The compostor used a fixed size of 4 floats to hold pixel data. this
patch will select size of a pixel based on its type.
It uses 1 float for Value, 3 float for vector and 4 floats for color
data types.
When benchmarking on shots (opening shot of caminandes) we get a
reduction of memory of 30% and a tiny speedup as less data
transformations needs to take place (but these are negligable.
More information of the patch can be found on
https://developer.blender.org/D627 and
http://wiki.blender.org/index.php/Dev:Ref/Proposals/Compositor2014_p1.1_TD
Developers: jbakker & mdewanchand
Thanks for Sergey for his indept review.
Distinguish the 3 different methods for acquiring pixel color values (executePixel, executePixelSampled, executePixelFiltered).
This makes it easier to keep track of the different sampling methods (and works nicer with IDEs that do code parsing).
Differential Revision: http://developer.blender.org/D7
The issue with wrapping is that it requires correct interpolation of the border pixels. Since interpolation is done at the far left end of the node tree in buffer/image/etc read operations, the wrapping
setting can not be used directly in those operations (otherwise in-line translate operations would cause conflicts). To make wrapping work correctly we need to add a buffer in front of the translate
operation, which can then be interpolated correctly based on wrapping. The WrapOperation becomes a variant of ReadBufferOperation, which uses its wrapping setting to determine the correct "extend" mode
for interpolation of the buffer.
