diff options
| author | darkvater <darkvater@openttd.org> | 2004-08-11 22:07:08 +0000 |
|---|---|---|
| committer | darkvater <darkvater@openttd.org> | 2004-08-11 22:07:08 +0000 |
| commit | f42201496093f04220e58b1c4cd4d69531839de4 (patch) | |
| tree | bbd3f2f0084e8bba00dd232cb07236b5bebd9d6a /rail_cmd.c | |
| parent | 6679afc48a1bec985b6687dee105730b89682224 (diff) | |
| download | openttd-f42201496093f04220e58b1c4cd4d69531839de4.tar.xz | |
(svn r23) -Some omments on the code (blathijs)
Diffstat (limited to 'rail_cmd.c')
| -rw-r--r-- | rail_cmd.c | 18 |
1 files changed, 15 insertions, 3 deletions
diff --git a/rail_cmd.c b/rail_cmd.c index 2b89a8977..66200d307 100644 --- a/rail_cmd.c +++ b/rail_cmd.c @@ -8,7 +8,7 @@ void ShowTrainDepotWindow(uint tile); -enum { +enum { /* These values are bitmasks for the map5 byte */ RAIL_TYPE_NORMAL = 0, RAIL_TYPE_SIGNALS = 0x40, RAIL_TYPE_SPECIAL = 0x80, // If this bit is set, then it's not a regular track. @@ -40,6 +40,9 @@ enum { * 01 abcdef => Rail with signals * 10 ?????? => Unused * 11 ????dd => Depot + * + * abcdef is a bitmask, which contains ones for all present tracks. Below the + * value for each track is given. */ /* 4 @@ -77,8 +80,12 @@ enum RailMap2Lower4 { }; -/* MAP2 byte: abcd???? => Signal On? - * MAP3LO byte: abcd???? => Signal Exists? +/* MAP2 byte: abcd???? => Signal On? Same coding as map3lo + * MAP3LO byte: abcd???? => Signal Exists? + * a and b are for diagonals, upper and left, + * one for each direction. (ie a == NE->SW, b == + * SW->NE, or v.v., I don't know. b and c are + * similar for lower and right. * MAP2 byte: ????abcd => Type of ground. * MAP3LO byte: ????abcd => Type of rail. * MAP5: 00abcdef => rail @@ -1796,6 +1803,7 @@ static uint32 GetTileTrackStatus_Track(uint tile, int mode) { ret = (m5 | (m5 << 8)) & 0x3F3F; if (!(m5 & RAIL_TYPE_SIGNALS)) { if ( (ret & 0xFF) == 3) + /* Diagonal crossing? */ ret |= 0x40; } else { /* has_signals */ @@ -1805,6 +1813,10 @@ static uint32 GetTileTrackStatus_Track(uint tile, int mode) { b &= a; + /* When signals are not present (in neither + * direction), we pretend them to be green. (So if + * signals are only one way, the other way will + * implicitely become `red' */ if ((a & 0xC0) == 0) { b |= 0xC0; } if ((a & 0x30) == 0) { b |= 0x30; } |