mirror of
https://github.com/lscharen/iigs-game-engine.git
synced 2024-06-27 08:29:33 +00:00
95058fb969
All of the sprite rendering has been deferred down to the level of
the tile drawing. Sprites are no longer drawn/erased, but instead
a sprite sheet is generated in AddSprite and referenced by the
renderer.
Because there is no longer a single off-screen buffer that holds
a copy of all the rendered sprites, the TileStore size must be
expanded to hold a reference to the sprite data address fo each
tile. This increase in data structure size require the TileStore
to be put into its own bank and appropriate code restructuring.
The benefits to the rewrite are significant:
1. Sprites are never drawn/erased off-screen. They are only
ever drawn directly to the screen or play field.
2. The concept of "damaged" sprites is gone. Every dirty tile
automatically renders just to portion of a sprite that it
intersects.
These two properties result in a substantial increase in throughput.
389 lines
9.5 KiB
ArmAsm
389 lines
9.5 KiB
ArmAsm
; Function to render a sprite from a sprite definition into the internal data buffers
|
|
;
|
|
; X = sprite index
|
|
_DrawSpriteSheet
|
|
phx
|
|
|
|
lda _Sprites+VBUFF_ADDR,y
|
|
sta tmp1
|
|
|
|
lda _Sprites+TILE_DATA_OFFSET,y
|
|
sta tmp2
|
|
|
|
lda _Sprites+SPRITE_DISP,y
|
|
and #-{SPRITE_VFLIP+SPRITE_HFLIP} ; dispatch to all of the different orientations
|
|
sta tmp3
|
|
|
|
; Set bank
|
|
phb
|
|
pea #^tiledata ; Set the bank to the tile data
|
|
plb
|
|
|
|
ldx tmp3
|
|
ldy tmp2
|
|
lda tmp1
|
|
jsr _DrawSprite
|
|
|
|
lda tmp3
|
|
ora #SPRITE_VFLIP
|
|
tax
|
|
ldy tmp2
|
|
lda tmp1
|
|
clc
|
|
adc #4*3
|
|
jsr _DrawSprite
|
|
|
|
lda tmp3
|
|
ora #SPRITE_HFLIP
|
|
tax
|
|
ldy tmp2
|
|
lda tmp1
|
|
clc
|
|
adc #4*6
|
|
jsr _DrawSprite
|
|
|
|
lda tmp3
|
|
ora #SPRITE_VFLIP
|
|
tax
|
|
ldy tmp2
|
|
lda tmp1
|
|
clc
|
|
adc #4*9
|
|
jsr _DrawSprite
|
|
|
|
; Restore bank
|
|
plb ; pop extra byte
|
|
plb
|
|
|
|
plx
|
|
rts
|
|
;
|
|
; X = _Sprites array offset
|
|
_DrawSprite
|
|
; ldx _Sprites+SPRITE_DISP,y ; use bits 9, 10, 11, 12 and 13 to dispatch
|
|
jmp (draw_sprite,x)
|
|
|
|
draw_sprite dw draw_8x8,draw_8x8h,draw_8x8v,draw_8x8hv
|
|
dw draw_8x16,draw_8x16h,draw_8x16v,draw_8x16hv
|
|
dw draw_16x8,draw_16x8h,draw_16x8v,draw_16x8hv
|
|
dw draw_16x16,draw_16x16h,draw_16x16v,draw_16x16hv
|
|
|
|
dw :rtn,:rtn,:rtn,:rtn ; hidden bit is set
|
|
dw :rtn,:rtn,:rtn,:rtn
|
|
dw :rtn,:rtn,:rtn,:rtn
|
|
dw :rtn,:rtn,:rtn,:rtn
|
|
:rtn rts
|
|
|
|
draw_8x8
|
|
draw_8x8h
|
|
tax
|
|
jmp _DrawTile8x8
|
|
|
|
draw_8x8v
|
|
draw_8x8hv
|
|
tax
|
|
jmp _DrawTile8x8V
|
|
|
|
draw_8x16
|
|
