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Routines |
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Used by the routine at HandlePickupAndDrop.
Drops the oldest carried object into the free object record in IY, at the position of the player. If there is no object in the oldest place in the inventory, the carried objects are only moved along. The player rises by 12, to be out of the way of the object that is dropped.
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| DropObject | 49175 | LD HL,42798 | Take the oldest of the carried objects, ObjectsCarried_Oldest. | |||||||
| 49178 | LD A,(HL) | Fetch the type of it. | ||||||||
| 49179 | INC HL | |||||||||
| 49180 | AND A | Jump to DropObject_MoveAlong to move the objects along if there is none. | ||||||||
| 49181 | JR Z,DropObject_MoveAlong | |||||||||
| 49183 | LD A,(42817) | Fetch the flag from NoRoomToDropFlag. | ||||||||
| 49186 | AND A | Jump to HandlePickupAndDrop_Done if there is no room above the player. | ||||||||
| 49187 | JR NZ,HandlePickupAndDrop_Done | |||||||||
| 49189 | DEC HL | Fetch the type of the object again. | ||||||||
| 49190 | LD A,(HL) | |||||||||
| 49191 | INC HL | |||||||||
| 49192 | LD (IY+0),A | Make it the type of the new object. | ||||||||
| 49195 | PUSH HL | Stash the address of the flags of the carried object on the stack. | ||||||||
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Copy the player to the new object, which gives it the position, the speeds and the room of the player.
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| 49196 | LD BC,31 | Set the number of bytes to copy in BC. | ||||||||
| 49199 | PUSH IX | Take the player, using the stack. | ||||||||
| 49201 | POP HL | |||||||||
| 49202 | PUSH IY | Take the new object, using the stack. | ||||||||
| 49204 | POP DE | |||||||||
| 49205 | INC DE | Move on to the second byte of each of them. | ||||||||
| 49206 | INC HL | |||||||||
| 49207 | LDIR | Copy the record of the player to the new object. | ||||||||
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Raise both of the object records of the player, to be above the dropped object.
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| 49209 | LD A,(IX+3) | Add 12 to the height of the legs. | ||||||||
| 49212 | ADD A,12 | |||||||||
| 49214 | LD (IX+3),A | |||||||||
| 49217 | LD A,(IX+35) | Add 12 to the height of the body. | ||||||||
| 49220 | ADD A,12 | |||||||||
| 49222 | LD (IX+35),A | |||||||||
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Make the new object ready to be drawn.
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| 49225 | PUSH IX | Stash the records of the player and the object on the stack. | ||||||||
| 49227 | PUSH IY | |||||||||
| 49229 | PUSH IY | Take the new object as the one being updated, using the stack. | ||||||||
| 49231 | POP IX | |||||||||
| 49233 | CALL SetSpriteOffset_Minus16_Minus8 | Call SetSpriteOffset_Minus16_Minus8 to set where the sprite is drawn. | ||||||||
| 49236 | CALL CalculatePixelCoordinates | Call CalculatePixelCoordinates to work out where the sprite goes on the screen. | ||||||||
| 49239 | CALL ApplyGravityAndMove | Call ApplyGravityAndMove to find where the object can be. | ||||||||
| 49242 | CALL SetWipeAndDrawFlags | Call SetWipeAndDrawFlags to mark the object to be drawn. | ||||||||
| 49245 | POP IY | Restore the records of the object and the player from the stack. | ||||||||
| 49247 | POP IX | |||||||||
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This entry point is used by the routine at PickUpObject.
Set up the dropped object, which is also done when an object is swapped for one that is picked up.
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| DropObject_SetUp | 49249 | LD (IY+4),5 | Set the half size along x to 5. | |||||||
| 49253 | LD (IY+5),5 | Set the half size along y to 5. | ||||||||
| 49257 | LD (IY+6),12 | Set the size along z to 12. | ||||||||
| 49261 | POP HL | Restore the address of the flags of the carried object from the stack. | ||||||||
| 49262 | LD A,(HL) | Fetch the flags of the carried object. | ||||||||
| 49263 | INC HL | |||||||||
| 49264 | LD (IY+7),A | Set them as the flags of the new object. | ||||||||
| 49267 | LD A,(IX+8) | Copy the room of the player to the new object. | ||||||||
| 49270 | LD (IY+8),A | |||||||||
| 49273 | LD A,(HL) | Fetch the low byte of the address of the object in the store. | ||||||||
| 49274 | INC HL | |||||||||
| 49275 | LD (IY+16),A | Keep the low byte of the store address in the new object. | ||||||||
| 49278 | LD A,(HL) | Fetch the high byte of the address of the object in the store. | ||||||||
| 49279 | LD (IY+17),A | |||||||||
| 49282 | LD H,A | Set HL to the address of the object in the store. | ||||||||
| 49283 | LD L,(IY+16) | |||||||||
| 49286 | LD A,(IY+0) | Write the type of the object to its entry in the store, so that it stays in the room. | ||||||||
| 49289 | LD (HL),A | |||||||||
| 49290 | SET 0,(IY+13) | Set bit 0 of the hit flags of the new object. | ||||||||
| 49294 | CALL SetWipeAndDrawFlagsForObject | Call SetWipeAndDrawFlagsForObject to mark the new object to be drawn. | ||||||||
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This entry point is used by the routine at PickUpObject.
Move the carried objects along one place, which gets rid of the oldest and leaves the first place empty.
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| DropObject_MoveAlong | 49297 | LD HL,42797 | Start at the last byte of the third entry of ObjectsCarried. | |||||||
| 49300 | LD DE,42801 | Take the last byte of the fourth entry. | ||||||||
| 49303 | LD BC,12 | Set the number of bytes in BC to 12, three objects. | ||||||||
| 49306 | LDDR | Move them along, copying down from the end. | ||||||||
| 49308 | LD DE,42786 | Take the first place of the inventory, ObjectsCarried. | ||||||||
| 49311 | LD B,4 | Set a counter in B of four bytes. | ||||||||
| 49313 | CALL ClearBytes | Call ClearBytes to clear the first place of the inventory. | ||||||||
| 49316 | JP HandlePickupAndDrop_Done | Jump to HandlePickupAndDrop_Done. | ||||||||
| Prev: 49166 | Up: Map | Next: 49319 |