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Routines |
| Prev: C290 | Up: Map | Next: C2F8 |
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Used by the routine at C20F.
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The byte at EB7D acts as an incrementing counter which is compared with room size (first byte in the room data sets at 61A9). 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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| C2C2 | LD A,($EB7D) | Get counter byte, starting at 1 | ||
| C2C5 | INC A | Increment and then re-store | ||
| C2C6 | LD ($EB7D),A | |||
| C2C9 | LD C,A | |||
| C2CA | LD A,($EB7C) | First room data byte from room data set at 61A9 - indicates room size | ||
| C2CD | SUB C | Subtract (check against) the counter | ||
| C2CE | JR C,$C2F8 | If counter is greater than the room data byte, the side and back wall joints have been calculated. Skip to C2F8 to deal with the corner/vertical wall connectors | ||
| C2D0 | CP $02 | Check which section we're dealing with | ||
| C2D2 | JR NC,$C2DE | |||
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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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| C2D4 | LD A,($EB79) | Increase vertical (Y) position by 16 pixels | ||
| C2D7 | ADD A,$10 | Each side wall part is 16 pixels tall (e.g. the right side wall section, so add 16 pixels from the current position | ||
| C2D9 | LD ($EB79),A | Store adjusted vertical graphic position | ||
| C2DC | JR $C2ED | |||
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Room size is 2 or more than the counter, so we're dealing with the scenery either on the left wall or the back wall scenery.
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| C2DE | LD A,($EB7D) | Get the counter byte | ||
| C2E1 | CP $04 | >=4? | ||
| C2E3 | JR NC,$C2ED | 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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| C2E5 | LD A,($EB79) | Vertical (Y) position | ||
| C2E8 | SUB $10 | Each side wall part is 16 pixels tall (e.g. the left side wall section, so subtract 16 pixels from the current position as they're drawn sequentially from left to right | ||
| C2EA | LD ($EB79),A | ...and re-store | ||
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Wall/floor sections (e.g. the connectors at 9DC8) 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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| C2ED | LD A,($EB78) | |||
| C2F0 | ADD A,$08 | Increase horizontal position by 8 half-character squares (32 pixels) | ||
| C2F2 | LD ($EB78),A | |||
| C2F5 | JP $C1E0 | Return to the next item to set up | ||
| Prev: C290 | Up: Map | Next: C2F8 |