Make use of glReadPixel to access the source's pixel data.
Use all classic CPU functions to blend and use that data.
Save pointer to the GL image and update it with the latest data
during target render.
Use ENFN's surface_lock, read_pixels, unlock.
Also, add some more error checks to make sure the images are valid,
or return an error at runtime.
This will inform the client whether an asynchronous filter properly
rendered or not.
I actually don't know any case where rendering can fail at runtime.
Proxy sources & objects were not properly unset.
This results either in crashes (especially in the Edje tests)
or dangling objects with tons of references.
Remove the refcount increase/decrease, as it is redundant.
Store pairs proxy+source instead of just the source in all hashes,
so we can unset the is_proxy flag on the proxy when there are no
sources anymore.
Remove compilation warnings: we don't really need cubic
interpolation at this point, we can still add it back
later if wanted.
Also, make it clear that buffer #2 is the output buffer.
Remove meaningless FIXME.
This patch implements the final draw from RGBA_Image to the
OpenGL surface. We can even steal the output buffer and
redraw it quickly, without having to re-render everything
(same as in SW).
Since the filters will have to decide on which engine (SW, GL) to
choose from to render the font and the effects, move the font
draw call inside the filters module.
It is not possible to logically handle padding and offset at the same
time for a proper mirror effect, unless this is handled directly at the
transformation level.
Also, add support for blend() operation padding computation.
This is the simplest solution I can come up with for "mirror" effects.
Displacement maps are HARD to generate and use properly, since the buffer
size is unknown until runtime.
Even if we align the map to the text itself (using the padding information),
it's still hard to describe properly how to apply the displacement map, and
to generate it... So let's just add a simple flip operation.
The displacement effect is way too complicated. Let's keep it
simple and have only one displacement map format (RG + Alpha).
Here's what's missing now:
- Alpha support, to blend in the input with a variable intensity
- Extra padding (see below)
Also, the intensity VS. map values are not perfectly defined yet.
Problems: How to create a complete mirror effect (map needs to go
over boundaries... add extra padding to the buffers).