import os
import sys
import unittest

import numpy as np

sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
import bl_convert as bc


class TestBaseTextureEncoding(unittest.TestCase):
    def test_base_texture_rgb_is_encoded_as_srgb_and_alpha_is_preserved(self):
        rgba = np.array([[[0.0, 0.18, 0.5, 0.37]]], dtype=np.float32)

        encoded = bc.encode_base_texture_for_png(rgba)

        expected_rgb = np.array([0.0, 0.461356, 0.735357], dtype=np.float32)
        np.testing.assert_allclose(encoded[0, 0, :3], expected_rgb, rtol=0, atol=1e-5)
        self.assertAlmostEqual(float(encoded[0, 0, 3]), 0.37, places=6)


if __name__ == "__main__":
    unittest.main()