dyna-draw-context.cpp revision 61f0bc9dfe9dee35ba3522153a7409cceb8434cd
#define __SP_DYNA_DRAW_CONTEXT_C__
/*
* Handwriting-like drawing mode
*
* Authors:
* Mitsuru Oka <oka326@parkcity.ne.jp>
* Lauris Kaplinski <lauris@kaplinski.com>
* bulia byak <buliabyak@users.sf.net>
* MenTaLguY <mental@rydia.net>
*
* The original dynadraw code:
* Paul Haeberli <paul@sgi.com>
*
* Copyright (C) 1998 The Free Software Foundation
* Copyright (C) 1999-2005 authors
* Copyright (C) 2001-2002 Ximian, Inc.
* Copyright (C) 2005-2007 bulia byak
* Copyright (C) 2006 MenTaLguY
*
* Released under GNU GPL, read the file 'COPYING' for more information
*/
#define noDYNA_DRAW_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/canvas-bpath.h"
#include "display/bezier-utils.h"
#include "display/curve.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 "prefs-utils.h"
#include "pixmaps/cursor-calligraphy.xpm"
#include "libnr/n-art-bpath.h"
#include "libnr/nr-path.h"
#include "libnr/nr-matrix-ops.h"
#include "libnr/nr-scale-translate-ops.h"
#include "libnr/nr-convert2geom.h"
#include "xml/repr.h"
#include "context-fns.h"
#include "sp-item.h"
#include "inkscape.h"
#include "color.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 <2geom/isnan.h>
#include <2geom/pathvector.h>
#include "dyna-draw-context.h"
#define DDC_RED_RGBA 0xff0000ff
#define TOLERANCE_CALLIGRAPHIC 0.1
#define DYNA_EPSILON 0.5e-6
#define DYNA_EPSILON_START 0.5e-2
#define DYNA_VEL_START 1e-5
#define DYNA_MIN_WIDTH 1.0e-6
// FIXME: move it to some shared file to be reused by both calligraphy and dropper
#define C1 0.552
static NArtBpath const hatch_area_circle[] = {
{ NR_MOVETO, 0, 0, 0, 0, -1, 0 },
{ NR_CURVETO, -1, C1, -C1, 1, 0, 1 },
{ NR_CURVETO, C1, 1, 1, C1, 1, 0 },
{ NR_CURVETO, 1, -C1, C1, -1, 0, -1 },
{ NR_CURVETO, -C1, -1, -1, -C1, -1, 0 },
{ NR_END, 0, 0, 0, 0, 0, 0 }
};
#undef C1
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, bool unionize);
static void add_cap(SPCurve *curve, NR::Point const &from, NR::Point const &to, 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 *dd_parent_class = 0;
GType sp_dyna_draw_context_get_type(void)
{
static GType type = 0;
if (!type) {
GTypeInfo info = {
sizeof(SPDynaDrawContextClass),
0, // base_init
0, // base_finalize
(GClassInitFunc)sp_dyna_draw_context_class_init,
0, // class_finalize
0, // class_data
sizeof(SPDynaDrawContext),
0, // n_preallocs
(GInstanceInitFunc)sp_dyna_draw_context_init,
0 // value_table
};
type = g_type_register_static(SP_TYPE_COMMON_CONTEXT, "SPDynaDrawContext", &info, static_cast<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;
dd_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)
{
ddc->cursor_shape = cursor_calligraphy_xpm;
ddc->hot_x = 4;
ddc->hot_y = 4;
ddc->vel_thin = 0.1;
ddc->flatness = 0.9;
ddc->cap_rounding = 0.0;
ddc->abs_width = false;
ddc->keep_selected = true;
ddc->hatch_spacing = 0;
ddc->hatch_spacing_step = 0;
new (&ddc->hatch_pointer_past) std::list<double>();
new (&ddc->hatch_nearest_past) std::list<double>();
ddc->hatch_last_nearest = NR::Point(0,0);
ddc->hatch_last_pointer = NR::Point(0,0);
ddc->hatch_vector_accumulated = NR::Point(0,0);
ddc->hatch_escaped = false;
ddc->hatch_area = NULL;
ddc->hatch_item = NULL;
ddc->hatch_livarot_path = NULL;
ddc->trace_bg = false;
}
static void
sp_dyna_draw_context_dispose(GObject *object)
{
SPDynaDrawContext *ddc = SP_DYNA_DRAW_CONTEXT(object);
if (ddc->hatch_area) {
gtk_object_destroy(GTK_OBJECT(ddc->hatch_area));
ddc->hatch_area = NULL;
}
G_OBJECT_CLASS(dd_parent_class)->dispose(object);
ddc->hatch_pointer_past.~list();
ddc->hatch_nearest_past.~list();
}
static void
sp_dyna_draw_context_setup(SPEventContext *ec)
{
