//
// ArraySegment<byte> を新規に確保して置き換える
//
public void Append(BufferAccessor a, int offset = -1)
{
if (AccessorType != a.AccessorType)
{
System.Console.WriteLine(AccessorType.ToString() + "!=" + a.AccessorType.ToString());
throw new Exception("different AccessorType");
}
// UNSIGNED_SHORT <-> UNSIGNED_INT の変換を許容して処理を続行
// 統合メッシュのprimitiveのIndexBufferが65,535（ushort.MaxValue)を超える場合や、変換前にindexBuffer.ComponetTypeがushortとuint混在する場合など
if (ComponentType != a.ComponentType)
{
switch (a.ComponentType)
{
//ushort to uint
case AccessorValueType.UNSIGNED_SHORT:
{
var src = SpanLike.Wrap <UInt16>(a.Bytes).Slice(0, a.Count);
var bytes = new byte[src.Length * 4];
var dst = SpanLike.Wrap <UInt32>(new ArraySegment <byte>(bytes));
for (int i = 0; i < src.Length; ++i)
{
dst[i] = (uint)src[i];
}
var accessor = new BufferAccessor(new ArraySegment <byte>(bytes), AccessorValueType.UNSIGNED_INT, AccessorVectorType.SCALAR, a.Count);
a = accessor;
break;
}
//uint to ushort (おそらく通ることはない)
case AccessorValueType.UNSIGNED_INT:
{
var src = SpanLike.Wrap <UInt32>(a.Bytes).Slice(0, a.Count);
var bytes = new byte[src.Length * 2];
var dst = SpanLike.Wrap <UInt16>(new ArraySegment <byte>(bytes));
for (int i = 0; i < src.Length; ++i)
{
dst[i] = (ushort)src[i];
}
var accessor = new BufferAccessor(new ArraySegment <byte>(bytes), ComponentType, AccessorVectorType.SCALAR, a.Count);
a = accessor;
break;
}
default:
throw new Exception("Cannot Convert ComponentType");
}
}
// 連結した新しいバッファを確保
var oldLength = Bytes.Count;
ToByteLength(oldLength + a.Bytes.Count);
// 後ろにコピー
Buffer.BlockCopy(a.Bytes.Array, a.Bytes.Offset, Bytes.Array, Bytes.Offset + oldLength, a.Bytes.Count);
Count += a.Count;
if (offset > 0)
{
// 後半にoffsetを足す
switch (ComponentType)
{
case AccessorValueType.UNSIGNED_SHORT:
{
var span = SpanLike.Wrap <UInt16>(Bytes.Slice(oldLength));
var ushortOffset = (ushort)offset;
for (int i = 0; i < span.Length; ++i)
{
span[i] += ushortOffset;
}
}
break;
case AccessorValueType.UNSIGNED_INT:
{
var span = SpanLike.Wrap <UInt32>(Bytes.Slice(oldLength));
var uintOffset = (uint)offset;
for (int i = 0; i < span.Length; ++i)
{
span[i] += uintOffset;
}
}
break;
default:
throw new NotImplementedException();
}
}
}
