private static List <Box> Cut(List <Box> list, Box toCut, Vec3.Component c, float val)
{
List <Box> newList = new List <Box>();
foreach (Box b in list)
{
b.Cut(toCut, c, val, newList);
}
return(newList);
}
public static Vec3 ProjectPointToPlane(Vec3 point, Vec3 planeOrigin,
Vec3 planeAxis1, Vec3 planeAxis2,
Vec3.Component projectionDirection)
{
Vec2 orig = planeOrigin.ProjectTo(projectionDirection);
Vec2 ax1 = planeAxis1.ProjectTo(projectionDirection);
Vec2 ax2 = planeAxis2.ProjectTo(projectionDirection);
Vec2 p = point.ProjectTo(projectionDirection);
Vec2 dummy;
double t1, t2;
Vec2.Intersection(orig, orig + ax1, p, p + ax2, out t1, out dummy);
Vec2.Intersection(orig, orig + ax2, p, p + ax1, out t2, out dummy);
return(planeOrigin + t1 * planeAxis1 + t2 * planeAxis2);
}
static Dictionary <Vec2, int> OrthoProject(List <Vec3> list, Vec3.Component direction)
{
Dictionary <Vec2, int> dic = new Dictionary <Vec2, int>();
int count = 0;
foreach (Vec3 v in list)
{
Vec2 v2 = v.ProjectTo(direction);
if (!dic.ContainsKey(v2))
{
dic.Add(v2, count);
}
++count;
}
return(dic);
}
private void Cut(Box toCut, Vec3.Component c, float val, List <Box> newList)
{
if (val <= min.GetComponent(c) || val >= max.GetComponent(c))
{
newList.Add(new Box(min, max));
return;
}
Box b1 = new Box(min, max);
b1.max.SetComponent(c, val);
Box b2 = new Box(min, max);
b2.min.SetComponent(c, val);
newList.Add(b1);
newList.Add(b2);
}
public static List <List <Vec3> > PolygonToTriangleStrips(List <Vec3> polygon)
{
Vec3 normal = (polygon[1] - polygon[0]).Cross(polygon[2] - polygon[0]);
normal.Normalize();
double max = Math.Max(Math.Abs(normal.X), Math.Max(Math.Abs(normal.Y), Math.Abs(normal.Z)));
Vec3.Component dir = Vec3.Component.X;
if (Math.Abs(normal.Y) == max)
{
dir = Vec3.Component.Y;
}
else if (Math.Abs(normal.Z) == max)
{
dir = Vec3.Component.Z;
}
polygon.RemoveAt(polygon.Count - 1);
Dictionary <Vec2, int> proj = OrthoProject(polygon, dir);
List <List <Vec2> > poly2d = PolygonToTriangleStrips(proj.Keys);
List <List <Vec3> > triStrips = new List <List <Vec3> >();
foreach (List <Vec2> vlist in poly2d)
{
List <Vec3> strip = new List <Vec3>();
foreach (Vec2 v in vlist)
{
if (!proj.ContainsKey(v))
{
strip.Add(Vec3.ProjectPointToPlane(Vec2.CreateVec3(v, dir), polygon[0], polygon[1] - polygon[0], polygon[2] - polygon[0], dir));
}
else
{
strip.Add(polygon[proj[v]]);
}
}
triStrips.Add(strip);
}
return(triStrips);
}
public Vec3 GetPointWithComponentAt(Vec3.Component component, float p)
{
float x1 = component == Vec3.Component.X ? p1.Y : p1.X;
float x2 = component == Vec3.Component.X ? p2.Y : p2.X;
float y1 = component == Vec3.Component.Z ? p1.Y : p1.Z;
float y2 = component == Vec3.Component.Z ? p2.Y : p2.Z;
float t1 = p1.GetComponent(component);
float t2 = p2.GetComponent(component);
if (t1 == t2)
{
return(null);
}
float factor = (p - t1) / (t2 - t1);
float x = x1 + factor * (x2 - x1);
float y = y1 + factor * (y2 - y1);
Vec3 ret = null;
switch (component)
{
case Vec3.Component.X:
ret = new Vec3(p, x, y);
break;
case Vec3.Component.Y:
ret = new Vec3(x, p, y);
break;
case Vec3.Component.Z:
ret = new Vec3(x, y, p);
break;
}
return(ret);
}
