mirror
/
OpenTTD
mirror of https://github.com/OpenTTD/OpenTTD
1
0
Fork 0
Code Issues

(svn r3838) Demystify building bridge middle parts a bit by removing some magic numbers and generic names

release/0.5
tron 2006-03-13 07:12:49 +00:00
parent 2732fc8d6f
commit 1067069e33
1 changed files with 18 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

29
tunnelbridge_cmd.c
View File

@ -197,7 +197,6 @@ bool CheckBridge_Stuff(byte bridge_type, uint bridge_len)
int32 CmdBuildBridge(int x, int y, uint32 flags, uint32 p1, uint32 p2)
{
int bridge_type;
byte m5;
TransportType transport;
RailType railtype;
int sx,sy;
@ -334,6 +333,7 @@ int32 CmdBuildBridge(int x, int y, uint32 flags, uint32 p1, uint32 p2)
tile = ti_start.tile;
delta = (direction == AXIS_X ? TileDiffXY(1, 0) : TileDiffXY(0, 1));
for (i = 0; i != bridge_len; i++) {
TransportType transport_under;
uint z;
tile += delta;
@ -346,14 +346,14 @@ int32 CmdBuildBridge(int x, int y, uint32 flags, uint32 p1, uint32 p2)
case MP_WATER:
if (!EnsureNoVehicle(tile)) return_cmd_error(STR_980E_SHIP_IN_THE_WAY);
if (_m[tile].m5 > 1) goto not_valid_below;
m5 = 0xC8;
transport_under = TRANSPORT_WATER;
break;
case MP_RAILWAY:
if (_m[tile].m5 != (direction == AXIS_X ? TRACK_BIT_Y : TRACK_BIT_X)) {
goto not_valid_below;
}
m5 = 0xE0;
transport_under = TRANSPORT_RAIL;
break;
case MP_STREET:
@ -361,7 +361,7 @@ int32 CmdBuildBridge(int x, int y, uint32 flags, uint32 p1, uint32 p2)
GetRoadBits(tile) != (direction == AXIS_X ? ROAD_Y : ROAD_X)) {
goto not_valid_below;
}
m5 = 0xE8;
transport_under = TRANSPORT_ROAD;
break;
default:
@ -370,13 +370,14 @@ not_valid_below:;
ret = DoCommandByTile(tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
if (CmdFailed(ret)) return ret;
cost += ret;
m5 = 0xC0;
transport_under = INVALID_TRANSPORT;
break;
}
/* do middle part of bridge */
if (flags & DC_EXEC) {
_m[tile].m5 = (byte)(m5 | direction | transport << 1);
uint piece;
SetTileType(tile, MP_TUNNELBRIDGE);
//bridges pieces sequence (middle parts)
@ -392,20 +393,26 @@ not_valid_below:;
// for odd bridges: #5 is going in the bridge middle if on even position, #4 on odd (counting from 0)
if (i == 0) { // first tile
m5 = 0;
piece = 0;
} else if (i == bridge_len - 1) { // last tile
m5 = 1;
piece = 1;
} else if (i == odd_middle_part) { // we are on the middle of odd bridge: #5 on even pos, #4 on odd
m5 = 5 - (i % 2);
piece = 5 - (i % 2);
} else {
// generate #2 and #3 in turns [i%2==0], after the middle of odd bridge
// this sequence swaps [... XOR (i>odd_middle_part)],
// for even bridges XOR does not apply as odd_middle_part==bridge_len
m5 = 2 + ((i % 2 == 0) ^ (i > odd_middle_part));
piece = 2 + ((i % 2 == 0) ^ (i > odd_middle_part));
}
_m[tile].m2 = (bridge_type << 4) | m5;
_m[tile].m2 = (bridge_type << 4) | piece;
SB(_m[tile].m3, 4, 4, railtype);
switch (transport_under) {
case TRANSPORT_RAIL: _m[tile].m5 = 0xE0 | TRANSPORT_RAIL << 3 | transport << 1 | direction; break; // rail
case TRANSPORT_ROAD: _m[tile].m5 = 0xE0 | TRANSPORT_ROAD << 3 | transport << 1 | direction; break; // road
case TRANSPORT_WATER: _m[tile].m5 = 0xC0 | 1 << 3 | transport << 1 | direction; break; // water
default: _m[tile].m5 = 0xC0 | 0 << 3 | transport << 1 | direction; break; // grass
}
MarkTileDirtyByTile(tile);
}