SPDynaDrawContext *ddc = SP_DYNA_DRAW_CONTEXT(ec);
if (((SPEventContextClass *) dd_parent_class)->setup)
((SPEventContextClass *) dd_parent_class)->setup(ec);
ddc->accumulated = new SPCurve(32);
ddc->currentcurve = new SPCurve(4);
ddc->cal1 = new SPCurve(32);
ddc->cal2 = new SPCurve(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);
{
SPCurve *c = SPCurve::new_from_foreign_bpath(hatch_area_circle);
ddc->hatch_area = sp_canvas_bpath_new(sp_desktop_controls(ec->desktop), c);
c->unref();
sp_canvas_bpath_set_fill(SP_CANVAS_BPATH(ddc->hatch_area), 0x00000000,(SPWindRule)0);
sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(ddc->hatch_area), 0x0000007f, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
sp_canvas_item_hide(ddc->hatch_area);
}
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, "keep_selected");
sp_event_context_read(ec, "cap_rounding");
ddc->is_drawing = false;
ddc->_message_context = new Inkscape::MessageContext((ec->desktop)->messageStack());
if (prefs_get_int_attribute("tools.calligraphic", "selcue", 0) != 0) {
ec->enableSelectionCue();
}
}
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, "tracebackground")) {
ddc->trace_bg = (val && strcmp(val, "0"));
} else if (!strcmp(key, "keep_selected")) {
ddc->keep_selected = (val && strcmp(val, "0"));
} else {
//pass on up to parent class to handle common attributes.
if ( dd_parent_class->set ) {
dd_parent_class->set(ec, key, val);
}
}
//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;
}
/* Get normalized point */
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);
}
/* Get view point */
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->vel_max = 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 force is below the absolute threshold DYNA_EPSILON,
// or we haven't yet reached DYNA_VEL_START (i.e. at the beginning of stroke)
// _and_ the force is below the (higher) DYNA_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 ( NR::L2(force) < DYNA_EPSILON || (dc->vel_max < DYNA_VEL_START && NR::L2(force) < DYNA_EPSILON_START)) {
return FALSE;
}
dc->acc = force / mass;
/* Calculate new velocity */
dc->vel += dc->acc;
if (NR::L2(dc->vel) > dc->vel_max)
dc->vel_max = NR::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) {
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);
// 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 = NR::L2(NR::Point (cos (new_ang), sin (new_ang)) - dc->ang);
if ( angle_delta / NR::L2(dc->vel) > 4000 ) {
return FALSE;
}
// convert to point
dc->ang = NR::Point (cos (new_ang), sin (new_ang));
// g_print ("force %g acc %g vel_max %g vel %g a1 %g a2 %g new_ang %g\n", NR::L2(force), NR::L2(dc->acc), dc->vel_max, NR::L2(dc->vel), a1, a2, 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);
// get the real brush point, not the same as pointer (affected by hatch tracking and/or mass
// drag)
NR::Point brush = sp_dyna_draw_get_vpoint(dc, dc->cur);
NR::Point brush_w = SP_EVENT_CONTEXT(dc)->desktop->d2w(brush);
double trace_thick = 1;
if (dc->trace_bg) {
// pick single pixel
NRPixBlock pb;
int x = (int) floor(brush_w[NR::X]);
int y = (int) floor(brush_w[NR::Y]);
nr_pixblock_setup_fast(&pb, NR_PIXBLOCK_MODE_R8G8B8A8P, x, y, x+1, y+1, TRUE);
sp_canvas_arena_render_pixblock(SP_CANVAS_ARENA(sp_desktop_drawing(SP_EVENT_CONTEXT(dc)->desktop)), &pb);
const unsigned char *s = NR_PIXBLOCK_PX(&pb);
double R = s[0] / 255.0;
double G = s[1] / 255.0;
double B = s[2] / 255.0;
double A = s[3] / 255.0;
double max = MAX (MAX (R, G), B);
double min = MIN (MIN (R, G), B);
double L = A * (max + min)/2 + (1 - A); // blend with white bg
trace_thick = 1 - L;
//g_print ("L %g thick %g\n", L, trace_thick);
}
