Adding more blending modes

[megamarc]

Hi!
Built-in blending tables are created in file Tables.c, in CreateBlendTables() function:
https://github.com/megamarc/Tilengine/bl...bles.c#L20

To add new modes, just expand the public enumeration TLN_Blend here:
https://github.com/megamarc/Tilengine/bl...gine.h#L83

And add the corresponding blend formula in the aforementioned CreateBlendTables()  with the desired effect.

For example formula for hypothetical logical AND should be:

Code:

_blend_tables[BLEND_AND][offset] = (a & b);

Parameters a and b are brightness levels between 0 and 255