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Routines |
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Used by the routine at 49679.
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The byte at 60285 acts as an incrementing counter which is compared with room size (first byte in the room data sets at 25001). This works out which bit of the room is being dealt with (left, back or right).
The routine then identifies the vertical and horizontal positions for each consecutive scenery components.
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| 49858 | LD A,(60285) | Get counter byte, starting at 1 | ||
| 49861 | INC A | Increment and then re-store | ||
| 49862 | LD (60285),A | |||
| 49865 | LD C,A | |||
| 49866 | LD A,(60284) | First room data byte from room data set at 25001 - indicates room size | ||
| 49869 | SUB C | Subtract (check against) the counter | ||
| 49870 | JR C,49912 | If counter is greater than the room data byte, the side and back wall joints have been calculated. Skip to 49912 to deal with the corner/vertical wall connectors | ||
| 49872 | CP 2 | Check which section we're dealing with | ||
| 49874 | JR NC,49886 | |||
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Room-size-minus-counter = 1 or 0. This means we're dealing with the RIGHT side of the room.
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| 49876 | LD A,(60281) | Increase vertical (Y) position by 16 pixels | ||
| 49879 | ADD A,16 | Each side wall part is 16 pixels tall (e.g. the right side wall section, so add 16 pixels from the current position | ||
| 49881 | LD (60281),A | Store adjusted vertical graphic position | ||
| 49884 | JR 49901 | |||
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Room size is 2 or more than the counter, so we're dealing with the scenery either on the left wall or the back wall scenery.
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| 49886 | LD A,(60285) | Get the counter byte | ||
| 49889 | CP 4 | >=4? | ||
| 49891 | JR NC,49901 | If so, we're dealing with the BACK WALL section - no need to adjust the vertical co-ordinate as it's all along the same level | ||
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Neither of the above checks were met, so we're dealing with the LEFT side of the room.
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| 49893 | LD A,(60281) | Vertical (Y) position | ||
| 49896 | SUB 16 | Each side wall part is 16 pixels tall (e.g. the left side wall section, so subtract 16 pixels from the current position as they're drawn sequentially from left to right | ||
| 49898 | LD (60281),A | ...and re-store | ||
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Wall/floor sections (e.g. the connectors at 40392) are 4 characters (32 pixels) wide.
Calculate the horizontal (X) position - this is easy as every room section is 32 pixels wide.
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| 49901 | LD A,(60280) | |||
| 49904 | ADD A,8 | Increase horizontal position by 8 half-character squares (32 pixels) | ||
| 49906 | LD (60280),A | |||
| 49909 | JP 49632 | Return to the next item to set up | ||
| Prev: 49808 | Up: Map | Next: 49912 |