// Vertex Source Interface
public void Rewind(int idx)
{
if (m_status == StrokeMath.status_e.initial)
{
m_src_vertices.close(m_closed != 0);
ShapePath.shorten_path(m_src_vertices, m_shorten, m_closed);
if (m_src_vertices.size() < 3)
{
m_closed = 0;
}
}
m_status = StrokeMath.status_e.ready;
m_src_vertex = 0;
m_out_vertex = 0;
}
static public void shorten_path(VertexSequence vs, double s, int closed)
{
if (s > 0.0 && vs.size() > 1)
{
double d;
int n = (int)(vs.size() - 2);
while (n != 0)
{
d = vs[n].dist;
if (d > s) break;
vs.RemoveLast();
s -= d;
--n;
}
if (vs.size() < 2)
{
vs.remove_all();
}
else
{
n = (int)vs.size() - 1;
VertexDistance prev = vs[n - 1];
VertexDistance last = vs[n];
d = (prev.dist - s) / prev.dist;
double x = prev.x + (last.x - prev.x) * d;
double y = prev.y + (last.y - prev.y) * d;
last.x = x;
last.y = y;
if (!prev.IsEqual(last)) vs.RemoveLast();
vs.close(closed != 0);
}
}
}
//-------------------------------------------------------calc_polygon_area
public static double calc_polygon_area(VertexSequence st)
{
int i;
double sum = 0.0;
double x = st[0].x;
double y = st[0].y;
double xs = x;
double ys = y;
for (i = 1; i < st.size(); i++)
{
VertexDistance v = st[i];
sum += x * v.y - y * v.x;
x = v.x;
y = v.y;
}
return (sum + x * ys - y * xs) * 0.5;
}
public ShapePath.FlagsAndCommand Vertex(ref double x, ref double y)
{
ShapePath.FlagsAndCommand cmd = ShapePath.FlagsAndCommand.LineTo;
while (!ShapePath.is_stop(cmd))
{
switch (m_status)
{
case StrokeMath.status_e.initial:
Rewind(0);
goto case StrokeMath.status_e.ready;
case StrokeMath.status_e.ready:
if (m_src_vertices.size() < 2 + (m_closed ? 1 : 0))
{
cmd = ShapePath.FlagsAndCommand.Stop;
break;
}
m_status = StrokeMath.status_e.outline1;
cmd = ShapePath.FlagsAndCommand.MoveTo;
m_src_vertex = 0;
m_out_vertex = 0;
goto case StrokeMath.status_e.outline1;
case StrokeMath.status_e.outline1:
if (m_src_vertex >= m_src_vertices.size())
{
m_status = StrokeMath.status_e.end_poly1;
break;
}
m_stroker.calc_join(m_out_vertices,
m_src_vertices.prev(m_src_vertex),
m_src_vertices.curr(m_src_vertex),
m_src_vertices.next(m_src_vertex),
m_src_vertices.prev(m_src_vertex).dist,
m_src_vertices.curr(m_src_vertex).dist);
++m_src_vertex;
m_status = StrokeMath.status_e.out_vertices;
m_out_vertex = 0;
goto case StrokeMath.status_e.out_vertices;
case StrokeMath.status_e.out_vertices:
if (m_out_vertex >= m_out_vertices.size())
{
m_status = StrokeMath.status_e.outline1;
}
else
{
Vector2 c = m_out_vertices[m_out_vertex++];
x = c.X;
y = c.Y;
return(cmd);
}
break;
case StrokeMath.status_e.end_poly1:
if (!m_closed)
{
return(ShapePath.FlagsAndCommand.Stop);
}
m_status = StrokeMath.status_e.stop;
return(ShapePath.FlagsAndCommand.EndPoly | ShapePath.FlagsAndCommand.FlagClose | ShapePath.FlagsAndCommand.FlagCCW);
case StrokeMath.status_e.stop:
return(ShapePath.FlagsAndCommand.Stop);
}
}
return(cmd);
}
