Avalon: Routine at E7FD

There are 5 sorts of spell type, the value stored in the current spell data byte at EBC7.

MOVE spell, which switches player control to Maroc (byte value = 1)
Spell which switches player control to a graphic/icon cursor, e.g. SERVANT, MISSILE, OPEN (byte value = 2)
Missile type spells that don't deactivate after a bolt is fired, reserved just for ELECTRIC and FLAME spells (byte value = 3)
Ongoing effect spell, e.g. SHIELD, WRAITHBANE (byte value = 4)
Instant effect spell, e.g. ENERGIZE, FREEZE, PORTAL (byte value = 5)

This routine checks for spell type, and jumps to the routine that deals with it.

Check for 'active effect' spell (type = 4):


There are 5 sorts of spell type, the value stored in the current spell data byte at EBC7. MOVE spell, which switches player control to Maroc (byte value = 1) Spell which switches player control to a graphic/icon cursor, e.g. SERVANT, MISSILE, OPEN (byte value = 2) Missile type spells that don't deactivate after a bolt is fired, reserved just for ELECTRIC and FLAME spells (byte value = 3) Ongoing effect spell, e.g. SHIELD, WRAITHBANE (byte value = 4) Instant effect spell, e.g. ENERGIZE, FREEZE, PORTAL (byte value = 5) This routine checks for spell type, and jumps to the routine that deals with it. Check for 'active effect' spell (type = 4):
E7FD	LD A,($EBC7)
E800	CP $04
E802	JP Z,$EA1D	Jump here if so, as casting this sort of spell may be cancelling an existing active spell.
Check for other types of spell:
E805	LD A,($EAE6)	Get spell number counter (for spell list at 6FBC)
E808	LD ($EAEC),A	...and put in temporary store
E80B	LD A,($EBC7)	Get spell type
Check for MOVE spell
E80E	CP $01
E810	JR NZ,$E819
E812	LD A,$20	Move spell selected. Set the spell selection byte accordingly.
E814	LD ($EAE1),A
E817	JR $E852
Check if spell is an 'instant effect' spell (ENERGIZE, HAIL, WAYSTONE, FREEZE, SUMMON, PORTAL, MESSAGE):
E819	CP $05
E81B	JR NZ,$E826
Spell is an 'instant effect' spell. These spells have an energy cost to their casting (positive in the case of ENERGIZE).
E81D	LD A,($EBC6)	Get energy cost of spell. This is the second byte in each spell set at 6DFC, e.g.: ENERGIZE = +64 HAIL = -1 WAYSTONE = -4 FREEZE = -4 SUMMON = -4 PORTAL = -8
E820	CALL $E3CC	Reduce/increase Maroc's energy
E823	JP $EA72	Reduce/increase Maroc's energy
The spell cast needs a controllable cursor (e.g. SERVANT, OPEN, MISSILE, FIND)
E826	LD A,$01
E828	LD ($EB50),A	Set graphic address pointer frame offset (1 = no offset, start at first graphics frame)
E82B	LD ($EC99),A	Copy to controllable spell cursor/graphic frame buffer
E82E	LD A,($EBCC)	Get graphic number for controllable cursor. This will either be a pointer to the servant graphic (9813/A0DC) or the flashing eye cursor (9817/A105)
E831	CALL $E0C2	Setup graphics (for servant or eye cursor)
Copy/initialize a few spell-related bytes in the spell data buffer:
E834	LD HL,($EB51)	Get cursor graphics address pointer (9813/9817)
E837	LD ($EC94),HL	...and store in temporary game buffer
E83A	LD A,($EB4F)	Pre-graphics data byte, indicating frames & if graphic can be 'flipped'
E83D	LD ($EC9A),A
E840	LD A,$28	Starting vertical position for the controllable graphic, in pixels, from the top of the playing area
E842	LD ($EAFF),A
E845	LD A,$70	Starting horizontal position for the controllable graphic, in pixels, from the left of the playing area
E847	LD ($EB00),A
E84A	LD A,$30	Spell selection status - 48 = servant/cursor controllable spell
E84C	LD ($EAE1),A
E84F	JP $E929