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Routines |
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Used by the routine at Action_CheckTheObjectFlags.
Finds an exit out of the current location.
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| TableFindAnExit | 40001 | PUSH IX | Save IX, IY and BC, and keep the location id in B. | |
| 40003 | PUSH IY | |||
| 40005 | PUSH BC | |||
| 40006 | LD B,A | |||
| 40007 | CALL LocateLocation | Call LocateLocation to locate location. | ||
| 40010 | LD A,(IX+1) | Read the location's volume. | ||
| 40013 | LD C,A | Copy the result into C. | ||
| 40014 | LD IX,49248 | Point IX at the slot before the object table. | ||
| TableFindAnExit_Loop | 40018 | CALL Table_StepThroughThreeByteRecords | Call Table_StepThroughThreeByteRecords to step to the next index entry. | |
| 40021 | JR Z,TableFindAnExit_ReturnTheCount | Jump to TableFindAnExit_ReturnTheCount at the end of the object index. | ||
| 40023 | LD A,(IY+0) | Jump back to TableFindAnExit_Loop unless this object has one copy. | ||
| 40026 | CP 1 | |||
| 40028 | JR NZ,TableFindAnExit_Loop | |||
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This object has one copy. Compare its location with the one being sought.
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| 40030 | LD A,B | Jump back to TableFindAnExit_Loop if the object's location is not the location being sought. | ||
| 40031 | CP (IY+16) | |||
| 40034 | JR NZ,TableFindAnExit_Loop | |||
| 40036 | LD A,C | Jump to TableFindAnExit_ReturnAZeroCount if the object's volume is above the location's volume. | ||
| 40037 | SUB (IY+2) | |||
| 40040 | JR C,TableFindAnExit_ReturnAZeroCount | |||
| 40042 | LD C,A | Copy the result into C. | ||
| 40043 | JR TableFindAnExit_Loop | Jump back to TableFindAnExit_Loop for the next index entry. | ||
| TableFindAnExit_ReturnTheCount | 40045 | LD A,C | Return what C was holding. | |
| 40046 | POP BC | |||
| 40047 | POP IY | |||
| 40049 | POP IX | |||
| 40051 | RET | |||
| TableFindAnExit_ReturnAZeroCount | 40052 | LD C,0 | Take a count of zero. | |
| 40054 | JR TableFindAnExit_ReturnTheCount | Jump back to TableFindAnExit_ReturnTheCount to return the count in C. | ||
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