- Add 'scratch' field to gif that holds temporary 'scratch buffer' used for rendering frames
- For DISPOSE_BACKGROUND: Set background color to transparent instead of 0
- For DISPOSE_BACKGROUND: Write background pixels into scratch after rendering current frame, so it will be used in next frame
- For DISPOSE_PREVIOUS: Save frames that are not disposed into 'previous' field in gif, when DISPOSE_PREVIOUS is specified start with that previous frame. see http://webreference.com/content/studio/disposal.html
- Add "ANIMEXTS1.0" to Application Extension parser
- Graphic Control Extension parser refactor
- Compare file contents to expected images for animated gifs in foreign tests
We used to try to spot webp images with no alpha and load them as plain
RGB, but it turns out this is difficult to do reliably, especially
for animated images.
This patch simply removes support, so all webp images now load as RGBA.
See https://github.com/libvips/libvips/issues/1351
The current behaviour (close input handles on unref) works for languages
like C / C++ / Python / Rust / etc. where things get unreffed automatically
when they go out of scope.
On languages like Ruby / C# / node / etc. where things are unreffed on GC,
files can stay open for a long time after you've finished with them. This
interacts in an unfortunate way with the Windows default of refusing to
remove open files.
This change closes file handles as soon as the scan of the input file
finishes, and therefore produces something closer to expected behaviour
for GCd languages on Windows.
see https://github.com/kleisauke/net-vips/issues/12
