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// -*- C++ -*-
/*
* Gnome Chemistry Utils
* gccv/arrow.cc
*
* Copyright (C) 2008-2011 Jean Bréfort <jean.brefort@normalesup.org>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 3 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301
* USA
*/
#include "config.h"
#include "canvas.h"
#include "group.h"
#include "arrow.h"
#include <cmath>
namespace gccv {
Arrow::Arrow (Canvas *canvas, double xstart, double ystart, double xend, double yend):
Line (canvas, xstart, ystart, xend, yend),
m_StartHead (ArrowHeadNone),
m_EndHead (ArrowHeadFull),
m_A (6.),
m_B (8.),
m_C (4.)
{
}
Arrow::Arrow (Group *parent, double xstart, double ystart, double xend, double yend, ItemClient *client):
Line (parent, xstart, ystart, xend, yend, client),
m_StartHead (ArrowHeadNone),
m_EndHead (ArrowHeadFull),
m_A (6.),
m_B (8.),
m_C (4.)
{
}
Arrow::~Arrow ()
{
}
double Arrow::Distance (double x, double y, Item **item) const
{
double dx, dy, dx1, dy1, length;
dx = m_xend - m_xstart;
dy = m_yend - m_ystart;
dx1 = x - m_xstart;
dy1 = y - m_ystart;
length = sqrt (dx * dx + dy * dy);
if (item)
*item = const_cast <Arrow *> (this);
if (length == 0.)
return sqrt (dx1 * dx1 + dy1 * dy1);
// project the (dx1, dy1) vector on the wedge axis.
double xx = (dx1 * dx + dy1 * dy) / length;
double yy = (dx1 * dy - dy1 * dx) / length;
double lw = GetLineWidth () / 2.;
if (xx < 0.) {
switch (m_StartHead) {
default:
case ArrowHeadNone:
break;
case ArrowHeadFull:
break;
case ArrowHeadLeft:
break;
case ArrowHeadRight:
break;
}
return sqrt (dx1 * dx1 + dy1 * dy1);
}
if (xx > length) {
dx1 = xx -length;
switch (m_EndHead) {
default:
case ArrowHeadNone:
break;
case ArrowHeadFull:
break;
case ArrowHeadLeft:
break;
case ArrowHeadRight:
break;
}
/* if (yy > m_Width / 2.)
yy -= m_Width / 2.;
else if (yy < -m_Width / 2.)
yy += m_Width / 2.;
else
return fabs (dx1);*/
return sqrt (dx1 * dx1 + yy * yy);
}
if (fabs (yy) < lw)
return 0.; // this might be wrong near the head, but still acceptable
yy += (yy > 0)? lw: -lw;
switch (m_StartHead) {
default:
case ArrowHeadNone:
break;
case ArrowHeadFull:
break;
case ArrowHeadLeft:
break;
case ArrowHeadRight:
break;
}
switch (m_StartHead) {
default:
case ArrowHeadNone:
break;
case ArrowHeadFull:
break;
case ArrowHeadLeft:
break;
case ArrowHeadRight:
break;
}
return fabs (yy);
}
void Arrow::Draw (cairo_t *cr, G_GNUC_UNUSED bool is_vector) const
{
double theta = atan2 (m_yend - m_ystart, m_xend -m_xstart),
length = sqrt ((m_yend - m_ystart) * (m_yend - m_ystart) + (m_xend -m_xstart) * (m_xend -m_xstart));
GOColor color = GetEffectiveLineColor ();
if (color != 0) {
cairo_save (cr);
cairo_translate (cr, m_xstart, m_ystart);
cairo_rotate (cr, theta);
cairo_move_to (cr, ((m_StartHead == ArrowHeadNone)? 0.: m_A), 0.);
