iigs-game-engine/src/render/Fast.s

305 lines
10 KiB
ArmAsm

; Collection of render function used when the engine is in "FAST" mode. In this mode
; there are no dynamic tile or two layer tiles enabled, so all of the tiles are comprised
; of PEA opcodes. These functions take advantage of this as the fact that masks are
; not needed to improve rendering speed.
ConstTile0Fast
lda #0
sta: $0001,y
sta: $0004,y
sta $1001,y
sta $1004,y
sta $2001,y
sta $2004,y
sta $3001,y
sta $3004,y
sta $4001,y
sta $4004,y
sta $5001,y
sta $5004,y
sta $6001,y
sta $6004,y
sta $7001,y
sta $7004,y
plb
rts
SpriteOverAFast
lda TileStore+TS_CODE_ADDR_HIGH,x ; load the bank of the target code field line
pha ; and put on the stack for later. Has TileStore bank in high byte.
ldy TileStore+TS_CODE_ADDR_LOW,x ; load the address of the code field
lda TileStore+TS_TILE_ADDR,x
tax
plb
_SpriteOverAFast ; Alternate entry point for the "Slow" routines
]line equ 0
lup 8
ldal tiledata+{]line*4},x
and tmp_sprite_mask+{]line*4}
ora tmp_sprite_data+{]line*4}
sta: $0004+{]line*$1000},y
ldal tiledata+{]line*4}+2,x
and tmp_sprite_mask+{]line*4}+2
ora tmp_sprite_data+{]line*4}+2
sta: $0001+{]line*$1000},y
]line equ ]line+1
--^
plb
rts
SpriteOverVFast
lda TileStore+TS_CODE_ADDR_HIGH,x ; load the bank of the target code field line
pha ; and put on the stack for later. Has TileStore bank in high byte.
ldy TileStore+TS_CODE_ADDR_LOW,x ; load the address of the code field
lda TileStore+TS_TILE_ADDR,x
tax
plb
_SpriteOverVFast
]src equ 7
]dest equ 0
lup 8
ldal tiledata+{]src*4},x
and tmp_sprite_mask+{]dest*4}
ora tmp_sprite_data+{]dest*4}
sta: $0004+{]dest*$1000},y
ldal tiledata+{]src*4}+2,x
and tmp_sprite_mask+{]dest*4}+2
ora tmp_sprite_data+{]dest*4}+2
sta: $0001+{]dest*$1000},y
]src equ ]src-1
]dest equ ]dest+1
--^
plb
rts
SpriteOver0Fast
lda TileStore+TS_CODE_ADDR_HIGH,x ; load the bank of the target code field line
pha ; and put on the stack for later. Has TileStore bank in high byte.
ldy TileStore+TS_CODE_ADDR_LOW,x ; load the address of the code field
plb
_SpriteOver0Fast
]line equ 0
lup 8
lda tmp_sprite_data+{]line*4}
sta: $0004+{]line*$1000},y
lda tmp_sprite_data+{]line*4}+2
sta: $0001+{]line*$1000},y
]line equ ]line+1
--^
plb
rts
SpriteUnderAFast
lda TileStore+TS_CODE_ADDR_HIGH,x ; load the bank of the target code field line
pha ; and put on the stack for later. Has TileStore bank in high byte.
ldy TileStore+TS_CODE_ADDR_LOW,x ; load the address of the code field
lda TileStore+TS_TILE_ADDR,x
tax
plb
_SpriteUnderAFast
]line equ 0
lup 8
lda tmp_sprite_data+{]line*4}
andl tiledata+{]line*4}+32,x
oral tiledata+{]line*4},x
sta: $0004+{]line*$1000},y
lda tmp_sprite_data+{]line*4}+2
andl tiledata+{]line*4}+32+2,x
oral tiledata+{]line*4}+2,x
sta: $0001+{]line*$1000},y
]line equ ]line+1
--^
plb
rts
SpriteUnderVFast
lda TileStore+TS_CODE_ADDR_HIGH,x ; load the bank of the target code field line
pha ; and put on the stack for later. Has TileStore bank in high byte.
ldy TileStore+TS_CODE_ADDR_LOW,x ; load the address of the code field
lda TileStore+TS_TILE_ADDR,x
tax
plb
_SpriteUnderVFast
]src equ 7
]dest equ 0
lup 8
lda tmp_sprite_data+{]dest*4}
andl tiledata+{]src*4}+32,x
oral tiledata+{]src*4},x
sta: $0004+{]dest*$1000},y
lda tmp_sprite_data+{]dest*4}+2
andl tiledata+{]src*4}+32+2,x
oral tiledata+{]src*4}+2,x
sta: $0001+{]dest*$1000},y
]src equ ]src-1
]dest equ ]dest+1
--^
plb
rts
SpriteUnder0Fast
lda TileStore+TS_CODE_ADDR_HIGH,x ; load the bank of the target code field line
pha ; and put on the stack for later. Has TileStore bank in high byte.
