65 lines
801 B
ArmAsm
65 lines
801 B
ArmAsm
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.importzp TEMP, _oam_off, sp
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.import popa, popax
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.include "nes.inc"
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.include "zpvars.inc"
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;unsigned char __fastcall__ oam_meta_spr(unsigned char x,unsigned char y,unsigned char sprid,const unsigned char *data);
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.export _oam_meta_spr
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_oam_meta_spr:
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sta <PTR
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stx <PTR+1
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ldy #2 ;three popa calls replacement, performed in reversed order
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lda (sp),y
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dey
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sta <SCRX
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lda (sp),y
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dey
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sta <SCRY
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lda (sp),y
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tax
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@1:
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lda (PTR),y ;x offset
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cmp #$80
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beq @2
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iny
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clc
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adc <SCRX
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sta OAM_BUF+3,x
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lda (PTR),y ;y offset
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iny
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clc
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adc <SCRY
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sta OAM_BUF+0,x
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lda (PTR),y ;tile
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iny
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sta OAM_BUF+1,x
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lda (PTR),y ;attribute
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iny
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sta OAM_BUF+2,x
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inx
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inx
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inx
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inx
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jmp @1
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@2:
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lda <sp
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adc #2 ;carry is always set here, so it adds 3
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sta <sp
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bcc @3
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inc <sp+1
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@3:
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txa
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ldx #$00
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rts
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