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Routines |
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Used by the routine at GameStart.
Walk entities marked as falling, apply gravity to their Y fields and clear the fall latch when they land.
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| Process_Falling_Entities | B1A9 | LD HL,$72B3 | Point HL at the game event flags (GameEventFlags). | |
| B1AC | BIT 2,(HL) | Is the falling-entity latch (bit 02 of GameEventFlags. set at B203) set? If not, return. | ||
| B1AE | RET Z | |||
| B1AF | RES 2,(HL) | Clear the falling-entity latch (bit 02 of GameEventFlags). | ||
| B1B1 | LD DE,$000E | Each entity record is 000E bytes long, then load that length into DE. | ||
| B1B4 | LD IX,$8B69 | Point IX at the simple entity table (StateData_SimpleEntities). | ||
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Scan for falling entities and advance each marked one up to three steps before clearing the latch.
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| Process_Falling_Entities_Scan | B1B8 | LD A,(IX+$00) | Fetch the current entity's type for the type test. | |
| B1BB | CP $FF | Is the current entity's entity type equal to FF? If so, return. | ||
| B1BD | RET Z | |||
| B1BE | BIT 0,(IX+$02) | Is bit 00 of the current entity's flags byte 2 set? If not, jump to Process_Falling_Entities_NextEntity. | ||
| B1C2 | JR Z,Process_Falling_Entities_NextEntity | |||
| B1C4 | CALL Advance_Falling_Entity | Call Advance_Falling_Entity to advance Falling Entity? If not, jump to Process_Falling_Entities_ClearFallBits. | ||
| B1C7 | JR NC,Process_Falling_Entities_ClearFallBits | |||
| B1C9 | CALL Advance_Falling_Entity | Call Advance_Falling_Entity again to advance Falling Entity? If not, jump to Process_Falling_Entities_ClearFallBits. | ||
| B1CC | JR NC,Process_Falling_Entities_ClearFallBits | |||
| B1CE | CALL Advance_Falling_Entity | Call Advance_Falling_Entity a third time to advance Falling Entity? If not, jump to Process_Falling_Entities_ClearFallBits. | ||
| B1D1 | JR NC,Process_Falling_Entities_ClearFallBits | |||
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Advance to the next entity in the falling-entity walk.
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| Process_Falling_Entities_NextEntity | B1D3 | ADD IX,DE | Advance IX to the next entity record. | |
| B1D5 | JR Process_Falling_Entities_Scan | Jump to Process_Falling_Entities_Scan to advance to the next falling entity. | ||
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This entry point is used by the routine at Advance_Falling_Entity.
Clear the falling flag, set the landed flag, raise a room/script event, and continue the scan.
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| Process_Falling_Entities_ClearFallBits | B1D7 | RES 0,(IX+$02) | Reset bit 00 of the current entity's flags byte 2. | |
| B1DB | SET 7,(IX+$01) | Set bit 07 of the current entity's flags byte 1. | ||
| B1DF | SET 0,(HL) | Set "room / script event raised" (bit 00 of GameEventFlags). | ||
| B1E1 | JR Process_Falling_Entities_NextEntity | Jump to Process_Falling_Entities_NextEntity to skip this falling entity. | ||
| Prev: B16E | Up: Map | Next: B1E3 |