/**
* Converts contained object to byte vector.
*
* @param bytes Vector to fill.
*/
void GridFloatHasheableObject::convertToBytes(std::vector<int8_t>& bytes) const {
int32_t val = floatToRawIntBits(floatVal);
bytes.resize(sizeof(val));
memset(&bytes[0], 0, sizeof(val));
GridClientByteUtils::valueToBytes(val, &bytes[0], sizeof(val), GridClientByteUtils::LITTLE_ENDIAN_ORDER);
}
/**
* Returns a representation of the specified floating-point value
* according to the IEEE 754 floating-point "single format" bit
* layout.
* <p>
* Bit 31 (the bit that is selected by the mask
* <code>0x80000000</code>) represents the sign of the floating-point
* number.
* Bits 30-23 (the bits that are selected by the mask
* <code>0x7f800000</code>) represent the exponent.
* Bits 22-0 (the bits that are selected by the mask
* <code>0x007fffff</code>) represent the significand (sometimes called
* the mantissa) of the floating-point number.
* <p>If the argument is positive infinity, the result is
* <code>0x7f800000</code>.
* <p>If the argument is negative infinity, the result is
* <code>0xff800000</code>.
* <p>If the argument is NaN, the result is <code>0x7fc00000</code>.
* <p>
* In all cases, the result is an integer that, when given to the
* {@link #intBitsToFloat(int)} method, will produce a floating-point
* value the same as the argument to <code>floatToIntBits</code>
* (except all NaN values are collapsed to a single
* "canonical" NaN value).
*
* @param value a floating-point number.
* @return the bits that represent the floating-point number.
*/
int32_t GridFloatHasheableObject::floatToIntBits(float val) {
int32_t result = floatToRawIntBits(val);
// Check for NaN based on values of bit fields, maximum
// exponent and nonzero significand.
if ( ((result & FloatConsts::EXP_BIT_MASK) == FloatConsts::EXP_BIT_MASK) &&
(result & FloatConsts::SIGNIF_BIT_MASK) != 0)
result = 0x7fc00000;
return result;
}
void BIH::subdivide(int left, int right, std::vector<uint32> &tempTree, buildData &dat, AABound &gridBox, AABound &nodeBox, int nodeIndex, int depth, BuildStats &stats)
{
if ((right - left + 1) <= dat.maxPrims || depth >= MAX_STACK_SIZE)
{
// write leaf node
stats.updateLeaf(depth, right - left + 1);
createNode(tempTree, nodeIndex, left, right);
return;
}
// calculate extents
int axis = -1, prevAxis, rightOrig;
float clipL = G3D::fnan(), clipR = G3D::fnan(), prevClip = G3D::fnan();
float split = G3D::fnan(), prevSplit;
bool wasLeft = true;
while (true)
{
prevAxis = axis;
prevSplit = split;
// perform quick consistency checks
Vector3 d( gridBox.hi - gridBox.lo );
if (d.x < 0 || d.y < 0 || d.z < 0)
throw std::logic_error("negative node extents");
for (int i = 0; i < 3; i++)
{
if (nodeBox.hi[i] < gridBox.lo[i] || nodeBox.lo[i] > gridBox.hi[i])
{
//UI.printError(Module.ACCEL, "Reached tree area in error - discarding node with: %d objects", right - left + 1);
throw std::logic_error("invalid node overlap");
}
}
// find longest axis
axis = d.primaryAxis();
split = 0.5f * (gridBox.lo[axis] + gridBox.hi[axis]);
// partition L/R subsets
clipL = -G3D::inf();
clipR = G3D::inf();
rightOrig = right; // save this for later
float nodeL = G3D::inf();
float nodeR = -G3D::inf();
for (int i = left; i <= right;)
{
int obj = dat.indices[i];
float minb = dat.primBound[obj].low()[axis];
float maxb = dat.primBound[obj].high()[axis];
float center = (minb + maxb) * 0.5f;
if (center <= split)
{
// stay left
i++;
if (clipL < maxb)
clipL = maxb;
}
else
{
// move to the right most
int t = dat.indices[i];
dat.indices[i] = dat.indices[right];
dat.indices[right] = t;
right--;
if (clipR > minb)
clipR = minb;
}
nodeL = std::min(nodeL, minb);
nodeR = std::max(nodeR, maxb);
}
// check for empty space
if (nodeL > nodeBox.lo[axis] && nodeR < nodeBox.hi[axis])
{
float nodeBoxW = nodeBox.hi[axis] - nodeBox.lo[axis];
float nodeNewW = nodeR - nodeL;
// node box is too big compare to space occupied by primitives?
