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- * UTIL.S GENERAL UTILITY ROUTINES
- * MOVE A CREATURE HORIZONTALLY
- * INPUT: A - CURRENT HORIZONTAL POS, Y - DIRECTION CREATURE FACING
- * OUTPUT:A - NEW HORIZONTAL POS
- HPOSADJ CLC
- ADC PHPOSTAB,Y
- RTS
- * MOVE A CREATURE VERTICALLY
- * INPUT: A - CURRENT VERTICAL POS, Y - DIRECTION CREATURE FACING
- * X - CURRENT VERTICAL OFFSET
- * OUTPUT:A - NEW VERTICAL POS
- VPOSADJ CPY #DUP
- BEQ VPAUP
- CPY #DDOWN
- BNE VPAOUT
- CLC ;MOVE IT DOWN
- ADC DNADJUST,X
- RTS
- VPAUP SEC ;MOVE IT UP
- SBC UPADJUST,X
- VPAOUT RTS
- * BODY OF MACRO PFILL
- PFILLIT LDY #0
- PFLOOP STA (TEMP0),Y
- DEY
- BNE PFLOOP
- INC TEMP1
- DEX
- BNE PFLOOP
- RTS
- * BODY OF MACRO PLOAD
- PLOADIT LDY #0
- PLLOOP LDA (TEMP2),Y
- STA (TEMP0),Y
- DEY
- BNE PLLOOP
- INC TEMP1
- INC TEMP3
- DEX
- BNE PLLOOP
- RTS
- * CONVERT HORIZONTAL BIT COUNT TO COLUMN
- HTOC SEC
- SBC #LEFTSIDE ;SHIFT ORIGIN
- LSR A
- LSR A ;AND SCALE
- RTS
- * CONVERT COLUMN TO HORIZONTAL BIT COUNT
- CTOH ASL A ;SCALE
- ASL A
- CLC
- ADC #LEFTSIDE ;SHIFT ORIGIN
- RTS
- * CONVERT VERTICAL BIT TO ZONE AND OFFSET
- * OUTPUT: ZONE IN Y, OFFSET IN A
- * USES Y!
- VTOZO LDY #$00 ;BRUTE FORCE - SLOW
- VTZAGAIN CMP #$06 ;SEE IF ANYTHING TO DO
- BCS VTZDOIT
- RTS
- VTZDOIT INY ;INCREMENT ZONE
- SEC ;SUBTRACT 6
- SBC #$06
- JMP VTZAGAIN
- * CONVERT ZONE TO VERTICAL BIT
- * USES Y!
- ZTOV TAY
- LDA #$00
- ZVLOOP CPY #$00
- BEQ ZVOUT
- CLC
- ADC #$06
- DEY
- JMP ZVLOOP
- ZVOUT RTS
- * TABLES FOR EASY MOVEMENT
- PHPOSTAB DB $01,$00,$FF,$00
- DNADJUST DB $02,$01,$01,$02,$01,$01
- UPADJUST DB $01,$01,$02,$01,$01,$02
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