cscg22-gearboy

CSCG 2022 Challenge 'Gearboy'
git clone https://git.sinitax.com/sinitax/cscg22-gearboy
Log | Files | Refs | sfeed.txt

set_data.s (1159B)

      1        .include        "global.s"
      2
      3        .area   _HOME
      4
      5_set_tile_data::
      6        ldhl sp, #6
      7        ld d,(hl)
      8        jr .copy_tiles
      9_set_bkg_data::
     10_set_win_data::
     11        ld d, #0x90
     12        ldh a, (.LCDC)
     13	and #LCDCF_BG8000
     14        jr z, .copy_tiles
     15_set_sprite_data::
     16        ld d, #0x80
     17.copy_tiles:
     18        push bc
     19        ldhl sp, #4
     20        ld a, (hl+) ; ID of 1st tile
     21        ld e, a
     22        ld a, (hl+) ; Nb of tiles
     23        ld c, a
     24        ld a, (hl+) ; Src ptr
     25        ld h, (hl)
     26        ld l, a
     27        
     28        ; Compute dest ptr
     29        swap e ; *16 (size of a tile)
     30        ld a, e
     31        and #0x0F ; Get high bits
     32        add d ; Add base offset of target tile "block"
     33        ld d, a
     34        ld a, e
     35        and #0xF0 ; Get low bits only
     36        ld e, a
     372$:
     38        ; Wrap from past $97FF to $8800 onwards
     39        ; This can be reduced to "bit 4 must be clear if bit 3 is set"
     40        bit 3, d
     41        jr z, 1$
     42        res 4, d
     431$:
     44        ld b, #16
     453$:
     46        WAIT_STAT
     47        ld a, (hl+)
     48        ld (de), a
     49        inc de
     50        
     51        dec b
     52        jr nz, 3$
     53
     54        dec c
     55        jr nz, 2$
     56        
     57        pop bc
     58        ret