public IEnumerable <CellCastInfo> CastCells(Vector3 origin, Vector3 dir, float maxDistance)
{
int currentX, currentY, currentZ;
Vector3 intersectPoint, faceNormal;
T startCell, endCell, currentCell;
var ray = new Ray(origin, dir);
GetCellIndices(origin, out currentX, out currentY, out currentZ);
intersectPoint = Vector3.zero;
float distance = 0f;
Vector3 normal;
if (IsValidCell(currentX, currentY, currentZ)) // Started inside a cell
{
intersectPoint = origin;
startCell = cells[currentX, currentY, currentZ];
}
else
{
if (bounds.Intersects(ray, maxDistance, out normal, out distance) == false)
{
//Console.Log("Does not intersect grid {0}", this);
yield break;
}
distance = Mathf.Abs(distance);
intersectPoint = origin + (dir * distance);
origin = intersectPoint + (dir * 0.001f);
GetCellIndices(origin, out currentX, out currentY, out currentZ);
if (!IsValidCell(currentX, currentY, currentZ))
{
yield break;
}
startCell = cells[currentX, currentY, currentZ];
}
var reverseRay = new Ray(ray.origin + (dir * maxDistance), -dir);
if (bounds.Intersects(ray, maxDistance, out normal, out distance) == false)
{
//Console.Log("Does not intersect grid reverse {0}", this);
yield break;
}
//Console.Log("R: {0}, d: {1}", ray, distance);
distance = Mathf.Abs(distance);
Vector3 endPoint = reverseRay.origin + (reverseRay.direction * (distance + 0.001f));
endCell = GetCell(endPoint);
faceNormal = GetCellFaceNormal(currentX, currentY, currentZ, intersectPoint);
var castInfo = new CellCastInfo(currentX, currentY, currentZ, startCell, intersectPoint, faceNormal);
yield return(castInfo);
Vector3 current = (origin - Position) / CellSize;
currentX = (int)current.x;
currentY = (int)current.y;
currentZ = (int)current.z;
GetCellIndices(origin, out currentX, out currentY, out currentZ);
int stepX, stepY, stepZ;
stepX = dir.x > 0 ? 1 : (dir.x < 0 ? -1 : 0);
stepY = dir.y > 0 ? 1 : (dir.y < 0 ? -1 : 0);
stepZ = dir.z > 0 ? 1 : (dir.z < 0 ? -1 : 0);
Vector3 rayDelta = dir * (maxDistance);
Vector3 tDelta = Vector3.zero; // size of voxel in terms of t
if (stepX != 0)
{
tDelta.x = CellSize / rayDelta.x;
}
else
{
tDelta.x = 10000000.0f;
}
if (stepY != 0)
{
tDelta.y = CellSize / rayDelta.y;
}
else
{
tDelta.y = 10000000.0f;
}
if (stepZ != 0)
{
tDelta.z = CellSize / rayDelta.z;
}
else
{
tDelta.z = 10000000.0f;
}
Vector3 tMax = Vector3.zero; // distance to next boundary (in terms of t)
if (stepX > 0)
{
tMax.x = tDelta.x * MathsHelper.FracPos(current.x);
}
else
{
tMax.x = tDelta.x * MathsHelper.FracNeg(current.x);
}
if (stepY > 0)
{
tMax.y = tDelta.y * MathsHelper.FracPos(current.y);
}
else
{
tMax.y = tDelta.y * MathsHelper.FracNeg(current.y);
}
if (stepZ > 0)
{
tMax.z = tDelta.z * MathsHelper.FracPos(current.z);
}
else
{
tMax.z = tDelta.z * MathsHelper.FracNeg(current.z);
}
currentCell = startCell;
int iters = 0;
const int MaxIters = 10000;
Directions movementDirection;
while (IsValidCell(currentX, currentY, currentZ) && iters < MaxIters)
{
++iters;
#if DEBUG
if (iters == MaxIters)
{
Console.LogWarning("Grid cell cast hit max iters");
}
#endif
if (Mathf.Abs(tMax.x) < Mathf.Abs(tMax.y))
{
if (Mathf.Abs(tMax.x) < Mathf.Abs(tMax.z))
{
if (stepX > 0)
{
movementDirection = Directions.Left;
}
else
{
movementDirection = Directions.Right;
}
currentX += stepX;
tMax.x += tDelta.x;
}
else
{
if (stepZ > 0)
{
movementDirection = Directions.Forward;
}
else
{
movementDirection = Directions.Backward;
}
currentZ += stepZ;
tMax.z += tDelta.z;
}
}
else
{
if (Mathf.Abs(tMax.y) < Mathf.Abs(tMax.z))
{
if (stepY > 0)
{
movementDirection = Directions.Down;
}
else
{
movementDirection = Directions.Up;
}
currentY += stepY;
tMax.y += tDelta.y;
}
else
{
if (stepZ > 0)
{
movementDirection = Directions.Forward;
}
else
{
movementDirection = Directions.Backward;
}
currentZ += stepZ;
tMax.z += tDelta.z;
}
}
if (!IsValidCell(currentX, currentY, currentZ))
{
break;
}
currentCell = cells[currentX, currentY, currentZ];
intersectPoint = tMax;
faceNormal = GetDirectionVector(movementDirection);
Bounds cellBounds = GetCellBounds(currentX, currentY, currentZ);
if (cellBounds.IntersectRay(ray, out distance))
{
intersectPoint = ray.origin + (ray.direction * distance);
}
if (distance > maxDistance)
{
//Console.Log("Over max distance {0}", this);
yield break;
}
castInfo = new CellCastInfo(currentX, currentY, currentZ, currentCell, intersectPoint, faceNormal);
yield return(castInfo);
}
}