.nolist
#include "ti83plus.inc"
#include "dcs7.inc"
.list
   .org userMem-2
   .db $BB,$6D
Init:
  B_CALL (_ClrLCDFull)
  ld hl,0

Loop:

  ld b,8
  ld ix,MyImage
  ld a,h
  push hl

  call iPutSprite        ;Display Image
  call iFastCopy         ;Put it in the buffer

  B_CALL(_GrBufClr)      ;Clears the graph screen

  ;Draw line code
  ld h,0
  ld l,63
  ld d,95
  ld e,63
  ld a,1

  call fastline
  ;End of draw line code

  ;Start of gravity code
  ld a,8
  add a,l
  ld e,a                 ;Sets e to y+8

  ld a,h                 ;Sets a to x

  call iGetPixel

  ld e,0
  and (hl)
  pop hl
  call z,SetGravity      ;If pixel below image is white, y=y+1

  ;End of gravity code

  pop hl

  ld a,l
  add a,e

  ld l,a

  ;Getkeys code
  ld a,$FE
  out (1),a
  nop
  nop
  nop
  in a,(1)

  bit 1,a
  call z,CheckMoveLeft

  bit 2,a
  call z,CheckMoveRight

  bit 3,a
  call z,CheckMoveUp
  ;End of getkeys code

  jp Loop

SetGravity:
  ld e,0
  inc e
  ret

CheckMoveUp:
  push af
  ld a,l
  cp 0

  call nz,MoveUp
  pop af
  ret

MoveUp:
  dec l
  dec l
  ret

CheckMoveLeft:
  push af
  ld a,h
  cp 0

  call nz,MoveLeft
  pop af
  ret

MoveLeft:
  dec h
  dec h
  ret

CheckMoveRight:
  push af
  ld a,h
  cp 87

  call c,MoveRight
  pop af
  ret

MoveRight:
  inc h
  inc h
  ret

MyImage:
  .db $FF,$81,$81,$81,$81,$81,$81,$FF