Blender Git Loki

Thumbnail Caching

The caching code is updated to allow for separate thumbnail storage. The size
is taken as 0.25*render size as of now. flag set up to control when to store
thumbs. Image scaling done in preprocess stage using already present code for
crop and transform.

Merge branch 'master' into soc-2021-vse-strip-thumbnails

Merge branch 'master' into soc-2021-vse-strip-thumbnails

VSE strip thumbnail improvements

The left handle now slides over the thumbs when moving and updates the thumb
under the left handle to represent seq->startdisp. Strip slip offset has fixed
thumbs and they don't update images as they move but rather move along with the
strip itself. Helps to make the strip feel like it is a container for the movie
and the handle areas cut the movie to the strip size. Better UX.

VSE strip thumbnail drawing function

Thumbnail Drawing Function Improvements T89144

The previous version drew the thumbnails but didn't take into consideration
The visible range where the thumbs should be seen and tried to draw till
end of strip. This version considers only those thumbails which can be seen
and leads to large performance gain. Multiple strips can be used smoothly.
Drawing logic was change to keep same thumbs when strip slide operation was
performed.

Differential Revision: https://developer.blender.org/D11616

Merge branch 'master' into soc-2021-vse-strip-thumbnails

VSE strip thumbnail drawing function