NAME
	DoCollision -- Test every gel in gel list for collisions.

   SYNOPSIS
	DoCollision(rp)
	            A1

	void DoCollision(struct RastPort *);

   FUNCTION
	Tests each gel in gel list for boundary and gel-to-gel collisions.
	On detecting one of these collisions, the appropriate collision-
	handling routine is called. See the documentation for a thorough
	description of which collision routine is called. This routine
	expects to find the gel list correctly sorted in Y,X order.
	The system routine SortGList performs this function for the user.

   INPUTS
	rp = pointer to a RastPort

   RESULT

   BUGS

   SEE ALSO
	InitGels()  SortGList()  graphics/gels.h  graphics/gels.h