep_selected) {

sp_desktop_selection(desktop)->set(dc->repr);

} else {

sp_desktop_selection(desktop)->clear();

}

}

abp = nr_artpath_affine(sp_curve_first_bpath(dc->accumulated), sp_desktop_dt2root_affine(desktop));

str = sp_svg_write_path(abp);

g_assert( str != NULL );

g_free(abp);

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

g_free(str);

} else {

if (dc->repr) {

sp_repr_unparent(dc->repr);

}

dc->repr = NULL;

}

sp_document_done(sp_desktop_document(desktop), SP_VERB_CONTEXT_CALLIGRAPHIC,

_("Create calligraphic stroke"));

}

static void

add_cap(SPCurve *curve,

NR::Point const &pre, NR::Point const &from,

NR::Point const &to, NR::Point const &post,

double rounding)

{

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

double mag = NR::L2(vel);

NR::Point v_in = from - pre;

double mag_in = NR::L2(v_in);

if ( mag_in > DYNA_EPSILON ) {

v_in = mag * v_in / mag_in;

} else {

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

}

NR::Point v_out = to - post;

double mag_out = NR::L2(v_out);

if ( mag_out > DYNA_EPSILON ) {

v_out = mag * v_out / mag_out;

} else {

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

}

if ( NR::L2(v_in) > DYNA_EPSILON || NR::L2(v_out) > DYNA_EPSILON ) {

sp_curve_curveto(curve, from + v_in, to + v_out, to);

}

}

static void

accumulate_calligraphic(SPDynaDrawContext *dc)

{

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

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

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

g_assert(dc->cal1->end > 1);

g_assert(rev_cal2->end > 1);

g_assert(SP_CURVE_SEGMENT(dc->cal1, 0)->code == NR_MOVETO_OPEN);

g_assert(SP_CURVE_SEGMENT(rev_cal2, 0)->code == NR_MOVETO_OPEN);

g_assert(SP_CURVE_SEGMENT(dc->cal1, 1)->code == NR_CURVETO);

g_assert(SP_CURVE_SEGMENT(rev_cal2, 1)->code == NR_CURVETO);

g_assert(SP_CURVE_SEGMENT(dc->cal1, dc->cal1->end-1)->code == NR_CURVETO);

g_assert(SP_CURVE_SEGMENT(rev_cal2, rev_cal2->end-1)->code == NR_CURVETO);

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

add_cap(dc->accumulated, SP_CURVE_SEGMENT(dc->cal1, dc->cal1->end-1)->c(2), SP_CURVE_SEGMENT(dc->cal1, dc->cal1->end-1)->c(3), SP_CURVE_SEGMENT(rev_cal2, 0)->c(3), SP_CURVE_SEGMENT(rev_cal2, 1)->c(1), dc->cap_rounding);

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

add_cap(dc->accumulated, SP_CURVE_SEGMENT(rev_cal2, rev_cal2->end-1)->c(2), SP_CURVE_SEGMENT(rev_cal2, rev_cal2->end-1)->c(3), SP_CURVE_SEGMENT(dc->cal1, 0)->c(3), SP_CURVE_SEGMENT(dc->cal1, 1)->c(1), dc->cap_rounding);

sp_curve_closepath(dc->accumulated);

sp_curve_unref(rev_cal2);

sp_curve_reset(dc->cal1);

sp_curve_reset(dc->cal2);

}

}

static double square(double const x)

{

return x * x;

}

static void

fit_and_split(SPDynaDrawContext *dc, gboolean release)

{

double const tolerance_sq = square( NR::expansion(SP_EVENT_CONTEXT(dc)->desktop->w2d()) * TOLERANCE_CALLIGRAPHIC );

#ifdef DYNA_DRAW_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 DYNA_DRAW_VERBOSE

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

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

#endif

/* Current calligraphic */

if ( dc->cal1->end == 0 || dc->cal2->end == 0 ) {

/* dc->npoints > 0 */

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

sp_curve_reset(dc->cal1);

sp_curve_reset(dc->cal2);

sp_curve_moveto(dc->cal1, dc->point1[0]);

sp_curve_moveto(dc->cal2, dc->point2[0]);

}

NR::Point b1[BEZIER_MAX_LENGTH];

gint const nb1 = sp_bezier_fit_cubic_r(b1, dc->point1, dc->npoints,

tolerance_sq, BEZIER_MAX_BEZIERS);

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

NR::Point b2[BEZIER_MAX_LENGTH];

gint const nb2 = sp_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 DYNA_DRAW_VERBOSE

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

#endif

/* CanvasShape */

if (! release) {

sp_curve_reset(dc->currentcurve);

sp_curve_moveto(dc->currentcurve, b1[0]);

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

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

bp1[2], bp1[3]);

}

sp_curve_lineto(dc->currentcurve,

b2[BEZIER_SIZE*(nb2-1) + 3]);

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

sp_curve_curveto(dc->currentcurve, 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);

}

sp_curve_closepath(dc->currentcurve);

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

}

/* Current calligraphic */

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

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

}

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

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

}

} else {

/* fixme: ??? */

#ifdef DYNA_DRAW_VERBOSE

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

#endif

draw_temporary_box(dc);

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

sp_curve_lineto(dc->cal1, dc->point1[i]);

}

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

sp_curve_lineto(dc->cal2, dc->point2[i]);

}

}

/* Fit and draw and copy last point */

#ifdef DYNA_DRAW_VERBOSE

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

#endif

if (!release) {

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

SPCanvasItem *cbp = sp_canvas_item_new(sp_desktop_sketch(SP_EVENT_CONTEXT(dc)->desktop),

SP_TYPE_CANVAS_BPATH,

NULL);

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

sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH (cbp), curve);

sp_curve_unref(curve);

guint32 fillColor = sp_desktop_get_color_tool (SP_ACTIVE_DESKTOP, "tools.calligraphic", true);

//guint32 strokeColor = sp_desktop_get_color_tool (SP_ACTIVE_DESKTOP, "tools.calligraphic", false);

double opacity = sp_desktop_get_master_opacity_tool (SP_ACTIVE_DESKTOP, "tools.calligraphic");

double fillOpacity = sp_desktop_get_opacity_tool (SP_ACTIVE_DESKTOP, "tools.calligraphic", true);

//double strokeOpacity = sp_desktop_get_opacity_tool (SP_ACTIVE_DESKTOP, "tools.calligraphic", 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), SP_EVENT_CONTEXT(dc)->desktop);

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

}

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(SPDynaDrawContext *dc)

{

sp_curve_reset(dc->currentcurve);

sp_curve_moveto(dc->currentcurve, dc->point1[0]);

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

sp_curve_lineto(dc->currentcurve, dc->point1[i]);

}

for (gint i = dc->npoints-1; i >= 0; i--) {

sp_curve_lineto(dc->currentcurve, dc->point2[i]);

}

add_cap(dc->currentcurve, dc->point2[1], dc->point2[0], dc->point1[0], dc->point1[1], dc->cap_rounding);

sp_curve_closepath(dc->currentcurve);

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

}