sp-star.cpp revision 1e26c94d38d46957b039b5ce059d093b5821ea18
#define __SP_STAR_C__
/*
* <sodipodi:star> implementation
*
* Authors:
* Mitsuru Oka <oka326@parkcity.ne.jp>
* Lauris Kaplinski <lauris@kaplinski.com>
* bulia byak <buliabyak@users.sf.net>
*
* Copyright (C) 1999-2002 Lauris Kaplinski
* Copyright (C) 2000-2001 Ximian, Inc.
*
* Released under GNU GPL, read the file 'COPYING' for more information
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include <cstring>
#include <string>
#include <glibmm/i18n.h>
#include "svg/svg.h"
#include "attributes.h"
#include "display/curve.h"
#include "xml/repr.h"
#include "document.h"
#include <2geom/pathvector.h>
#include "sp-star.h"
static void sp_star_class_init (SPStarClass *klass);
static void sp_star_init (SPStar *star);
static void sp_star_build (SPObject * object, SPDocument * document, Inkscape::XML::Node * repr);
static Inkscape::XML::Node *sp_star_write (SPObject *object, Inkscape::XML::Document *doc, Inkscape::XML::Node *repr, guint flags);
static void sp_star_set (SPObject *object, unsigned int key, const gchar *value);
static void sp_star_update (SPObject *object, SPCtx *ctx, guint flags);
static gchar * sp_star_description (SPItem * item);
static void sp_star_snappoints(SPItem const *item, bool const target, SnapPointsWithType &p, Inkscape::SnapPreferences const *snapprefs);
static void sp_star_set_shape (SPShape *shape);
static void sp_star_update_patheffect (SPLPEItem *lpeitem, bool write);
static SPShapeClass *parent_class;
GType
sp_star_get_type (void)
{
static GType type = 0;
if (!type) {
GTypeInfo info = {
sizeof (SPStarClass),
NULL, NULL,
(GClassInitFunc) sp_star_class_init,
NULL, NULL,
sizeof (SPStar),
16,
(GInstanceInitFunc) sp_star_init,
NULL, /* value_table */
};
type = g_type_register_static (SP_TYPE_SHAPE, "SPStar", &info, (GTypeFlags)0);
}
return type;
}
static void
sp_star_class_init (SPStarClass *klass)
{
GObjectClass * gobject_class;
SPObjectClass * sp_object_class;
SPItemClass * item_class;
SPLPEItemClass * lpe_item_class;
SPShapeClass * shape_class;
gobject_class = (GObjectClass *) klass;
sp_object_class = (SPObjectClass *) klass;
item_class = (SPItemClass *) klass;
lpe_item_class = (SPLPEItemClass *) klass;
shape_class = (SPShapeClass *) klass;
parent_class = (SPShapeClass *)g_type_class_ref (SP_TYPE_SHAPE);
sp_object_class->build = sp_star_build;
sp_object_class->write = sp_star_write;
sp_object_class->set = sp_star_set;
sp_object_class->update = sp_star_update;
item_class->description = sp_star_description;
item_class->snappoints = sp_star_snappoints;
lpe_item_class->update_patheffect = sp_star_update_patheffect;
shape_class->set_shape = sp_star_set_shape;
}
static void
sp_star_init (SPStar * star)
{
star->sides = 5;
star->center = Geom::Point(0, 0);
star->r[0] = 1.0;
star->r[1] = 0.001;
star->arg[0] = star->arg[1] = 0.0;
star->flatsided = 0;
star->rounded = 0.0;
star->randomized = 0.0;
}
static void
sp_star_build (SPObject * object, SPDocument * document, Inkscape::XML::Node * repr)
{
