# gfx.posteffects library A library for post-processing effects control. The effect slot is a resource and must be declared in resources.json in the root directory of the pack: ```json { "post-effect-slot": [ "slot_name" ] } ``` ```lua -- Returns the index of the effect slot by name (pack:slot_name). -- If the specified slot does not exist, returns -1 gfx.posteffect.index(name: str) --> int -- Assigns the effect to the slot gfx.posteffect.set(slot: int, effect: str) -- Returns the effect intensity (from 0.0 to 1.0) -- If the slot is empty, returns 0.0 gfx.posteffect.get_intensity(slot: int) --> number -- Sets the effect intensity (from 0.0 to 1.0) -- (The correctness of processing the parameter between 0.0 and 1.0 -- depends on the effect) gfx.posteffect.set_intensity(slot: int, intensity: number) -- Returns true if the slot is not empty and the effect intensity is non-zero gfx.posteffect.is_active(slot: int) --> bool -- Sets parameters values ('param' directives) gfx.posteffect.set_params(params: table) ```