Sherlock: Routine at C9BF

Used by the routine at ProcessObjectDisplayEntry.

HL points at a display record (flags, value, optional handler word, optional five extra bytes). Checks the record against the current object, character and graphics, runs its handler if bit 6 is set, and then either returns the address after the record (bit 7 set) or runs the code that follows it via CA64. A non-zero return means the script step succeeded.

Used by the routine at ProcessObjectDisplayEntry. HL points at a display record (flags, value, optional handler word, optional five extra bytes). Checks the record against the current object, character and graphics, runs its handler if bit 6 is set, and then either returns the address after the record (bit 7 set) or runs the code that follows it via CA64. A non-zero return means the script step succeeded.
ProcessDisplayRecord	C9BF	PUSH HL	Point IY at the display record and call CheckObjectVisibility to check whether the object is visible.
	C9C0	POP IY
	C9C2	CALL CheckObjectVisibility
	C9C5	JR NC,ProcessDisplayRecord_TestHandler	Go to ProcessDisplayRecord_TestHandler if CheckObjectVisibility finds the object is not visible.
Bit 5 of the record flags is clear?
	C9C7	LD A,(IY+$00)	Jump to ProcessDisplayRecord_TestHandler if bit 5 of the record flags is clear.
	C9CA	AND $20
	C9CC	JR Z,ProcessDisplayRecord_TestHandler
	C9CE	LD HL,$CBBB	Point HL at the failure step at CBBB.
ProcessDisplayRecord_Fail	C9D1	XOR A	Clear A.
	C9D2	RET	Return.
Test the character field, the graphics field and the handler bit.
ProcessDisplayRecord_TestHandler	C9D3	CALL TestLowBitsOfCharacter	Go to ProcessDisplayRecord_Fail if the character test on this record fails.
	C9D6	JR Z,ProcessDisplayRecord_Fail
	C9D8	CALL TestLowBitsOfGraphics	Go to ProcessDisplayRecord_Fail if the graphics test on this record fails.
	C9DB	JR Z,ProcessDisplayRecord_Fail
	C9DD	BIT 6,(IY+$00)	Skip ahead to ProcessDisplayRecord_TestParser unless bit 6 of the record flags is set.
	C9E1	JR Z,ProcessDisplayRecord_TestParser
	C9E3	LD L,(IY+$02)	Read the handler word at bytes 02/03 of the record and save IY.
	C9E6	LD H,(IY+$03)
	C9E9	PUSH IY
	C9EB	CALL $CB34	Run the handler via CB34.
	C9EE	POP IY	Restore IY from the stack.
	C9F0	JR Z,ProcessDisplayRecord_Fail	Go to ProcessDisplayRecord_Fail if the handler returns zero.
ProcessDisplayRecord_TestParser	C9F2	LD A,($A00B)	Jump to ProcessDisplayRecord_StoreCount if the parser flag at A00B is set.
	C9F5	AND A
	C9F6	JR NZ,ProcessDisplayRecord_StoreCount
	C9F8	OR %00000001	Reset the zero flag.
	C9FA	RET	Return.
Take the high nibble of the record's value byte (01) as the count and store it at CharacterScriptCycles.
ProcessDisplayRecord_StoreCount	C9FB	PUSH IY	Save the record pointer and read the value byte (01).
	C9FD	LD A,(IY+$01)	Save the record pointer and read the value byte (01).
	CA00	RRCA	Shift that byte down by four bits.
	CA01	RRCA
	CA02	RRCA
	CA03	RRCA
	CA04	AND $0F	Keep the high nibble.
	CA06	LD L,A	Use that nibble as the low byte of the count.
	CA07	LD H,$00	Clear the high byte.
	CA09	LD ($A01F),HL	Store the count at CharacterScriptCycles.
ProcessDisplayRecord_ComputeLength	CA0C	POP HL	Restore the record address from the stack.
	CA0D	LD DE,$0002	Step over the two-byte header.
	CA10	ADD HL,DE	Step over the two-byte header.
	CA11	BIT 6,(IY+$00)	Skip ahead to ProcessDisplayRecord_TestFiveExtraBytes unless bit 6 of the record flags is set.
	CA15	JR Z,ProcessDisplayRecord_TestFiveExtraBytes
	CA17	ADD HL,DE	Step over the handler word.
ProcessDisplayRecord_TestFiveExtraBytes	CA18	LD DE,$0005	Skip ahead to ProcessDisplayRecord_SaveAttributes unless bit 4 of the record flags is set.
	CA1B	BIT 4,(IY+$00)
	CA1F	JR Z,ProcessDisplayRecord_SaveAttributes
	CA21	ADD HL,DE	Step over the five extra bytes.
ProcessDisplayRecord_SaveAttributes	CA22	LD A,($A00A)	Read the character attribute and store it in the workspace byte at C491.
	CA25	LD ($C491),A
	CA28	LD IX,($A013)	Point IX at the current object.
	CA2C	LD A,(IX+$0F)	Read the object's attribute and store it in the workspace byte at C492, then save the address after the record.
	CA2F	LD ($C492),A
	CA32	PUSH HL
	CA33	PUSH IY	Save the record, store 01 in the parser flag at A00C, and call ReadSavedCharacter.
	CA35	LD A,$01
	CA37	LD ($A00C),A
	CA3A	CALL ReadSavedCharacter
	CA3D	POP IY	Restore the pointers from the stack.
	CA3F	POP HL	Restore the pointers from the stack.
	CA40	BIT 7,(IY+$00)	And skip ahead to ProcessDisplayRecord_FillLocationLow unless bit 7 of the record flags is set.
	CA44	JR Z,ProcessDisplayRecord_FillLocationLow
	CA46	SCF	Set the carry.
	CA47	RET	Return with HL pointing past the record, so the script resumes there.
Fill a location byte that is still FF from the room parameters.
ProcessDisplayRecord_FillLocationLow	CA48	LD A,($9FD7)	Go to ProcessDisplayRecord_FillLocationHigh unless the low byte of LocationValue is FF.
	CA4B	INC A
	CA4C	JR NZ,ProcessDisplayRecord_FillLocationHigh
	CA4E	LD A,($A034)	Copy the room display parameter into LocationValue.
	CA51	LD ($9FD7),A	Copy the room display parameter into LocationValue.
ProcessDisplayRecord_FillLocationHigh	CA54	LD A,($9FD8)	Go to ProcessDisplayRecord_RunFollowingCode unless the high byte of LocationValue is FF.
	CA57	INC A
	CA58	JR NZ,ProcessDisplayRecord_RunFollowingCode
	CA5A	LD A,($A035)	Copy the room graphics parameter into the high byte of LocationValue.
	CA5D	LD ($9FD8),A
ProcessDisplayRecord_RunFollowingCode	CA60	XOR A	Clear the flag at CAAE and run the code that follows the record (at HL) via RunDisplayRecordCode.
	CA61	LD ($CAAE),A
	CA64	CALL RunDisplayRecordCode
	CA67	PUSH AF	Call ReadCharacterTimetable, saving result and the pointer.
	CA68	PUSH HL
	CA69	CALL ReadCharacterTimetable
	CA6C	LD A,($CAAE)	Call CheckCharacterDisguise if the room flag at CAAE is clear.
	CA6F	AND A
	CA70	CALL Z,CheckCharacterDisguise
	CA73	POP HL	Restore the pointer from the stack.
	CA74	POP AF	Restore AF from the stack.
	CA75	RET	Return.