Krakout: Move the player's bat

9988: Move the player's bat

Moves the player's bat up and down once per frame, from the sampled controls.

The chosen control style, direct or inertia, decides the step. Whatever is attached comes with it, both the bat extension and any ball caught on the bat.

Three gates can suppress the move, and the double bat tail runs even then.

Both control styles test the same three travel bounds before they move the bat.

Bound	Bat Y	Applies
Top	38	always
Bottom	154	with the bat on its own
Bottom	138	while the bat extension is attached

move_bat

9988

LD IX,object_table

Only the bat's Y moves here. The side the player chose fixes its column.

998C

LD A,(bat_sting_freeze)

Gate 1: the sting freeze. The bee sets it on its overlap with the bat itself, never on a sweep hit. While it is set, jump straight to the double bat tail. That skips all bat movement, so the player cannot steer the bat. Cleared when the last ball is lost (lose_ball_last) or by the level setup (clear_state_buffers).

998F

OR A

9990

JP NZ,track_double_bat

9993

LD A,(bat_freeze)

Gate 2: the bat freeze. If clear, go on to the third gate. If set, run the release timer below and hold position.

9996

OR A

9997

JR Z,pick_bat_control

9999

LD HL,bat_freeze_timer

Frozen: count the freeze timer up by one this frame.

999C

INC (HL)

999D

LD A,(HL)

999E

CP $0F

Release the bat freeze once the hold runs out; either way jump to the double bat tail, and leave the bat where it is.

99A0

JP NZ,track_double_bat

99A3

XOR A

99A4

LD (HL),A

99A5

LD (bat_freeze),A

99A8

JP track_double_bat

pick_bat_control

99AB

LD A,(death_pause_timer)

Gate 3: the death-pause timer is set – skip all movement, but still run the double bat tail.

99AE

OR A

99AF

JP NZ,track_double_bat

99B2

LD A,(bat_control_type)

Pick the control style: inertia runs inertia control, and either dual-speed style runs direct control below.

99B5

OR A

99B6

JR NZ,apply_direct_control

99B8

CALL apply_inertia_control

99BB

JP track_double_bat

The direct control style. The step follows the control bits of the current frame, with nothing carried over from the frames before it.

The step is the slow speed, or the fast speed while fire is also held. The options screen sets both, on the rows it prints as DUAL SPEED SLOW and DUAL SPEED FAST. Up decreases the bat Y, down increases it. The edge test uses the position before the step, so a large step can carry the bat past the limit.

apply_direct_control

99BE

LD HL,controls

Read the live control bits into HL.

99C1

BIT 3,(HL)

Up held?

99C3

JR Z,direct_down

99C5

LD A,(bat_speed_slow)

Take the slow speed as the step.

99C8

LD B,A

99C9

LD A,(IX+$01)

Current bat Y

99CC

CP $26

Blocked at the top edge – the bat cannot move further up.

99CE

JP C,track_double_bat

99D1

SUB B

Move the bat up by the slow speed.

99D2

LD (IX+$01),A

99D5

CALL drag_attached_up

Drag the bat extension up with it.

99D8

LD A,(bat_speed_slow)

99DB

CALL drag_caught_up

Drag any caught ball up with it.

99DE

BIT 4,(HL)

Fire also held? Apply the fast-speed bonus.

99E0

JP Z,track_double_bat

99E3

LD A,(bat_speed_slow)

Take the difference between the fast and slow speeds as the extra step.

99E6

LD C,A

99E7

LD A,(bat_speed_fast)

99EA

SUB C

99EB

LD B,A

99EC

LD A,(IX+$01)

99EF

SUB B

Move up by the extra amount, for a total step of the fast speed this frame.

99F0

LD (IX+$01),A

99F3

CALL drag_attached_up

99F6

LD A,B

99F7

CALL drag_caught_up

99FA

JR track_double_bat

direct_down

99FC

BIT 2,(HL)

Down held?

99FE

JR Z,track_double_bat

9A00

LD A,(expand_active)

An attached extension raises the bottom travel limit.

9A03

OR A

9A04

JR Z,direct_down_clamp

9A06

LD A,(IX+$01)

9A09

CP $8A

Extension attached: the raised bottom limit applies.

9A0B

JR NC,track_double_bat

9A0D

JR direct_down_apply

direct_down_clamp

9A0F

LD A,(IX+$01)

No extension: take the bat's Y on its own.

9A12

CP $9A

Otherwise the plain bottom limit applies.

9A14

JR NC,track_double_bat

direct_down_apply

9A16

LD A,(bat_speed_slow)

Move the bat down by the slow speed and drag the extension and caught ball with it.

