private void DrawPolygon(IGraphics g, Center c, PortableColor color)
{
//only used if Center c is on the edge of the graph. allows for completely filling in the outer polygons
Corner edgeCorner1 = null;
Corner edgeCorner2 = null;
c.area = 0;
foreach (Center n in c.neighbors)
{
Edge e = EdgeWithCenters(c, n);
if (e.v0 == null)
{
//outermost voronoi edges aren't stored in the graph
continue;
}
//find a corner on the exterior of the graph
//if this Edge e has one, then it must have two,
//finding these two corners will give us the missing
//triangle to render. this special triangle is handled
//outside this for loop
Corner cornerWithOneAdjacent = e.v0.border ? e.v0 : e.v1;
if (cornerWithOneAdjacent.border)
{
if (edgeCorner1 == null)
{
edgeCorner1 = cornerWithOneAdjacent;
}
else
{
edgeCorner2 = cornerWithOneAdjacent;
}
}
DrawTriangle(g, color, e.v0, e.v1, c);
c.area += Math.Abs(c.loc.X * (e.v0.loc.Y - e.v1.loc.Y)
+ e.v0.loc.X * (e.v1.loc.Y - c.loc.Y)
+ e.v1.loc.X * (c.loc.Y - e.v0.loc.Y)) / 2;
}
//handle the missing triangle
if (edgeCorner2 != null)
{
//if these two outer corners are NOT on the same exterior edge of the graph,
//then we actually must render a polygon (w/ 4 points) and take into consideration
//one of the four corners (either 0,0 or 0,height or width,0 or width,height)
//note: the 'missing polygon' may have more than just 4 points. this
//is common when the number of sites are quite low (less than 5), but not a problem
//with a more useful number of sites.
//TODO: find a way to fix this
if (CloseEnough(edgeCorner1.loc.X, edgeCorner2.loc.X, 1))
{
DrawTriangle(g, color, edgeCorner1, edgeCorner2, c);
}
else
{
var points = new PointInt32[] {
new PointInt32((int)c.loc.X, (int)c.loc.Y),
new PointInt32((int)edgeCorner1.loc.X, (int)edgeCorner1.loc.Y),
new PointInt32((int)((CloseEnough(edgeCorner1.loc.X, bounds.x, 1) || CloseEnough(edgeCorner2.loc.X, bounds.x, .5)) ? bounds.x : bounds.right), (int)((CloseEnough(edgeCorner1.loc.Y, bounds.y, 1) || CloseEnough(edgeCorner2.loc.Y, bounds.y, .5)) ? bounds.y : bounds.bottom)),
new PointInt32((int)edgeCorner2.loc.X, (int)edgeCorner2.loc.Y),
};
g.FillPolygon(color, points);
c.area += 0; //TODO: area of polygon given vertices
}
}
}
private void DrawPolygon3D <T>(Center c, PortableColor color, IVertexFactory <T> factory, List <T> vertexBuffer)
{
//only used if Center c is on the edge of the graph. allows for completely filling in the outer polygons
Corner edgeCorner1 = null;
Corner edgeCorner2 = null;
foreach (Center n in c.neighbors)
{
var e = EdgeWithCenters(c, n);
if (e.v0 == null)
{
//outermost voronoi edges aren't stored in the graph
continue;
}
//find a corner on the exterior of the graph
//if this Edge e has one, then it must have two,
//finding these two corners will give us the missing
//triangle to render. this special triangle is handled
//outside this for loop
var cornerWithOneAdjacent = e.v0.border ? e.v0 : e.v1;
if (cornerWithOneAdjacent.border)
{
if (edgeCorner1 == null)
{
edgeCorner1 = cornerWithOneAdjacent;
}
else
{
edgeCorner2 = cornerWithOneAdjacent;
}
}
var p = Transform((float)c.loc.X, (float)c.loc.Y, (float)c.elevation);
var q = Transform((float)e.v0.loc.X, (float)e.v0.loc.Y, (float)e.v0.elevation);
var r = Transform((float)e.v1.loc.X, (float)e.v1.loc.Y, (float)e.v1.elevation);
AddTriangle(p, r, q, color, factory, vertexBuffer);
}
//handle the missing triangle
if (edgeCorner2 != null)
{
//if these two outer corners are NOT on the same exterior edge of the graph,
//then we actually must render a polygon (w/ 4 points) and take into consideration
//one of the four corners (either 0,0 or 0,height or width,0 or width,height)
//note: the 'missing polygon' may have more than just 4 points. this
//is common when the number of sites are quite low (less than 5), but not a problem
//with a more useful number of sites.
//TODO: find a way to fix this
if (CloseEnough(edgeCorner1.loc.X, edgeCorner2.loc.X, 1))
{
var p = Transform((float)c.loc.X, (float)c.loc.Y, (float)c.elevation);
var q = Transform((float)edgeCorner1.loc.X, (float)edgeCorner1.loc.Y, (float)edgeCorner1.elevation);
var r = Transform((float)edgeCorner2.loc.X, (float)edgeCorner2.loc.Y, (float)edgeCorner2.elevation);
AddTriangle(p, r, q, color, factory, vertexBuffer);
}
else
{
/*
* var points = new PointInt32[] {
* new PointInt32((int)c.loc.X, (int)c.loc.Y),
* new PointInt32((int)edgeCorner1.loc.X, (int)edgeCorner1.loc.Y),
* new PointInt32((int)((CloseEnough(edgeCorner1.loc.X, bounds.x, 1) || CloseEnough(edgeCorner2.loc.X, bounds.x, .5)) ? bounds.x : bounds.right), (int)((CloseEnough(edgeCorner1.loc.Y, bounds.y, 1) || CloseEnough(edgeCorner2.loc.Y, bounds.y, .5)) ? bounds.y : bounds.bottom)),
* new PointInt32((int)edgeCorner2.loc.X, (int)edgeCorner2.loc.Y),
* };
*
* g.FillPolygon(color, points);
* c.area += 0; //TODO: area of polygon given vertices*/
}
}
}