public IEnumerable<PatchDescriptor> GetPatches(TerrainTile tile, Frustum f, Vector3 eyeWorld)
{
// create root node
var root = new QuadTreeNode(tile);
return root.GetPatches(eyeWorld,f);
}
private void DebugRenderFrustum(Frustum f)
{
lineBuffer.SetColour(new Vector4(1f, 1f, 1f, 1f));
lineBuffer.MoveTo(f.NearTopLeftCorner.Xyz.TopDown());
lineBuffer.LineTo(f.NearTopRightCorner.Xyz.TopDown());
lineBuffer.LineTo(f.FarTopRightCorner.Xyz.TopDown());
lineBuffer.LineTo(f.FarTopLeftCorner.Xyz.TopDown());
lineBuffer.LineTo(f.NearTopLeftCorner.Xyz.TopDown());
lineBuffer.SetColour(new Vector4(1f, 1f, 1f, .5f));
lineBuffer.MoveTo(f.NearBottomLeftCorner.Xyz.TopDown());
lineBuffer.LineTo(f.NearBottomRightCorner.Xyz.TopDown());
lineBuffer.LineTo(f.FarBottomRightCorner.Xyz.TopDown());
lineBuffer.LineTo(f.FarBottomLeftCorner.Xyz.TopDown());
lineBuffer.LineTo(f.NearBottomLeftCorner.Xyz.TopDown());
lineBuffer.SetColour(new Vector4(1f, 0f, 0f, 1f));
lineBuffer.MoveTo(f.NearTopLeftCorner.Xyz.TopDown());
lineBuffer.LineTo(f.FarTopLeftCorner.Xyz.TopDown());
lineBuffer.LineTo(f.FarBottomLeftCorner.Xyz.TopDown());
lineBuffer.LineTo(f.NearBottomLeftCorner.Xyz.TopDown());
lineBuffer.LineTo(f.NearTopLeftCorner.Xyz.TopDown());
lineBuffer.SetColour(new Vector4(0f, 1f, 0f, 1f));
lineBuffer.MoveTo(f.NearTopRightCorner.Xyz.TopDown());
lineBuffer.LineTo(f.FarTopRightCorner.Xyz.TopDown());
lineBuffer.LineTo(f.FarBottomRightCorner.Xyz.TopDown());
lineBuffer.LineTo(f.NearBottomRightCorner.Xyz.TopDown());
lineBuffer.LineTo(f.NearTopRightCorner.Xyz.TopDown());
}
public IEnumerable<PatchDescriptor> GetPatches(Vector3 eye, Frustum f)
{
bool childFrustumCheck = true;
// frustum cull
if (checkFrustum)
{
var clipresult = f.TestBox(this.vertex);
if (clipresult == Frustum.ObjectClipResult.TotallyOutside)
{
yield break;
}
if (clipresult == Frustum.ObjectClipResult.TotallyInside)
{
childFrustumCheck = false;
}
}
// get eye y-difference (0 within min/max height)
//float eyeY = U.Max(U.Max(eye.Y - MaxHeight, 0f), U.Max(MinHeight - eye.Y, 0f));
float eyeYdiff = 0f;
if (eye.Y > MaxHeight)
{
eyeYdiff = eye.Y - MaxHeight;
}
else if (eye.Y < MinHeight)
{
eyeYdiff = MinHeight - eye.Y;
}
eyeYdiff *= eyeYdiff;
int i = 0;
distance[i++] = (float)Math.Sqrt((eye.X - vertex[i].X).Sqr() + eyeYdiff + (eye.Z - vertex[i].Z).Sqr());
distance[i++] = (float)Math.Sqrt((eye.X - vertex[i].X).Sqr() + eyeYdiff + (eye.Z - vertex[i].Z).Sqr());
distance[i++] = (float)Math.Sqrt((eye.X - vertex[i].X).Sqr() + eyeYdiff + (eye.Z - vertex[i].Z).Sqr());
distance[i++] = (float)Math.Sqrt((eye.X - vertex[i].X).Sqr() + eyeYdiff + (eye.Z - vertex[i].Z).Sqr());
distance[i++] = U.DistanceToSquare(
vertex[(int)Corner.BottomNearLeft].X, vertex[(int)Corner.BottomNearLeft].Z,
vertex[(int)Corner.BottomFarRight].X, vertex[(int)Corner.BottomFarRight].Z,
eye.X, eye.Z,
