public void DrawFilledPolys(Polygon[] polygons, Matrix View, Color color)
{
int len = 0;
for (int x = 0; x < polygons.Length; x++)
{
len += polygons[x].Edges.Length * 3;
}
be.View = View;
be.CurrentTechnique.Passes[0].Apply();
VertexPositionColor[] vertices = new VertexPositionColor[len];
int count = 0;
for (int x = 0; x < polygons.Length; x++)
{
for (int y = 0; y < polygons[x].Edges.Length; y++)
{
vertices[count] = new VertexPositionColor(new Microsoft.Xna.Framework.Vector3(polygons[x].Edges[y].Start.X, polygons[x].Edges[y].Start.Z, 0), color);
vertices[count + 1] = new VertexPositionColor(new Microsoft.Xna.Framework.Vector3(polygons[x].Edges[y].End.X, polygons[x].Edges[y].End.Z, 0), color);
vertices[count + 2] = new VertexPositionColor(new Microsoft.Xna.Framework.Vector3(polygons[x].Center.X, polygons[x].Center.Z, 0), color);
count += 3;
}
}
if (len < 2)
return;
device.DrawUserPrimitives<VertexPositionColor>(PrimitiveType.TriangleList, vertices, 0, len / 3, VertexPositionColor.VertexDeclaration);
}
public Structure(Map map, Vector3 position, Vector3[] vertices, string characterfile, int teamID)
{
this.position = position;
this.collisionPolygon = new Polygon(vertices);
this.characterFile = characterfile;
info = new CharacterInfo(characterfile);
health = info.maxHealth;
this.teamID = teamID;
this.map = map;
}
public Structure(Map map, BinaryReader reader)
{
position = reader.ReadVector3();
collisionPolygon = new Polygon(reader);
characterFile = reader.ReadString();
teamID = reader.ReadInt32();
info = new CharacterInfo(characterFile);
health = info.maxHealth;
this.map = map;
}
public Collision(Vector3[] vertices)
{
collisionPolygon = new Polygon(vertices);
}
public Collision(BinaryReader reader)
{
collisionPolygon = new Polygon(reader);
}
public Bush(int id, Vector3[] vertices)
{
this.id = id;
this.boundary = new Polygon(vertices);
}
public Bush(BinaryReader reader)
{
id = reader.ReadInt32();
boundary = new Polygon(reader);
}
private bool InternalSATIntersect(Polygon polygon)
{
//For every normal check if the projection of this polygon
//intersects with the projection of the other one
//If yes try next normal, if not we don't intersect
Vector3 extent = Vector3.Zero;
for (int x = 0; x < satHelpers.Length; x++)
{
extent.X = float.MaxValue;
extent.Y = float.MinValue;
for (int y = 0; y < polygon.edges.Length; y++)
{
float proj = Vector3.Dot(edges[x].Normal, polygon.edges[y].Start - center);
if (proj < extent.X)
extent.X = proj;
if (proj > extent.Y)
extent.Y = proj;
}
if (!RangeOverlaps(satHelpers[x], extent))
return false;
}
return true;
}
// 1. iterate through each Vertex on the source
// 2. iterate through each of this polygons normals
// 3. calculate time to that each vertex in source will collide against this's normals
// 4. the vertex with the lowest time to collide against a normal is the one we collide with soonest
// 5. store vertex -> T (inverse time to collide)
// 6. find the vertex with the lowest T
private void FindFirstCollidingEdge(Polygon source, Vector3 velocity, out Edge edgeCollidedWith, out float collideTime)
{
Edge collidesFirstEdge = new Edge();
float collidesFirstTime = float.MaxValue;
foreach (Vector3 vertex in source.points)
{
Edge closestEdge = new Edge();
float closestEdgeTime = 0;
float closestNotEdgeTime = float.MaxValue;
bool found = false;
foreach (Edge edge in this.edges)
{
// time = -(nx*px)+(ny*py)/(vx*nx)+(vy*ny)
float top = Vector3.Dot(vertex - edge.Start, edge.Normal);
float bot = Vector3.Dot(velocity, edge.Normal);
float time = -((top) / bot);
bool facing = top >= 0;
// the normal with the highest T is the one we collide with soonest
if (facing && time > closestEdgeTime)
{
closestEdge = edge;
closestEdgeTime = time;
found = true;
}
else if (!facing && time > 0 && time < closestNotEdgeTime)
{
closestNotEdgeTime = time;
}
}
// the vertex with the lowest T is the vertex that will collide first
if (found && closestEdgeTime < collidesFirstTime && closestEdgeTime < closestNotEdgeTime)
{
collidesFirstEdge = closestEdge;
collidesFirstTime = closestEdgeTime;
}
}
edgeCollidedWith = collidesFirstEdge;
collideTime = collidesFirstTime;
}
public bool Intersects(Polygon polygon)
{
//Check SAT, SAT will yield correct negatives for all polygons
//But may yield false positives for concave polygons
//So we check SAT first since we expect most things not to intersect
//And if SAT says we collide and one polygon is not convex we test more intensively
if (!InternalSATIntersect(polygon))
return false;
if (!polygon.InternalSATIntersect(this))
return false;
//For convex polygons SAT is sufficient
if (IsConvex && polygon.IsConvex)
return true;
//TODO: For concave polygons we will need a more extensive check
return true;
}
public static void FindCollidingEdge(Polygon source, Polygon dest, Vector3 velocity, out Edge thatCollidesWith)
{
Edge edgeSource;
float timeSource;
Edge edgeDest;
float timeDest;
source.FindFirstCollidingEdge(dest, -velocity, out edgeSource, out timeSource);
dest.FindFirstCollidingEdge(source, velocity, out edgeDest, out timeDest);
thatCollidesWith = timeSource < timeDest ? edgeSource : edgeDest;
}
public Bush(int id, Vector3[] vertices)
{
this.id = id;
this.boundary = new Polygon(vertices);
}
public Bush(BinaryReader reader)
{
id = reader.ReadInt32();
boundary = new Polygon(reader);
}