/*
public override void setMaterial(Material m)
{
int numobjs = objs.Count;
for(int i = 0; i < numobjs; i++)
{
objs[i].setMaterial(m);
}
}
*/
public static CompoundRenderable LoadCompoundRenderable(XmlElement def)
{
CompoundRenderable toReturn = new CompoundRenderable();
//Select all renderable children of this compound object container
XmlNodeList children = def.SelectNodes("renderable");
foreach(XmlElement e in children)
{
//Load each child and store in list
RenderableObject rend = RenderableObject.LoadRenderableObject(e);
if (rend != null)
toReturn.AddObject(rend);
}
return toReturn;
}
/*
public override BoundingBox get_bounding_box()
{
return bbox;
}
*/
/// <summary>
/// Sets up the grid acceleration structure
/// </summary>
public void SetupCells()
{
//Construct bounding box
Point3D pmin = MinimumCoordinates();
Point3D pmax = max_coordinates();
_boundingBox.corner0 = pmin.Coordinates;
_boundingBox.corner1 = pmax.Coordinates;
//bbox.x0 = pmin.coords.X; bbox.y0 = pmin.coords.Y; bbox.z0 = pmin.coords.Z;
//bbox.x1 = pmax.coords.X; bbox.y1 = pmax.coords.Y; bbox.z1 = pmax.coords.Z;
int numobjs = containedObjects.Count;
//Find width of grid structure
float wx = pmax.X - pmin.X;
float wy = pmax.Y - pmin.Y;
float wz = pmax.Z - pmin.Z;
float multiplier = 2.0f; //For approximately 8x the number of cells as objects.
//Calculate number of cells according to formulae given by Shirley (2000)
//s = (wxwywz/n)^(1/3)
//n = trunc(mw/s) + 1;
float s = (float)Math.Pow((double)((wx * wy * wz) / numobjs), (1.0 / 3.0));
nx = (int)(multiplier * wx / s + 1);
ny = (int)(multiplier * wy / s + 1);
nz = (int)(multiplier * wz / s + 1);
//Get the computed number of cells
int num_cells = nx * ny * nz;
//Null initialize the set of cells
cells = new RenderableObject[num_cells];
for(int i = 0; i < num_cells; i++)
{
cells[i] = null;
}
//Temporary list to hold the number of objects in each cell
int[] counts = new int[num_cells];
for(int i = 0;i < num_cells;i++)
{
counts[i] = 0;
}
BoundingBox objectBoundingBox;
int index;
//Put objects in cells
for(int i = 0; i < numobjs; i++)
{
objectBoundingBox = containedObjects[i].BoundingBox;
//Find the corners of the bounding box in terms of cell indices of the grid
//According to the mathematical relationship f(p) = (px - p0x)/(p1x-p0x) [0.0,1.0]
//index = nf(p)
int ixmin = (int)Clamp((objectBoundingBox.corner0.X - pmin.X) * nx / (pmax.X - pmin.X), 0, nx - 1);
int iymin = (int)Clamp((objectBoundingBox.corner0.Y - pmin.Y) * ny / (pmax.Y - pmin.Y), 0, ny - 1);
int izmin = (int)Clamp((objectBoundingBox.corner0.Z - pmin.Z) * nz / (pmax.Z - pmin.Z), 0, nz - 1);
int ixmax = (int)Clamp((objectBoundingBox.corner1.X - pmin.X) * nx / (pmax.X - pmin.X), 0, nx - 1);
int iymax = (int)Clamp((objectBoundingBox.corner1.Y - pmin.Y) * ny / (pmax.Y - pmin.Y), 0, ny - 1);
int izmax = (int)Clamp((objectBoundingBox.corner1.Z - pmin.Z) * nz / (pmax.Z - pmin.Z), 0, nz - 1);
//int ixmin = (int)clamp((object_bbox.x0 - pmin.coords.X) * nx / (pmax.coords.X - pmin.coords.X), 0, nx - 1);
//int iymin = (int)clamp((object_bbox.y0 - pmin.coords.Y) * ny / (pmax.coords.Y - pmin.coords.Y), 0, ny - 1);
//int izmin = (int)clamp((object_bbox.z0 - pmin.coords.Z) * nz / (pmax.coords.Z - pmin.coords.Z), 0, nz - 1);
//int ixmax = (int)clamp((object_bbox.x1 - pmin.coords.X) * nx / (pmax.coords.X - pmin.coords.X), 0, nx - 1);
//int iymax = (int)clamp((object_bbox.y1 - pmin.coords.Y) * ny / (pmax.coords.Y - pmin.coords.Y), 0, ny - 1);
//int izmax = (int)clamp((object_bbox.z1 - pmin.coords.Z) * nz / (pmax.coords.Z - pmin.coords.Z), 0, nz - 1);
//With the index information traverse all cells and add objects to cells that they are contained in.
for(int iz = izmin; iz <= izmax; iz++)
{
for(int iy = iymin; iy <= iymax; iy++)
{
for(int ix = ixmin; ix<= ixmax;ix++)
{
index = ix + (nx * iy) + (nx * ny * iz);
//Just add the object if no objects are stored in cell already
if(counts[index] == 0)
{
cells[index] = containedObjects[i];
counts[index]++;
}
//If object is already stored in cell, create a new compound object and store
//the two objects in it
else if(counts[index] == 1)
{
CompoundRenderable compoundObject = new CompoundRenderable();
compoundObject.AddObject(cells[index]);
compoundObject.AddObject(containedObjects[i]);
cells[index] = compoundObject;
counts[index]++;
}
//If more than one object is in the cell, just add it to the compound object already contained in the cell
else if(counts[index] > 1)
{
//Safe to assume that if this code is running, the object at cells[index] is a compoundrenderable
((CompoundRenderable)cells[index]).AddObject(containedObjects[i]);
counts[index]++;
}
}
}
}
}
}
