diff options
Diffstat (limited to 'main.asm')
| -rw-r--r-- | main.asm | 1547 |
1 files changed, 1537 insertions, 10 deletions
@@ -35,7 +35,7 @@ SECTION "rst38",HOME[$38] ; Unused rst $38 SECTION "vblank",HOME[$40] ; vblank interrupt - jp $0283 + jp VBlank SECTION "lcd",HOME[$48] ; lcd interrupt jp $0552 @@ -56,7 +56,541 @@ Start: SECTION "start",HOME[$150] -INCBIN "baserom.gbc",$150,$45a - $150 +INCBIN "baserom.gbc",$150,$283 - $150 + +VBlank: ; 283 + push af + push bc + push de + push hl + +; get vblank type + ld a, [$ff9e] + and $7 + +; get fn pointer + ld e, a + ld d, $0 + ld hl, .VBlanks + add hl, de + add hl, de + ld a, [hli] + ld h, [hl] + ld l, a + +; down to business + call JpHl + +; since this is called once per frame + call GameTimer + + pop hl + pop de + pop bc + pop af + reti +; 2a1 + +.VBlanks ; 2a1 + dw VBlank0 ; 0 + dw VBlank1 ; 1 + dw VBlank2 ; 2 + dw VBlank3 ; 3 + dw VBlank4 ; 4 + dw VBlank5 ; 5 + dw VBlank6 ; 6 + dw VBlank0 ; 7 +; 2b1 + + +VBlank0: ; 2b1 +; normal operation + +; rng +; scx, scy, wy, wx +; bg map buffer +; palettes +; dma transfer +; bg map +; tiles +; oam +; joypad +; sound + +; inc frame counter + ld hl, $ff9b + inc [hl] + +; advance rng + ld a, [$ff04] ; divider + ld b, a + ld a, [$ffe1] + adc b + ld [$ffe1], a + + ld a, [$ff04] ; divider + ld b, a + ld a, [$ffe2] + sbc b + ld [$ffe2], a + +; save bank + ld a, [$ff9d] ; current bank + ld [$ff8a], a + +; scroll x + ld a, [$ffcf] + ld [$ff43], a ; scx +; scroll y + ld a, [$ffd0] + ld [$ff42], a ; scy +; window y + ld a, [$ffd2] + ld [$ff4a], a ; wy +; window x + 7 + ld a, [$ffd1] + ld [$ff4b], a ; wx + +; some time management is in order +; only have time for one of these during vblank + +; bg map buffer has priority + call UpdateBGMapBuffer + jr c, .doneframeaction + +; then pals + call UpdatePalsIfCGB + jr c, .doneframeaction + +; dma transfer + call DMATransfer + jr c, .doneframeaction + +; bg map + call UpdateBGMap + +; these have their own timing checks + call SafeLoadTiles + call SafeLoadTiles2 + call SafeTileAnimation + +.doneframeaction +; oam update off? + ld a, [$ffd8] + and a + jr nz, .vblankoccurred + +; update oam by dma transfer + call $ff80 +; 403f: +; ld a, $c4 +; ld [$ff46], a ; oam dma +; ld a, $28 +; .loop +; dec a +; jr nz, .loop +; ret + + +; vblank-sensitive operations are done + +.vblankoccurred +; tell other fns vblank happened + xor a + ld [VBlankOccurred], a + +; dec $cfb1 until 0 + ld a, [$cfb1] + and a + jr z, .textdelay + dec a + ld [$cfb1], a + +.textdelay +; dec text delay counter until 0 + ld a, [TextDelayFrames] + and a + jr z, .joypad + dec a + ld [TextDelayFrames], a + +.joypad + call Joypad + +; update sound + ld a, BANK(UpdateSound) + rst Bankswitch ; bankswitch + call UpdateSound + ld a, [$ff8a] + rst Bankswitch ; restore bank + +; + ld a, [$ff98] + ld [$ffe3], a + + ret +; 325 + + +VBlank2: ; 325 +; sound only + +; save bank + ld a, [$ff9d] + ld [$ff8a], a + +; update sound + ld a, BANK(UpdateSound) + rst Bankswitch ; bankswitch + call UpdateSound + +; restore bank + ld a, [$ff8a] + rst Bankswitch + +; tell other fns vblank happened + xor a + ld [VBlankOccurred], a + ret +; 337 + + +VBlank1: ; 337 +; scx, scy +; palettes +; bg map +; tiles +; oam +; sound / lcd stat + +; save bank + ld a, [$ff9d] + ld [$ff8a], a + +; scroll x + ld a, [$ffcf] + ld [$ff43], a ; scx + +; scroll y + ld a, [$ffd0] + ld [$ff42], a ; scy + +; time-sensitive fns + call UpdatePals + jr c, .vblankoccurred + +; these have their own timing checks + call UpdateBGMap + call LoadTiles +; update oam by dma transfer + call $ff80 +; 403f: +; ld a, $c4 +; ld [$ff46], a ; oam dma +; ld a, $28 +; .loop +; dec a +; jr nz, .loop +; ret + +.vblankoccurred +; tell other fns vblank happened + xor a + ld [VBlankOccurred], a + +; get requested ints + ld a, [$ff0f] ; IF + ld b, a +; discard requested ints + xor a + ld [$ff0f], a ; IF +; enable lcd stat + ld a, %10 ; lcd stat + ld [$ffff], a ; IE +; rerequest serial int if applicable (still disabled) +; request lcd stat + ld a, b + and %1000 ; serial + or %10 ; lcd stat + ld [$ff0f], a ; IF + + ei +; update sound + ld a, BANK(UpdateSound) + rst Bankswitch ; bankswitch + call UpdateSound +; restore bank + ld a, [$ff8a] + rst Bankswitch + di + +; get requested ints + ld a, [$ff0f] ; IF + ld b, a +; discard requested ints + xor a + ld [$ff0f], a ; IF +; enable ints besides joypad + ld a, %1111 ; serial timer lcdstat vblank + ld [$ffff], a ; IE +; rerequest ints + ld a, b + ld [$ff0f], a ; IF + ret +; 37f + + +UpdatePals: ; 37f +; update pals for either dmg or cgb + +; check cgb + ld a, [$ffe6] + and a + jp nz, UpdateCGBPals + +; update gb pals + ld a, [$cfc7] + ld [$ff47], a ; BGP + + ld a, [$cfc8] + ld [$ff48], a ; OBP0 + + ld a, [$cfc9] + ld [$ff49], a ; 0BP1 + + and a + ret +; 396 + + +VBlank3: ; 396 +; scx, scy +; palettes +; bg map +; tiles +; oam +; sound / lcd stat + +; save bank + ld a, [$ff9d] + ld [$ff8a], a + +; scroll x + ld a, [$ffcf] + ld [$ff43], a ; scx +; scroll y + ld a, [$ffd0] + ld [$ff42], a ; scy + +; any pals to update? + ld a, [$ffe5] + and a + call nz, ForceUpdateCGBPals + jr c, .vblankoccurred +; else + call UpdateBGMap + call LoadTiles + +; update oam by dma transfer + call $ff80 +; 403f: +; ld a, $c4 ; Sprites / $100 +; ld [$ff46], a ; oam dma +; ld a, $28 +; .loop +; dec a +; jr nz, .loop +; ret + +.vblankoccurred +; tell other fns vblank happened + xor a + ld [VBlankOccurred], a + +; save int flag + ld a, [$ff0f] ; IF + push af +; reset ints + xor a + ld [$ff0f], a ; IF +; force lcdstat int during sound update + ld a, %10 ; lcd stat + ld [$ffff], a ; IE + ld [$ff0f], a ; IF + + ei +; update sound + ld a, BANK(UpdateSound) + rst Bankswitch ; bankswitch + call UpdateSound +; restore bank + ld a, [$ff8a] + rst Bankswitch + di + +; request lcdstat + ld a, [$ff0f] ; IF + ld b, a +; and any