double width = (pressure_thick * trace_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;
dc->point1[dc->npoints] = brush + del_left;
dc->point2[dc->npoints] = brush - del_right;
dc->del = 0.5*(del_left + del_right);
dc->npoints++;
}
void
sp_ddc_update_toolbox (SPDesktop *desktop, const gchar *id, double value)
{
desktop->setToolboxAdjustmentValue (id, value);
}
static void
calligraphic_cancel(SPDynaDrawContext *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) {
gtk_object_destroy(GTK_OBJECT(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;
}
}
gint
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 && !event_context->space_panning) {
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);
dc->accumulated->reset();
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;
sp_canvas_force_full_redraw_after_interruptions(desktop->canvas, 3);
dc->is_drawing = true;
}
break;
case GDK_MOTION_NOTIFY:
{
NR::Point const motion_w(event->motion.x,
event->motion.y);
NR::Point motion_dt(desktop->w2d(motion_w));
sp_dyna_draw_extinput(dc, event);
dc->_message_context->clear();
// for hatching:
double hatch_dist = 0;
NR::Point hatch_unit_vector(0,0);
NR::Point nearest(0,0);
NR::Point pointer(0,0);
NR::Matrix motion_to_curve(NR::identity());
if (event->motion.state & GDK_CONTROL_MASK) { // hatching - sense the item
SPItem *selected = sp_desktop_selection(desktop)->singleItem();
if (selected && (SP_IS_SHAPE(selected) || SP_IS_TEXT(selected))) {
// One item selected, and it's a path;
// let's try to track it as a guide
if (selected != dc->hatch_item) {
dc->hatch_item = selected;
if (dc->hatch_livarot_path)
delete dc->hatch_livarot_path;
dc->hatch_livarot_path = Path_for_item (dc->hatch_item, true, true);
dc->hatch_livarot_path->ConvertWithBackData(0.01);
}
// calculate pointer point in the guide item's coords
motion_to_curve = from_2geom(sp_item_dt2i_affine(selected) * sp_item_i2doc_affine(selected));
pointer = motion_dt * motion_to_curve;
// calculate the nearest point on the guide path
NR::Maybe<Path::cut_position> position = get_nearest_position_on_Path(dc->hatch_livarot_path, pointer);
nearest = get_point_on_Path(dc->hatch_livarot_path, position->piece, position->t);
// distance from pointer to nearest
hatch_dist = NR::L2(pointer - nearest);
// unit-length vector
hatch_unit_vector = (pointer - nearest)/hatch_dist;
dc->_message_context->set(Inkscape::NORMAL_MESSAGE, _("<b>Guide path selected</b>; start drawing along the guide with <b>Ctrl</b>"));
} else {
dc->_message_context->set(Inkscape::NORMAL_MESSAGE, _("<b>Select a guide path</b> to track with <b>Ctrl</b>"));
}
}
if ( dc->is_drawing && (event->motion.state & GDK_BUTTON1_MASK) && !event_context->space_panning) {
dc->dragging = TRUE;
if (event->motion.state & GDK_CONTROL_MASK && dc->hatch_item) { // hatching
#define SPEED_ELEMENTS 12
#define SPEED_MIN 0.12
#define SPEED_NORMAL 0.65
// speed is the movement of the nearest point along the guide path, divided by
// the movement of the pointer at the same period; it is averaged for the last
// SPEED_ELEMENTS motion events. Normally, as you track the guide path, speed
// is about 1, i.e. the nearest point on the path is moved by about the same
// distance as the pointer. If the speed starts to decrease, we are losing
// contact with the guide; if it drops below SPEED_MIN, we are on our own and
// not attracted to guide anymore. Most often this happens when you have
// tracked to the end of a guide calligraphic stroke and keep moving
// further. We try to handle this situation gracefully: not stick with the
// guide forever but let go of it smoothly and without sharp jerks (non-zero
// mass recommended; with zero mass, jerks are still quite noticeable).
