Gif timeserie

[jlarouche]

Pull request related to http://www.mapserver.org/development/rfc/ms-rfc-111.html

This pull request adds a new format to MapCache, Gif. It also has a new write_frames function to encode an animated image.

It includes new attributes for the time dimension, animate and delay.

The check to see if we need to animate is in mapcache_core_get_map. It checks the assembly_type of the Tileset.

[tbonfort]

please don't pollute the core_get_map function with this switch, instead branch off to the specific assembly method inside mapcache_assemble_maps()

[jlarouche]

I've modified the assemble_map function to work with animated and non-animated request. It loops on the number of frames needed. So in the case of a non-animated map, it loops only once.

I am also wondering, to remove write_frame and use only write, I would still need to make a check if the tileset is animated since I have to pass the delay to the GIF encoding function, would that work? Since the delay is confirgured in the tileset and it isn't available in the encoding function I have to pass it before. That's why we were wondering if having an animted GIF format, separate from a standard non-animated gif, where we would set the delay in the format setting would be better?

When you say I could put the quantize functions in another file, would making a file like quantize.c and putting the quantizes functions in there and then including it where needed works?

Thanks for the comments

[juliensam]

Note: We will simply modify other image writers to support more then one image. If more than one images are passed png and jpeg will fail and gif will animate them,