if (((SPObjectClass *) parent_class)->build)
((SPObjectClass *) parent_class)->build (object, document, repr);
sp_object_read_attr (object, "sodipodi:cx");
sp_object_read_attr (object, "sodipodi:cy");
sp_object_read_attr (object, "sodipodi:sides");
sp_object_read_attr (object, "sodipodi:r1");
sp_object_read_attr (object, "sodipodi:r2");
sp_object_read_attr (object, "sodipodi:arg1");
sp_object_read_attr (object, "sodipodi:arg2");
sp_object_read_attr (object, "inkscape:flatsided");
sp_object_read_attr (object, "inkscape:rounded");
sp_object_read_attr (object, "inkscape:randomized");
}
static Inkscape::XML::Node *
sp_star_write (SPObject *object, Inkscape::XML::Document *xml_doc, Inkscape::XML::Node *repr, guint flags)
{
SPStar *star = SP_STAR (object);
if ((flags & SP_OBJECT_WRITE_BUILD) && !repr) {
repr = xml_doc->createElement("svg:path");
}
if (flags & SP_OBJECT_WRITE_EXT) {
repr->setAttribute("sodipodi:type", "star");
sp_repr_set_int (repr, "sodipodi:sides", star->sides);
sp_repr_set_svg_double(repr, "sodipodi:cx", star->center[Geom::X]);
sp_repr_set_svg_double(repr, "sodipodi:cy", star->center[Geom::Y]);
sp_repr_set_svg_double(repr, "sodipodi:r1", star->r[0]);
sp_repr_set_svg_double(repr, "sodipodi:r2", star->r[1]);
sp_repr_set_svg_double(repr, "sodipodi:arg1", star->arg[0]);
sp_repr_set_svg_double(repr, "sodipodi:arg2", star->arg[1]);
sp_repr_set_boolean (repr, "inkscape:flatsided", star->flatsided);
sp_repr_set_svg_double(repr, "inkscape:rounded", star->rounded);
sp_repr_set_svg_double(repr, "inkscape:randomized", star->randomized);
}
sp_star_set_shape ((SPShape *) star);
char *d = sp_svg_write_path (((SPShape *) star)->curve->get_pathvector());
repr->setAttribute("d", d);
g_free (d);
if (((SPObjectClass *) (parent_class))->write)
((SPObjectClass *) (parent_class))->write (object, xml_doc, repr, flags);
return repr;
}
static void
sp_star_set (SPObject *object, unsigned int key, const gchar *value)
{
SVGLength::Unit unit;
SPStar *star = SP_STAR (object);
/* fixme: we should really collect updates */
switch (key) {
case SP_ATTR_SODIPODI_SIDES:
if (value) {
star->sides = atoi (value);
star->sides = NR_CLAMP(star->sides, 3, 1024);
} else {
star->sides = 5;
}
object->requestDisplayUpdate(SP_OBJECT_MODIFIED_FLAG);
break;
case SP_ATTR_SODIPODI_CX:
if (!sp_svg_length_read_ldd (value, &unit, NULL, &star->center[Geom::X]) ||
(unit == SVGLength::EM) ||
(unit == SVGLength::EX) ||
(unit == SVGLength::PERCENT)) {
star->center[Geom::X] = 0.0;
}
object->requestDisplayUpdate(SP_OBJECT_MODIFIED_FLAG);
break;
case SP_ATTR_SODIPODI_CY:
if (!sp_svg_length_read_ldd (value, &unit, NULL, &star->center[Geom::Y]) ||
(unit == SVGLength::EM) ||
(unit == SVGLength::EX) ||
(unit == SVGLength::PERCENT)) {
star->center[Geom::Y] = 0.0;
}
object->requestDisplayUpdate(SP_OBJECT_MODIFIED_FLAG);
break;
case SP_ATTR_SODIPODI_R1:
if (!sp_svg_length_read_ldd (value, &unit, NULL, &star->r[0]) ||
(unit == SVGLength::EM) ||
(unit == SVGLength::EX) ||
(unit == SVGLength::PERCENT)) {
star->r[0] = 1.0;
}
/* fixme: Need CLAMP (Lauris) */
object->requestDisplayUpdate(SP_OBJECT_MODIFIED_FLAG);
break;
case SP_ATTR_SODIPODI_R2:
if (!sp_svg_length_read_ldd (value, &unit, NULL, &star->r[1]) ||
(unit == SVGLength::EM) ||
(unit == SVGLength::EX) ||
(unit == SVGLength::PERCENT)) {
star->r[1] = 0.0;
}
object->requestDisplayUpdate(SP_OBJECT_MODIFIED_FLAG);
return;
case SP_ATTR_SODIPODI_ARG1:
if (value) {
star->arg[0] = g_ascii_strtod (value, NULL);
} else {
star->arg[0] = 0.0;
}
object->requestDisplayUpdate(SP_OBJECT_MODIFIED_FLAG);
break;
case SP_ATTR_SODIPODI_ARG2:
if (value) {
star->arg[1] = g_ascii_strtod (value, NULL);
} else {
star->arg[1] = 0.0;
}
object->requestDisplayUpdate(SP_OBJECT_MODIFIED_FLAG);
break;
case SP_ATTR_INKSCAPE_FLATSIDED:
if (value && !strcmp (value, "true"))
star->flatsided = true;
else star->flatsided = false;
object->requestDisplayUpdate(SP_OBJECT_MODIFIED_FLAG);
break;
case SP_ATTR_INKSCAPE_ROUNDED:
if (value) {
star->rounded = g_ascii_strtod (value, NULL);
} else {
star->rounded = 0.0;
}
object->requestDisplayUpdate(SP_OBJECT_MODIFIED_FLAG);
break;
case SP_ATTR_INKSCAPE_RANDOMIZED:
if (value) {
star->randomized = g_ascii_strtod (value, NULL);
} else {
star->randomized = 0.0;
}
object->requestDisplayUpdate(SP_OBJECT_MODIFIED_FLAG);
break;
default:
if (((SPObjectClass *) parent_class)->set)
((SPObjectClass *) parent_class)->set (object, key, value);
break;
}
}
static void
sp_star_update (SPObject *object, SPCtx *ctx, guint flags)
{
if (flags & (SP_OBJECT_MODIFIED_FLAG |
SP_OBJECT_STYLE_MODIFIED_FLAG |
SP_OBJECT_VIEWPORT_MODIFIED_FLAG)) {
sp_shape_set_shape ((SPShape *) object);
}
if (((SPObjectClass *) parent_class)->update)
((SPObjectClass *) parent_class)->update (object, ctx, flags);
}
static void
sp_star_update_patheffect(SPLPEItem *lpeitem, bool write)
{
SPShape *shape = (SPShape *) lpeitem;
sp_star_set_shape(shape);
if (write) {
Inkscape::XML::Node *repr = SP_OBJECT_REPR(shape);
if ( shape->curve != NULL ) {
gchar *str = sp_svg_write_path(shape->curve->get_pathvector());
repr->setAttribute("d", str);
g_free(str);
} else {
repr->setAttribute("d", NULL);
}
}
((SPObject *)shape)->requestDisplayUpdate(SP_OBJECT_MODIFIED_FLAG);
}
static gchar *
sp_star_description (SPItem *item)
{
SPStar *star = SP_STAR (item);
// while there will never be less than 3 vertices, we still need to
// make calls to ngettext because the pluralization may be different
// for various numbers >=3. The singular form is used as the index.
if (star->flatsided == false )
return g_strdup_printf (ngettext("<b>Star</b> with %d vertex",
"<b>Star</b> with %d vertices",
star->sides), star->sides);
else
return g_strdup_printf (ngettext("<b>Polygon</b> with %d vertex",
"<b>Polygon</b> with %d vertices",
star->sides), star->sides);
}
/**
Returns a unit-length vector at 90 degrees to the direction from o to n
*/
static Geom::Point
rot90_rel (Geom::Point o, Geom::Point n)
{
return ((1/Geom::L2(n - o)) * Geom::Point ((n - o)[Geom::Y], (o - n)[Geom::X]));
}
/**
Returns a unique 32 bit int for a given point.
