Pentagram: Routine at B66E

B66E: Resolve Object Order

The routines selected by the table at SortJumpTable, once DrawObjectsInOrder has compared two objects. IX holds the object that is being considered and IY holds the object that it has been compared with.
The order of the objects is not known, so look at the next object.
ResolveObjectOrder	B66E	JP DrawObjectsInOrder_NextOther	Jump to DrawObjectsInOrder_NextOther to compare the object considered with the next object in the list.
The object considered is behind the other, so it needs no wait: look at the next object.
ResolveObjectOrder_Behind	B671	JP DrawObjectsInOrder_NextOther	Jump to DrawObjectsInOrder_NextOther to compare the object considered with the next object in the list.
The object considered is in front of the other so it must be drawn after it. Make the other one the object that is being considered, unless it has already been tried, and so is part of a loop.
ResolveObjectOrder_InFront	B674	LD HL,($A71B)	Fetch the list pointer, which is just after the entry of the other object.
	B677	DEC HL	Point HL at the entry.
	B678	LD C,(HL)	Fetch the number of the object in C.
	B679	LD DE,$B6CD	Point DE at the list of the objects that have been tried, ObjectsTriedList.
ResolveObjectOrder_FindTried	B67C	LD A,(DE)	Fetch the next number in the list of the objects tried.
	B67D	CP $FF	Jump to ResolveObjectOrder_AddTried if the end of that list has been reached.
	B67F	JR Z,ResolveObjectOrder_AddTried
	B681	CP C	Jump to ResolveObjectOrder_Loop if the object has already been tried, which means that there is a loop.
	B682	JR Z,ResolveObjectOrder_Loop
	B684	INC DE	Move on in the list.
	B685	JR ResolveObjectOrder_FindTried	Jump to ResolveObjectOrder_FindTried to look at the next number.
Add the object to the list of the objects tried.
ResolveObjectOrder_AddTried	B687	LD A,C	Fetch the number of the object.
	B688	LD (DE),A	Add it to the list.
	B689	INC DE	Move on in the list.
	B68A	LD A,$FF	Set A to FF.
	B68C	LD (DE),A	Mark the end of the list.
Make the other object the one that is considered and start the search again from the top of the list.
	B68D	PUSH IY	Copy IY to IX (using the stack).
	B68F	POP IX	Copy IY to IX (using the stack).
	B691	LD HL,($A71B)	Fetch the list pointer.
	B694	LD ($A719),HL	Make it the pointer to the entry of the object that is considered.
	B697	LD DE,$B55A	Point DE at the start of the draw list, DrawList.
	B69A	JP DrawObjectsInOrder_NextOther	Jump to DrawObjectsInOrder_NextOther to compare the object with the others.
The object has been tried before, so there is a loop. Draw it, to break the loop, once its place in the list has been found.
ResolveObjectOrder_Loop	B69D	LD HL,$B55A	Point HL at the start of the draw list, DrawList.
ResolveObjectOrder_FindEntry	B6A0	LD A,(HL)	Fetch the next number from the list.
	B6A1	INC HL	Fetch the next number from the list.
	B6A2	CP $FF	Jump to DrawObjectsInOrder_Restart if the end of the list has been reached.
	B6A4	JP Z,DrawObjectsInOrder_Restart
	B6A7	CP C	Jump to ResolveObjectOrder_FindEntry if it is not the entry of the object.
	B6A8	JR NZ,ResolveObjectOrder_FindEntry
	B6AA	PUSH IY	Copy IY to IX (using the stack).
	B6AC	POP IX	Copy IY to IX (using the stack).
	B6AE	JR ResolveObjectOrder_DrawEntry	Jump to ResolveObjectOrder_DrawEntry to draw the object.
The two objects overlap completely, so look at the next object.
ResolveObjectOrder_Overlap	B6B0	JP DrawObjectsInOrder_NextOther	Jump to DrawObjectsInOrder_NextOther to compare the object considered with the next object in the list.
This entry point is used by the routine at DrawObjectsInOrder. Nothing has to be drawn before the object considered, so draw it now.
ResolveObjectOrder_Draw	B6B3	LD HL,($A719)	Fetch the pointer to the entry of the object in the list.
ResolveObjectOrder_DrawEntry	B6B6	DEC HL	Point HL at the entry.
	B6B7	SET 7,(HL)	Set bit 7 of the entry, to show that the object has been drawn.
	B6B9	LD A,$FF	Set A to FF.
	B6BB	LD ($B6CD),A	Empty the list of the objects that have been tried.
	B6BE	LD HL,$A714	Point HL at the count of the objects drawn, DrawingWorkCount.
	B6C1	INC (HL)	Count the object.
	B6C2	CALL DrawObject	Call DrawObject to draw the object.
	B6C5	JP DrawObjectsInOrder_Restart	Jump to DrawObjectsInOrder_Restart to look for the next object to draw.
This entry point is used by the routine at DrawObjectsInOrder. All the objects have been drawn.
ResolveObjectOrder_Done	B6C8	POP IY	Restore IY and IX from the stack.
	B6CA	POP IX	Restore IY and IX from the stack.
	B6CC	RET	Return.