/// <summary>
/// Marshals data from an array of managed object to an unmanaged block of memory,
/// writes the unmanaged data to <paramref name="offset"/> from given <paramref name="ptr"/>.
/// </summary>
/// <typeparam name="T">The type of the element of the array.</typeparam>
/// <param name="array">An array of managed object.</param>
/// <param name="ptr">The unmanaged base address to write, must
/// have been allocated of enough memory by the caller.</param>
/// <param name="offset">The offset to write to.</param>
public static void ArrayToPtr <T>(T[] array, IntPtr ptr, int offset) where T : struct
{
// 32 bits platform
if (IntPtr.Size == sizeof(Int32))
{
int ptrValue = ptr.ToInt32() + offset;
for (uint i = 0; i < array.Length; i++)
{
int elementSize = TypeMarshal.GetNativeMemorySize <T>();
SafeIntPtr safePtr = TypeMarshal.ToIntPtr <T>(array[i]);
AppendToPtrList(ptr, safePtr);
NativeMethods.RtlMoveMemory(new IntPtr(ptrValue), safePtr, (uint)elementSize);
ptrValue += elementSize;
}
}
// 64 bits platform
else if (IntPtr.Size == sizeof(Int64))
{
long ptrValue = ptr.ToInt64() + offset;
for (uint i = 0; i < array.Length; i++)
{
int elementSize = TypeMarshal.GetNativeMemorySize <T>();
SafeIntPtr safePtr = TypeMarshal.ToIntPtr <T>(array[i]);
AppendToPtrList(safePtr, safePtr);
NativeMethods.RtlMoveMemory(new IntPtr(ptrValue), safePtr, (uint)elementSize);
ptrValue += elementSize;
}
}
// not supported
else
{
throw new NotSupportedException("Platform is neither 32 bits nor 64 bits.");
}
}
// Add a SafeIntPtr to pending release list
private static void AppendToPtrList(IntPtr key, SafeIntPtr safeIntPtr)
{
List <SafeIntPtr> list;
if (!ptrList.TryGetValue(key, out list))
{
list = new List <SafeIntPtr>();
ptrList.Add(key, list);
}
list.Add(safeIntPtr);
}