if (1.3f * nodeNewW < nodeBoxW)
{
stats.updateBVH2();
int nextIndex = tempTree.size();
// allocate child
tempTree.push_back(0);
tempTree.push_back(0);
tempTree.push_back(0);
// write bvh2 clip node
stats.updateInner();
tempTree[nodeIndex + 0] = (axis << 30) | (1 << 29) | nextIndex;
tempTree[nodeIndex + 1] = floatToRawIntBits(nodeL);
tempTree[nodeIndex + 2] = floatToRawIntBits(nodeR);
// update nodebox and recurse
nodeBox.lo[axis] = nodeL;
nodeBox.hi[axis] = nodeR;
subdivide(left, rightOrig, tempTree, dat, gridBox, nodeBox, nextIndex, depth + 1, stats);
return;
}
}
// ensure we are making progress in the subdivision
if (right == rightOrig)
{
// all left
if (prevAxis == axis && G3D::fuzzyEq(prevSplit, split)) {
// we are stuck here - create a leaf
stats.updateLeaf(depth, right - left + 1);
createNode(tempTree, nodeIndex, left, right);
return;
}
if (clipL <= split) {
// keep looping on left half
gridBox.hi[axis] = split;
prevClip = clipL;
wasLeft = true;
continue;
}
gridBox.hi[axis] = split;
prevClip = G3D::fnan();
}
else if (left > right)
{
// all right
if (prevAxis == axis && G3D::fuzzyEq(prevSplit, split)) {
// we are stuck here - create a leaf
stats.updateLeaf(depth, right - left + 1);
createNode(tempTree, nodeIndex, left, right);
return;
}
right = rightOrig;
if (clipR >= split) {
// keep looping on right half
gridBox.lo[axis] = split;
prevClip = clipR;
wasLeft = false;
continue;
}
gridBox.lo[axis] = split;
prevClip = G3D::fnan();
}
else
{
// we are actually splitting stuff
if (prevAxis != -1 && !isnan(prevClip))
{
// second time through - lets create the previous split
// since it produced empty space
int nextIndex = tempTree.size();
// allocate child node
tempTree.push_back(0);
tempTree.push_back(0);
tempTree.push_back(0);
if (wasLeft) {
// create a node with a left child
// write leaf node
stats.updateInner();
tempTree[nodeIndex + 0] = (prevAxis << 30) | nextIndex;
tempTree[nodeIndex + 1] = floatToRawIntBits(prevClip);
tempTree[nodeIndex + 2] = floatToRawIntBits(G3D::inf());
} else {
// create a node with a right child
// write leaf node
stats.updateInner();
tempTree[nodeIndex + 0] = (prevAxis << 30) | (nextIndex - 3);
tempTree[nodeIndex + 1] = floatToRawIntBits(-G3D::inf());
tempTree[nodeIndex + 2] = floatToRawIntBits(prevClip);
}
// count stats for the unused leaf
depth++;
stats.updateLeaf(depth, 0);
// now we keep going as we are, with a new nodeIndex:
nodeIndex = nextIndex;
}
break;
}
}
// compute index of child nodes
int nextIndex = tempTree.size();
// allocate left node
int nl = right - left + 1;
int nr = rightOrig - (right + 1) + 1;
if (nl > 0) {
tempTree.push_back(0);
tempTree.push_back(0);
tempTree.push_back(0);
} else
nextIndex -= 3;
// allocate right node
if (nr > 0) {
tempTree.push_back(0);
tempTree.push_back(0);
tempTree.push_back(0);
}
// write leaf node
stats.updateInner();
tempTree[nodeIndex + 0] = (axis << 30) | nextIndex;
tempTree[nodeIndex + 1] = floatToRawIntBits(clipL);
tempTree[nodeIndex + 2] = floatToRawIntBits(clipR);
// prepare L/R child boxes
AABound gridBoxL(gridBox), gridBoxR(gridBox);
AABound nodeBoxL(nodeBox), nodeBoxR(nodeBox);
gridBoxL.hi[axis] = gridBoxR.lo[axis] = split;
nodeBoxL.hi[axis] = clipL;
nodeBoxR.lo[axis] = clipR;
// recurse
if (nl > 0)
subdivide(left, right, tempTree, dat, gridBoxL, nodeBoxL, nextIndex, depth + 1, stats);
else
stats.updateLeaf(depth + 1, 0);
if (nr > 0)
subdivide(right + 1, rightOrig, tempTree, dat, gridBoxR, nodeBoxR, nextIndex + 3, depth + 1, stats);
else
stats.updateLeaf(depth + 1, 0);
}