9A19

LD B,A

9A1A

LD A,(IX+$01)

9A1D

ADD A,B

9A1E

LD (IX+$01),A

9A21

CALL drag_attached_down

9A24

LD A,(bat_speed_slow)

9A27

CALL drag_caught_down

9A2A

BIT 4,(HL)

Fire also held? Apply the fast-speed bonus downward too.

9A2C

JR Z,track_double_bat

9A2E

LD A,(bat_speed_slow)

9A31

LD B,A

9A32

LD A,(bat_speed_fast)

9A35

SUB B

9A36

LD B,A

9A37

LD A,(IX+$01)

9A3A

ADD A,B

Move down by the extra amount, for a total step of the fast speed.

9A3B

LD (IX+$01),A

9A3E

CALL drag_attached_down

9A41

LD A,B

9A42

CALL drag_caught_down

Double bat tail, run every frame. It acts only while the double bat flag is set, with no missile shot in flight and no retract or bomb effect armed. It then parks the secondary object at the bat's current Y on the bat's side and activates it. Drawn with the bat sprite, it is the second bat, which follows the bat's Y.

track_double_bat

9A45

LD A,(double_bat_active)

Skip unless the double bat flag is set.

9A48

OR A

9A49

JR Z,launch_missile

9A4B

LD A,(missile_shot)

Skip while the missile shot is in flight, or while the retract or bomb effect is armed.

9A4E

OR A

9A4F

JR NZ,launch_missile

9A51

LD A,(fx_retract_arm)

9A54

OR A

9A55

JR NZ,launch_missile

9A57

LD A,(fx_bomb_arm)

9A5A

OR A

9A5B

JR NZ,launch_missile

9A5D

LD B,(IX+$01)

Take the bat's current Y.

9A60

PUSH IX

9A62

LD IX,obj2_object

Target the secondary object and pick its X column from the bat side: the right bat parks it at x 188.

9A66

LD A,(bat_side)

9A69

OR A

9A6A

JR NZ,track_double_bat_left

9A6C

LD (IX+$00),$BC

9A70

JR track_double_bat_set

track_double_bat_left

9A72

LD (IX+$00),$34

The left bat parks it at the mirrored column.

track_double_bat_set

9A76

LD (IX+$01),B

Set the second bat's Y to the bat's, point it at the bat sprite, and set its active flag.

9A79

LD DE,slot_bat_normal

9A7C

LD (IX+$06),E

9A7F

LD (IX+$07),D

9A82

SET 0,(IX+$08)

9A86

POP IX

Launch the missile shot on fire. When the missile bat is armed and fire is held in the controls, it spawns the secondary object at the bat's Y. It also seeds ball B's motion state. The shot moves outward from the bat's side. Returns immediately when nothing is armed or fire is not held.

launch_missile

9A88

LD A,(missile_active)

No missile bat armed? Return.

9A8B

OR A

9A8C

RET Z

9A8D

BIT 4,(HL)

Fire not held? Return. HL points at the control bitfield only under direct control, or under inertia while the bat stands still. On every other path, this tests a byte that is not the controls – see Defects.

9A8F

RET Z

9A90

XOR A

Disarm the missile bat and clear ball B's combo. Cancel the swap to the missile-bat sprite and arm the swap back to the normal bat.

9A91

LD (missile_active),A

9A94

LD (combo_b),A

9A97

LD (fx_bat_missile_arm),A

9A9A

INC A

9A9B

LD (fx_bat_normal_arm),A

9A9E

LD B,(IX+$01)

Spawn the secondary object at the bat's Y. The side the bat plays from picks the X column (x 204 right / x 36 left) and the launch heading for that side.

9AA1

LD IX,obj2_object

9AA5

LD A,(bat_side)

9AA8

OR A

9AA9

JR NZ,launch_missile_left

9AAB

LD (IX+$00),$CC

9AAF

LD C,$63

9AB1

JR launch_missile_set

launch_missile_left

9AB3

LD (IX+$00),$24

The left bat mirrors the column and takes the opposite heading code.

9AB7

LD C,$87

launch_missile_set

9AB9

LD (IX+$01),B

Store the position, point at the missile-shot sprite and activate the object. Seed ball B's motion with the launch heading, its speed and counters, and set the two-ball and missile-shot flags. The shot then travels as the secondary object and clears every brick it passes through, the golden one included. A missile run thus cuts a lane the ball cannot.

9ABC

LD DE,slot_missile_shot

9ABF

LD (IX+$06),E

9AC2

LD (IX+$07),D

9AC5

SET 0,(IX+$08)

9AC9

LD A,C

9ACA

LD (ball_b_heading),A