other ints + pop af + or b + ld b, a +; reset ints + xor a + ld [$ff0f], a ; IF +; enable ints besides joypad + ld a, %1111 ; serial timer lcdstat vblank + ld [$ffff], a ; IE +; request ints + ld a, b + ld [$ff0f], a ; IF + ret +; 3df + + +VBlank4: ; 3df +; bg map +; tiles +; oam +; joypad +; serial +; sound + +; save bank + ld a, [$ff9d] + ld [$ff8a], a + + call UpdateBGMap + call SafeLoadTiles + +; update oam by dma transfer + call $ff80 +; 403f: +; ld a, $c4 +; ld [$ff46], a ; oam dma +; ld a, $28 +; .loop +; dec a +; jr nz, .loop +; ret + +; update joypad + call Joypad + +; tell other fns vblank happened + xor a + ld [VBlankOccurred], a + +; handshake + call AskSerial + +; update sound + ld a, BANK(UpdateSound) + rst Bankswitch ; bankswitch + call UpdateSound +; restore bank + ld a, [$ff8a] + rst Bankswitch + ret +; 400 + + +VBlank5: ; 400 +; scx +; palettes +; bg map +; tiles +; joypad +; + +; save bank + ld a, [$ff9d] + ld [$ff8a], a + +; scroll x + ld a, [$ffcf] + ld [$ff43], a ; scx + +; if we can update pals, skip this part + call UpdatePalsIfCGB + jr c, .vblankoccurred + + call UpdateBGMap + call SafeLoadTiles + +.vblankoccurred +; tell other fns vblank happened + xor a + ld [VBlankOccurred], a + +; joypad + call Joypad + +; discard requested ints + xor a + ld [$ff0f], a ; IF +; enable lcd stat + ld a, %10 ; lcd stat + ld [$ffff], a ; IE +; request lcd stat + ld [$ff0f], a ; IF + + ei +; update sound + ld a, BANK(UpdateSound) + rst Bankswitch ; bankswitch + call UpdateSound +; restore bank + ld a, [$ff8a] + rst Bankswitch + di + +; discard requested ints + xor a + ld [$ff0f], a ; IF +; enable ints besides joypad + ld a, %1111 ; serial timer lcdstat vblank + ld [$ffff], a ; IE + ret +; 436 + + +VBlank6: ; 436 +; palettes +; tiles +; dma transfer +; sound + +; save bank + ld a, [$ff9d] + ld [$ff8a], a + +; inc frame counter + ld hl, $ff9b + inc [hl] + + call UpdateCGBPals + jr c, .vblankoccurred + + call SafeLoadTiles + call SafeLoadTiles2 + call DMATransfer + +.vblankoccurred +; tell other fns vblank happened + xor a + ld [VBlankOccurred], a + +; update sound + ld a, BANK(UpdateSound) + rst Bankswitch ; bankswitch + call UpdateSound +; restore bank + ld a, [$ff8a] + rst Bankswitch + ret +; 45a + DelayFrame: ; 0x45a ; delay for one frame @@ -369,10 +903,8 @@ FixTime: ; 61d ret ; 658 - INCBIN "baserom.gbc",$658,$691 - $658 - SetClock: ; 691 ; set clock data from hram @@ -421,7 +953,87 @@ SetClock: ; 691 ret ; 6c4 -INCBIN "baserom.gbc",$6c4,$984 - $6c4 +INCBIN "baserom.gbc",$6c4,$935 - $6c4 + +Joypad: ; 935 +; update joypad state +; $ffa2: released +; $ffa3: pressed +; $ffa4: input +; $ffa5: total pressed + +; + ld a, [$cfbe] + and $d0 + ret nz + +; pause game update? + ld a, [$c2cd] + and a + ret nz + +; d-pad + ld a, $20 + ld [$ff00], a + ld a, [$ff00] + ld a, [$ff00] +; hi nybble + cpl + and $f + swap a + ld b, a + +; buttons + ld a, $10 + ld [$ff00], a +; wait to