Robotron: 2084: Routine at E262

Used by the routines at Handle_Horizontal_Enemy_Entity and Process_Wall_Bouncing_Enemy.

Walks the wave entity list between the snapshot pointer at C50B and the write pointer at C50D. For each entity with a type nibble below 04 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 04 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 C50B and the write pointer at C50D. For each entity with a type nibble below 04 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 04 or higher are skipped as non-collidable. Called from Handle_Horizontal_Enemy_Entity and Process_Wall_Bouncing_Enemy.
Find_Colliding_Wave_Enemy	E262	EXX	Switch to alternate registers and load the entity list snapshot pointer from C50B.
	E263	LD HL,($C50B)
Find_Colliding_Wave_Enemy_Next	E266	EX DE,HL	Compare the snapshot against the write pointer; return with carry set (no match) if the list is exhausted.
	E267	LD HL,($C50D)
	E26A	AND A
	E26B	SBC HL,DE
	E26D	SCF
	E26E	EX DE,HL
	E26F	RET Z	Advance three bytes past the handler word, read the entity type nibble, and mask to the low 4 bits.
	E270	INC HL
	E271	INC HL
	E272	INC HL
	E273	LD A,(HL)
	E274	AND %00001111	Mask the type to the low nibble.
	E276	CP $04	Jump to Find_Colliding_Wave_Enemy_1 to skip this entity if the type is 04 or higher (non-collidable).
	E278	INC HL
	E279	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.
	E27C	CALL HitTestBounds8AtHL
	E27F	RET NC	No overlap: step the alternate HL back three bytes and loop.
	E280	EXX
	E281	DEC HL
	E282	DEC HL
	E283	DEC HL
	E284	EXX
Find_Colliding_Wave_Enemy_0	E285	INC HL	Advance two bytes to the next entity record and loop.
	E286	INC HL
	E287	JP Find_Colliding_Wave_Enemy_Next
Find_Colliding_Wave_Enemy_1	E28A	INC HL	Wide entity: advance three more bytes and loop.
	E28B	INC HL
	E28C	INC HL
	E28D	JP Find_Colliding_Wave_Enemy_0