diff options
Diffstat (limited to 'home/decompress.asm')
| -rw-r--r-- | home/decompress.asm | 14 |
1 files changed, 4 insertions, 10 deletions
diff --git a/home/decompress.asm b/home/decompress.asm index 1d555529..b1e2ba5e 100644 --- a/home/decompress.asm +++ b/home/decompress.asm @@ -19,10 +19,8 @@ Decompress:: ; This function decompresses lz-compressed data from hl to de. - LZ_END EQU $ff ; Compressed data is terminated with $ff. - ; A typical control command consists of: LZ_CMD EQU %11100000 ; command id (bits 5-7) @@ -30,8 +28,8 @@ LZ_LEN EQU %00011111 ; length n (bits 0-4) ; Additional parameters are read during command execution. - ; Commands: + LZ_LITERAL EQU 0 << 5 ; Read literal data for n bytes. LZ_ITERATE EQU 1 << 5 ; Write the same byte for n bytes. LZ_ALTERNATE EQU 2 << 5 ; Alternate two bytes for n bytes. @@ -49,7 +47,6 @@ LZ_REPEAT EQU 4 << 5 ; Repeat n bytes from the offset. LZ_FLIP EQU 5 << 5 ; Repeat n bitflipped bytes. LZ_REVERSE EQU 6 << 5 ; Repeat n bytes in reverse. - ; If the value in the count needs to be larger than 5 bits, ; LZ_LONG can be used to expand the count to 10 bits. LZ_LONG EQU 7 << 5 @@ -64,10 +61,8 @@ LZ_LONG_HI EQU %00000011 ; x: the new control command ; y: the length - ; For more information, refer to the code below and in extras/gfx.py. - ; Save the output address ; for rewrite commands. ld a, e @@ -75,7 +70,7 @@ LZ_LONG_HI EQU %00000011 ld a, d ld [wLZAddress + 1], a -.Main +.Main: ld a, [hl] cp LZ_END ret z @@ -95,7 +90,7 @@ LZ_LONG_HI EQU %00000011 add a ; << 3 add a - ; This is our new control code. + ; This is our new control code. and LZ_CMD push af @@ -109,7 +104,6 @@ LZ_LONG_HI EQU %00000011 inc bc jr .command - .short push af @@ -139,7 +133,7 @@ LZ_LONG_HI EQU %00000011 cp LZ_ZERO jr z, .Zero -.Literal +.Literal: ; Read literal data for bc bytes. .lloop dec c |