unsafe static void BuildNode(Node *node, Point3 *points, int offset, int length, int depth)
{
// pick median
int median = length >> 1;
// pick splitting axis
int axis = depth % 3;
// split points by median
SelectByAxis(median, points + offset, length, axis);
// calc offsets
var offsetL = offset;
var offsetR = offset + median + 1;
var lengthL = median;
var lengthR = length - median - 1;
var stepL = lengthL > 0 ? 1 : 0;
var stepR = lengthR > 0 ? 1 + lengthL : 0;
// make node
node->point = offset + median;
node->stepL = stepL;
node->stepR = stepR;
// build subtrees
if (lengthL > 0)
{
BuildNode(node + stepL, points, offsetL, lengthL, depth + 1);
}
if (lengthR > 0)
{
BuildNode(node + stepR, points, offsetR, lengthR, depth + 1);
}
}
unsafe static void SelectByAxis(int nth, Point3 *points, int length, int axis)
{
// note: this function has been adapted from public domain
// variants listed in 'KdTree_nth_element.txt'
const int strideLsh = 2;
var i = 0;
var j = length - 1;
var v = &points->x + axis;
while (i < j)
{
var r = i;
var w = j;
float k = v[((r + w) >> 1) << strideLsh];
while (r < w)
{
if (v[r << strideLsh] >= k)
{
Point3 pw = points[w];
points[w] = points[r];
points[r] = pw;
w--;
}
else
{
r++;
}
}
if (v[r << strideLsh] > k)
{
r--;
}
if (nth <= r)
{
j = r;
}
else
{
i = r + 1;
}
}
}
unsafe static void BuildNodeDeferSubtrees(Node *node, Point3 *points, int offset, int length, int depth)
{
// pick median
int median = length >> 1;
// pick splitting axis
int axis = depth % 3;
// split points by median
SelectByAxis(median, points + offset, length, axis);
// calc offsets
var lengthL = median;
var lengthR = length - median - 1;
var stepL = lengthL > 0 ? 1 : 0;
var stepR = lengthR > 0 ? 1 + lengthL : 0;
// make node
node->point = offset + median;
node->stepL = stepL;
node->stepR = stepR;
}
unsafe static void ScheduleNode(ref JobHandle *jobSched, JobHandle *jobDepends, Node *node, Point3 *points, int offset, int length, int depth, int depthSingleThreaded)
{
// pick median
int median = length >> 1;
// calc offsets
var offsetL = offset;
var offsetR = offset + median + 1;
var lengthL = median;
var lengthR = length - median - 1;
var stepL = lengthL > 0 ? 1 : 0;
var stepR = lengthR > 0 ? 1 + lengthL : 0;
// make job
var job = new BuildNodeJob()
{
node = node,
points = points,
offset = offset,
length = length,
depth = depth,
leaf = (depth >= depthSingleThreaded),
};
var jobHandle = jobSched++;
if (jobDepends != null)
{
*jobHandle = job.Schedule(*jobDepends);
}
else
{
*jobHandle = job.Schedule();
}
if (depth == 0)
{
JobHandle.ScheduleBatchedJobs();
}
if (job.leaf)
{
return;
}
// schedule subtrees
if (lengthL > 0)
{
ScheduleNode(ref jobSched, jobHandle, node + stepL, points, offsetL, lengthL, depth + 1, depthSingleThreaded);
}
if (lengthR > 0)
{
ScheduleNode(ref jobSched, jobHandle, node + stepR, points, offsetR, lengthR, depth + 1, depthSingleThreaded);
}
}
public unsafe static void Uniform3(int uniformLocation, int count, Point3 *values)
{
Delegates.Uniform3ivARB(uniformLocation, count, (int *)values);
}
