float LocalFrameBuffer::endFrame(const float errorThreshold)
{
if (hasVarianceBuffer) {
// process regions first, but don't process newly split regions again
int regions = errorThreshold > 0.f ? errorRegion.size() : 0;
for (int i = 0; i < regions; i++) {
box2i& region = errorRegion[i];
float err = 0.f;
float maxErr = 0.0f;
for (int y = region.lower.y; y < region.upper.y; y++)
for (int x = region.lower.x; x < region.upper.x; x++) {
int idx = y * tilesx + x;
err += tileErrorBuffer[idx];
maxErr = std::max(maxErr, tileErrorBuffer[idx]);
}
// set all tiles of this region to local max error to enforce their refinement as a group
for (int y = region.lower.y; y < region.upper.y; y++)
for (int x = region.lower.x; x < region.upper.x; x++) {
int idx = y * tilesx + x;
tileErrorBuffer[idx] = maxErr;
}
vec2i size = region.size();
int area = reduce_mul(size);
err /= area; // avg
if (err < 4.f*errorThreshold) { // split region?
if (area <= 2) { // would just contain single tile after split: remove
regions--;
errorRegion[i] = errorRegion[regions];
errorRegion[regions]= errorRegion.back();
errorRegion.pop_back();
i--;
continue;
}
vec2i split = region.lower + size / 2; // TODO: find split with equal variance
errorRegion.push_back(region); // region reference might become invalid
if (size.x > size.y) {
errorRegion[i].upper.x = split.x;
errorRegion.back().lower.x = split.x;
} else {
errorRegion[i].upper.y = split.y;
errorRegion.back().lower.y = split.y;
}
}
}
float maxErr = 0.0f;
for (int i = 0; i < tiles; i++)
maxErr = std::max(maxErr, tileErrorBuffer[i]);
return maxErr;
} else
return inf;
}
void fe25519_mul(fe25519 *r, const fe25519 *x, const fe25519 *y)
{
int i,j;
crypto_uint32 t[63];
for(i=0;i<63;i++)t[i] = 0;
for(i=0;i<32;i++)
for(j=0;j<32;j++)
t[i+j] += x->v[i] * y->v[j];
for(i=32;i<63;i++)
r->v[i-32] = t[i-32] + times38(t[i]);
r->v[31] = t[31]; /* result now in r[0]...r[31] */
reduce_mul(r);
}
