// draws a an arc to two tangents connecting (current) to (x1,y1) and (x1,y1) to (x2,y2), also a straight line from (current) to (x1,y1)
void wxGraphicsPathData::AddArcToPoint( wxDouble x1, wxDouble y1 , wxDouble x2, wxDouble y2, wxDouble r )
{
wxPoint2DDouble current;
GetCurrentPoint(¤t.m_x,¤t.m_y);
wxPoint2DDouble p1(x1,y1);
wxPoint2DDouble p2(x2,y2);
wxPoint2DDouble v1 = current - p1;
v1.Normalize();
wxPoint2DDouble v2 = p2 - p1;
v2.Normalize();
wxDouble alpha = v1.GetVectorAngle() - v2.GetVectorAngle();
if ( alpha < 0 )
alpha = 360 + alpha;
// TODO obtuse angles
alpha = DegToRad(alpha);
wxDouble dist = r / sin(alpha/2) * cos(alpha/2);
// calculate tangential points
wxPoint2DDouble t1 = dist*v1 + p1;
wxPoint2DDouble nv1 = v1;
nv1.SetVectorAngle(v1.GetVectorAngle()-90);
wxPoint2DDouble c = t1 + r*nv1;
wxDouble a1 = v1.GetVectorAngle()+90;
wxDouble a2 = v2.GetVectorAngle()-90;
AddLineToPoint(t1.m_x,t1.m_y);
AddArc(c.m_x,c.m_y,r,DegToRad(a1),DegToRad(a2),true);
AddLineToPoint(p2.m_x,p2.m_y);
}
void wxGraphicsPathData::AddRectangle( wxDouble x, wxDouble y, wxDouble w, wxDouble h )
{
MoveToPoint(x,y);
AddLineToPoint(x,y+h);
AddLineToPoint(x+w,y+h);
AddLineToPoint(x+w,y);
CloseSubpath();
}
void wxGraphicsPath::AddLineToPoint( const wxPoint2DDouble& p)
{
AddLineToPoint( p.m_x , p.m_y);
}