;;; $889E: Enemy projectile block collision reaction - vertical ;;;
{
;; Parameters:
;;     $14: Enemy projectile Y velocity (used only for sign)
;;     $18: Target Y position
;;     $1A: Number of blocks left to check (0 if final (rightmost) block)
;;     $1C: Enemy projectile X radius
;;     $1E: Enemy projectile Y radius
;;     $20: Enemy projectile X block span
;;     $22: Target boundary position (top/bottom depending on sign of enemy projectile velocity)
;; Returns:
;;     Carry: Set if collision, clear otherwise

$86:889E DA          PHX
$86:889F 8E C4 0D    STX $0DC4  [$7E:0DC4]  ;\
$86:88A2 4E C4 0D    LSR $0DC4  [$7E:0DC4]  ;} Current block index = [X] / 2
$86:88A5 BF 02 00 7F LDA $7F0002,x[$7F:00EA];\
$86:88A9 29 00 F0    AND #$F000             ;|
$86:88AC EB          XBA                    ;|
$86:88AD 4A          LSR A                  ;|
$86:88AE 4A          LSR A                  ;} Execute [$8866 + (block type) * 2]
$86:88AF 4A          LSR A                  ;|
$86:88B0 AA          TAX                    ;|
$86:88B1 FC 66 88    JSR ($8866,x)[$86:858A];/
$86:88B4 FA          PLX
$86:88B5 60          RTS
}