double speed = 1;
if (NR::L2(dc->hatch_last_nearest) != 0) {
// the distance nearest moved since the last motion event
double nearest_moved = NR::L2(nearest - dc->hatch_last_nearest);
// the distance pointer moved since the last motion event
double pointer_moved = NR::L2(pointer - dc->hatch_last_pointer);
// store them in stacks limited to SPEED_ELEMENTS
dc->hatch_nearest_past.push_front(nearest_moved);
if (dc->hatch_nearest_past.size() > SPEED_ELEMENTS)
dc->hatch_nearest_past.pop_back();
dc->hatch_pointer_past.push_front(pointer_moved);
if (dc->hatch_pointer_past.size() > SPEED_ELEMENTS)
dc->hatch_pointer_past.pop_back();
// If the stacks are full,
if (dc->hatch_nearest_past.size() == SPEED_ELEMENTS) {
// calculate the sums of all stored movements
double nearest_sum = std::accumulate (dc->hatch_nearest_past.begin(), dc->hatch_nearest_past.end(), 0.0);
double pointer_sum = std::accumulate (dc->hatch_pointer_past.begin(), dc->hatch_pointer_past.end(), 0.0);
// and divide to get the speed
speed = nearest_sum/pointer_sum;
//g_print ("nearest sum %g pointer_sum %g speed %g\n", nearest_sum, pointer_sum, speed);
}
}
if ( dc->hatch_escaped // already escaped, do not reattach
|| (speed < SPEED_MIN) // stuck; most likely reached end of traced stroke
|| (dc->hatch_spacing > 0 && hatch_dist > 50 * dc->hatch_spacing) // went too far from the guide
) {
// We are NOT attracted to the guide!
//g_print ("\nlast_nearest %g %g nearest %g %g pointer %g %g pos %d %g\n", dc->last_nearest[NR::X], dc->last_nearest[NR::Y], nearest[NR::X], nearest[NR::Y], pointer[NR::X], pointer[NR::Y], position->piece, position->t);
// Remember hatch_escaped so we don't get
// attracted again until the end of this stroke
dc->hatch_escaped = true;
} else {
// Calculate angle cosine of this vector-to-guide and all past vectors
// summed, to detect if we accidentally flipped to the other side of the
// guide
double dot = NR::dot (pointer - nearest, dc->hatch_vector_accumulated);
dot /= NR::L2(pointer - nearest) * NR::L2(dc->hatch_vector_accumulated);
if (dc->hatch_spacing != 0) { // spacing was already set
double target;
if (speed > SPEED_NORMAL) {
// all ok, strictly obey the spacing
target = dc->hatch_spacing;
} else {
// looks like we're starting to lose speed,
// so _gradually_ let go attraction to prevent jerks
target = (dc->hatch_spacing * speed + hatch_dist * (SPEED_NORMAL - speed))/SPEED_NORMAL;
}
if (!IS_NAN(dot) && dot < -0.5) {// flip
target = -target;
}
// This is the track pointer that we will use instead of the real one
NR::Point new_pointer = nearest + target * hatch_unit_vector;
// some limited feedback: allow persistent pulling to slightly change
// the spacing
dc->hatch_spacing += (hatch_dist - dc->hatch_spacing)/3500;
// return it to the desktop coords
motion_dt = new_pointer * motion_to_curve.inverse();
} else {
// this is the first motion event, set the dist
dc->hatch_spacing = hatch_dist;
}
// remember last points
dc->hatch_last_pointer = pointer;
dc->hatch_last_nearest = nearest;
dc->hatch_vector_accumulated += (pointer - nearest);
}
dc->_message_context->set(Inkscape::NORMAL_MESSAGE, dc->hatch_escaped? _("Tracking: <b>connection to guide path lost!</b>") : _("<b>Tracking</b> a guide path"));
} else {
dc->_message_context->set(Inkscape::NORMAL_MESSAGE, _("<b>Drawing</b> a calligraphic stroke"));
}
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;
}
// Draw the hatching circle if necessary
if (event->motion.state & GDK_CONTROL_MASK) {
if (dc->hatch_spacing == 0 && hatch_dist != 0) {
// Haven't set spacing yet: gray, center free, update radius live
NR::Point c = desktop->w2d(motion_w);
NR::Matrix const sm (NR::scale(hatch_dist, hatch_dist) * NR::translate(c));
sp_canvas_item_affine_absolute(dc->hatch_area, sm);
sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(dc->hatch_area), 0x7f7f7fff, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
sp_canvas_item_show(dc->hatch_area);
} else if (dc->dragging && !dc->hatch_escaped) {
// Tracking: green, center snapped, fixed radius
NR::Point c = motion_dt;
NR::Matrix const sm (NR::scale(dc->hatch_spacing, dc->hatch_spacing) * NR::translate(c));
sp_canvas_item_affine_absolute(dc->hatch_area, sm);
sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(dc->hatch_area), 0x00FF00ff, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
sp_canvas_item_show(dc->hatch_area);
} else if (dc->dragging && dc->hatch_escaped) {
// Tracking escaped: red, center free, fixed radius
NR::Point c = desktop->w2d(motion_w);
NR::Matrix const sm (NR::scale(dc->hatch_spacing, dc->hatch_spacing) * NR::translate(c));
sp_canvas_item_affine_absolute(dc->hatch_area, sm);
sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(dc->hatch_area), 0xFF0000ff, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
sp_canvas_item_show(dc->hatch_area);
} else {
// Not drawing but spacing set: gray, center snapped, fixed radius
NR::Point c = (nearest + dc->hatch_spacing * hatch_unit_vector) * motion_to_curve.inverse();
if (!IS_NAN(c[NR::X]) && !IS_NAN(c[NR::Y])) {
NR::Matrix const sm (NR::scale(dc->hatch_spacing, dc->hatch_spacing) * NR::translate(c));
sp_canvas_item_affine_absolute(dc->hatch_area, sm);
sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(dc->hatch_area), 0x7f7f7fff, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
sp_canvas_item_show(dc->hatch_area);
}
}
} else {
sp_canvas_item_hide(dc->hatch_area);
}
}
break;
case GDK_BUTTON_RELEASE:
{
NR::Point const motion_w(event->button.x, event->button.y);
NR::Point const motion_dt(desktop->w2d(motion_w));
sp_canvas_item_ungrab(SP_CANVAS_ITEM(desktop->acetate), event->button.time);
sp_canvas_end_forced_full_redraws(desktop->canvas);
dc->is_drawing = false;
if (dc->dragging && event->button.button == 1 && !event_context->space_panning) {
dc->dragging = FALSE;
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, event->button.state & GDK_SHIFT_MASK); // performs document_done
/* reset accumulated curve */
dc->accumulated->reset();
clear_current(dc);
if (dc->repr) {
dc->repr = NULL;
}
if (!dc->hatch_pointer_past.empty()) dc->hatch_pointer_past.clear();
if (!dc->hatch_nearest_past.empty()) dc->hatch_nearest_past.clear();
dc->hatch_last_nearest = NR::Point(0,0);
dc->hatch_last_pointer = NR::Point(0,0);
dc->hatch_vector_accumulated = NR::Point(0,0);
dc->hatch_escaped = false;
dc->hatch_item = NULL;
dc->hatch_livarot_path = NULL;
if (dc->hatch_spacing != 0 && !dc->keep_selected) {
// we do not select the newly drawn path, so increase spacing by step
if (dc->hatch_spacing_step == 0) {
dc->hatch_spacing_step = dc->hatch_spacing;
}
dc->hatch_spacing += dc->hatch_spacing_step;
}
dc->_message_context->clear();
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_Home:
case GDK_KP_Home:
dc->width = 0.01;
sp_ddc_update_toolbox (desktop, "altx-calligraphy", dc->width * 100);
ret = TRUE;
break;
case GDK_End:
case GDK_KP_End:
dc->width = 1.0;
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:
if (dc->is_drawing) {
// if drawing, cancel, otherwise pass it up for deselecting
calligraphic_cancel (dc);
ret = TRUE;
}
break;
case GDK_z:
case GDK_Z:
if (MOD__CTRL_ONLY && dc->is_drawing) {
// if drawing, cancel, otherwise pass it up for undo
calligraphic_cancel (dc);
ret = TRUE;
}
break;
default:
break;
}
break;
case GDK_KEY_RELEASE:
switch (get_group0_keyval(&event->key)) {
case GDK_Control_L:
case GDK_Control_R:
dc->_message_context->clear();
dc->hatch_spacing = 0;
dc->hatch_spacing_step = 0;
break;
default:
break;
}
default:
break;
}
if (!ret) {
