From d79fa8dc4dc28fc49dbdbecbd481bc21657f24c6 Mon Sep 17 00:00:00 2001 From: Sergey Sharybin Date: Fri, 25 Aug 2017 14:54:44 +0200 Subject: Another optimization of tangent space calculation Don't use quick sort for small arrays, bubble sort works way faster for small arrays due to cache coherency. This is what qsort() from libc is doing actually. We can also experiment unrolling some extra small arrays, for example 3 and 4 element arrays. This reduces tangent space calculation for dragon from 3.1sec to 2.9sec. --- intern/mikktspace/mikktspace.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) (limited to 'intern/mikktspace') diff --git a/intern/mikktspace/mikktspace.c b/intern/mikktspace/mikktspace.c index 479443805bf..2e8e58d37d4 100644 --- a/intern/mikktspace/mikktspace.c +++ b/intern/mikktspace/mikktspace.c @@ -1677,6 +1677,19 @@ static void QuickSortEdges(SEdge * pSortBuffer, int iLeft, int iRight, const int } return; } + else if(iElems < 16) { + int i, j; + for (i = 0; i < iElems - 1; i++) { + for (j = 0; j < iElems - i - 1; j++) { + int index = iLeft + j; + if (pSortBuffer[index].array[channel] > pSortBuffer[index + 1].array[channel]) { + sTmp = pSortBuffer[index]; + pSortBuffer[index] = pSortBuffer[index]; + pSortBuffer[index + 1] = sTmp; + } + } + } + } // Random t=uSeed&31; -- cgit v1.2.3