Source code for silx.gui._glutils.utils

# coding: utf-8
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"""This module provides conversion functions between OpenGL and numpy types.
"""

__authors__ = ["T. Vincent"]
__license__ = "MIT"
__date__ = "10/01/2017"

from . import gl
import numpy


_GL_TYPE_SIZES = {
    gl.GL_FLOAT: 4,
    gl.GL_BYTE: 1,
    gl.GL_SHORT: 2,
    gl.GL_INT: 4,
    gl.GL_UNSIGNED_BYTE: 1,
    gl.GL_UNSIGNED_SHORT: 2,
    gl.GL_UNSIGNED_INT: 4,
}


def sizeofGLType(type_):
    """Returns the size in bytes of an element of type `type_`"""
    return _GL_TYPE_SIZES[type_]


_TYPE_CONVERTER = {
    numpy.dtype(numpy.float32): gl.GL_FLOAT,
    numpy.dtype(numpy.int8): gl.GL_BYTE,
    numpy.dtype(numpy.int16): gl.GL_SHORT,
    numpy.dtype(numpy.int32): gl.GL_INT,
    numpy.dtype(numpy.uint8): gl.GL_UNSIGNED_BYTE,
    numpy.dtype(numpy.uint16): gl.GL_UNSIGNED_SHORT,
    numpy.dtype(numpy.uint32): gl.GL_UNSIGNED_INT,
}


def isSupportedGLType(type_):
    """Test if a numpy type or dtype can be converted to a GL type."""
    return numpy.dtype(type_) in _TYPE_CONVERTER


def numpyToGLType(type_):
    """Returns the GL type corresponding the provided numpy type or dtype."""
    return _TYPE_CONVERTER[numpy.dtype(type_)]