/// <summary>
/// Will update the object in order to allow editing of the collision vertexes
/// Can be replaced in the inheritting class. It only needs called if the vertex editing is
/// needed feature, otherwise it can be skipped.
///
/// The return value must retain the purpose described here. The ObjectManager and
/// Particle engines will attempt to purge this object if it returns false.
/// </summary>
/// <param name="CurrTime"></param>
/// <returns>True indicates the object still exists, false means the update decided the
/// object can be removed</returns>
public virtual bool Update(GameTime CurrTime)
{
Rectangle Handle;
int nVertCtr;
Vector2 vVertPos;
MouseState CurrMouse = Mouse.GetState();
if (cbVertexEdits == true)
{
if ((CurrMouse.LeftButton == ButtonState.Pressed) && (cnMouseVertex >= 0))
{
//User is draging a vertex around
vVertPos.X = CurrMouse.X;
vVertPos.Y = CurrMouse.Y;
cPolyGon.UpdateVertex(cnMouseVertex, vVertPos);
CenterPoint = CenterPoint;
}
if ((CurrMouse.LeftButton == ButtonState.Pressed) && (cPriorMouse.LeftButton == ButtonState.Released))
{
//User just clicked, see if they got a polygon vertex
List <CollisionRegion> CollList = new List <CollisionRegion>(cPolyGon.GetCollisionRegions());
Handle.Width = nHandleWidth;
Handle.Height = nHandleWidth;
nVertCtr = 0;
foreach (Vector2 vCurrVert in CollList[0].Vertexes)
{
Handle.X = (int)(vCurrVert.X - (nHandleWidth / 2));
Handle.Y = (int)(vCurrVert.Y - (nHandleWidth / 2));
if (MGMath.IsPointInRect(CurrMouse.Position, Handle) == true)
{
cnMouseVertex = nVertCtr;
break;
}
nVertCtr += 1;
}
}
if (CurrMouse.LeftButton == ButtonState.Released)
{
cnMouseVertex = -1;
}
}
cPriorMouse = CurrMouse;
//Raise the event handler for external logic
if (Updating != null)
{
return(Updating.Invoke(this, CurrTime));
}
else
{
return(true); //Returning true means the object should stick around
}
}
/// <summary>
/// Tests if this object overlaps or collides with another region
/// </summary>
/// <param name="TestRegions">List of regions to test for collisions with</param>
/// <returns>True if a collisions has occurred, false otherwise</returns>
public bool TestCollision(IEnumerable <CollisionRegion> TestRegions)
{
foreach (CollisionRegion CurrReg in TestRegions)
{
switch (CurrReg.Type)
{
case CollideType.ConvexPolygon:
Int32 nMeCtr, nThemCtr;
//See if this polygon is hitting the other one
foreach (Vector2 Vertex in cCollisionList.Vertexes)
{
if (MGMath.PointInConvexPolygon(Vertex, CurrReg.Vertexes) == true)
{
return(true);
}
}
//See if the other polygon is inside this one
foreach (Vector2 Vertex in CurrReg.Vertexes)
{
if (MGMath.PointInConvexPolygon(Vertex, cCollisionList.Vertexes) == true)
{
return(true);
}
}
//Need a test for when edges completely span the other polygon.
//Vertexes are all outside, edges intersect
for (nMeCtr = 1; nMeCtr < cCollisionList.Vertexes.Count; nMeCtr += 1)
{
for (nThemCtr = 1; nThemCtr < CurrReg.Vertexes.Count; nThemCtr += 1)
{
if (MGMath.LineSegmentIntesection(cCollisionList.Vertexes[nMeCtr], cCollisionList.Vertexes[nMeCtr - 1], CurrReg.Vertexes[nThemCtr], CurrReg.Vertexes[nThemCtr - 1]) == true)
{
return(true);
}
}
}
return(false);
case CollideType.Rectangle:
Point Coord;
Vector2 Corner;
//See if this polygon is hitting the rectangle
foreach (Vector2 Vertex in cCollisionList.Vertexes)
{
Coord.X = (int)Vertex.X;
Coord.Y = (int)Vertex.Y;
if (MGMath.IsPointInRect(Coord, CurrReg.RectOffsets) == true)
{
return(true);
}
}
Corner.X = CurrReg.RectOffsets.X;
Corner.Y = CurrReg.RectOffsets.Y;
if (MGMath.PointInConvexPolygon(Corner, cCollisionList.Vertexes) == true)
{
return(true);
}
Corner.X = CurrReg.RectOffsets.X + CurrReg.RectOffsets.Width;
Corner.Y = CurrReg.RectOffsets.Y;
if (MGMath.PointInConvexPolygon(Corner, cCollisionList.Vertexes) == true)
{
return(true);
}
Corner.X = CurrReg.RectOffsets.X;
Corner.Y = CurrReg.RectOffsets.Y + CurrReg.RectOffsets.Height;
if (MGMath.PointInConvexPolygon(Corner, cCollisionList.Vertexes) == true)
{
return(true);
}
Corner.X = CurrReg.RectOffsets.X + CurrReg.RectOffsets.Width;
Corner.Y = CurrReg.RectOffsets.Y + CurrReg.RectOffsets.Height;
if (MGMath.PointInConvexPolygon(Corner, cCollisionList.Vertexes) == true)
{
return(true);
}
return(false);
case CollideType.Circle:
//Need to work out this math.
//If any vertex of the polygon is closer to the circle center than the radius, collides
//If a line from the center perpendicular to a side of the polygon hits the side and
//is shorter than the radius of the circle, collide
return(false);
default:
return(false);
}
}
return(false);
}