Routines
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34465: Position Sprite
Convert the actor's world position into a screen column relative to Jetman_Position, then fetch its sprite.
Input
IX Actor slot
Convert the actor world X into a screen column.
PositionSprite 34465 LD L,(IX+2) Fetch the actor's world X position.
34468 LD H,(IX+3)
34471 LD BC,120 Add the 0120 draw offset.
34474 ADD HL,BC
34475 LD BC,(24698) Fetch the scroll position from Jetman_Position.
34479 AND A Subtract the scroll position.
34480 SBC HL,BC
34482 LD A,H Fetch the high byte of the screen column.
34483 AND %00011111 Keep only bits 0-4.
34485 JR NZ,ResetSpriteFields Jump to ResetSpriteFields if the actor is off-screen.
34487 LD A,L Jump to ResetSpriteFields if the column is at least 240.
34488 CP 240
34490 JR NC,ResetSpriteFields
Store the column and look up the actor sprite.
34492 LD (IX+1),L Store the screen column in *IX+1.
34495 CALL FetchActorSprite Call FetchActorSprite.
Build the pixel-shift index from the column.
PositionSprite_Apply 34498 LD L,(IX+1) Fetch the screen column and actor Y.
34501 LD H,(IX+4)
34504 LD A,L Build a pixel-shift index from the column.
34505 DEC A
34506 RLCA
34507 AND %00001110 Keep only bits 1-3.
34509 CP 14 Jump to PositionSprite_StoreShift if the shift is not 14.
34511 JR NZ,PositionSprite_StoreShift
34513 LD A,232 Set the shift operand to 232.
Store the pixel shift for the sprite drawing code.
PositionSprite_StoreShift 34515 LD (34333),A Write the shift to 34333 and *IX+9.
34518 LD (IX+9),A
Choose the scratch width from the shift.
34521 LD A,2 Set the scratch width to 2.
34523 JR Z,PositionSprite_StoreWidth Jump to PositionSprite_StoreWidth if the shift was 14.
34525 INC A Widen the scratch width to 3.
PositionSprite_StoreWidth 34526 LD (24151),A Write the scratch width and cache the actor Y.
34529 LD (IX+11),H
Work out the screen address, then cache the sprite details on the actor.
34532 CALL ScreenAddress Call ScreenAddress.
34535 LD A,(DE) Copy the sprite height into SpriteRowsLeft, SpriteHeight and *IX+10.
34536 INC DE
34537 LD (24153),A
34540 LD (24152),A
34543 LD (IX+10),A
34546 LD (IX+12),E Cache the graphic pointer and screen address on the actor.
34549 LD (IX+13),D
34552 LD (IX+14),L
34555 LD (IX+15),H
34558 LD C,0 Clear the row counter.
34560 RET Return.
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