Source code for openalea.plantconvert.gltf.buffer_tools

import pygltflib as gltf

from .. import binary_tools

# consider the gltf as a dictionary
GLTF_DICT = gltf.__dict__

# associate component types with with component length
COMPONENT_NB = {
    gltf.SCALAR: 1,
    gltf.VEC2: 2,
    gltf.VEC3: 3,
    gltf.VEC4: 4,
    gltf.MAT2: 4,
    gltf.MAT3: 9,
    gltf.MAT4: 16,
}




def get_key(d: dict, value):
    for k, v in d.items():
        if v == value:
            return k





def get_buffer(acsr: gltf.Accessor, g: gltf.GLTF2):
    """Get the buffer referenced by the accessor in a gltf asset."""
    return g.buffers[g.bufferViews[acsr.bufferView].buffer]





def get_data(byte_string, acsr: gltf.Accessor, buffer_view: gltf.BufferView):
    dtype = get_key(GLTF_DICT, acsr.componentType)
    component_nb = COMPONENT_NB[acsr.type]
    offset = acsr.byteOffset + buffer_view.byteOffset
    count = acsr.count

    unpacked = binary_tools._unpack_byte_string(
        byte_string, offset, count, component_nb, dtype
    )

    if buffer_view.target == gltf.ELEMENT_ARRAY_BUFFER:
        unpacked = [tuple(unpacked[i : i + 3]) for i in range(0, len(unpacked), 3)]
    return unpacked