Nightshade: Routine at CEF8

CEF8: Next Sprite Number

Moves an object on to the next of its four sprites, by adding one to the lowest two bits of the type and wrapping around.

Input
IX	Object

NextSpriteNumber

CEF8

LD A,(IX+$00)

Add one to the lowest two bits of the type, wrapping round, to choose the next sprite.

CEFB

LD C,A

CEFC

INC A

CEFD

AND $03

CEFF

LD B,A

CF00

LD A,C

Put them back in the type of the object.

CF01

AND $FC

CF03

OR B

CF04

LD (IX+$00),A

CF07

RET

Return.

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