5.5 Mix_EffectFunc_t

typedef void (*Mix_EffectFunc_t)(int chan, void *stream, int len, void *udata);

chan

The channel number that this effect is effecting now.
MIX_CHANNEL_POST is passed in for post processing effects over the final mix.

stream

The buffer containing the current sample to process.

len

The length of stream in bytes.

udata

User data pointer that was passed in to Mix_RegisterEffect when registering this effect processor function.

This is the prototype for effect processing functions. These functions are used to apply effects processing on a sample chunk. As a channel plays a sample, the registered effect functions are called. Each effect would then read and perhaps alter the len bytes of stream. It may also be advantageous to keep the effect state in the udata, with would be setup when registering the effect function on a channel.

See Also:
4.6.1 Mix_RegisterEffect 4.6.2 Mix_UnregisterEffect