Robotron: 2084: Routine at 57954

Used by the routines at Handle_Horizontal_Enemy_Entity and Process_Wall_Bouncing_Enemy.

Walks the wave entity list between the snapshot pointer at 50443 and the write pointer at 50445. For each entity with a type nibble below 4 tests bounds overlap via HitTestBounds8AtHL; returns without carry set if an overlapping entity is found with its position left in alternate HL. Returns with carry set if the list is exhausted without a match. Entities with a type nibble of 4 or higher are skipped as non-collidable. Called from Handle_Horizontal_Enemy_Entity and Process_Wall_Bouncing_Enemy.

Used by the routines at Handle_Horizontal_Enemy_Entity and Process_Wall_Bouncing_Enemy. Walks the wave entity list between the snapshot pointer at 50443 and the write pointer at 50445. For each entity with a type nibble below 4 tests bounds overlap via HitTestBounds8AtHL; returns without carry set if an overlapping entity is found with its position left in alternate HL. Returns with carry set if the list is exhausted without a match. Entities with a type nibble of 4 or higher are skipped as non-collidable. Called from Handle_Horizontal_Enemy_Entity and Process_Wall_Bouncing_Enemy.
Find_Colliding_Wave_Enemy	57954	EXX	Switch to alternate registers and load the entity list snapshot pointer from 50443.
	57955	LD HL,(50443)
Find_Colliding_Wave_Enemy_Next	57958	EX DE,HL	Compare the snapshot against the write pointer; return with carry set (no match) if the list is exhausted.
	57959	LD HL,(50445)
	57962	AND A
	57963	SBC HL,DE
	57965	SCF
	57966	EX DE,HL
	57967	RET Z	Advance three bytes past the handler word, read the entity type nibble, and mask to the low 4 bits.
	57968	INC HL
	57969	INC HL
	57970	INC HL
	57971	LD A,(HL)
	57972	AND %00001111	Mask the type to the low nibble.
	57974	CP 4	Jump to Find_Colliding_Wave_Enemy_1 to skip this entity if the type is 4 or higher (non-collidable).
	57976	INC HL
	57977	JP NC,Find_Colliding_Wave_Enemy_1	Test whether this entity's bounds overlap the current position via HitTestBounds8AtHL; advance and loop if they do not.
	57980	CALL HitTestBounds8AtHL
	57983	RET NC	No overlap: step the alternate HL back three bytes and loop.
	57984	EXX
	57985	DEC HL
	57986	DEC HL
	57987	DEC HL
	57988	EXX
Find_Colliding_Wave_Enemy_0	57989	INC HL	Advance two bytes to the next entity record and loop.
	57990	INC HL
	57991	JP Find_Colliding_Wave_Enemy_Next
Find_Colliding_Wave_Enemy_1	57994	INC HL	Wide entity: advance three more bytes and loop.
	57995	INC HL
	57996	INC HL
	57997	JP Find_Colliding_Wave_Enemy_0