Routines
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AEED: Play Movement Sound
Used by the routine at MovePlayerForward.
Plays a tone every few frames while a figure is moving, and alternates between a high and a low tone. A figure which is going slowly makes the sound every fourth frame, and a figure which is going fast every other frame.
The sounds played by this routine are:
Speed Sound
Slow Movement Sound
Fast Movement Sound
Input
IX The address of the object
PlayMovementSound AEED LD HL,$A207 Point HL at the sound counter.
AEF0 INC (HL) Add one to the counter.
AEF1 LD A,(IX+$05) Fetch the speed of the object.
AEF4 CP $0C Jump to PlayMovementSound_Fast if the speed is 0C or more.
AEF6 JR NC,PlayMovementSound_Fast
AEF8 LD A,(HL) Fetch the counter.
AEF9 BIT 2,A Jump to PlayMovementSound_Low unless bit 2 of the counter is set.
AEFB JR Z,PlayMovementSound_Low
AEFD AND %00000011 Return unless this is every fourth frame.
AEFF RET NZ
AF00 LD BC,$4004 Choose the high tone.
AF03 JR PlayWaveSequence Play it.
Play the low tone of a slow movement.
PlayMovementSound_Low AF05 AND %00000011 Return unless this is every fourth frame.
AF07 RET NZ
AF08 LD BC,$6004 Choose the low tone.
AF0B JR PlayWaveSequence Play it.
Play a tone every other frame when the object is going fast.
PlayMovementSound_Fast AF0D LD A,(HL) Fetch the counter.
AF0E BIT 1,A Jump to PlayMovementSound_FastLow unless bit 1 of the counter is set.
AF10 JR Z,PlayMovementSound_FastLow
AF12 AND %00000001 Return unless this is every other frame.
AF14 RET NZ
AF15 LD BC,$4004 Choose the high tone.
AF18 JR PlayWaveSequence Play it.
Play the low tone of a fast movement.
PlayMovementSound_FastLow AF1A AND %00000001 Return unless this is every other frame.
AF1C RET NZ
AF1D LD BC,$6004 Choose the low tone.
AF20 JR PlayWaveSequence Play it.
View the equivalent code in;
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