RE:Vision Effects needs that. This was reviewed with TuttleOFX last year in the generic mailing list.
renamed for consistency:
Sometimes it is good for a plugin to know where the native origin of the host is and whether the coordinate system is Y-Up or Y-Down. This is strictly a UI hint to plugin.
It's good we have a simple base image / frame buffer model (lower-left, RGBA, rowbytes...) - however some applications are natively not lower-left which makes integration of the plugin complicated - for example point parameters (and overlay drawing) if they can be connected to a tracker from the host are suddenly upside down of where they should be.
All this hint does is tell plugin that the host world is different than OFX. Historically the first two hosts that exhibited this issue could be Fusion (upper left is 0,0 natively) and Toxic (Center is 0,0).
Add in a property to the host's property set, one that describe the location of the origin.
kOfxImageEffectHostPropNativeOrigin - a 1D string prop that can be one of
kOfxHostNativeOriginBottomLeft // default - same as before
This has no effect on image data, an host can pass negative rowbytes to avoid flipping the image to pass to OFX plugins.
The second item is related to image scanline order. This in theory is defined by the sign of rowbytes.
So I removed: