Fix crashing bug when replacing BG1 tiles with BG0 tiles

This commit is contained in:
Lucas Scharenbroich 2021-08-19 01:21:37 -05:00
parent 07ac2b017f
commit 4c5b090afe

View File

@ -44,6 +44,119 @@ TILE_VFLIP_BIT equ $0400
TILE_HFLIP_BIT equ $0200
TILE_CTRL_MASK equ $1E00
; On entry
;
; B is set to the correct BG1 data bank
; A is set to the the tile descriptor
; Y is set to the top-left address of the tile in the BG1 data bank
;
; tmp0/tmp1 is reserved
RenderTileBG1
tax ; Save the tile descriptor
and #TILE_ID_MASK ; Mask out the ID and save just that
_Mul128 ; multiplied by 128
pha
txa
and #TILE_VFLIP_BIT+TILE_HFLIP_BIT ; Only horizontal and vertical flips are supported for BG1
xba
tax
jmp (:actions,x)
:actions dw bg1_noflip,bg1_hflip,bg1_vflip,bg1_hvflip
bg1_noflip
pla
brl _CopyTileBG1
bg1_hflip
pla
clc
adc #64 ; Advance to the flipped version
brl _CopyTileBG1
bg1_vflip
pla
brl _CopyTileBG1V
bg1_hvflip
pla
clc
adc #64 ; Advance to the flipped version
brl _CopyTileBG1V
_CopyTileBG1 tax
ldal tiledata+0,x
sta: $0000,y
ldal tiledata+2,x
sta: $0002,y
ldal tiledata+4,x
sta $0100,y
ldal tiledata+6,x
sta $0102,y
ldal tiledata+8,x
sta $0200,y
ldal tiledata+10,x
sta $0202,y
ldal tiledata+12,x
sta $0300,y
ldal tiledata+14,x
sta $0302,y
ldal tiledata+16,x
sta $0400,y
ldal tiledata+18,x
sta $0402,y
ldal tiledata+20,x
sta $0500,y
ldal tiledata+22,x
sta $0502,y
ldal tiledata+24,x
sta $0600,y
ldal tiledata+26,x
sta $0602,y
ldal tiledata+28,x
sta $0700,y
ldal tiledata+30,x
sta $0702,y
rts
_CopyTileBG1V tax
ldal tiledata+0,x
sta: $0700,y
ldal tiledata+2,x
sta: $0702,y
ldal tiledata+4,x
sta $0600,y
ldal tiledata+6,x
sta $0602,y
ldal tiledata+8,x
sta $0500,y
ldal tiledata+10,x
sta $0502,y
ldal tiledata+12,x
sta $0400,y
ldal tiledata+14,x
sta $0402,y
ldal tiledata+16,x
sta $0300,y
ldal tiledata+18,x
sta $0302,y
ldal tiledata+20,x
sta $0200,y
ldal tiledata+22,x
sta $0202,y
ldal tiledata+24,x
sta $0100,y
ldal tiledata+26,x
sta $0102,y
ldal tiledata+28,x
sta $0000,y
ldal tiledata+30,x
sta $0002,y
rts
; On entry
;
; B is set to the correct code field bank
@ -77,18 +190,6 @@ RenderTile
dw masked,masked_hflip,masked_vflip,masked_hvflip
dw dyn_masked,dyn_masked,dyn_masked,dyn_masked
; _CopyTile
;
; Copy a solid tile into one of the code banks
;
; B = bank of the code field
; A = Tile ID (0 - 1023)
; Y = Base Adddress in the code field
_CopyTile cmp #$0000 ; Fast-path the special zero tile
_Mul128 ; Take care of getting the right tile address
bne CopyTileMem
FillWord0
sta: $0001,y
sta: $0004,y
@ -105,32 +206,24 @@ FillWord0
sta $6001,y
sta $6004,y
sta $7001,y
sta $7004,y ; Fall through here intentionally
sta $7004,y
bra FillPEAOpcode
; For solid tiles
FillPEAOpcode
sep #$20
lda #$F4
sta: $0000,y
sta: $0003,y
sta $1000,y
sta $1003,y
sta $2000,y
sta $2003,y
sta $3000,y
sta $3003,y
sta $4000,y
sta $4003,y
sta $5000,y
sta $5003,y
sta $6000,y
sta $6003,y
sta $7000,y
sta $7003,y
rep #$20
rts
; _CopyTile
;
; Copy a solid tile into one of the code banks
;
; B = bank of the code field
; A = Tile ID (0 - 1023)
; Y = Base Adddress in the code field
_CopyTile cmp #$0000 ; Fast-path the special zero tile
beq FillWord0
CopyTileMem
_Mul128 ; Take care of getting the right tile address
CopyTileMem0
tax
@ -165,7 +258,29 @@ CopyTileMem0
ldal tiledata+28,x
sta $7004,y
ldal tiledata+30,x
sta $7001,y
sta $7001,y ; Fall through
; For solid tiles
FillPEAOpcode
sep #$20
lda #$F4
sta: $0000,y
sta: $0003,y
sta $1000,y
sta $1003,y
sta $2000,y
sta $2003,y
sta $3000,y
sta $3003,y
sta $4000,y
sta $4003,y
sta $5000,y
sta $5003,y
sta $6000,y
sta $6003,y
sta $7000,y
sta $7003,y
rep #$20
rts
; Masked tiles
@ -612,3 +727,47 @@ CopyTile
plb ; restore the data bank and return
rts
; CopyTileBG1
;
; A low-level function that copies 8x8 tiles directly into the BG1 data buffer.
;
; A = Tile ID (0 - 511)
; X = Tile column (0 - 40)
; Y = Tile row (0 - 25)
CopyTileBG1
phb ; save the current bank
phx ; save the original x-value
pha ; save the tile ID
tya ; lookup the address of the virtual line (y * 8)
asl
asl
asl
asl
tay
txa
asl
asl ; 4 bytes per tile column
clc
adc BG1YTable,y
tay
pei BG1DataBank
plb
plb ; set the bank
pla ; pop the tile ID
jsr RenderTileBG1
plx ; pop the x-register
plb ; restore the data bank and return
rts