public static int ExtendBufferAndGetAccessorIndex <T>(this glTF gltf, int bufferIndex,
ArraySegment <T> array,
glBufferTarget target = glBufferTarget.NONE,
float[] min = null,
float[] max = null) where T : struct
{
if (array.Count == 0)
{
return(-1);
}
var viewIndex = ExtendBufferAndGetViewIndex(gltf, bufferIndex, array, target);
// index buffer's byteStride is unnecessary
gltf.bufferViews[viewIndex].byteStride = 0;
var accessorIndex = gltf.accessors.Count;
var accessor = new glTFAccessor
{
bufferView = viewIndex,
byteOffset = 0,
componentType = GetComponentType <T>(),
type = GetAccessorType <T>(),
count = array.Count,
};
if (min != null)
{
accessor.min = min;
}
if (max != null)
{
accessor.max = max;
}
gltf.accessors.Add(accessor);
return(accessorIndex);
}
IEnumerable <int> _GetIndices(glTFAccessor accessor, out int count)
{
count = accessor.count;
var view = bufferViews[accessor.bufferView];
switch ((glComponentType)accessor.componentType)
{
case glComponentType.UNSIGNED_BYTE:
{
return(GetAttrib <Byte>(accessor, view).Select(x => (int)(x)));
}
case glComponentType.UNSIGNED_SHORT:
{
return(GetAttrib <UInt16>(accessor, view).Select(x => (int)(x)));
}
case glComponentType.UNSIGNED_INT:
{
return(GetAttrib <UInt32>(accessor, view).Select(x => (int)(x)));
}
}
throw new NotImplementedException("GetIndices: unknown componenttype: " + accessor.componentType);
}
T[] GetAttrib <T>(glTFAccessor accessor, glTFBufferView view) where T : struct
{
return(GetAttrib <T>(accessor.count, accessor.byteOffset, view));
}