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pick_items(3)			  Arcan Lua API 		   pick_items(3)

NAME
     pick_items - Pick a number of objects based on a screen-space coordinate.

SYNOPSIS
     vidtbl:results
     pick_items( number:x, number:y )
     pick_items( number:x, number:y, number:limit=8 )
     pick_items( number:x, number:y, number:limit=8 )
     pick_items( number:x, number:y, number:limit=8<=64, bool:reverse=false )
     pick_items(  number:x,  number:y,	number:limit=8<=64,  bool:reverse=false,
     vid:rtgt=WORLDID )

DESCRIPTION
     pick_items is a low level	function  for  building  user-interface  related
     picking  tools.  It  takes  a screen- or rendertarget- space coordinate and
     sweeps through the pipeline based on their render order (see order_image ).
     If reverse  is provided it will sweep from high to low, otherwise from  low
     to high. It will early out once limit  objects have been found. It will al-
     ways  return  an  integer	indexed table of zero to limit	number of VID s.
     Limit is not allowed to exceed 64.

NOTES
     1	    All VID s start out as eligible for picking. This can be  controlled
	    by setting the MASK_UNPICKABLE  mask, see image_mask_set . This mask
	    value  is  not  inherited  by default through linking. This means it
	    needs to be set for each new object regardless of how link_image  is
	    being used.

     2	    Clipping and alpha channel is ignored and will need to be considered
	    manually by testing against any possible clipping parents.

     3	    This function can be very costly based  on	the  complexity  of  the
	    scene  and some caching mechanism should be used if a high number of
	    calls is expected, for instance when tied to a touch or mouse- input
	    device event handler.

     4	    The cost progression is  roughly  (low  to	high)  normal,	rotated,
	    linked, 3d object, rotated-linked, rotated-linked-3d object.

     5	    If	an object is shader displayed or manually manipulated by skewing
	    vertices through image_tesselation	or a vertex  stage  shader,  the
	    picking operation result is undefined.

SEE ALSO:
     image_hit(3)

image				   August 2026			   pick_items(3)

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