Cursor SetPosition

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Synopsis

Header: fxcg/display.h (Not yet in libfxcg)
Syscall index: 0x01F1
Function signature: int Cursor_SetPosition(int x, int y)

Sets the cursor position for Print_OS.

Parameters

  • x Must be in range of [0,20]
  • y Must be in range of [0,7]

Returns

0 on failure, 1 on success.

Comments

This function like locate_OS does bounds checking. It is better to use this function as opposed to locate_OS to avoid a duplication of bounds checking.

Cursor_SetPosition:
	cmp/pz  r4
	bf      Cursor_SetPosition_OutOfBounds
	mov     #21, r2
	cmp/ge  r2, r4
	bt      Cursor_SetPosition_OutOfBounds
	cmp/pz  r5
	bf      Cursor_SetPosition_OutOfBounds
	mov     #8, r2
	cmp/ge  r2, r5
	bf      loc_8004E744

Cursor_SetPosition_OutOfBounds:
	rts
	mov     #0, r0
! ---------------------------------------------------------------------------

loc_8004E744:
	mov.l   #CursorXpos, r1
	mov     #1, r0
	mov.l   #CursorYpos, r6
	mov.l   r4, @r1
	rts
	mov.l   r5, @r6
! End of function Cursor_SetPosition