Idea originated from Cedric the b0rker.
This is a big fat search-and-replace commit.
This commit also introduces space changes... Sorry for the mix.
NOTE: This commit may have one side effect as there was some very
dubious code chaning the dst image's alpha flag in the
Gfx get functions. Logically this didn't make sense (at
draw time the dst alpha should already be well defined),
so it should be safe.
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.
The structure should not be changed, despite the union modification.
I am renaming for consistency with older branches that had a mask
field in RGBA_Image. Also, the mask.data or data8 is really just
a way to avoid casting between DATA8 and DATA32 (and it shows
clearly what kind of data you are dealing with).
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
These functions differ from normal blending as they will use
a mask on top of input and output buffers.
So, basically they blend input+mask into a third buffer output.
If output is RGBA then mask or input MUST be RGBA.
Jean-Philippe Andre