public GLTFBufferView Extend(IntPtr p, int bytesLength, int stride, GLTFBufferTarget target)
{
var tmp = m_bytes;
// alignment
var padding = m_used % stride == 0 ? 0 : stride - m_used % stride;
if (m_bytes == null || m_used + padding + bytesLength > m_bytes.Length)
{
// recreate buffer
m_bytes = new Byte[m_used + padding + bytesLength];
if (m_used > 0)
{
Buffer.BlockCopy(tmp, 0, m_bytes, 0, m_used);
}
}
if (m_used + padding + bytesLength > m_bytes.Length)
{
throw new ArgumentOutOfRangeException();
}
Marshal.Copy(p, m_bytes, m_used + padding, bytesLength);
var result = new GLTFBufferView
{
buffer = 0,
byteLength = bytesLength,
byteOffset = m_used + padding,
byteStride = stride,
target = target,
};
m_used = m_used + padding + bytesLength;
return(result);
}
public int AddBufferView(GLTFBufferView view)
{
var index = bufferViews.Count;
bufferViews.Add(view);
return(index);
}
T[] GetAttrib <T>(int count, int byteOffset, GLTFBufferView view) where T : struct
{
var attrib = new T[count];
//
var segment = buffers[view.buffer].GetBytes();
var bytes = new ArraySegment <Byte>(segment.Array, segment.Offset + view.byteOffset + byteOffset, count * view.byteStride);
bytes.MarshalCoyTo(attrib);
return(attrib);
}
IEnumerable <int> GetIndices(GLTFBufferView view, int count, int byteOffset, GLTFComponentType componentType)
{
switch (componentType)
{
case GLTFComponentType.UNSIGNED_BYTE:
{
return(GetAttrib <Byte>(count, byteOffset, view).Select(x => (int)(x)));
}
case GLTFComponentType.UNSIGNED_SHORT:
{
return(GetAttrib <UInt16>(count, byteOffset, view).Select(x => (int)(x)));
}
case GLTFComponentType.UNSIGNED_INT:
{
return(GetAttrib <UInt32>(count, byteOffset, view).Select(x => (int)(x)));
}
}
throw new NotImplementedException("GetIndices: unknown componenttype: " + componentType);
}
T[] GetAttrib <T>(GLTFAccessor accessor, GLTFBufferView view) where T : struct
{
return(GetAttrib <T>(accessor.count, accessor.byteOffset, view));
}