stabilize + ld a, [$ff00] + ld a, [$ff00] + ld a, [$ff00] + ld a, [$ff00] + ld a, [$ff00] + ld a, [$ff00] +; lo nybble + cpl + and $f + or b + ld b, a + +; reset joypad + ld a, $30 + ld [$ff00], a + +; get change in input + ld a, [$ffa4] ; last frame's input + ld e, a + xor b ; current frame input + ld d, a +; released + and e + ld [$ffa2], a +; pressed + ld a, d + and b + ld [$ffa3], a + +; total pressed + ld c, a + ld a, [$ffa5] + or c + ld [$ffa5], a + +; original input + ld a, b + ld [$ffa4], a + +; A+B+SELECT+START + and $f + cp $f + jp z, $0150 ; reset + + ret +; 984 + GetJoypadPublic: ; 984 ; update mirror joypad input from $ffa4 (real input) @@ -588,7 +1200,136 @@ StopAutoInput: ; a0a ret ; a1b -INCBIN "baserom.gbc",$a1b,$c9f - $a1b +INCBIN "baserom.gbc",$a1b,$c2f - $a1b + +UpdatePalsIfCGB: ; c2f +; update bgp data from BGPals +; update obp data from OBPals +; return carry if successful + +; check cgb + ld a, [$ffe6] + and a + ret z + +UpdateCGBPals: ; c33 +; return carry if successful +; any pals to update? + ld a, [$ffe5] + and a + ret z + +ForceUpdateCGBPals: ; c37 +; save wram bank + ld a, [$ff70] ; wram bank + push af +; bankswitch + ld a, 5 ; BANK(BGPals) + ld [$ff70], a ; wram bank +; get bg pal buffer + ld hl, BGPals ; 5:d080 + +; update bg pals + ld a, %10000000 ; auto increment, index 0 + ld [$ff68], a ; BGPI + ld c, $69 ; $ff69 + ld b, 4 ; NUM_PALS / 2 + +.bgp +; copy 16 bytes (8 colors / 2 pals) to bgpd + ld a, [hli] + ld [$ff00+c], a + ld a, [hli] + ld [$ff00+c], a + ld a, [hli] + ld [$ff00+c], a + ld a, [hli] + ld [$ff00+c], a + ld a, [hli] + ld [$ff00+c], a + ld a, [hli] + ld [$ff00+c], a + ld a, [hli] + ld [$ff00+c], a + ld a, [hli] + ld [$ff00+c], a + ld a, [hli] + ld [$ff00+c], a + ld a, [hli] + ld [$ff00+c], a + ld a, [hli] + ld [$ff00+c], a + ld a, [hli] + ld [$ff00+c], a + ld a, [hli] + ld [$ff00+c], a + ld a, [hli] + ld [$ff00+c], a + ld a, [hli] + ld [$ff00+c], a + ld a, [hli] + ld [$ff00+c], a +; done? + dec b + jr nz, .bgp + +; hl is now 5:d0c0 OBPals + +; update obj pals + ld a, %10000000 ; auto increment, index 0 + ld [$ff6a], a + ld c, $6b ; $ff6b - $ff00 + ld b, 4 ; NUM_PALS / 2 + +.obp +; copy 16 bytes (8 colors / 2 pals) to obpd + ld a, [hli] + ld [$ff00+c], a + ld a, [hli] + ld [$ff00+c], a + ld a, [hli] + ld [$ff00+c], a + ld a, [hli] + ld [$ff00+c], a + ld a, [hli] + ld [$ff00+c], a + ld a, [hli] + ld [$ff00+c], a + ld a, [hli] + ld [$ff00+c], a + ld a, [hli] + ld [$ff00+c], a + ld a, [hli] + ld [$ff00+c], a + ld a, [hli] + ld [$ff00+c], a + ld a, [hli] + ld [$ff00+c], a + ld a, [hli] + ld [$ff00+c], a + ld a, [hli] + ld [$ff00+c], a + ld a, [hli] + ld [$ff00+c], a + ld a, [hli] + ld [$ff00+c], a + ld a, [hli] + ld [$ff00+c], a +; done? + dec b + jr nz, .obp + +; restore wram bank + pop af + ld [$ff70], a ; wram bank +; clear pal update queue + xor a + ld [$ffe5], a +; successfully updated palettes + scf + ret +; c9f + DmgToCgbBGPals: ; c9f ; exists to forego reinserting cgb-converted image data @@ -1074,7 +1815,617 @@ Char5F: ; 0x1356 pop hl ret -INCBIN "baserom.gbc",$135a,$185d - $135a +INCBIN "baserom.gbc",$135a,$15d8 - $135a + +DMATransfer: ; 15d8 +; DMA transfer +; return carry if successful + +; anything to transfer? + ld a, [$ffe8] + and a + ret z +; start transfer + ld [$ff55], a ; hdma5 +; indicate that transfer has occurred + xor a + ld [$ffe8], a +; successful transfer + scf + ret +; 15e3 + + +UpdateBGMapBuffer: ; 15e3 +; write [$ffdc] 16x8 tiles from BGMapBuffer to bg map addresses in BGMapBufferPtrs +; [$ffdc] must be even since this is done in 16x16 blocks + +; return carry if successful + +; any tiles to update? + ld a, [$ffdb] + and a + ret z +; save wram bank + ld a, [$ff4f] ; vram bank + push af +; save sp + ld [$ffd9], sp + +; temp stack + ld hl, BGMapBufferPtrs + ld sp, hl +; we can now pop the addresses of affected spots in bg map + +; get pal and tile buffers + ld hl, BGMapPalBuffer + ld de, BGMapBuffer + +.loop +; draw one 16x16 block + +; top half: + +; get bg map address + pop bc +; update palettes + ld a, $1 + ld [$ff4f], a ; vram bank +; tile 1 + ld a, [hli] + ld [bc], a + inc c +; tile 2 + ld a, [hli] + ld [bc], a + dec c +; update tiles + ld a, $0 + ld [$ff4f], a ; vram bank +; tile 1 + ld a, [de] + inc de + ld [bc], a + inc c +; tile 2 + ld a, [de] + inc de + ld [bc], a + +; bottom half: + +; get bg map address + pop bc +; update palettes + ld a, $1 + ld [$ff4f], a ; vram bank +; tile 1 + ld a, [hli] + ld [bc], a + inc c +; tile 2 + ld a, [hli] + ld [bc], a + dec c +; update tiles + ld a, $0 + ld [$ff4f], a ; vram bank +; tile 1 + ld a, [de] + inc de + ld [bc], a + inc c +; tile 2 + ld a, [de] + inc de + ld [bc], a + +; we've done 2 16x8 blocks + ld a, [$ffdc] + dec a + dec a + ld [$ffdc], a + +; if there are more left, get the next 16x16 block + jr nz, .loop + + +; restore sp + ld a, [$ffd9] + ld l, a + ld a, [$ffda] + ld h, a + ld sp, hl + +; restore vram bank + pop af + ld [$ff4f], a ; vram bank + +; we don't need to update bg map until new tiles are loaded + xor a + ld [$ffdb], a + +; successfully updated bg map + scf + ret +; 163a + + +WaitTop: ; 163a + ld a, [$ffd4] + and a + ret z + +; wait until top third of bg map can be updated + ld a, [$ffd5] + and a + jr z, .quit + + call DelayFrame + jr WaitTop + +.quit + xor a + ld [$ffd4], a + ret +; 164c + + +UpdateBGMap: ; 164c +; get mode + ld a, [$ffd4] + and a + ret z + +; don't save bg map address + dec a ; 1 + jr z, .tiles + dec a ; 2 + jr z, .attr + dec a ; ? + +; save bg map address + ld a, [$ffd6] + ld l, a + ld a, [$ffd7] + ld h, a + push hl + +; bg map 1 ($9c00) + xor a + ld [$ffd6], a + ld a, $9c + ld [$ffd7], a + +; get mode again + ld a, [$ffd4] + push af + cp 3 + call z, .tiles + pop af + cp 4 + call z, .attr + +; restore bg map address + pop hl + ld a, l + ld [$ffd6], a + ld a, h + ld [$ffd7], a + ret + +.attr +; switch vram banks + ld a, 1 + ld [$ff4f], a ; vram bank +; bg map 1 + ld hl, AttrMap + call .getthird +; restore vram bank + ld a, 0 + ld [$ff4f], a ; vram bank + ret + +.tiles +; bg map 0 + ld hl, TileMap + +.getthird +; save sp + ld [$ffd9], sp + +; # tiles to move down * 6 (which third?) + ld a, [$ffd5] + and a ; 0 + jr z, .top + dec a ; 1 + jr z, .middle + +; .bottom ; 2 +; move 12 tiles down + ld de, $00f0 ; TileMap(0,12) - TileMap + add hl, de +; stack now points to source + ld sp, hl +; get bg map address + ld a, [$ffd7] + ld h, a + ld a, [$ffd6] + ld l, a +; move 12 tiles down + ld de, $0180 ; bgm(0,12) + add hl, de +; start at top next time + xor a + jr .start + +.middle +; move 6 tiles down + ld de, $0078 ; TileMap(0,6) - TileMap + add hl, de +; stack now points to source + ld sp, hl +; get bg map address + ld a, [$ffd7] + ld h, a + ld a, [$ffd6] + ld l, a +; move 6 tiles down + ld de, $00c0 ; bgm(0,6) + add hl, de +; start at bottom next time + ld a, 2 + jr .start + +.top +; stack now points to source + ld sp, hl +; get bg map address + ld a, [$ffd7] + ld h, a + ld a, [$ffd6] + ld l, a +; start at middle next time + ld a, 1 + +.start +; which third to draw next update + ld [$ffd5], a +; # rows per third + ld a, 6 ; SCREEN_HEIGHT / 3 +; # tiles from the edge of the screen to the next row + ld bc, $000d ; BG_WIDTH + 1 - SCREEN_WIDTH + +.row +; write a row of 20 tiles + pop de + ld [hl], e + inc l + ld [hl], d + inc l + pop de + ld [hl], e + inc l + ld [hl], d + inc l + pop de + ld [hl], e + inc l + ld [hl], d + inc l + pop de + ld [hl], e + inc l + ld [hl], d + inc l + pop de + ld [hl], e + inc l + ld [hl], d + inc l + pop de + ld [hl], e + inc l + ld [hl], d + inc l + pop de + ld [hl], e + inc l + ld [hl], d + inc l + pop de + ld [hl], e + inc l + ld [hl], d + inc l + pop de + ld [hl], e + inc l + ld [hl], d + inc l + pop de + ld [hl], e + inc l + ld [hl], d +; next row + add hl, bc +; done? + dec a + jr nz, .row + +; restore sp + ld a, [$ffd9] + ld l, a + ld a, [$ffda] + ld h, a + ld sp, hl + ret +; 170a + + +SafeLoadTiles2: ; 170a +; only execute during first fifth of vblank +; any tiles to draw? + ld a, [$cf6c] + and a + ret z +; abort if too far into vblank + ld a, [$ff44] ; LY +; ly = 144-145? + cp 144 + ret c + cp 146 + ret nc + +GetTiles2: ; 1717 +; load [$cf6c] tiles from [$cf6d-e] to [$cf6f-70] +; save sp + ld [$ffd9], sp + +; sp = [$cf6d-e] tile source + ld hl, $cf6d + ld a, [hli] + ld h, [hl] + ld l, a + ld sp, hl + +; hl = [$cf6f-70] tile dest + ld hl, $cf6f + ld a, [hli] + ld h, [hl] + ld l, a + +; # tiles to draw + ld a, [$cf6c] + ld b, a + +; clear tile queue + xor a + ld [$cf6c], a + +.loop +; put 1 tile (16 bytes) into hl from sp + pop de + ld [hl], e + inc l + ld [hl], e + inc l + ld [hl], d + inc l + ld [hl], d + inc l + pop de + ld [hl], e + inc l + ld [hl], e + inc l + ld [hl], d + inc l + ld [hl], d + inc l + pop de + ld [hl], e + inc l + ld [hl], e + inc l + ld [hl], d + inc l + ld [hl], d + inc l + pop de + ld [hl], e + inc l + ld [hl], e + inc l + ld [hl], d + inc l + ld [hl], d +; next tile + inc hl +; done? + dec b + jr nz, .loop + +; update $cf6f-70 + ld a, l + ld [$cf6f], a + ld a, h + ld [$cf70], a + +; update $cf6d-e + ld [$cf6d], sp + +; restore sp + ld a, [$ffd9] + ld l, a + ld a, [$ffda] + ld h, a + ld sp, hl + ret +; 1769 + + +SafeLoadTiles: ; 1769 +; only execute during first fifth of vblank +; any tiles to draw? + ld a, [$cf67] + and a + ret z +; abort if too far into vblank + ld a, [$ff44] ; LY +; ly = 144-145? + cp 144 + ret c + cp 146 + ret nc + jr GetTiles + +LoadTiles: ; 1778 +; use only if time is allotted +; any tiles to draw? + ld a, [$cf67] + and a + ret z +; get tiles + +GetTiles: ; 177d +; load [$cf67] tiles from [$cf68-9] to [$cf6a-b] + +; save sp + ld [$ffd9], sp + +; sp = [$cf68-9] tile source + ld hl, $cf68 + ld a, [hli] + ld h, [hl] + ld l, a + ld sp, hl + +; hl = [$cf6a-b] tile dest + ld hl, $cf6a + ld a, [hli] + ld h, [hl] + ld l, a + +; # tiles to draw + ld a, [$cf67] + ld b, a +; clear tile queue + xor a + ld [$cf67], a + +.loop +; put 1 tile (16 bytes) into hl from sp + pop de + ld [hl], e + inc l + ld [hl], d + inc l + pop de + ld [hl], e + inc l + ld [hl], d + inc l + pop de + ld [hl], e + inc l + ld [hl], d + inc l + pop de + ld [hl], e + inc l + ld [hl], d + inc l + pop de + ld [hl], e + inc l + ld [hl], d + inc l + pop de + ld [hl], e + inc l + ld [hl], d + inc l + pop de + ld [hl], e + inc l + ld [hl], d + inc l + pop de + ld [hl], e + inc l + ld [hl], d +; next tile + inc hl +; done? + dec b + jr nz, .loop + +; update $cf6a-b + ld a, l + ld [$cf6a], a + ld a, h + ld [$cf6b], a + +; update $cf68-9 + ld [$cf68], sp + +; restore sp + ld a, [$ffd9] + ld l, a + ld a, [$ffda] + ld h, a + ld sp, hl + ret +; 17d3 + + +SafeTileAnimation: ; 17d3 +; call from vblank + + ld a, [$ffde] + and a + ret z + +; abort if too far into vblank + ld a, [$ff44] ; LY +; ret unless ly = 144-150 + cp 144 + ret c + cp 151 + ret nc + +; save affected banks +; switch to new banks + ld a, [$ff9d] + push af ; save bank + ld a, BANK(DoTileAnimation) + rst Bankswitch ; bankswitch + + ld a, [$ff70] ; wram bank + push af ; save wram bank + ld a, $1 ; wram bank 1 + ld [$ff70], a ; wram bank + + ld a, [$ff4f] ; vram bank + push af ; save vram bank + ld a, $0 ; vram bank 0 + ld [$ff4f], a ; vram bank + +; take care of tile animation queue + call DoTileAnimation + +; restore affected banks + pop af + ld [$ff4f], a ; vram bank + pop af + ld [$ff70], a ; wram bank + pop af + rst Bankswitch ; bankswitch + ret +; 17ff + +INCBIN "baserom.gbc",$17ff,$185d - $17ff GetTileType: ; 185d ; checks the properties of a tile @@ -1099,7 +2450,177 @@ GetTileType: ; 185d ret ; 1875 -INCBIN "baserom.gbc",$1875,$261f - $1875 +INCBIN "baserom.gbc",$1875,$2063 - $1875 + +AskSerial: ; 2063 +; send out a handshake while