Pentagram: Routine at 52899

52899: Run Slider X

The handler of the object type 87, which is a block that goes backwards and forwards along x. It moves 2 for each frame, carrying anything that stands on it, and turns around when it is stopped. Bit 0 of the number at 16 of its record is the direction that it is going in.

Input
IX	Object record

RunSliderX

52899

CALL SetSpriteOffset_Minus16_Minus8

Call SetSpriteOffset_Minus16_Minus8 to set the offsets of the sprite.

52902

XOR A

Set the speeds along y and z to zero.

52903

LD (IX+10),A

52906

LD (IX+11),A

Go towards the end of the run, or turn around if the block is stopped.

52909

BIT 0,(IX+16)

Jump to RunSliderX_Start if the block is going to the start.

52913

JR Z,RunSliderX_Start

52915

LD (IX+9),2

Set the speed along x to 2.

52919

CALL ApplyGravityAndMove_Move

Call ApplyGravityAndMove_Move to move the block, without gravity.

52922

BIT 0,(IX+12)

Jump to RunSliderX_Finish if the block was not stopped along x.

52926

JR Z,RunSliderX_Finish

52928

RES 0,(IX+16)

Make the block go to the start.

RunSliderX_Finish

52932

JP SetWipeAndDrawFlags

Jump to SetWipeAndDrawFlags to flag the block as moved.

Go towards the start of the run.

RunSliderX_Start

52935

LD (IX+9),254

Set the speed along x to 254.

52939

CALL ApplyGravityAndMove_Move

Call ApplyGravityAndMove_Move to move the block, without gravity.

52942

BIT 0,(IX+12)

Jump to RunSliderX_Finish if the block was not stopped along x.

52946

JR Z,RunSliderX_Finish

52948

SET 0,(IX+16)

Make the block go to the end.

52952

JR RunSliderX_Finish

Jump to RunSliderX_Finish to finish.