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).