Obvious (but acceptable for my purposes) limits to uniqueness:
- returned value for x,y repeats for x+n*1024,y+n*1024
- returned value is unchanged when the point is moved by less than 1/1024 of px
*/
static guint32
point_unique_int (Geom::Point o)
{
return ((guint32)
65536 *
(((int) floor (o[Geom::X] * 64)) % 1024 + ((int) floor (o[Geom::X] * 1024)) % 64)
+
(((int) floor (o[Geom::Y] * 64)) % 1024 + ((int) floor (o[Geom::Y] * 1024)) % 64)
);
}
/**
Returns the next pseudorandom value using the Linear Congruential Generator algorithm (LCG)
with the parameters (m = 2^32, a = 69069, b = 1). These parameters give a full-period generator,
i.e. it is guaranteed to go through all integers < 2^32 (see http://random.mat.sbg.ac.at/~charly/server/server.html)
*/
static inline guint32
lcg_next(guint32 const prev)
{
return (guint32) ( 69069 * prev + 1 );
}
/**
Returns a random number in the range [-0.5, 0.5) from the given seed, stepping the given number of steps from the seed.
*/
static double
rnd (guint32 const seed, unsigned steps) {
guint32 lcg = seed;
for (; steps > 0; steps --)
lcg = lcg_next (lcg);
return ( lcg / 4294967296. ) - 0.5;
}
static Geom::Point
sp_star_get_curvepoint (SPStar *star, SPStarPoint point, gint index, bool previ)
{
// the point whose neighboring curve handle we're calculating
Geom::Point o = sp_star_get_xy (star, point, index);
// indices of previous and next points
gint pi = (index > 0)? (index - 1) : (star->sides - 1);
gint ni = (index < star->sides - 1)? (index + 1) : 0;
// the other point type
SPStarPoint other = (point == SP_STAR_POINT_KNOT2? SP_STAR_POINT_KNOT1 : SP_STAR_POINT_KNOT2);
// the neighbors of o; depending on flatsided, they're either the same type (polygon) or the other type (star)
Geom::Point prev = (star->flatsided? sp_star_get_xy (star, point, pi) : sp_star_get_xy (star, other, point == SP_STAR_POINT_KNOT2? index : pi));
Geom::Point next = (star->flatsided? sp_star_get_xy (star, point, ni) : sp_star_get_xy (star, other, point == SP_STAR_POINT_KNOT1? index : ni));
// prev-next midpoint
Geom::Point mid = 0.5 * (prev + next);
// point to which we direct the bissector of the curve handles;
// it's far enough outside the star on the perpendicular to prev-next through mid
Geom::Point biss = mid + 100000 * rot90_rel (mid, next);
// lengths of vectors to prev and next
gdouble prev_len = Geom::L2 (prev - o);
gdouble next_len = Geom::L2 (next - o);
// unit-length vector perpendicular to o-biss
Geom::Point rot = rot90_rel (o, biss);
// multiply rot by star->rounded coefficient and the distance to the star point; flip for next
Geom::Point ret;
if (previ) {
ret = (star->rounded * prev_len) * rot;
} else {
ret = (star->rounded * next_len * -1) * rot;
}
if (star->randomized == 0) {
// add the vector to o to get the final curvepoint
return o + ret;
} else {
// the seed corresponding to the exact point
guint32 seed = point_unique_int (o);
// randomly rotate (by step 3 from the seed) and scale (by step 4) the vector
ret = ret * Geom::Matrix (Geom::Rotate (star->randomized * M_PI * rnd (seed, 3)));
ret *= ( 1 + star->randomized * rnd (seed, 4));
// the randomized corner point
Geom::Point o_randomized = sp_star_get_xy (star, point, index, true);
return o_randomized + ret;
}
}
#define NEXT false
