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Fix T48634: Interpolation and distribution of Children Particles breaks. 

Own stupid off-by-one regression in rB019ce363b01bba0afe1 and later...
This commit is contained in:
Bastien Montagne 2016-06-11 14:37:47 +02:00
parent 07925b6316
commit 4ec1c76afc
Notes: blender-bot 2023-02-14 07:50:13 +01:00 
Referenced by issue #48634, Interpolation and distribution of Children Particles breaks
1 changed files with 13 additions and 10 deletions
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23
source/blender/blenkernel/intern/particle_distribute.c
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@ -392,22 +392,25 @@ static int distribute_binary_search(float *sum, int n, float value)
{
int mid, low = 0, high = n - 1;
if (high == low)
return low;
if (sum[low] >= value)
return low;
if (sum[high] < value)
if (sum[high - 1] < value)
return high;
while (low < high) {
mid = (low + high) / 2;
if ((sum[mid] < value) && (sum[mid + 1] >= value))
if ((sum[mid] >= value) && (sum[mid - 1] < value))
return mid;
if (sum[mid] >= value) {
if (sum[mid] > value) {
high = mid - 1;
}
else if (sum[mid] < value) {
else {
low = mid + 1;
}
}
@ -1024,7 +1027,7 @@ static int psys_thread_context_init_distribute(ParticleThreadContext *ctx, Parti
/* Calculate cumulative weights.
* We remove all null-weighted elements from element_sum, and create a new mapping
* 'activ'_elem_index -> orig_elem_index.
* This simplifies greatly the filtering of zero-weighted items - and can be much mor efficient
* This simplifies greatly the filtering of zero-weighted items - and can be much more efficient
* especially in random case (reducing a lot the size of binary-searched array)...
*/
float *element_sum = MEM_mallocN(sizeof(*element_sum) * totmapped, __func__);
@ -1047,13 +1050,13 @@ static int psys_thread_context_init_distribute(ParticleThreadContext *ctx, Parti
/* Finally assign elements to particles */
if ((part->flag & PART_TRAND) || (part->simplify_flag & PART_SIMPLIFY_ENABLE)) {
float pos;
for (p = 0; p < totpart; p++) {
/* In theory element_sum[totelem - 1] should be 1.0,
/* In theory element_sum[totmapped - 1] should be 1.0,
* but due to float errors this is not necessarily always true, so scale pos accordingly. */
pos = BLI_frand() * element_sum[totmapped - 1];
particle_element[p] = element_map[distribute_binary_search(element_sum, totmapped, pos)];
const float pos = BLI_frand() * element_sum[totmapped - 1];
const int eidx = distribute_binary_search(element_sum, totmapped, pos);
particle_element[p] = element_map[eidx];
BLI_assert(pos <= element_sum[eidx] && pos > (eidx ? element_sum[eidx - 1] : 0.0f));
jitter_offset[particle_element[p]] = pos;
}
}