ldy TileStore+TS_CODE_ADDR_LOW,x ; load the address of the code field
plb
_SpriteUnder0Fast
lda #0
]line equ 0
lup 8
sta: $0004+{]line*$1000},y
sta: $0001+{]line*$1000},y
]line equ ]line+1
--^
plb
rts
; Simple pair of routines that copies just the tile data to the direct page workspace. Data Bank
; must be set to the TileData bank in entry.
;
; Preserves the X-register
FastCopyTileDataA
ldy TileStore+TS_TILE_ADDR,x ; load the tile address
pei DP2_TILEDATA_AND_TILESTORE_BANKS
plb ; set to the tiledata bank
]line equ 0
lup 8
lda tiledata+{]line*4},y
sta tmp_tile_data+{]line*4}
lda tiledata+{]line*4}+2,y
sta tmp_tile_data+{]line*4}+2
]line equ ]line+1
--^
plb
rts
FastCopyTileDataV
ldy TileStore+TS_TILE_ADDR,x ; load the tile address
pei DP2_TILEDATA_AND_TILESTORE_BANKS
plb ; set to the tiledata bank
]src equ 7
]dest equ 0
lup 8
lda tiledata+{]src*4},y
sta tmp_tile_data+{]dest*4}
lda tiledata+{]src*4}+2,y
sta tmp_tile_data+{]dest*4}+2
]src equ ]src-1
]dest equ ]dest+1
--^
plb
rts
FastCopyTileDataAndMaskA
ldy TileStore+TS_TILE_ADDR,x ; load the tile address
pei DP2_TILEDATA_AND_TILESTORE_BANKS
plb ; set to the tiledata bank
]line equ 0
lup 8
lda tiledata+{]line*4},y
sta tmp_tile_data+{]line*4}
lda tiledata+{]line*4}+32,y
sta tmp_tile_mask+{]line*4}
lda tiledata+{]line*4}+2,y
sta tmp_tile_data+{]line*4}+2
lda tiledata+{]line*4}+32+2,y
sta tmp_tile_mask+{]line*4}+2
]line equ ]line+1
--^
plb
rts
FastCopyTileDataAndMaskV
ldy TileStore+TS_TILE_ADDR,x ; load the tile address
pei DP2_TILEDATA_AND_TILESTORE_BANKS
plb ; set to the tiledata bank
]src equ 7
]dest equ 0
lup 8
lda tiledata+{]src*4},y
sta tmp_tile_data+{]dest*4}
lda tiledata+{]src*4}+32,y
sta tmp_tile_mask+{]dest*4}
lda tiledata+{]src*4}+2,y
sta tmp_tile_data+{]dest*4}+2
lda tiledata+{]src*4}+32+2,y
sta tmp_tile_mask+{]dest*4}+2
]src equ ]src-1
]dest equ ]dest+1
--^
plb
rts
; The workhorse blitter. This blitter copies tile data into the code field without masking. This is the
; most common blitter function. It is slightly optimized to fall through to the code that sets the PEA
; opcodes in order to be slightly more efficient given it's frequent usage.
;
; There is a small variation of this blitter that just copies the data without setting the PEA opcodes. This
; is used by the engine when the capabilitiy bits have turned off the second background layer. In fact, most
; of the tile rendering routines have an optimized version for this important use case. Skipping the opcode
; step results in a 37% speed boost in tile rendering.
;
; This does not increase the FPS by 37% because only a small number of tiles are drawn each frame, but it
; has an impact and can significantly help out when sprites trigger more dirty tile updates than normal.
; This is called via a JMP (abs,x) with an extra byte on the stack that holds the bank
; register value. This must be restored prior to returning
CopyTileAFast
tax
_CopyTileAFast
]line equ 0
lup 8
ldal tiledata+{]line*4},x
sta: $0004+{]line*$1000},y
ldal tiledata+{]line*4}+2,x
sta: $0001+{]line*$1000},y
]line equ ]line+1
--^
plb
rts
CopyTileVFast
tax
_CopyTileVFast
]src equ 7
]dest equ 0
lup 8
ldal tiledata+{]src*4},x
sta: $0004+{]dest*$1000},y
ldal tiledata+{]src*4}+2,x
sta: $0001+{]dest*$1000},y
]src equ ]src-1
]dest equ ]dest+1
--^
plb
rts