#define PREV true
static void
sp_star_set_shape (SPShape *shape)
{
SPStar *star = SP_STAR (shape);
// perhaps we should convert all our shapes into LPEs without source path
// and with knotholders for parameters, then this situation will be handled automatically
// by disabling the entire stack (including the shape LPE)
if (sp_lpe_item_has_broken_path_effect(SP_LPE_ITEM(shape))) {
g_warning ("The star shape has unknown LPE on it! Convert to path to make it editable preserving the appearance; editing it as star will remove the bad LPE");
if (SP_OBJECT_REPR(shape)->attribute("d")) {
// unconditionally read the curve from d, if any, to preserve appearance
Geom::PathVector pv = sp_svg_read_pathv(SP_OBJECT_REPR(shape)->attribute("d"));
SPCurve *cold = new SPCurve(pv);
sp_shape_set_curve_insync (shape, cold, TRUE);
cold->unref();
}
return;
}
SPCurve *c = new SPCurve ();
gint sides = star->sides;
bool not_rounded = (fabs (star->rounded) < 1e-4);
// note that we pass randomized=true to sp_star_get_xy, because the curve must be randomized;
// other places that call that function (e.g. the knotholder) need the exact point
// draw 1st segment
c->moveto(sp_star_get_xy (star, SP_STAR_POINT_KNOT1, 0, true));
if (star->flatsided == false) {
if (not_rounded) {
c->lineto(sp_star_get_xy (star, SP_STAR_POINT_KNOT2, 0, true));
} else {
c->curveto(sp_star_get_curvepoint (star, SP_STAR_POINT_KNOT1, 0, NEXT),
sp_star_get_curvepoint (star, SP_STAR_POINT_KNOT2, 0, PREV),
sp_star_get_xy (star, SP_STAR_POINT_KNOT2, 0, true));
}
}
// draw all middle segments
for (gint i = 1; i < sides; i++) {
if (not_rounded) {
c->lineto(sp_star_get_xy (star, SP_STAR_POINT_KNOT1, i, true));
} else {
if (star->flatsided == false) {
c->curveto(sp_star_get_curvepoint (star, SP_STAR_POINT_KNOT2, i - 1, NEXT),
sp_star_get_curvepoint (star, SP_STAR_POINT_KNOT1, i, PREV),
sp_star_get_xy (star, SP_STAR_POINT_KNOT1, i, true));
} else {
c->curveto(sp_star_get_curvepoint (star, SP_STAR_POINT_KNOT1, i - 1, NEXT),
sp_star_get_curvepoint (star, SP_STAR_POINT_KNOT1, i, PREV),
sp_star_get_xy (star, SP_STAR_POINT_KNOT1, i, true));
}
}
if (star->flatsided == false) {
if (not_rounded) {
c->lineto(sp_star_get_xy (star, SP_STAR_POINT_KNOT2, i, true));
} else {
c->curveto(sp_star_get_curvepoint (star, SP_STAR_POINT_KNOT1, i, NEXT),
sp_star_get_curvepoint (star, SP_STAR_POINT_KNOT2, i, PREV),
sp_star_get_xy (star, SP_STAR_POINT_KNOT2, i, true));
}
}
}
// draw last segment
if (not_rounded) {
c->lineto(sp_star_get_xy (star, SP_STAR_POINT_KNOT1, 0, true));
} else {
if (star->flatsided == false) {
c->curveto(sp_star_get_curvepoint (star, SP_STAR_POINT_KNOT2, sides - 1, NEXT),
sp_star_get_curvepoint (star, SP_STAR_POINT_KNOT1, 0, PREV),
sp_star_get_xy (star, SP_STAR_POINT_KNOT1, 0, true));
} else {
c->curveto(sp_star_get_curvepoint (star, SP_STAR_POINT_KNOT1, sides - 1, NEXT),
sp_star_get_curvepoint (star, SP_STAR_POINT_KNOT1, 0, PREV),
sp_star_get_xy (star, SP_STAR_POINT_KNOT1, 0, true));
}
}
c->closepath();
/* Reset the shape'scurve to the "original_curve"
* This is very important for LPEs to work properly! (the bbox might be recalculated depending on the curve in shape)*/
sp_shape_set_curve_insync (shape, c, TRUE);
