/*
Order vertices (1st arg) based on the visual angle seen from a click point (3rd arg).
The 2nd argument carries contour information.
*/
vector<Vertex<FragmentInfo>*>
orderVertices(vector<Vertex<FragmentInfo>*>& vertices,
vector<ContourEQW>& contours,
CParticleF& click)
{
vector<Vertex<FragmentInfo>*> ordered;
vector<indexedData> vdata;
for(int i=0; i<vertices.size(); ++i)
{
int c = vertices[i]->key.contourID;
int p = vertices[i]->key.pointID;
float x = contours[c].X[p];
float y = contours[c].Y[p];
indexedData d;
d.data = GetVisualDirection(x, y, click.m_X, click.m_Y);
if(d.data < 0)
{
d.data += 2*PI;
}
d.index = i;
vdata.push_back(d);
vertices[i]->key.angle = d.data;
}
sort(vdata.begin(), vdata.end());
for(int i=0; i<vdata.size(); ++i)
{
ordered.push_back(vertices[vdata[i].index]);
}
return ordered;
}
bool GetOrientation(FragmentInfo& start,
FragmentInfo& dest,
CParticleF& click,
vector<ContourEQW>& contours)
{
float x1 = contours[start.contourID].X[start.pointID];
float y1 = contours[start.contourID].Y[start.pointID];
float x2 = contours[dest.contourID].X[dest.pointID];
float y2 = contours[dest.contourID].Y[dest.pointID];
float d1 = GetVisualDirection(x1, y1, click.m_X, click.m_Y);
float d2 = GetVisualDirection(x2, y2, click.m_X, click.m_Y);
if(d2 < d1)
{
d2 += 2*PI;
}
if(d2-d1 < PI) return true;
else return false;
}
/*
return a unit vector that bisects the angle formed by three points: a-o-b.
*/
CParticleF
bisector(CParticleF& o, CParticleF& a, CParticleF& b)
{
CParticleF x = NormalizedDirection(a, o);
CParticleF y = NormalizedDirection(b, o);
CParticleF z((x.m_X + y.m_X) / 2, (x.m_Y + y.m_Y) / 2);
float vx = z.m_X;
float vy = z.m_Y;
float len0 = sqrt(vx*vx + vy*vy);
if (len0 <= 1.0e-5) //this is a colinear point.
{
float ang = GetVisualDirection(b.m_X, b.m_Y, a.m_X, a.m_Y) - PI / 2.0;
vx = cos(ang);
vy = sin(ang);
}
else
{
vx = vx / len0;
vy = vy / len0;
}
CParticleF bs(o.m_X + vx, o.m_Y + vy);
//There are two bisector directions.
//We consistently choose one that is in clock-wise direction.
vector<CParticleF> pnts(4);
pnts[0] = o;
pnts[1] = a;
pnts[2] = bs;
pnts[3] = b;
if (ClockWise(pnts)<0)
{
vx = -vx;
vy = -vy;
}
return CParticleF(vx, vy);
}
