private static int GetByteStride(Accessor accessor, BufferView view)
{
int len = 0;
if (view.ByteStride == 0)
{
len = GetByteLength((GLenum)accessor.ComponentType);
String type = accessor.Type;
if (type == "SCALAR")
{
len *= 1;
}
else if (type == "VEC2")
{
len *= 2;
}
else if (type == "VEC3")
{
len *= 3;
}
else if (type == "VEC4")
{
len *= 4;
}
else if (type == "MAT2")
{
len *= 4;
}
else if (type == "MAT3")
{
len *= 9;
}
else if (type == "MAT4")
{
len *= 16;
}
else
{
len = 0;
}
return(len);
}
else
{
/*len = GetByteLength((GLenum)accessor.ComponentType);
* if ((view.ByteStride % len) != 0) {
* return 0;
* }*/
return(view.ByteStride);
}
}
/// <summary>
/// バイナリデータをAccessorをもとに切り出す
/// </summary>
/// <param name="accessor">VRM Model Accessor</param>
/// <param name="view">VRM Model Buffer View</param>
/// <returns></returns>
public MemoryStream ParseBinary(Accessor accessor, BufferView view)
{
// 切り出し
byte[] buffer = new byte[view.ByteLength];
byte[] temp = new byte[view.ByteLength - accessor.ByteOffset];
Array.Copy(Binary, view.ByteOffset, buffer, 0, view.ByteLength);
Array.Copy(buffer, accessor.ByteOffset, temp, 0, temp.Length);
// Byte Stride 算出
int len = GetByteStride(accessor, view);
// 展開
using (var stream = new MemoryStream(len * accessor.Count)) {
for (int j = 0; j < accessor.Count * len; j++)
{
stream.WriteByte(temp[j]);
}
stream.Position = 0;
return(new MemoryStream(stream.GetBuffer()));
}
}