Echo Effects

Functions
u8	audioDisableEcho (void)
	Disable echo for all voices.
u8	audioEnableEcho (u8 voiceMask)
	Enable echo for specific voices.
u8	audioSetEcho (u8 delay, s8 feedback, s8 volumeL, s8 volumeR)
	Configure echo parameters.
u8	audioSetEchoFilter (const s8 fir[8])
	Set FIR filter coefficients for echo.

Detailed Description

Function Documentation

audioDisableEcho()

u8 audioDisableEcho

(

void

)

Disable echo for all voices.

audioEnableEcho()

u8 audioEnableEcho

(

u8

voiceMask

)

Enable echo for specific voices.

Parameters

voiceMask

Bitmask (bit 0 = voice 0, etc.)

audioSetEcho()

u8 audioSetEcho	(	u8	delay,
		s8	feedback,
		s8	volumeL,
		s8	volumeR )

Configure echo parameters.

Parameters

delay	Echo delay 1-7 (delay_ms = value * 16; values above 7 are clamped — the echo ring takes up to 14 KB from $C000, and the first call brings the sample area down from 62 KB to 46 KB: see audioGetFreeMemory())
feedback	Feedback amount (-128 to 127)
volumeL	Left echo volume (-128 to 127)
volumeR	Right echo volume (-128 to 127)

Reconfiguration clears the whole echo ring before re-enabling echo writes (~9 ms per delay unit) — call at scene setup, not per frame. Call this BEFORE audioEnableEcho().

Returns

AUDIO_OK; AUDIO_ERR_NO_MEMORY when samples already loaded reach past $C000, where the ring goes (nothing is changed then); AUDIO_ERR_TIMEOUT if the driver does not answer

audioSetEchoFilter()

u8 audioSetEchoFilter

(

const s8

fir[8]

)

Set FIR filter coefficients for echo.

Parameters

fir	Array of 8 signed coefficients