draw_8x16h
|
|
tax
|
|
jsr _DrawTile8x8
|
|
clc
|
|
txa
|
|
adc #{8*SPRITE_PLANE_SPAN}
|
|
tax
|
|
tya
|
|
adc #{128*32} ; 32 tiles to the next vertical one, each tile is 128 bytes
|
|
tay
|
|
jmp _DrawTile8x8
|
|
|
|
draw_8x16v
|
|
draw_8x16hv
|
|
tax
|
|
jsr _DrawTile8x8V
|
|
clc
|
|
txa
|
|
adc #{8*SPRITE_PLANE_SPAN}
|
|
tax
|
|
tya
|
|
adc #{128*32}
|
|
tay
|
|
jmp _DrawTile8x8V
|
|
|
|
draw_16x8
|
|
tax
|
|
jsr _DrawTile8x8
|
|
clc
|
|
txa
|
|
adc #4
|
|
tax
|
|
tya
|
|
adc #128 ; Next tile is 128 bytes away
|
|
tay
|
|
jmp _DrawTile8x8
|
|
|
|
draw_16x8h
|
|
clc
|
|
tax
|
|
tya
|
|
pha
|
|
adc #128
|
|
tay
|
|
jsr _DrawTile8x8
|
|
txa
|
|
adc #4
|
|
tax
|
|
ply
|
|
jmp _DrawTile8x8
|
|
|
|
draw_16x8v
|
|
tax
|
|
jsr _DrawTile8x8V
|
|
clc
|
|
txa
|
|
adc #4
|
|
tax
|
|
tya
|
|
adc #128
|
|
tay
|
|
jmp _DrawTile8x8V
|
|
|
|
draw_16x8hv
|
|
clc
|
|
tax
|
|
tya
|
|
pha
|
|
adc #128
|
|
tay
|
|
jsr _DrawTile8x8V
|
|
txa
|
|
adc #4
|
|
tax
|
|
ply
|
|
jmp _DrawTile8x8V
|
|
|
|
draw_16x16
|
|
clc
|
|
tax
|
|
jsr _DrawTile8x8
|
|
txa
|
|
adc #4
|
|
tax
|
|
tya
|
|
adc #128
|
|
tay
|
|
jsr _DrawTile8x8
|
|
txa
|
|
adc #{8*SPRITE_PLANE_SPAN}-4
|
|
tax
|
|
tya
|
|
adc #{128*{32-1}}
|
|
tay
|
|
jsr _DrawTile8x8
|
|
txa
|
|
adc #4
|
|
tax
|
|
tya
|
|
adc #128
|
|
tay
|
|
jmp _DrawTile8x8
|
|
|
|
draw_16x16h
|
|
clc
|
|
tax
|
|
tya
|
|
pha
|
|
adc #128
|
|
tay
|
|
jsr _DrawTile8x8
|
|
|
|
txa
|
|
adc #4
|
|
tax
|
|
ply
|
|
jsr _DrawTile8x8
|
|
|
|
txa
|
|
adc #{8*SPRITE_PLANE_SPAN}-4
|
|
tax
|
|
tya
|
|
adc #{128*32}
|
|
pha
|
|
adc #128
|
|
tay
|
|
jsr _DrawTile8x8
|
|
|
|
txa
|
|
adc #4
|
|
tax
|
|
ply
|
|
jmp _DrawTile8x8
|
|
|
|
draw_16x16v
|
|
clc
|
|
tax
|
|
tya
|
|
pha ; store some copies
|
|
phx
|
|
pha
|
|
adc #{128*32}
|
|
tay
|
|
jsr _DrawTile8x8V
|
|
|
|
txa
|
|
adc #{8*SPRITE_PLANE_SPAN}
|
|
tax
|
|
ply
|
|
jsr _DrawTile8x8V
|
|
|
|
pla
|
|
adc #4
|
|
tax
|
|
lda 1,s
|
|
adc #{128*{32+1}}
|
|
tay
|
|
jsr _DrawTile8x8V
|
|
|
|
txa
|
|
adc #{8*SPRITE_PLANE_SPAN}
|
|
tax
|
|
pla
|
|
adc #128
|
|
tay
|
|
jmp _DrawTile8x8V
|
|
|
|
draw_16x16hv
|
|
clc
|
|
tax
|
|
tya
|
|
pha
|
|
adc #128+{128*32} ; Bottom-right source to top-left
|
|
tay
|
|
jsr _DrawTile8x8V
|
|
|
|
txa
|
|
adc #4
|
|
tax
|
|
lda 1,s
|
|
adc #{128*32}
|
|
tay
|
|
jsr _DrawTile8x8V
|
|
|
|
txa
|
|
adc #{8*SPRITE_PLANE_SPAN}-4
|
|
tax
|
|
lda 1,s
|
|
adc #128
|
|
tay
|
|
jsr _DrawTile8x8V
|
|
|
|
txa
|
|
adc #4
|
|
tax
|
|
ply
|
|
jmp _DrawTile8x8V
|
|
|
|
|
|
; X = sprite vbuff address
|
|
; Y = tile data pointer
|
|
_DrawTile8x8
|
|
_CopyTile8x8
|
|
]line equ 0
|
|
lup 8
|
|
lda: tiledata+32+{]line*4},y
|
|
stal spritemask+{]line*SPRITE_PLANE_SPAN},x
