/* MapLine::seg
* Returns this line as a segment.
*******************************************************************/
fseg2_t MapLine::seg()
{
return fseg2_t(vertex1->point(), vertex2->point());
}
bool PolygonSplitter::splitFromEdge(int splitter_edge)
{
// Get vertices
int v1 = edges[splitter_edge].v1;
int v2 = edges[splitter_edge].v2;
// First up, find the closest vertex on the front side of the edge
double min_dist = 999999;
int closest = -1;
for (unsigned a = 0; a < vertices.size(); a++)
{
if (MathStuff::lineSide(vertices[a], fseg2_t(vertices[v1], vertices[v2])) > 0 && vertices[a].ok)
{
vertices[a].distance = MathStuff::distance(vertices[v2], vertices[a]);
if (vertices[a].distance < min_dist)
{
min_dist = vertices[a].distance;
closest = a;
}
}
else
vertices[a].distance = 999999;
}
// If there's nothing on the front side, something is wrong
if (closest == -1)
return false;
// See if we can split to here without crossing anything
// (this will be the case most of the time)
bool intersect = false;
fpoint2_t pointi;
for (unsigned a = 0; a < edges.size(); a++)
{
// Ignore edge if adjacent to the vertices we are looking at
if (edges[a].v1 == closest || edges[a].v2 == closest || edges[a].v1 == v2 || edges[a].v2 == v2 || !edges[a].ok)
continue;
// Intersection test
if (MathStuff::linesIntersect(fseg2_t(vertices[v2], vertices[closest]), fseg2_t(vertices[edges[a].v1], vertices[edges[a].v2]), pointi))
{
intersect = true;
break;
}
}
if (!intersect)
{
// No edge intersections, create split
int e1 = addEdge(v2, closest);
int e2 = addEdge(closest, v2);
edges[e1].sister = e2;
edges[e2].sister = e1;
return true;
}
// Otherwise, we'll have to find the next closest vertex
vector<vdist_t> sorted_verts;
// Build a list of potential vertices, ordered by distance
for (unsigned a = 0; a < vertices.size(); a++)
{
if (vertices[a].distance < 999999)
sorted_verts.push_back(vdist_t(a, vertices[a].distance));
}
// Go through potential split vertices, closest first
std::sort(sorted_verts.begin(), sorted_verts.end());
for (unsigned a = 0; a < sorted_verts.size(); a++)
{
int index = sorted_verts[a].index;
vertex_t& vert = vertices[index];
// Check if a split from the edge to this vertex would cross any other edges
intersect = false;
for (unsigned a = 0; a < edges.size(); a++)
{
// Ignore edge if adjacent to the vertices we are looking at
if (edges[a].v1 == index || edges[a].v2 == index || edges[a].v1 == v2 || edges[a].v2 == v2 || !edges[a].ok)
continue;
// Intersection test
if (MathStuff::linesIntersect(fseg2_t(vertices[v2], vert), fseg2_t(vertices[edges[a].v1], vertices[edges[a].v2]), pointi))
{
intersect = true;
break;
}
}
if (!intersect)
{
// No edge intersections, create split
int e1 = addEdge(v2, index);
int e2 = addEdge(index, v2);
edges[e1].sister = e2;
edges[e2].sister = e1;
return true;
}
}
// No split created
return false;
}
