keen: make more things use tilemap lookup
only saves handful of cycles it seems
This commit is contained in:
Vince Weaver
parent
ed5053bb1e
commit
0ec8efc1be
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@ -69,7 +69,7 @@ level1.o: level1.s zp.inc hardware.inc \
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graphics/keen_graphics.inc sprites/keen_sprites.inc \
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maps/level1_map.lzsa \
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status_bar.s draw_keen.s move_keen.s gr_putsprite_crop.s \
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draw_tilemap.s \
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draw_tilemap.s tilemap_lookup.s \
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level1_sfx.s longer_sound.s \
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keyboard.s handle_laser.s
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ca65 -o level1.o level1.s -l level1.lst
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@ -4,62 +4,64 @@
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; tilemap is 20x12 grid with 2x4 (well, 2x2) tiles
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draw_tilemap:
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ldy #0 ; current screen Ypos to draw at
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sty TILEY ; (we draw two at a time as lores
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; is two blocks per byte)
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ldx #0 ; offset in current tilemap ; 2
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stx TILEMAP_OFFSET ; ; 3
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ldx #0 ; offset in current tilemap
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stx TILEMAP_OFFSET ;
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; ldy #0 ; current screen Ypos to draw at ; 2
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stx TILEY ; (we draw two at a time as lores ; 3
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; is two blocks per byte)
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lda #0 ; init odd/even
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sta TILE_ODD ; (tiles are two rows tall)
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; lda #0 ; init odd/even ; 2
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stx TILE_ODD ; (tiles are two rows tall) ; 3
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tilemap_outer_loop:
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ldy TILEY ; setup output pointer to current Ypos
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ldy TILEY ; setup output pointer to current Ypos ; 3
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lda gr_offsets,Y ; get address of start of row
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sta GBASL
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lda gr_offsets+1,Y
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clc
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adc DRAW_PAGE ; adjust for page
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sta GBASH
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lda gr_offsets,Y ; get address of start of row ; 4+
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sta GBASL ; 3
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lda gr_offsets+1,Y ; 4+
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clc ; 2
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adc DRAW_PAGE ; adjust for page ; 3
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sta GBASH ; 3
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ldy #0 ; draw row from 0..39
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; might be faster to count backwards
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; but would have to adjust a lot
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ldy #0 ; draw row from 0..39 ; 2
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; might be faster to count backwards
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; but would have to adjust a lot
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tilemap_loop:
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ldx TILEMAP_OFFSET ; get actual tile number
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lda small_tilemap,X ; from tilemap
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ldx TILEMAP_OFFSET ; get actual tile number ; 3
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lda small_tilemap,X ; from tilemap ; 4
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asl ; *4 ; point to tile to draw (4 bytes each)
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asl
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tax
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asl ; *4 ; point to tile to draw (4 bytes each) ; 2
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asl ; 2
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tax ; 2
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lda TILE_ODD ; check to see if top or bottom
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beq not_odd_line
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inx ; point to bottom half of tile
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inx
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lda TILE_ODD ; check to see if top or bottom ; 3
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beq not_odd_line ; 2/3
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inx ; point to bottom half of tile ; 2
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inx ; 2
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not_odd_line:
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; draw two blocks
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; note we don't handle transparency in the keen engine
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lda tiles,X
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sta (GBASL),Y ; draw upper right
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lda tiles,X ; 4
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sta (GBASL),Y ; draw upper right ; 6
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iny
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iny ; 2
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lda tiles+1,X
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sta (GBASL),Y ; draw upper left
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lda tiles+1,X ; 4
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sta (GBASL),Y ; draw upper left ; 6
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iny
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iny ; 2
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inc TILEMAP_OFFSET ; point to next tile
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inc TILEMAP_OFFSET ; point to next tile ; 5
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cpy #40 ; until done
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bne tilemap_loop
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cpy #40 ; until done ; 2
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bne tilemap_loop ; 2/3
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@ -126,22 +128,35 @@ copy_tilemap_subset:
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lda #0
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sta tilemap_count_smc+1
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; original worse case: 23 cycles
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; lookup table: 19 cycles
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; set start
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lda TILEMAP_Y
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lsr
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ldx TILEMAP_Y ; 3
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lda tilemap_lookup_high,X ; 4
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sta cptl1_smc+2 ; set proper row in big tilemap ; 4
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lda tilemap_lookup_low,X ; 4
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sta cptl1_smc+1 ; set proper row in big tilemap ; 4
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; set start
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; lda TILEMAP_Y ; 3
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; lsr ; 2
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; set odd/even
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ldx #0
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bcc skip_odd_row
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ldx #$80
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skip_odd_row:
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stx cptl1_smc+1
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; ldx #0 ; 2
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; bcc skip_odd_row ; 2/3
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; ldx #$80 ; 2
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;skip_odd_row:
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; stx cptl1_smc+1 ; 4
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clc ; set start
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adc #>big_tilemap ; each even row is a page, so adding
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; Y to top byte is indexing to row
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; clc ; set start ; 2
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; adc #>big_tilemap ; each even row is a page, so adding ; 2
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; Y to top byte is indexing to row
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; sta cptl1_smc+2 ; set proper row in big tilemap ; 4
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sta cptl1_smc+2 ; set proper row in big tilemap
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lda #<small_tilemap
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@ -153,14 +168,15 @@ cp_tilemap_outer_loop:
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ldy #0
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cp_tilemap_inner_loop:
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; FIXME: make cptl1 take into account X offset and use one index?
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; TODO: optimize, totally unroll?
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cptl1_smc:
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lda $9400,X
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lda $9400,X ; 4
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cptl2_smc:
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sta $BC00,Y
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iny
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inx
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sta $BC00,Y ; 5
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iny ; 2
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inx ; 2
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cpy #TILEMAP_X_COPY_SIZE
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bne cp_tilemap_inner_loop
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@ -302,5 +302,7 @@ level1_levelover:
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.include "random16.s"
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.include "tilemap_lookup.s"
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level1_data_zx02:
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.incbin "maps/level1_map.zx02"
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