Routines
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55991: Throw Item
Used by the routine at UpdatePlayerLegs.
Throws the last item that was picked up, if the fire button has been pressed and the previous throw has finished. An item that belongs to a monster (items 1 to 4) is dropped into the object for the monster. Any other item becomes a shot, in one of the two objects from ObjectTable_Shots; if both are busy, the one that was not used last is turned into a burst.
Input
E Controls
See No Throw Delay.
ThrowItem 55991 LD HL,48072 Fetch the time left before another item can be thrown.
55994 LD A,(HL)
55995 AND A
55996 JR Z,ThrowItem_Ready
55998 DEC (HL) Count down the time and return if it has not run out.
55999 RET
ThrowItem_Ready 56000 BIT 3,E Return if the fire button has not been pressed.
56002 RET Z
56003 LD HL,48141 Point HL at the last place in the inventory, and set a counter of eleven places.
56006 LD B,11
ThrowItem_Find 56008 LD A,(HL) Jump to ThrowItem_Found if there is an item in this place.
56009 AND A
56010 JR NZ,ThrowItem_Found
56012 DEC HL Move to the place before it and loop back until all of the places have been checked.
56013 DJNZ ThrowItem_Find
56015 RET Return.
An item has been found. Monster items are dropped; any other item becomes a shot.
ThrowItem_Found 56016 CP 5 Jump to ThrowItem_Drop if the item is one of the monster items (1 to 4).
56018 JR C,ThrowItem_Drop
56020 LD IY,48302 Point IY at the first shot, and set the size of an object to 16 bytes.
56024 LD DE,16
56027 LD C,2 Set a counter of two shots.
ThrowItem_Shot 56029 LD A,(IY+0) Jump to ThrowItem_Free if this shot is free.
56032 AND A
56033 JR Z,ThrowItem_Free
56035 ADD IY,DE Move on to the next shot and loop back until both have been checked.
56037 DEC C
56038 JR NZ,ThrowItem_Shot
56040 LD HL,48302 Choose the shot that was not used last.
56043 LD A,(48116) Fetch which shot was used last (0 or 16).
56046 AND 16
56048 LD C,A
56049 LD B,0 Set the offset of the shot.
56051 ADD HL,BC Point at the shot.
56052 LD A,(HL) Fetch the type of the shot, and subtract 80.
56053 SUB 80
56055 CP 16
56057 RET NC Return if the shot has not got a type of 80 to 95.
56058 LD (HL),12 Turn the shot into a burst.
56060 RET Return.
This shot is free, so the item is copied from the player into it.
ThrowItem_Free 56061 LD A,(48116) Change the shot that was used last.
56064 XOR 16
56066 LD (48116),A
56069 PUSH BC Keep the counter and the place in the inventory.
56070 PUSH HL
56071 LD A,(HL) Fetch the item and remove it from the inventory.
56072 LD (HL),0
56074 LD HL,48270 Use the player as the source of the copy.
56077 PUSH IY Use the shot as the destination of the copy (using the stack).
56079 POP DE
56080 LD BC,16 Copy the player into the shot.
56083 LDIR
56085 ADD A,A Make the type of the shot from the item.
56086 ADD A,A
56087 ADD A,60
ThrowItem_Set 56089 LD (IY+0),A Set the type of the object.
56092 LD (IY+5),12 Set the speed of the object to 12.
56096 LD A,16 Set the width and the depth of the object to 16.
56098 LD (IY+8),A
56101 LD (IY+9),A
56104 LD (IY+12),248 Set the X offset of the sprite.
56108 LD (IY+13),4 Set the Y offset of the sprite.
56112 LD A,2 Set the time before the next throw to two frames.
56114 LD (48072),A
56117 POP HL Restore the inventory place and the counter from the stack.
56118 POP BC
56119 LD A,B Work out the number of the place counted from the start of the inventory.
56120 NEG
56122 ADD A,12
56124 LD B,A
56125 CALL DrawInventoryItem Redraw the item in the inventory tube.
56128 JP PlaySweepSound Jump to PlaySweepSound.
The item is one of the monster items, which is dropped into the object for the monster.
ThrowItem_Drop 56131 PUSH BC Keep the counter, the place in the inventory and the item.
56132 PUSH HL
56133 PUSH AF
56134 LD (HL),0 Remove the item from the inventory.
56136 NEG Work out the offset of the object from the number of the item.
56138 ADD A,4
56140 ADD A,A
56141 ADD A,A
56142 ADD A,A
56143 ADD A,A
56144 LD HL,48414 Find the object for the monster.
56147 CALL AddAToHL
56150 PUSH HL Point IY at the object, and keep the address of the object.
56151 PUSH HL
56152 POP IY
56154 POP DE
56155 LD HL,48270 Copy the player into the object.
56158 LD BC,16
56161 LDIR
56163 POP AF Make the type of the object from the item, and jump to ThrowItem_Set.
56164 ADD A,7
56166 JR ThrowItem_Set
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