eyeYdiff);
for (i = 0; i < 5; i++)
{
lod[i] = GetLOD(distance[i], depth);
}
int patchLOD = lod.Max();
int LODDiff = patchLOD - lod.Min();
float patchDistance = distance.Min();
// recusion limit, or not enough lod difference
if (depth > MaxDepth || LODDiff <= MaxLODDiff)
{
yield return new PatchDescriptor
{
Tile = this.tile,
TileModelMatrix = this.tile.ModelMatrix,
TileSize = tileSize,
MeshSize = GetMeshSize(tileSize, patchLOD),
//Offset = (vertex[(int)Corner.BottomNearLeft].Xz - TileOffset.Xz) / (float)this.tile.Width,
Scale = (float)tileSize / (float)tile.Width,
Offset = this.Offset,
Distance = patchDistance,
LOD = patchLOD
};
}
else
{
// recurse
var BottomNearCentre = vertex[(int)Corner.BottomNearLeft];
BottomNearCentre.X = BottomCentre.X;
var BottomCentreLeft = vertex[(int)Corner.BottomNearLeft];
BottomCentreLeft.Z = BottomCentre.Z;
var BottomFarCentre = vertex[(int)Corner.BottomFarLeft];
BottomFarCentre.X = BottomCentre.X;
var BottomCentreRight = vertex[(int)Corner.BottomNearRight];
BottomCentreRight.Z = BottomCentre.Z;
var TopNearCentre = vertex[(int)Corner.TopNearLeft];
TopNearCentre.X = TopCentre.X;
var TopCentreLeft = vertex[(int)Corner.TopNearLeft];
TopCentreLeft.Z = TopCentre.Z;
var TopFarCentre = vertex[(int)Corner.TopFarLeft];
TopFarCentre.X = TopCentre.X;
var TopCentreRight = vertex[(int)Corner.TopNearRight];
TopCentreRight.Z = TopCentre.Z;
float offsetfactor = 1.0f/(1 << (depth+1));
// near left quadrant
foreach (var pd in new QuadTreeNode(this, tile, tileSize >> 1, depth + 1, childFrustumCheck, Offset,
vertex[(int)Corner.BottomNearLeft],
BottomNearCentre,
BottomCentreLeft,
BottomCentre,
vertex[(int)Corner.TopNearLeft],
TopNearCentre,
TopCentreLeft,
TopCentre
).GetPatches(eye, f))
{
yield return pd;
}
// near right quadrant
foreach (var pd in new QuadTreeNode(this, tile, tileSize >> 1, depth + 1, childFrustumCheck, Offset + new Vector2(offsetfactor, 0f),
BottomNearCentre,
vertex[(int)Corner.BottomNearRight],
BottomCentre,
BottomCentreRight,
TopNearCentre,
vertex[(int)Corner.TopNearRight],
TopCentre,
TopCentreRight
).GetPatches(eye, f))
{
yield return pd;
}
// far left quadrant
foreach (var pd in new QuadTreeNode(this, tile, tileSize >> 1, depth + 1, childFrustumCheck, Offset + new Vector2(0f, offsetfactor),
BottomCentreLeft,
BottomCentre,
vertex[(int)Corner.BottomFarLeft],
BottomFarCentre,
TopCentreLeft,
TopCentre,
vertex[(int)Corner.TopFarLeft],
TopFarCentre
).GetPatches(eye, f))
{
yield return pd;
}
// far right quadrant
foreach (var pd in new QuadTreeNode(this, tile, tileSize >> 1, depth + 1, childFrustumCheck, Offset + new Vector2(offsetfactor, offsetfactor),
BottomCentre,
BottomCentreRight,
BottomFarCentre,
vertex[(int)Corner.BottomFarRight],
TopCentre,
TopCentreRight,
TopFarCentre,
vertex[(int)Corner.TopFarRight]
).GetPatches(eye, f))
{
yield return pd;
}
}
}
