# Copyright 2017-2018 The dm_control Authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#    http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or  implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# ============================================================================

"""Integration tests for rendering."""

import os
import platform

from absl.testing import absltest
from absl.testing import parameterized
from dm_control import _render
from dm_control import mujoco
from dm_control.mujoco.testing import decorators
from dm_control.mujoco.testing import image_utils


DEBUG_IMAGE_DIR = os.environ.get('TEST_UNDECLARED_OUTPUTS_DIR',
                                 absltest.get_default_test_tmpdir())

# TODO(nimrod): Reduce the tolerance if we can figure out why the tests
# fail.
_RMS_TOLERANCE = 80.0

# Context creation with GLFW is not threadsafe.
if _render.BACKEND == 'glfw':
  # On Linux we are able to create a GLFW window in a single thread that is not
  # the main thread.
  # On Mac we are only allowed to create windows on the main thread, so we
  # disable the `run_threaded` wrapper entirely.
  NUM_THREADS = None if platform.system() == 'Darwin' else 1
else:
  NUM_THREADS = 4
CALLS_PER_THREAD = 1


class RenderTest(parameterized.TestCase):

  @parameterized.named_parameters(image_utils.SEQUENCES.items())
  @image_utils.save_images_on_failure(output_dir=DEBUG_IMAGE_DIR)
  @decorators.run_threaded(num_threads=NUM_THREADS,
                           calls_per_thread=CALLS_PER_THREAD)
  def test_render(self, sequence):
    for expected, actual in zip(sequence.iter_load(), sequence.iter_render()):
      image_utils.assert_images_close(
          expected, actual, tolerance=_RMS_TOLERANCE
      )

  @decorators.run_threaded(num_threads=NUM_THREADS,
                           calls_per_thread=CALLS_PER_THREAD)
  @image_utils.save_images_on_failure(output_dir=DEBUG_IMAGE_DIR)
  def test_render_multiple_physics_per_thread(self):
    cartpole = image_utils.cartpole
    humanoid = image_utils.humanoid
    cartpole_frames = []
    humanoid_frames = []
    for cartpole_frame, humanoid_frame in zip(cartpole.iter_render(),
                                              humanoid.iter_render()):
      cartpole_frames.append(cartpole_frame)
      humanoid_frames.append(humanoid_frame)

    for expected, actual in zip(cartpole.iter_load(), cartpole_frames):

      image_utils.assert_images_close(
          expected, actual, tolerance=_RMS_TOLERANCE
      )

    for expected, actual in zip(humanoid.iter_load(), humanoid_frames):
      image_utils.assert_images_close(
          expected, actual, tolerance=_RMS_TOLERANCE
      )

  @decorators.run_threaded(num_threads=NUM_THREADS, calls_per_thread=1)
  def test_repeatedly_create_and_destroy_rendering_contexts(self):
    # Tests for errors that may occur due to per-thread GL resource leakage.
    physics = mujoco.Physics.from_xml_string('<mujoco/>')
    for _ in range(500):
      physics._make_rendering_contexts()
      physics._free_rendering_contexts()

if __name__ == '__main__':
  absltest.main()