if (((SPEventContextClass *) dd_parent_class)->root_handler) {
ret = ((SPEventContextClass *) dd_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 */
dc->currentcurve->reset();
dc->cal1->reset();
dc->cal2->reset();
/* reset points */
dc->npoints = 0;
}
static void
set_to_accumulated(SPDynaDrawContext *dc, bool unionize)
{
SPDesktop *desktop = SP_EVENT_CONTEXT(dc)->desktop;
if (!dc->accumulated->is_empty()) {
if (!dc->repr) {
/* Create object */
Inkscape::XML::Document *xml_doc = sp_document_repr_doc(desktop->doc());
Inkscape::XML::Node *repr = xml_doc->createElement("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();
}
Geom::PathVector pathv = dc->accumulated->get_pathvector() * to_2geom(sp_desktop_dt2root_affine(desktop));
gchar *str = sp_svg_write_path(pathv);
g_assert( str != NULL );
dc->repr->setAttribute("d", str);
g_free(str);
if (unionize) {
sp_desktop_selection(desktop)->add(dc->repr);
sp_selected_path_union_skip_undo();
} else {
if (dc->keep_selected) {
sp_desktop_selection(desktop)->set(dc->repr);
}
}
} else {
if (dc->repr) {
sp_repr_unparent(dc->repr);
}
dc->repr = NULL;
}
sp_document_done(sp_desktop_document(desktop), SP_VERB_CONTEXT_CALLIGRAPHIC,
_("Draw calligraphic stroke"));
}
static void
add_cap(SPCurve *curve,
NR::Point const &from,
NR::Point const &to,
double rounding)
{
if (NR::L2( to - from ) > DYNA_EPSILON) {
NR::Point vel = rounding * NR::rot90( to - from ) / sqrt(2.0);
double mag = NR::L2(vel);
NR::Point v = mag * NR::rot90( to - from ) / NR::L2( to - from );
curve->curveto(from + v, to + v, to);
}
}
static void
accumulate_calligraphic(SPDynaDrawContext *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)[3], (*rev_cal2_firstseg)[3], dc->cap_rounding);
dc->accumulated->append(rev_cal2, true);
add_cap(dc->accumulated, (*rev_cal2_lastseg)[3], (*dc_cal1_firstseg)[3], 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(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->get_length() == 0 || dc->cal2->get_length() == 0 ) {
/* dc->npoints > 0 */
/* g_print("calligraphics(1|2) reset\n"); */
dc->cal1->reset();
dc->cal2->reset();
dc->cal1->moveto(dc->point1[0]);
dc->cal2->moveto(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) {
dc->currentcurve->reset();
dc->currentcurve->moveto(b1[0]);
for (NR::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 (NR::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[0], b1[0], dc->cap_rounding);
}
dc->currentcurve->closepath();
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) {
dc->cal1->curveto(bp1[1], bp1[2], bp1[3]);
}
for (NR::Point *bp2 = b2; bp2 < b2 + BEZIER_SIZE * nb2; bp2 += BEZIER_SIZE) {
dc->cal2->curveto(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++) {
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 DYNA_DRAW_VERBOSE
g_print("[%d]Yup\n", dc->npoints);
#endif
if (!release) {
g_assert(!dc->currentcurve->is_empty());
SPCanvasItem *cbp = sp_canvas_item_new(sp_desktop_sketch(SP_EVENT_CONTEXT(dc)->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 (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)
{
dc->currentcurve->reset();
dc->currentcurve->moveto(dc->point2[dc->npoints-1]);
for (gint i = dc->npoints-2; i >= 0; i--) {
dc->currentcurve->lineto(dc->point2[i]);
}
for (gint i = 0; i < dc->npoints; i++) {
dc->currentcurve->lineto(dc->point1[i]);
}
if (dc->npoints >= 2) {
add_cap(dc->currentcurve, dc->point1[dc->npoints-1], dc->point2[dc->npoints-1], dc->cap_rounding);
}
dc->currentcurve->closepath();
sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(dc->currentshape), dc->currentcurve);
}
/*
Local Variables:
mode:c++
c-file-style:"stroustrup"
c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
indent-tabs-mode:nil
fill-column:99
End:
*/
// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :