Routines
Prev: 27092 Up: Map Next: 27206
27141: Change Actor Speeds
Used by the routines at HandleTackWasherBolt and HandleChocolate.
Changes the speeds of the actor by one towards the direction in byte 6 of the actor (bit 0 is set for down, and bit 1 is set for right), but only every other frame. The speeds are limited to 2 in either direction. The actor is then moved by MoveBouncingActor.
Input
IX Actor
ChangeActorSpeeds 27141 BIT 0,(IX+7) Jump to ChangeActorSpeeds_Move if bit 0 of the frame counter is set.
27145 JR NZ,ChangeActorSpeeds_Move
27147 BIT 0,(IX+6) Jump to ChangeActorSpeeds_Up if the actor is not moving down.
27151 JR Z,ChangeActorSpeeds_Up
27153 LD A,(IX+5) Fetch the vertical speed.
27156 CP 2 Jump to ChangeActorSpeeds_Horizontal if it is already at the limit.
27158 JR Z,ChangeActorSpeeds_Horizontal
27160 INC (IX+5) Increase the vertical speed by one.
ChangeActorSpeeds_Horizontal 27163 BIT 1,(IX+6) Jump to ChangeActorSpeeds_Left if the actor is not moving right.
27167 JR Z,ChangeActorSpeeds_Left
27169 LD A,(IX+4) Fetch the horizontal speed.
27172 CP 2 Jump to ChangeActorSpeeds_Move if it is already at the limit.
27174 JR Z,ChangeActorSpeeds_Move
27176 INC (IX+4) Increase the horizontal speed by one.
This entry point is used by the routine at HandleChocolate.
ChangeActorSpeeds_Move 27179 JP MoveBouncingActor Move the actor using MoveBouncingActor.
ChangeActorSpeeds_Up 27182 LD A,(IX+5) Fetch the vertical speed.
27185 CP 254 Jump to ChangeActorSpeeds_Horizontal if it is already at the limit.
27187 JR Z,ChangeActorSpeeds_Horizontal
27189 DEC (IX+5) Decrease the vertical speed by one.
27192 JR ChangeActorSpeeds_Horizontal Jump to ChangeActorSpeeds_Horizontal.
ChangeActorSpeeds_Left 27194 LD A,(IX+4) Fetch the horizontal speed.
27197 CP 254 Jump to ChangeActorSpeeds_Move if it is already at the limit.
27199 JR Z,ChangeActorSpeeds_Move
27201 DEC (IX+4) Decrease the horizontal speed by one.
27204 JR ChangeActorSpeeds_Move Jump to ChangeActorSpeeds_Move.
Prev: 27092 Up: Map Next: 27206