68k_aabb_2cmp.s

; 68000 2xCMP AABB check between box A and B
;
; d0=ax1,ay1    coordinates of top-left of A
; d3=bx2,by2    coordinates of bottom-right of B
; d5=-(aw+bw)   -(A width + B width)
; d6=-(ah+bh)   -(A height + B height)

sub.w        d3,d0      ;d0=ay1-by2
cmp.w        d6,d0      ;cmp #-(ah+bh)
bls          .cd_done1  ;Skip if Y out of range

swap         d0         ;Get ax1-bx2 in d0
swap         d3
sub.w        d3,d0
cmp.w        d5,d0      ;cmp #-(aw+bw)
bls          .cd_done0  ;Skip if X out of range

; Handle Collision
...

.cd_done0:
swap         d3         ;restore d3=bx2,by2
.cd_done1: