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.
Quick and dirty solution to support the OpenGL engine:
[1] Allocate CPU buffers
[2] Render text and process all effects to these buffers
[3] Push final image as an OpenGL texture.
This patch implements [1].
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).
This is the first possible optimization: save the rendered
text (since we already have the output buffer anyways), and
reuse it if the text + filter didn't change.
Add parameters l, r, t, b to clip the fill area.
While l=x and t=y, the width and height of the clip are determined
at filter run-time, since we don't know the buffer size before.
Brutal method for now: allocate YET ANOTHER buffer,
render scaled image to it (smooth scaling, oh yeah),
use this as a new mask.
For now, supports:
Alpha Input, RGBA mask, RGBA output, X,Y,XY stretching
malloc() and mmap() don't return empty buffers, so blending on top
will present tons of artifacts.
Visible mostly on very small buffers as they are malloc()'ed from
previously used memory segments.
evas_filter.c contains the entry points for the evas filters subsystem,
in particular, the filter API, the (yet very basic) buffer management
system, the command queue and main context handling functions.
Right now, the Evas engine is left untouched, so these implementations
will work ONLY in the software engine.
NOTE: This will not compile on its own (thus, not added to Makefile.am),
as it will require the filter implementations to be linked.
Jean-Philippe Andre