mirror of
https://github.com/lscharen/iigs-game-engine.git
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165 lines
6.9 KiB
ArmAsm
165 lines
6.9 KiB
ArmAsm
; If the engine mode has the second background layer disabled, we take advantage of that to
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; be more efficient in our rendering. Basically, without the second layer, there is no need
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; to use the tile mask information.
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;
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; If there are no sprites, then we copy the tile data into the code field as fast as possible.
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; If there are sprites, then the sprite data is flattened and stored into a direct page buffer
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; and then copied into the code field
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_RenderTileFast
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lda TileStore+TS_SPRITE_FLAG,x ; any sprites on this line?
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bne SpriteDispatch
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NoSpriteFast
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lda TileStore+TS_CODE_ADDR_HIGH,x ; load the bank of the target code field line
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pha ; and put on the stack for later. Has TileStore bank in high byte.
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ldy TileStore+TS_CODE_ADDR_LOW,x ; load the address of the code field
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lda TileStore+TS_BASE_TILE_DISP,x ; go to the tile copy routine (just basics)
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stal nsf_patch+1
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lda TileStore+TS_TILE_ADDR,x ; load the address of this tile's data (pre-calculated)
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plb ; set the code field bank
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nsf_patch jmp $0000
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; The TS_BASE_TILE_DISP routines will come from this table when ENGINE_MODE_TWO_LAYER and
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; ENGINE_MODE_DYN_TILES are both off.
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FastTileProcs dw _TBCopyDataFast,_TBCopyDataFast,_TBCopyDataFast,_TBCopyDataFast
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; dw _TBCopyDataFast,_TBCopyDataFast,_TBCopyDataVFast,_TBCopyDataVFast
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; NOTE: Inlining the dispatch would eliminate a JSR,RTS,LDX, and JMP (abs,x) because the exit code
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; could jump directly to the target address. Net savings of 20 cycles per tile. For a 16x16
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; sprite with a 3x3 block coverage this is 180 cycles per frame per block... This would also
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; preserve a register
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;
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; For comparison, a fast one sprite copy takes 22 cycles per word, so this would save
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; about 1/2 block of render time per tile.
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;
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; Need to determine if the sprite or tile data is on top, as that will decide whether the
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; sprite or tile data is copied into the temporary buffer first. Also, if TWO_LAYER is set
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; then the mask information must be copied as well....This is the last decision point.
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SpriteDispatch
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txy
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SpriteBitsToVBuffAddrs OneSpriteFast;OneSpriteFast;OneSpriteFast;OneSpriteFast
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; Where there are sprites involved, the first step is to call a routine to copy the
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; tile data into a temporary buffer. Then the sprite data is merged and placed into
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; the code field.
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;
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; A = vbuff address
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; Y = tile store address
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OneSpriteFast
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sta sprite_ptr0
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ldx TileStore+TS_TILE_ADDR,y
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jsr _CopyTileDataToDP2 ; preserves Y
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lda TileStore+TS_CODE_ADDR_HIGH,y ; load the bank of the target code field line
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pha ; and put on the stack for later. Has TileStore bank in high byte.
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ldx sprite_ptr0 ; address of sprite vbuff info
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lda TileStore+TS_CODE_ADDR_LOW,y ; load the address of the code field
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tay
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plb
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; jmp _TBApplySpriteData2
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_TBApplySpriteData2
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]line equ 0
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lup 8
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lda tmp_tile_data+{]line*4}
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andl spritemask+{]line*SPRITE_PLANE_SPAN},x
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oral spritedata+{]line*SPRITE_PLANE_SPAN},x
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sta: $0004+{]line*$1000},y
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lda tmp_tile_data+{]line*4}+2
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andl spritemask+{]line*SPRITE_PLANE_SPAN}+2,x
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oral spritedata+{]line*SPRITE_PLANE_SPAN}+2,x
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sta: $0001+{]line*$1000},y
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]line equ ]line+1
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--^
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plb
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rts
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OneSpriteFastX
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tax ; address of the sprite data
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lda TileStore+TS_BASE_TILE_COPY,y ; copy routine (handles flips and other behaviors)
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stal osf_copy+1
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osf_copy jsr $0000
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; ldx TileStore+TS_VBUFF_ADDR_0,y ; address of the sprite data
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lda TileStore+TS_CODE_ADDR_HIGH,y ; load the bank of the target code field line
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pha ; and put on the stack for later.
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lda TileStore+TS_CODE_ADDR_LOW,y
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tay
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plb ; set the code field bank
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OneSpriteToCodeField 0
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OneSpriteToCodeField 1
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OneSpriteToCodeField 2
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OneSpriteToCodeField 3
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OneSpriteToCodeField 4
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OneSpriteToCodeField 5
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OneSpriteToCodeField 6
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OneSpriteToCodeField 7
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rts
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TwoSpritesFast
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; tyx
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; lda TileStore+TS_TILE_ADDR,y
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; per :-1
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; jmp (TileStore+TS_BASE_TILE_COPY,x) ; Copy the tile data to the temporary buffer
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;:
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; lda TileStore+TS_VBUFF_ADDR_0,y ; address of the sprite data
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; sta spritedata_0
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; sta spritemask_0
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; lda TileStore+TS_VBUFF_ADDR_1,y ; address of the sprite data
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; sta spritedata_1
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; sta spritemask_1
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lda TileStore+TS_CODE_ADDR_HIGH,y ; load the bank of the target code field line
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pha ; and put on the stack for later.
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lda TileStore+TS_CODE_ADDR_LOW,y
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tay
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plb ; set the code field bank
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; TwoSpritesToCodeField 0
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; TwoSpritesToCodeField 1
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; TwoSpritesToCodeField 2
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; TwoSpritesToCodeField 3
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; TwoSpritesToCodeField 4
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; TwoSpritesToCodeField 5
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; TwoSpritesToCodeField 6
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; TwoSpritesToCodeField 7
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rts
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ThreeSpritesFast
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FourSpritesFast
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; tyx
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; lda TileStore+TS_TILE_ADDR,y
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; per :-1
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; jmp (TileStore+TS_BASE_TILE_COPY,x) ; Copy the tile data to the temporary buffer
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;:
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; lda TileStore+TS_VBUFF_ADDR_0,y ; address of the sprite data
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; sta spritedata_0
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; sta spritemask_0
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; lda TileStore+TS_VBUFF_ADDR_1,y
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; sta spritedata_1
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; sta spritemask_1
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; lda TileStore+TS_VBUFF_ADDR_2,y
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; sta spritedata_2
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; sta spritemask_2
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lda TileStore+TS_CODE_ADDR_HIGH,y ; load the bank of the target code field line
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pha ; and put on the stack for later.
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lda TileStore+TS_CODE_ADDR_LOW,y
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tay
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plb ; set the code field bank
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; ThreeSpritesToCodeField 0
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; ThreeSpritesToCodeField 1
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; ThreeSpritesToCodeField 2
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; ThreeSpritesToCodeField 3
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; ThreeSpritesToCodeField 4
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; ThreeSpritesToCodeField 5
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; ThreeSpritesToCodeField 6
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; ThreeSpritesToCodeField 7
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rts |