|
|
lda: tiledata+{]line*4},y
|
|
stal spritedata+{]line*SPRITE_PLANE_SPAN},x
|
|
|
|
lda: tiledata+32+{]line*4}+2,y
|
|
stal spritemask+{]line*SPRITE_PLANE_SPAN}+2,x
|
|
lda: tiledata+{]line*4}+2,y
|
|
stal spritedata+{]line*SPRITE_PLANE_SPAN}+2,x
|
|
]line equ ]line+1
|
|
--^
|
|
rts
|
|
|
|
_DrawTile8x8V
|
|
_CopyTile8x8V
|
|
]line equ 0
|
|
lup 8
|
|
lda: tiledata+32+{{7-]line}*4},y
|
|
stal spritemask+{]line*SPRITE_PLANE_SPAN},x
|
|
lda: tiledata+{{7-]line}*4},y
|
|
stal spritedata+{]line*SPRITE_PLANE_SPAN},x
|
|
|
|
lda: tiledata+32+{{7-]line}*4}+2,y
|
|
stal spritemask+{]line*SPRITE_PLANE_SPAN}+2,x
|
|
lda: tiledata+{{7-]line}*4}+2,y
|
|
stal spritedata+{]line*SPRITE_PLANE_SPAN}+2,x
|
|
]line equ ]line+1
|
|
--^
|
|
rts
|
|
|
|
; X = sprite vbuff address
|
|
; Y = tile data pointer
|
|
;_DrawTile8x8
|
|
; phb
|
|
; pea #^tiledata ; Set the bank to the tile data
|
|
; plb
|
|
;
|
|
;]line equ 0
|
|
; lup 8
|
|
; lda: tiledata+32+{]line*4},y
|
|
; andl spritemask+{]line*SPRITE_PLANE_SPAN},x
|
|
; stal spritemask+{]line*SPRITE_PLANE_SPAN},x
|
|
;
|
|
; ldal spritedata+{]line*SPRITE_PLANE_SPAN},x
|
|
; and: tiledata+32+{]line*4},y
|
|
; ora: tiledata+{]line*4},y
|
|
; stal spritedata+{]line*SPRITE_PLANE_SPAN},x
|
|
;
|
|
; lda: tiledata+32+{]line*4}+2,y
|
|
; andl spritemask+{]line*SPRITE_PLANE_SPAN}+2,x
|
|
; stal spritemask+{]line*SPRITE_PLANE_SPAN}+2,x
|
|
;
|
|
; ldal spritedata+{]line*SPRITE_PLANE_SPAN}+2,x
|
|
; and: tiledata+32+{]line*4}+2,y
|
|
; ora: tiledata+{]line*4}+2,y
|
|
; stal spritedata+{]line*SPRITE_PLANE_SPAN}+2,x
|
|
;]line equ ]line+1
|
|
; --^
|
|
;
|
|
; plb ; pop extra byte
|
|
; plb
|
|
; rts
|
|
|
|
; X = sprite vbuff address
|
|
; Y = tile data pointer
|
|
;
|
|
; Draws the tile vertically flipped
|
|
;_DrawTile8x8V
|
|
; phb
|
|
; pea #^tiledata ; Set the bank to the tile data
|
|
; plb
|
|
|
|
;]line equ 0
|
|
; lup 8
|
|
; lda: tiledata+32+{{7-]line}*4},y
|
|
; andl spritemask+{]line*SPRITE_PLANE_SPAN},x
|
|
; stal spritemask+{]line*SPRITE_PLANE_SPAN},x
|
|
;
|
|
; ldal spritedata+{]line*SPRITE_PLANE_SPAN},x
|
|
; and: tiledata+32+{{7-]line}*4},y
|
|
; ora: tiledata+{{7-]line}*4},y
|
|
; stal spritedata+{]line*SPRITE_PLANE_SPAN},x
|
|
|
|
; lda: tiledata+32+{{7-]line}*4}+2,y
|
|
; andl spritemask+{]line*SPRITE_PLANE_SPAN}+2,x
|
|
; stal spritemask+{]line*SPRITE_PLANE_SPAN}+2,x
|
|
;
|
|
; ldal spritedata+{]line*SPRITE_PLANE_SPAN}+2,x
|
|
; and: tiledata+32+{{7-]line}*4}+2,y
|
|
; ora: tiledata+{{7-]line}*4}+2,y
|
|
; stal spritedata+{]line*SPRITE_PLANE_SPAN}+2,x
|
|
;]line equ ]line+1
|
|
; --^
|
|
;
|
|
; plb ; pop extra byte
|
|
; plb
|
|
; rts
|