Routines
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6EC0: Land Hit Actor
Used by the routine at MoveHitActor.
Part of MoveHitActor, used when the actor has reached the bottom of the play area (a vertical co-ordinate of A0 or more). The mixing bowl and the four dustbins are along the bottom of the screen, and the actor is tested against them with TestLandingPosition. This depends on the vertical co-ordinate of the actor:
Vertical co-ordinate What happens
A0 to B7 Nothing, if the actor is over the bowl or a dustbin; otherwise it bounces off the gap (see LandHitActor_Bounce)
B8 to BF The actor is over the bowl (see CatchHitActor), over a dustbin (see RemoveFallenActor_Pillar), or bounces off the gap (see LandHitActor_Bounce)
C0 or more See TestFallenActor
Input
A The new vertical co-ordinate
IX Actor
LandHitActor 6EC0 LD (IX+$02),A Update the vertical co-ordinate.
6EC3 INC (IX+$07) Increase the counter in byte 07 of the actor by one, to make up for it being decreased.
6EC6 CP $C0 Jump to TestFallenActor if the actor has gone as far as the bottom.
6EC8 JR NC,TestFallenActor
6ECA CP $B8 Jump to LandHitActor_BottomRow if the actor is on the bottom row.
6ECC JR NC,LandHitActor_BottomRow
6ECE CALL TestLandingPosition Test the position of the actor using TestLandingPosition.
6ED1 RET NC Return if the actor is over the bowl or a dustbin.
The actor is over a gap, so make it bounce.
LandHitActor_Bounce 6ED2 LD A,(IX+$02) Fetch the vertical co-ordinate.
6ED5 CP $A8 Jump to LandHitActor_Rebound if the actor is A8 or lower.
6ED7 JR NC,LandHitActor_Rebound
6ED9 LD (IX+$05),$FC Set the vertical speed to FC (-4, to bounce the actor upwards).
6EDD JR MoveHitActor_TestHorizontalSpeed Jump to MoveHitActor_TestHorizontalSpeed.
The actor is low down in the gap, so make it move the other way.
LandHitActor_Rebound 6EDF LD A,(IX+$04) Fetch the horizontal speed.
6EE2 NEG Reverse the direction by negating the horizontal speed.
6EE4 LD (IX+$04),A Update the horizontal speed.
6EE7 LD (IX+$05),$04 Set the vertical speed to 04 (moving down).
6EEB RET Return.
The actor is on the bottom row.
LandHitActor_BottomRow 6EEC CALL TestLandingPosition Test the position of the actor using TestLandingPosition.
6EEF JR C,LandHitActor_Bounce Jump to LandHitActor_Bounce if the actor is over a gap.
6EF1 LD A,B Fetch the result of the landing test (zero for the bowl).
6EF2 AND A Is the actor over the bowl?
6EF3 JR NZ,RemoveFallenActor_Pillar Jump to RemoveFallenActor_Pillar if it is over a dustbin.
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