/// <summary>
/// Check if the given bounding box is occluded.
/// </summary>
/// <param name="box">A bounding box in local (non deformed) coordinates.</param>
/// <returns>Returns 'True' if the given bounding box is occluded by the bounding boxes previously added as occluders by <see cref="AddOccluder"/></returns>
public bool IsOccluded(Box3d box)
{
if (!UseHorizonCulling || LocalCameraPosition.z > TerrainQuadRoot.ZMax)
{
return(false);
}
var corners = new Vector2d[4];
var plane = LocalCameraPosition.XY();
corners[0] = LocalCameraDirection * (new Vector2d(box.xmin, box.ymin) - plane);
corners[1] = LocalCameraDirection * (new Vector2d(box.xmin, box.ymax) - plane);
corners[2] = LocalCameraDirection * (new Vector2d(box.xmax, box.ymin) - plane);
corners[3] = LocalCameraDirection * (new Vector2d(box.xmax, box.ymax) - plane);
if (corners[0].y <= 0.0 || corners[1].y <= 0.0 || corners[2].y <= 0.0 || corners[3].y <= 0.0)
{
return(false);
}
var dz = box.zmax - LocalCameraPosition.z;
corners[0] = new Vector2d(corners[0].x, dz) / corners[0].y;
corners[1] = new Vector2d(corners[1].x, dz) / corners[1].y;
corners[2] = new Vector2d(corners[2].x, dz) / corners[2].y;
corners[3] = new Vector2d(corners[3].x, dz) / corners[3].y;
var xmin = Math.Min(Math.Min(corners[0].x, corners[1].x), Math.Min(corners[2].x, corners[3].x)) * 0.33 + 0.5;
var xmax = Math.Max(Math.Max(corners[0].x, corners[1].x), Math.Max(corners[2].x, corners[3].x)) * 0.33 + 0.5;
var zmax = Math.Max(Math.Max(corners[0].y, corners[1].y), Math.Max(corners[2].y, corners[3].y));
var imin = Math.Max((int)Math.Floor(xmin * HORIZON_SIZE), 0);
var imax = Math.Min((int)Math.Ceiling(xmax * HORIZON_SIZE), HORIZON_SIZE - 1);
for (int i = imin; i <= imax; ++i)
{
if (zmax > Horizon[i])
{
return(false);
}
}
return(imax >= imin);
}
public LocalCameraPosition GetPosition()
{
LocalCameraPosition ret = VidyoLocalCameraGetPositionNative(objPtr);
return(ret);
}
/// <summary>
/// Adds the given bounding box as an occluder. The bounding boxes must be added in front to back order.
/// </summary>
/// <param name="occluder">A bounding box in local (non deformed) coordinates.</param>
/// <returns>Returns 'True' if the given bounding box is occluded by the bounding boxes previously added as occluders by this method.</returns>
public bool AddOccluder(Box3d occluder)
{
if (!UseHorizonCulling || LocalCameraPosition.z > TerrainQuadRoot.ZMax)
{
return(false);
}
var corners = new Vector2d[4];
var plane = LocalCameraPosition.XY();
corners[0] = LocalCameraDirection * (new Vector2d(occluder.xmin, occluder.ymin) - plane);
corners[1] = LocalCameraDirection * (new Vector2d(occluder.xmin, occluder.ymax) - plane);
corners[2] = LocalCameraDirection * (new Vector2d(occluder.xmax, occluder.ymin) - plane);
corners[3] = LocalCameraDirection * (new Vector2d(occluder.xmax, occluder.ymax) - plane);
if (corners[0].y <= 0.0 || corners[1].y <= 0.0 || corners[2].y <= 0.0 || corners[3].y <= 0.0)
{
// Skips bounding boxes that are not fully behind the "near plane" of the reference frame used for horizon occlusion culling
return(false);
}
var dzmin = occluder.zmin - LocalCameraPosition.z;
var dzmax = occluder.zmax - LocalCameraPosition.z;
var bounds = new Vector3d[4];
bounds[0] = new Vector3d(corners[0].x, dzmin, dzmax) / corners[0].y;
bounds[1] = new Vector3d(corners[1].x, dzmin, dzmax) / corners[1].y;
bounds[2] = new Vector3d(corners[2].x, dzmin, dzmax) / corners[2].y;
bounds[3] = new Vector3d(corners[3].x, dzmin, dzmax) / corners[3].y;
var xmin = Math.Min(Math.Min(bounds[0].x, bounds[1].x), Math.Min(bounds[2].x, bounds[3].x)) * 0.33 + 0.5;
var xmax = Math.Max(Math.Max(bounds[0].x, bounds[1].x), Math.Max(bounds[2].x, bounds[3].x)) * 0.33 + 0.5;
var zmin = Math.Min(Math.Min(bounds[0].y, bounds[1].y), Math.Min(bounds[2].y, bounds[3].y));
var zmax = Math.Max(Math.Max(bounds[0].z, bounds[1].z), Math.Max(bounds[2].z, bounds[3].z));
var imin = Math.Max((int)Math.Floor(xmin * HORIZON_SIZE), 0);
var imax = Math.Min((int)Math.Ceiling(xmax * HORIZON_SIZE), HORIZON_SIZE - 1);
// First checks if the bounding box projection is below the current horizon line
var occluded = (imax >= imin);
for (int i = imin; i <= imax; ++i)
{
if (zmax > Horizon[i])
{
occluded = false;
break;
}
}
if (!occluded)
{
// If it is not, updates the horizon line with the projection of this bounding box
imin = Math.Max((int)Math.Ceiling(xmin * HORIZON_SIZE), 0);
imax = Math.Min((int)Math.Floor(xmax * HORIZON_SIZE), HORIZON_SIZE - 1);
for (int i = imin; i <= imax; ++i)
{
Horizon[i] = (float)Math.Max(Horizon[i], zmin);
}
}
return(occluded);
}
