Robotron: 2084: Routine at E346

E346: Apply Direction Delta

Used by the routine at Spawn_Tracked_Enemy_Entities. Reads the direction byte from (DE), and uses it as an index into the direction animation table at Direction_Animation_Offset_Table (direction × 4). Adds the Y delta at table[index] to the byte at (DE+1) and the X delta at table[index+1] to the byte at (DE+2), writing the updated coordinates back in place. Called from Spawn_Tracked_Enemy_Entities_Record when building entity records.
Apply_Direction_Delta	E346	EX DE,HL	Exchange DE and HL and load the direction table base at Direction_Animation_Offset_Table.
	E347	LD HL,$E7AF
	E34A	LD A,(DE)
	E34B	AND %00000111	Mask the direction byte to 3 bits.
	E34D	RLA	Double the index (two left shifts) and form the zero-extended byte offset in BC.
	E34E	RLA
	E34F	LD C,A
	E350	LD B,$00
	E352	ADD HL,BC
	E353	INC DE	Apply the Y delta to (DE+1) and the X delta to (DE+2) and write both coordinates back in place.
	E354	LD A,(DE)
	E355	ADD A,(HL)
	E356	LD (DE),A
	E357	INC HL
	E358	INC DE
	E359	LD A,(DE)
	E35A	ADD A,(HL)
	E35B	LD (DE),A
	E35C	DEC DE
	E35D	DEC DE
	E35E	EX DE,HL	Exchange DE and HL to restore the entity pointer and return.
	E35F	RET