cscg22-gearboy

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

get_addr.s (761B)

      1.include "global.s"
      2
      3.area _CODE
      4
      5_get_win_xy_addr::
      6        ldh     a, (.LCDC)
      7        and     #LCDCF_WIN9C00
      8        jr      z, .is98
      9        jr      .is9c
     10
     11_get_bkg_xy_addr::
     12        ldh     a, (.LCDC)
     13        and     #LCDCF_BG9C00
     14        jr      nz, .is9c
     15.is98:
     16        ld      d, #0x98        ; DE = origin
     17        jr      .calculate_ofs
     18.is9c:
     19        ld      d, #0x9C        ; DE = origin
     20
     21.calculate_ofs:
     22        ldhl    sp, #3
     23
     24        ld      a, (hl-)
     25        ld      l, (hl)
     26
     27        ld      e, d
     28        swap    a
     29        rlca
     30        ld      h, a
     31        and     #0x03
     32        add     e
     33        ld      d, a
     34        ld      a, #0xE0
     35        and     h
     36        add     l
     37        ld      e, a            ; dest DE = BASE + 0x20 * Y + X
     38
     39        ret