private static void *PxAllocatorCallback_Allocate(PxAllocatorCallback * @this, nuint size, byte *typeName, byte *filePath, int lineNumber)
{
AllocationCount++;
// Allocate memory
// Over-provision it by sizeof(AllocationInformation) so we can store our extra info and 16 bytes for alignment
const ulong alignment = 16ul;
ulong bytesToAllocate = size + (ulong)sizeof(AllocationInformation) + alignment;
byte * actualAllocation = (byte *)Marshal.AllocHGlobal((IntPtr)bytesToAllocate);
// Skip the allocation information
byte *physXMemory = actualAllocation + sizeof(AllocationInformation);
// Align
physXMemory += alignment - (((ulong)physXMemory) % alignment);
Debug.Assert(((ulong)physXMemory) % alignment == 0, "The memory must be appropriately aligned!");
Debug.Assert((((ulong)physXMemory) & 15) == 0, "The memory must be appropriately aligned!"); // This is the same assert PhysX uses internally.
// Record the pointer to the actual allocation
AllocationInformation *info = (AllocationInformation *)(physXMemory - sizeof(AllocationInformation));
info->ActualAllocation = actualAllocation;
// Return the buffer
return(physXMemory);
}
private static void PxAllocatorCallback_Deallocate(PxAllocatorCallback * @this, void *ptr)
{
AllocationInformation *info = (AllocationInformation *)((byte *)ptr - sizeof(AllocationInformation));
Console.Write("Deallocating ");
Console.Out.WriteAnsi(info->TypeName);
Console.Write($" ({info->AllocationSize} bytes) for ");
Console.Out.WriteAnsi(info->FilePath);
Console.WriteLine($":{info->LineNumber}");
Marshal.FreeHGlobal((IntPtr)info->ActualAllocation);
}
private static void PxAllocatorCallback_Deallocate(PxAllocatorCallback * @this, void *ptr)
{
AllocationInformation *info = (AllocationInformation *)((byte *)ptr - sizeof(AllocationInformation));
Marshal.FreeHGlobal((IntPtr)info->ActualAllocation);
}
