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-rw-r--r--home/copy.asm430
1 files changed, 85 insertions, 345 deletions
diff --git a/home/copy.asm b/home/copy.asm
index 5780beb95..018986cf2 100644
--- a/home/copy.asm
+++ b/home/copy.asm
@@ -1,391 +1,131 @@
-; Functions to copy data from ROM.
-
-Get2bpp_2::
- ldh a, [rLCDC]
- bit rLCDC_ENABLE, a
- jp z, Copy2bpp
-
- homecall _Get2bpp
-
- ret
-
-Get1bpp_2::
- ldh a, [rLCDC]
- bit rLCDC_ENABLE, a
- jp z, Copy1bpp
-
- homecall _Get1bpp
-
+CopyBytes::
+; copy bc bytes from hl to de
+ inc b ; we bail the moment b hits 0, so include the last run
+ inc c ; same thing; include last byte
+ jr .HandleLoop
+.CopyByte:
+ ld a, [hli]
+ ld [de], a
+ inc de
+.HandleLoop:
+ dec c
+ jr nz, .CopyByte
+ dec b
+ jr nz, .CopyByte
ret
-FarCopyBytesDouble_DoubleBankSwitch::
- ldh [hBuffer], a
- ldh a, [hROMBank]
+SwapBytes::
+; swap bc bytes between hl and de
+.Loop:
+ ; stash [hl] away on the stack
+ ld a, [hl]
push af
- ldh a, [hBuffer]
- rst Bankswitch
- call FarCopyBytesDouble
+ ; copy a byte from [de] to [hl]
+ ld a, [de]
+ ld [hli], a
+ ; retrieve the previous value of [hl]; put it in [de]
pop af
- rst Bankswitch
- ret
+ ld [de], a
+ inc de
-OldDMATransfer::
- dec c
- ldh a, [hBGMapMode]
- push af
- xor a
- ldh [hBGMapMode], a
- ldh a, [hROMBank]
- push af
+ ; handle loop stuff
+ dec bc
ld a, b
- rst Bankswitch
-
-.loop
-; load the source and target MSB and LSB
- ld a, d
- ldh [rHDMA1], a ; source MSB
- ld a, e
- and $f0
- ldh [rHDMA2], a ; source LSB
- ld a, h
- and $1f
- ldh [rHDMA3], a ; target MSB
- ld a, l
- and $f0
- ldh [rHDMA4], a ; target LSB
-; stop when c < 8
- ld a, c
- cp $8
- jr c, .done
-; decrease c by 8
- sub $8
- ld c, a
-; DMA transfer state
- ld a, $f
- ldh [hDMATransfer], a
- call DelayFrame
-; add $100 to hl and de
- ld a, l
- add LOW($100)
- ld l, a
- ld a, h
- adc HIGH($100)
- ld h, a
- ld a, e
- add LOW($100)
- ld e, a
- ld a, d
- adc HIGH($100)
- ld d, a
- jr .loop
-
-.done
- ld a, c
- and $7f ; pretty silly, considering at most bits 0-2 would be set
- ldh [hDMATransfer], a
- call DelayFrame
- pop af
- rst Bankswitch
-
- pop af
- ldh [hBGMapMode], a
+ or c
+ jr nz, .Loop
ret
-ReplaceKrisSprite::
- farcall _ReplaceKrisSprite
- ret
-
-LoadStandardFont::
- farcall _LoadStandardFont
- ret
-
-LoadFontsBattleExtra::
- farcall _LoadFontsBattleExtra
- ret
-
-LoadFontsExtra::
- farcall _LoadFontsExtra1
- farcall _LoadFontsExtra2
- ret
-
-LoadFontsExtra2::
- farcall _LoadFontsExtra2
- ret
-
-DecompressRequest2bpp::
- push de
- ld a, BANK(sScratch)
- call GetSRAMBank
- push bc
-
- ld de, sScratch
- ld a, b
- call FarDecompress
-
- pop bc
- pop hl
-
- ld de, sScratch
- call Request2bpp
- call CloseSRAM
+ByteFill::
+; fill bc bytes with the value of a, starting at hl
+ inc b ; we bail the moment b hits 0, so include the last run
+ inc c ; same thing; include last byte
+ jr .HandleLoop
+.PutByte:
+ ld [hli], a
+.HandleLoop:
+ dec c
+ jr nz, .PutByte
+ dec b
+ jr nz, .PutByte
ret
-FarCopyBytes::
-; copy bc bytes from a:hl to de
-
+GetFarByte::
+; retrieve a single byte from a:hl, and return it in a.
+ ; bankswitch to new bank
ldh [hBuffer], a
ldh a, [hROMBank]
push af
ldh a, [hBuffer]
rst Bankswitch
- call CopyBytes
+ ; get byte from new bank
+ ld a, [hl]
+ ldh [hBuffer], a
+ ; bankswitch to previous bank
pop af
rst Bankswitch
- ret
-FarCopyBytesDouble::
-; Copy bc bytes from a:hl to bc*2 bytes at de,
-; doubling each byte in the process.
+ ; return retrieved value in a
+ ldh a, [hBuffer]
+ ret
+GetFarHalfword::
+; retrieve a halfword from a:hl, and return it in hl.
