Routines
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8580: Sort SPRITE_LIST by place in PLANES
Used by the routine at DRAW_VIEW.
A bubble sort into ascending order, repeated until a pass swaps nothing.
SORT_SPRITES 8580 LD C,$00 C = 0: nothing swapped.
SORT_SPRITES_0 8582 LD B,$07 Seven comparisons a pass.
8584 LD IX,SPRITE_LIST
SORT_SPRITES_1 8588 LD L,(IX+$00) This entry's place against the next's.
858B LD H,(IX+$01)
858E LD E,(IX+$03)
8591 LD D,(IX+$04)
8594 LD A,D
8595 CP H
8596 JR NZ,SORT_SPRITES_2
8598 LD A,E
8599 CP L
SORT_SPRITES_2 859A JR NC,SORT_SPRITES_3
859C LD (IX+$00),E Out of order: swap places and frames, and note it.
859F LD (IX+$01),D
85A2 LD (IX+$03),L
85A5 LD (IX+$04),H
85A8 LD C,(IX+$02)
85AB LD A,(IX+$05)
85AE LD (IX+$02),A
85B1 LD (IX+$05),C
85B4 LD C,$01
SORT_SPRITES_3 85B6 INC IX
85B8 INC IX
85BA INC IX
85BC DJNZ SORT_SPRITES_1
85BE DEC C Swapped something: another pass.
85BF JR Z,SORT_SPRITES_0
85C1 RET
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