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Routines |
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Used by the routines at Primary_Enemy_Entity_Handler, Handle_Homing_Enemy, Process_Tracked_Enemy_Entity, Process_Cluster_Entity, Process_Wall_Bouncing_Enemy and Process_Final_Phase_Enemy_Entity.
Walks the entity list from Entity_List, testing each record's bounds against the current entity via HitTestBounds8AtHL. Returns without carry if no collision is found (list exhausted). Returns with carry set if the current entity's position overlaps another entity's bounds.
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| Find_Colliding_Entity | CD18 | LD HL,$6000 | Point HL to the start of the entity list at Entity_List. | |
| Find_Colliding_Entity_Check | CD1B | INC HL | Skip the handler address and read the state byte. If it is the FF sentinel, set carry and return (end of list reached). | |
| CD1C | INC HL | |||
| CD1D | LD A,(HL) | |||
| CD1E | CP $FF | |||
| CD20 | SCF | |||
| CD21 | RET Z | |||
| CD22 | INC HL | Advance past three more bytes and test this entity's bounds against the current position via HitTestBounds8AtHL. | ||
| CD23 | INC HL | |||
| CD24 | INC HL | |||
| CD25 | CALL HitTestBounds8AtHL | |||
| CD28 | EXX | Adjust alternate HL back by three and return without carry if the bounds do not overlap. | ||
| CD29 | DEC HL | |||
| CD2A | DEC HL | |||
| CD2B | DEC HL | |||
| CD2C | EXX | |||
| CD2D | RET NC | Advance four bytes to the next entity record. | ||
| CD2E | INC HL | |||
| CD2F | INC HL | |||
| CD30 | INC HL | |||
| CD31 | INC HL | |||
| CD32 | JR Find_Colliding_Entity_Check | Check the next entity. | ||
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