cairo_line_to (cr, ((m_EndHead == ArrowHeadNone)? length: length - m_A), 0.);
cairo_set_line_width (cr, GetLineWidth ());
cairo_set_source_rgba (cr, GO_COLOR_TO_CAIRO (color));
cairo_stroke (cr);
cairo_set_line_width (cr, 0.);
switch (m_StartHead) {
default:
case ArrowHeadNone:
break;
case ArrowHeadFull:
cairo_move_to (cr, m_A, GetLineWidth () / 2.);
cairo_line_to (cr, m_B, GetLineWidth () / 2. + m_C);
cairo_line_to (cr, 0., 0.);
cairo_line_to (cr, m_B, -GetLineWidth () / 2. - m_C);
cairo_line_to (cr, m_A, -GetLineWidth () / 2.);
cairo_close_path (cr);
cairo_fill (cr);
break;
case ArrowHeadLeft:
cairo_move_to (cr, m_A, -GetLineWidth () / 2.);
cairo_line_to (cr, m_B, -GetLineWidth () / 2. - m_C);
cairo_line_to (cr, 0., GetLineWidth () / 2.);
cairo_line_to (cr, m_A, GetLineWidth () / 2.);
cairo_close_path (cr);
cairo_fill (cr);
break;
case ArrowHeadRight:
cairo_move_to (cr, m_A, GetLineWidth () / 2.);
cairo_line_to (cr, m_B, GetLineWidth () / 2. + m_C);
cairo_line_to (cr, 0., -GetLineWidth () / 2.);
cairo_line_to (cr, m_A, -GetLineWidth () / 2.);
cairo_close_path (cr);
cairo_fill (cr);
break;
}
switch (m_EndHead) {
default:
case ArrowHeadNone:
break;
case ArrowHeadFull:
cairo_move_to (cr, length - m_A, GetLineWidth () / 2.);
cairo_line_to (cr, length - m_B, GetLineWidth () / 2. + m_C);
cairo_line_to (cr, length, 0.);
cairo_line_to (cr, length - m_B, -GetLineWidth () / 2. - m_C);
cairo_line_to (cr, length - m_A, -GetLineWidth () / 2.);
cairo_close_path (cr);
cairo_fill (cr);
break;
case ArrowHeadLeft:
cairo_move_to (cr, length - m_A, -GetLineWidth () / 2.);
cairo_line_to (cr, length - m_B, -GetLineWidth () / 2. - m_C);
cairo_line_to (cr, length, GetLineWidth () / 2.);
cairo_line_to (cr, length - m_A, GetLineWidth () / 2.);
cairo_close_path (cr);
cairo_fill (cr);
break;
case ArrowHeadRight:
cairo_move_to (cr, length - m_A, GetLineWidth () / 2.);
cairo_line_to (cr, length - m_B, GetLineWidth () / 2. + m_C);
cairo_line_to (cr, length, -GetLineWidth () / 2.);
cairo_line_to (cr, length - m_A, -GetLineWidth () / 2.);
cairo_close_path (cr);
cairo_fill (cr);
break;
}
}
cairo_restore (cr);
}
void Arrow::UpdateBounds ()
{
// FIXME: take arrow heads into account
double lw = GetLineWidth () / 2., lh;
double angle = atan2 (m_yend - m_ystart, m_xend - m_xstart);
// TODO: take line cap into account
lh = fabs (lw * cos (angle));
lw = fabs (lw * sin (angle));
if (m_xstart < m_xend) {
m_x0 = m_xstart - lw;
m_x1 = m_xend + lw;
} else {
m_x0 = m_xend - lw;
m_x1 = m_xstart + lw;
}
if (m_ystart < m_yend) {
m_y0 = m_ystart - lh;
m_y1 = m_yend + lh;
} else {
m_y0 = m_yend - lh;
m_y1 = m_ystart + lh;
}
// FIXME: really take arrow heads into account
m_y0 -= m_C;
m_y1 += m_C;
m_x0 -= m_C;
m_x1 += m_C;
Item::UpdateBounds ();
}
}
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