User:Nightmareci/SRS
Offsets
| 0° | (+0, +0) | (-1, +0) | (+2, +0) | (-1, +0) | (+2, +0) |
|---|---|---|---|---|---|
| 90° | (-1, +0) | (+0, +0) | (+0, +0) | (+0, +1) | (+0, -2) |
| 180° | (-1, +1) | (+1, +1) | (-2, +1) | (+1, +0) | (-2, +0) |
| 270° | (+0, +1) | (+0, +1) | (+0, +1) | (+0, -1) | (+0, +2) |
| 0° | (+0, +0) | (+0, +0) | (+0, +0) | (+0, +0) | (+0, +0) |
|---|---|---|---|---|---|
| 90° | (+0, +0) | (+1, +0) | (+1, -1) | (+0, +2) | (+1, +2) |
| 180° | (+0, +0) | (+0, +0) | (+0, +0) | (+0, +0) | (+0, +0) |
| 270° | (+0, +0) | (-1, +0) | (-1, -1) | (+0, +2) | (-1, +2) |
| 0° | (+0, +0) |
|---|---|
| 90° | (+0, -1) |
| 180° | (-1, -1) |
| 270° | (-1, +0) |
Explanation of Offsets
Upon pressing a rotation input, clockwise or counterclockwise, there is orientation-start (the orientation before the rotation input is sent) and orientation-end (the orientation that will possibly be changed to). True rotation is performed from orientation-start to orientation-end, even if intersection occurs. Next, the first offset pair is attempted; given (a, b) as the first offset for orientation-start and (c, d) as the offset for orientation-end, the number of columns the offset attempt goes rightward is a-c when a-c is positive and leftward if a-c is negative, and the number of rows upward is b-d if b-d is positive and downward if b-d is negative. If applying the first pair of offsets results in some intersection with the field or walls, then the next offset pair is tried, and so on, until an offset pair succeeds; if none succeed, then no change in state will have occurred.