encode.asm

Positions turned about, totals, and other helpers. Download · All the source

; ----------------------------------------------------------------- util; index: A = (HL + A), HL left pointing there.index:        add a,l        ld l,a        jr nc,.n        inc h.n:     ld a,(hl)        ret; total: A = the sum of the 25 bytes at HL.total:        ld b,25        xor a.l:     add a,(hl)        inc hl        djnz .l        ret; highest: A = the highest index of the 25 bytes at HL not zero, or $ff.; Keeps C.highest:        ld de,25        add hl,de        ld b,25.l:     dec hl        ld a,(hl)        or a        jr nz,.f        djnz .l.f:     ld a,b        dec a        ret; mul: HL = A x DE (A unsigned), from A's low bits up. Keeps DE.mul:        ld hl,0        push de.l:     srl a        jr nc,.n        add hl,de.n:     jr z,.x        ex de,hl        add hl,hl        ex de,hl        jr .l.x:     pop de        ret; ratio: A = min(7, HL / DE), 0 for HL negative: a feature's count.ratio:        xor a        bit 7,h        ret nz.l:     and a        sbc hl,de        ret c        inc a        cp 7        jr nz,.l        ret; contact: carry if PA and PB can still hit each other.contact:        ld hl,PA        call highest        ld c,a        ld hl,PB        call highest        ld b,a        or c        jp m,.no        ld a,b        add a,c        cp 24        ccf        ret.no:    or a        ret