+ ; bankswitch to new bank
ldh [hBuffer], a
ldh a, [hROMBank]
push af
ldh a, [hBuffer]
rst Bankswitch
-; switcheroo, de <> hl
- ld a, h
- ld h, d
- ld d, a
- ld a, l
- ld l, e
- ld e, a
-
- inc b
- inc c
- jr .dec
-
-.loop
- ld a, [de]
- inc de
- ld [hli], a
- ld [hli], a
-.dec
- dec c
- jr nz, .loop
- dec b
- jr nz, .loop
+ ; get halfword from new bank, put it in hl
+ ld a, [hli]
+ ld h, [hl]
+ ld l, a
+ ; bankswitch to previous bank and return
pop af
rst Bankswitch
ret
-Request2bpp::
-; Load 2bpp at b:de to occupy c tiles of hl.
- ldh a, [hBGMapMode]
- push af
- xor a
- ldh [hBGMapMode], a
-
- ldh a, [hROMBank]
- push af
- ld a, b
- rst Bankswitch
-
- ldh a, [hTilesPerCycle]
+FarCopyWRAM::
+ ldh [hBuffer], a
+ ldh a, [rSVBK]
push af
- ld a, $8
- ldh [hTilesPerCycle], a
-
- ld a, [wLinkMode]
- cp LINK_MOBILE
- jr nz, .NotMobile
- ldh a, [hMobile]
- and a
- jr nz, .NotMobile
- ld a, $6
- ldh [hTilesPerCycle], a
-
-.NotMobile:
- ld a, e
- ld [wRequested2bppSource], a
- ld a, d
- ld [wRequested2bppSource + 1], a
- ld a, l
- ld [wRequested2bppDest], a
- ld a, h
- ld [wRequested2bppDest + 1], a
-.loop
- ld a, c
- ld hl, hTilesPerCycle
- cp [hl]
- jr nc, .iterate
-
- ld [wRequested2bpp], a
-.wait
- call DelayFrame
- ld a, [wRequested2bpp]
- and a
- jr nz, .wait
-
- pop af
- ldh [hTilesPerCycle], a
+ ldh a, [hBuffer]
+ ldh [rSVBK], a
- pop af
- rst Bankswitch
+ call CopyBytes
pop af
- ldh [hBGMapMode], a
+ ldh [rSVBK], a
ret
-.iterate
- ldh a, [hTilesPerCycle]
- ld [wRequested2bpp], a
-
-.wait2
- call DelayFrame
- ld a, [wRequested2bpp]
- and a
- jr nz, .wait2
-
- ld a, c
- ld hl, hTilesPerCycle
- sub [hl]
- ld c, a
- jr .loop
-
-Request1bpp::
-; Load 1bpp at b:de to occupy c tiles of hl.
- ldh a, [hBGMapMode]
- push af
- xor a
- ldh [hBGMapMode], a
-
- ldh a, [hROMBank]
- push af
- ld a, b
- rst Bankswitch
-
- ldh a, [hTilesPerCycle]
+GetFarWRAMByte::
+ ldh [hBuffer], a
+ ldh a, [rSVBK]
push af
- ld a, $8
- ldh [hTilesPerCycle], a
-
- ld a, [wLinkMode]
- cp LINK_MOBILE
- jr nz, .NotMobile
- ldh a, [hMobile]
- and a
- jr nz, .NotMobile
- ld a, $6
- ldh [hTilesPerCycle], a
-
-.NotMobile:
- ld a, e
- ld [wRequested1bppSource], a
- ld a, d
- ld [wRequested1bppSource + 1], a
- ld a, l
- ld [wRequested1bppDest], a
- ld a, h
- ld [wRequested1bppDest + 1], a
-.loop
- ld a, c
- ld hl, hTilesPerCycle
- cp [hl]
- jr nc, .iterate
-
- ld [wRequested1bpp], a
-.wait
- call DelayFrame
- ld a, [wRequested1bpp]
- and a
- jr nz, .wait
-
- pop af
- ldh [hTilesPerCycle], a
-
- pop af
- rst Bankswitch
-
+ ldh a, [hBuffer]
+ ldh [rSVBK], a
+ ld a, [hl]
+ ldh [hBuffer], a
pop af
- ldh [hBGMapMode], a
+ ldh [rSVBK], a
+ ldh a, [hBuffer]
ret
-.iterate
- ldh a, [hTilesPerCycle]
- ld [wRequested1bpp], a
-
-.wait2
- call DelayFrame
- ld a, [wRequested1bpp]
- and a
- jr nz, .wait2
-
- ld a, c
- ld hl, hTilesPerCycle
- sub [hl]
- ld c, a
- jr .loop
-
-Get2bpp::
- ldh a, [rLCDC]
- bit rLCDC_ENABLE, a
- jp nz, Request2bpp
-
-Copy2bpp::
-; copy c 2bpp tiles from b:de to hl
-
- push hl
- ld h, d
- ld l, e
- pop de
-
-; bank
- ld a, b
-
-; bc = c * $10
- push af
- swap c
- ld a, $f
- and c
- ld b, a
- ld a, $f0
- and c
- ld c, a
- pop af
-
- jp FarCopyBytes
-
-Get1bpp::
- ldh a, [rLCDC]
- bit rLCDC_ENABLE, a
- jp nz, Request1bpp
-
-Copy1bpp::
-; copy c 1bpp tiles from b:de to hl
-
- push de
- ld d, h
- ld e, l
-
-; bank
- ld a, b
-
-; bc = c * $10 / 2
+GetFarWRAMWord::
+ ldh [hBuffer], a
+ ldh a, [rSVBK]
push af
- ld h, 0
- ld l, c
- add hl, hl
- add hl, hl
- add hl, hl
- ld b, h
- ld c, l
+ ldh a, [hBuffer]
+ ldh [rSVBK], a
+ ld a, [hli]
+ ld h, [hl]
+ ld l, a
pop af
-
- pop hl
- jp FarCopyBytesDouble
+ ldh [rSVBK], a
+ ret
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