serial int is off + ld a, [$c2d4] + bit 0, a + ret z + + ld a, [$c2d5] + and a + ret nz + +; once every 6 frames + ld hl, $ca8a + inc [hl] + ld a, [hl] + cp 6 + ret c + + xor a + ld [hl], a + + ld a, $c + ld [$c2d5], a + +; handshake + ld a, $88 + ld [$ff01], a + +; switch to internal clock + ld a, %00000001 + ld [$ff02], a + +; start transfer + ld a, %10000001 + ld [$ff02], a + + ret +; 208a + +INCBIN "baserom.gbc",$208a,$209e - $208a + +GameTimer: ; 209e +; precautionary + nop + +; save wram bank + ld a, [$ff70] ; wram bank + push af + + ld a, $1 + ld [$ff70], a ; wram bank + + call UpdateGameTimer + +; restore wram bank + pop af + ld [$ff70], a ; wram bank + ret +; 20ad + + +UpdateGameTimer: ; 20ad +; increment the game timer by one frame +; capped at 999:59:59.00 after exactly 1000 hours + +; pause game update? + ld a, [$c2cd] + and a + ret nz + +; game timer paused? + ld hl, GameTimerPause + bit 0, [hl] + ret z + +; reached cap? (999:00:00.00) + ld hl, GameTimeCap + bit 0, [hl] + ret nz + +; increment frame counter + ld hl, GameTimeFrames ; frame counter + ld a, [hl] + inc a + +; reached 1 second? + cp 60 ; frames/second + jr nc, .second ; 20c5 $2 + +; update frame counter + ld [hl], a + ret + +.second +; reset frame counter + xor a + ld [hl], a + +; increment second counter + ld hl, GameTimeSeconds + ld a, [hl] + inc a + +; reached 1 minute? + cp 60 ; seconds/minute + jr nc, .minute + +; update second counter + ld [hl], a + ret + +.minute +; reset second counter + xor a + ld [hl], a + +; increment minute counter + ld hl, GameTimeMinutes + ld a, [hl] + inc a + +; reached 1 hour? + cp 60 ; minutes/hour + jr nc, .hour + +; update minute counter + ld [hl], a + ret + +.hour +; reset minute counter + xor a + ld [hl], a + +; increment hour counter + ld a, [GameTimeHours] + ld h, a + ld a, [GameTimeHours+1] + ld l, a + inc hl + +; reached 1000 hours? + ld a, h + cp $3 ; 1000 / $100 + jr c, .updatehr + + ld a, l + cp $e8 ; 1000 & $ff + jr c, .updatehr + +; cap at 999:59:59.00 + ld hl, GameTimeCap + set 0, [hl] ; stop timer + + ld a, 59 + ld [GameTimeMinutes], a + ld [GameTimeSeconds], a + +; this will never be run again + ret + +.updatehr + ld a, h + ld [GameTimeHours], a + ld a, l + ld [GameTimeHours+1], a + ret +; 210f + +INCBIN "baserom.gbc",$210f,$261f - $210f PushScriptPointer: ; 261f ; used to call a script from asm @@ -1496,7 +3017,11 @@ CloseSRAM: ; 2fe1 ret ; 2fec -INCBIN "baserom.gbc",$2fec,$300b-$2fec +JpHl: ; 2fec + jp [hl] +; 2fed + +INCBIN "baserom.gbc",$2fed,$300b-$2fed ClearSprites: ; 300b ld hl, Sprites @@ -2399,7 +3924,7 @@ SFXChannelsOff: ; 3e21 ret ; 3e32 -INCBIN "baserom.gbc",$3e32,$4000 - $3e32 +INCBIN "baserom.gbc",$3e32,$3fb5 - $3e32 SECTION "bank1",DATA,BANK[$1] @@ -89886,6 +91411,8 @@ INCBIN "baserom.gbc",$FBCCF,$fc000-$fbccf SECTION "bank3F",DATA,BANK[$3F] +DoTileAnimation: + INCBIN "baserom.gbc",$FC000,$fcdc2-$fc000 LoadTradesPointer: ; 0xfcdc2 |