thanks everybody for the feedback. i'm glad it's working fine on linux.
pob: let me know how it goes, i'm quite sure it's going to fall apart on windows.
rep: i updated the glsl code, the warning should be gone now. what's wrong with the blur masks? it's weird, they are plain jpg images.
dubtub and glitchpop: i'm planning to release some stuff soon. glsl is fast and it's actually easier to learn that it seems but the profound lack of documentation for that part in gem makes everything difficult. i guess this article might be a nice start to understand how glsl works, have a look. feel free to use the [pix_shader] abstraction when loading a shader in gem, it's nothing fancy but it makes the task even easier.