void InstantiateEntitiesGroup(Entity *srcEntities, int srcEntityCount,
Entity *outputRootEntities, int instanceCount)
{
int totalCount = srcEntityCount * instanceCount;
var tempAllocSize = sizeof(Entity) * totalCount +
sizeof(InstantiateRemapChunk) * totalCount + sizeof(Entity) * instanceCount;
byte * allocation;
const int kMaxStackAllocSize = 16 * 1024;
if (tempAllocSize > kMaxStackAllocSize)
{
allocation = (byte *)UnsafeUtility.Malloc(tempAllocSize, 16, Allocator.Temp);
}
else
{
var temp = stackalloc byte[tempAllocSize];
allocation = temp;
}
var entityRemap = (Entity *)allocation;
var remapChunks = (InstantiateRemapChunk *)(entityRemap + totalCount);
var outputEntities = (Entity *)(remapChunks + totalCount);
var remapChunksCount = 0;
for (int i = 0; i != srcEntityCount; i++)
{
var srcEntity = srcEntities[i];
remapChunksCount = InstantiateEntitiesOne(srcEntity,
outputEntities, instanceCount, remapChunks, remapChunksCount);
for (int r = 0; r != instanceCount; r++)
{
var ptr = entityRemap + (r * srcEntityCount + i);
* ptr = outputEntities[r];
}
if (i == 0)
{
for (int r = 0; r != instanceCount; r++)
{
outputRootEntities[r] = outputEntities[r];
}
}
}
for (int i = 0; i != remapChunksCount; i++)
{
var chunk = remapChunks[i].Chunk;
var dstArchetype = chunk->Archetype;
var allocatedCount = remapChunks[i].AllocatedCount;
var indexInChunk = remapChunks[i].IndexInChunk;
var instanceBeginIndex = remapChunks[i].InstanceBeginIndex;
var localRemap = entityRemap + instanceBeginIndex * srcEntityCount;
EntityRemapUtility.PatchEntitiesForPrefab(dstArchetype->ScalarEntityPatches + 1, dstArchetype->ScalarEntityPatchCount - 1,
dstArchetype->BufferEntityPatches, dstArchetype->BufferEntityPatchCount,
chunk->Buffer, indexInChunk, allocatedCount, srcEntities, localRemap, srcEntityCount);
if (dstArchetype->ManagedEntityPatchCount > 0)
{
ManagedChangesTracker.PatchEntitiesForPrefab(dstArchetype, chunk, indexInChunk, allocatedCount, srcEntities, localRemap, srcEntityCount, Allocator.Temp);
}
}
if (tempAllocSize > kMaxStackAllocSize)
{
UnsafeUtility.Free(allocation, Allocator.Temp);
}
}