Source code for c4dynamics.utils.gen_gif

import os
import imageio
import natsort
import warnings

import sys 
sys.path.append('.')
import c4dynamics as c4d 




def gif(dirname, gif_name, duration = None):
  '''

    Gif creator.

    `gif` creates a Gif from a directory containing image files.

    Parameters
    ----------

    dirname : str
        The path to the directory containing image files.

    gif_name : str
        The desired name of the output GIF file.

    duration : float, optional
        The duration (in seconds) for each frame of the GIF. 
        If None, default duration is used.

        
    Example
    -------

    Let's generate images of an F16 aircraft in different orientations and create a gif from them.
    
    1. Prepare trajectory to animate. 


    Import required packages:

    .. code::

      >>> import c4dynamics as c4d 
      >>> from IPython.display import Image
      >>> import numpy as np 
      >>> import os 

      
    Settings and initial conditions:

    .. code::

      >>> f16 = c4d.rigidbody()
      >>> dt = 0.01

    
    Main loop:

    .. code::

      >>> for t in np.arange(0, 9, dt): 
      ...  # in 3 seconds make 180 deg: 
      ...  if t < 3: 
      ...    f16.psi += dt * 180 * c4d.d2r / 3
      ...  elif t < 6: 
      ...    f16.theta += dt * 180 * c4d.d2r / 3
      ...  else:
      ...    f16.phi -= dt * 180 * c4d.d2r / 3 
      ...  f16.store(t)

      
    2. Animate and save image files. 
   
    (Use c4dynamics' :mod:`datasets <c4dynamics.datasets>` to fetch F16 3D model.)

    .. code::

      >>> f16path = c4d.datasets.d3_model('f16') 
      Fetched successfully
      >>> x0 = [90 * c4d.d2r, 0, 180 * c4d.d2r] 
      >>> outfol = os.path.join('tests', '_out', 'f16b')
      >>> f16.animate(f16path, savedir = outfol, angle0 = x0, modelcolor = [0, 0, 0], cbackground = [230 / 255, 230 / 255, 255 / 255])
      
      
    3. Export images as gif.

    .. code::

      >>> gifname = 'f16_monochrome_gif.gif'
      >>> c4d.gif(outfol, gifname, duration = 1)
      >>> Image(filename = os.path.join(outfol, gifname))  # doctest: +IGNORE_OUTPUT

    .. figure:: /_examples/animate/f16_monochrome_gif.gif
    
  '''
  dirfiles = natsort.natsorted(os.listdir(dirname)) 
  imgfiles = [f for f in dirfiles if f.lower().endswith(('.png', '.jpg', '.jpeg', 'bmp', '.tiff'))] 

  if not imgfiles: 
    warnings.warn(f"""No image files in {dirfiles}. ('.png', '.jpg', '.jpeg', 'bmp', '.tiff', are supported). """ , c4d.c4warn)
    return None

  fps = 60 # 60hz (60frames per second) -> 16.6msec
  if duration is None: 
    interval = 1
  else: 
    # FIXME sth here is wrong. see the test test_specified_fps_effect currently disabled. 
    interval = max(int(len(imgfiles) / (duration * fps)), 1)

  images = []

  for i in range(0, len(imgfiles), interval):
    images.append(imageio.v2.imread(os.path.join(dirname, imgfiles[i])))

  gif_name = gif_name if gif_name.endswith('.gif') else gif_name + '.gif'
  imageio.mimsave(os.path.join(dirname, gif_name)
                      , images, loop = 0, duration = int(1000 * 1 / fps))



if __name__ == "__main__":

  import doctest, contextlib
  from c4dynamics import IgnoreOutputChecker, cprint
  
  # Register the custom OutputChecker
  doctest.OutputChecker = IgnoreOutputChecker

  tofile = False 
  optionflags = doctest.FAIL_FAST

  if tofile: 
    with open(os.path.join('tests', '_out', 'output.txt'), 'w') as f:
      with contextlib.redirect_stdout(f), contextlib.redirect_stderr(f):
        result = doctest.testmod(optionflags = optionflags) 
  else: 
    result = doctest.testmod(optionflags = optionflags)

  if result.failed == 0:
    cprint(os.path.basename(__file__) + ": all tests passed!", 'g')
  else:
    print(f"{result.failed}")