godot_voxel/storage/funcs.cpp

59 lines
2.2 KiB
C++

#include "funcs.h"
#include "../util/math/box3i.h"
namespace zylann::voxel {
void copy_3d_region_zxy(Span<uint8_t> dst, Vector3i dst_size, Vector3i dst_min, Span<const uint8_t> src,
Vector3i src_size, Vector3i src_min, Vector3i src_max, size_t item_size) {
//
Vector3iUtil::sort_min_max(src_min, src_max);
clip_copy_region(src_min, src_max, src_size, dst_min, dst_size);
const Vector3i area_size = src_max - src_min;
if (area_size.x <= 0 || area_size.y <= 0 || area_size.z <= 0) {
// Degenerate area, we'll not copy anything.
return;
}
#ifdef DEBUG_ENABLED
if (src.data() == dst.data()) {
ERR_FAIL_COND_MSG(
Box3i::from_min_max(src_min, src_max).intersects(Box3i::from_min_max(dst_min, dst_min + area_size)),
"Copy across the same buffer to an overlapping area is not supported");
}
ERR_FAIL_COND(Vector3iUtil::get_volume(area_size) * item_size > dst.size());
ERR_FAIL_COND(Vector3iUtil::get_volume(area_size) * item_size > src.size());
#endif
if (area_size == src_size && area_size == dst_size) {
// Copy everything
ERR_FAIL_COND(dst.size() != src.size());
memcpy(dst.data(), src.data(), dst.size());
} else {
// Copy area row by row:
// This offset is how much to move in order to advance by one row (row direction is Y),
// essentially doing y+1
const unsigned int src_row_offset = src_size.y * item_size;
const unsigned int dst_row_offset = dst_size.y * item_size;
Vector3i pos;
for (pos.z = 0; pos.z < area_size.z; ++pos.z) {
pos.x = 0;
unsigned int src_ri = Vector3iUtil::get_zxy_index(Vector3i(src_min + pos), src_size) * item_size;
unsigned int dst_ri = Vector3iUtil::get_zxy_index(Vector3i(dst_min + pos), dst_size) * item_size;
for (; pos.x < area_size.x; ++pos.x) {
#ifdef DEBUG_ENABLED
ERR_FAIL_COND(dst_ri >= dst.size());
ERR_FAIL_COND(dst.size() - dst_ri < area_size.y * item_size);
#endif
// TODO Cast src and dst to `restrict` so the optimizer can assume adresses don't overlap,
// which might allow to write as a for loop (which may compile as a `memcpy`)?
memcpy(&dst[dst_ri], &src[src_ri], area_size.y * item_size);
src_ri += src_row_offset;
dst_ri += dst_row_offset;
}
}
}
}
} // namespace zylann::voxel