if (sp_lpe_item_has_path_effect(SP_LPE_ITEM(shape)) && sp_lpe_item_path_effects_enabled(SP_LPE_ITEM(shape))) {
SPCurve *c_lpe = c->copy();
bool success = sp_lpe_item_perform_path_effect(SP_LPE_ITEM (shape), c_lpe);
if (success) {
sp_shape_set_curve_insync (shape, c_lpe, TRUE);
}
c_lpe->unref();
}
c->unref();
}
void
sp_star_position_set (SPStar *star, gint sides, Geom::Point center, gdouble r1, gdouble r2, gdouble arg1, gdouble arg2, bool isflat, double rounded, double randomized)
{
g_return_if_fail (star != NULL);
g_return_if_fail (SP_IS_STAR (star));
star->sides = NR_CLAMP(sides, 3, 1024);
star->center = center;
star->r[0] = MAX (r1, 0.001);
if (isflat == false) {
star->r[1] = NR_CLAMP(r2, 0.0, star->r[0]);
} else {
star->r[1] = NR_CLAMP( r1*cos(M_PI/sides) ,0.0, star->r[0] );
}
star->arg[0] = arg1;
star->arg[1] = arg2;
star->flatsided = isflat;
star->rounded = rounded;
star->randomized = randomized;
SP_OBJECT(star)->requestDisplayUpdate(SP_OBJECT_MODIFIED_FLAG);
}
static void sp_star_snappoints(SPItem const *item, bool const target, SnapPointsWithType &p, Inkscape::SnapPreferences const *snapprefs)
{
// We will determine the star's midpoint ourselves, instead of trusting on the base class
// Therefore setSnapObjectMidpoints() is set to false temporarily
Inkscape::SnapPreferences local_snapprefs = *snapprefs;
local_snapprefs.setSnapObjectMidpoints(false);
if (((SPItemClass *) parent_class)->snappoints) {
((SPItemClass *) parent_class)->snappoints (item, target, p, &local_snapprefs);
}
// Help enforcing strict snapping, i.e. only return nodes when we're snapping nodes to nodes or a guide to nodes
if (!(snapprefs->getSnapModeNode() || snapprefs->getSnapModeGuide())) {
return;
}
if (snapprefs->getSnapObjectMidpoints()) {
Geom::Matrix const i2d (sp_item_i2d_affine (item));
int type = target ? int(Inkscape::SNAPTARGET_OBJECT_MIDPOINT) : int(Inkscape::SNAPSOURCE_OBJECT_MIDPOINT);
p.push_back(std::make_pair(SP_STAR(item)->center * i2d, type));
}
}
/**
* sp_star_get_xy: Get X-Y value as item coordinate system
* @star: star item
* @point: point type to obtain X-Y value
* @index: index of vertex
* @p: pointer to store X-Y value
* @randomized: false (default) if you want to get exact, not randomized point
*
* Initial item coordinate system is same as document coordinate system.
*/
Geom::Point
sp_star_get_xy (SPStar *star, SPStarPoint point, gint index, bool randomized)
{
gdouble darg = 2.0 * M_PI / (double) star->sides;
double arg = star->arg[point];
arg += index * darg;
Geom::Point xy = star->r[point] * Geom::Point(cos(arg), sin(arg)) + star->center;
if (!randomized || star->randomized == 0) {
// return the exact point
return xy;
} else { // randomize the point
// find out the seed, unique for this point so that randomization is the same so long as the original point is stationary
guint32 seed = point_unique_int (xy);
// the full range (corresponding to star->randomized == 1.0) is equal to the star's diameter
double range = 2 * MAX (star->r[0], star->r[1]);
// find out the random displacement; x is controlled by step 1 from the seed, y by the step 2
Geom::Point shift (star->randomized * range * rnd (seed, 1), star->randomized * range * rnd (seed, 2));
// add the shift to the exact point
return xy + shift;
}
}
/*
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 :