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(svn r5809) Turn the tests for valid bridge ramp slopes into something comprehensible

release/0.5
tron 2006-08-08 07:12:33 +00:00
parent b3cda6ee62
commit f94a754c14
1 changed files with 35 additions and 43 deletions
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78
tunnelbridge_cmd.c
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@ -103,52 +103,45 @@ static inline const PalSpriteID *GetBridgeSpriteTable(int index, byte table)
static inline byte GetBridgeFlags(int index) { return _bridge[index].flags;}
/** check if bridge can be built on slope
* direction 0 = X-axis, direction 1 = Y-axis
* is_start_tile = false <-- end tile
* is_start_tile = true <-- start tile
/** Check the slope at the bridge ramps in three easy steps:
* - valid slopes without foundation
* - valid slopes with foundation
* - rest is invalid
*/
static uint32 CheckBridgeSlope(Axis direction, Slope tileh, bool is_start_tile)
{
if (IsSteepSlope(tileh)) return CMD_ERROR;
if (is_start_tile) {
/* check slope at start tile
- no extra cost
*/
#define M(x) (1 << (x))
if (HASBIT(M(SLOPE_FLAT) | (direction == AXIS_X ? M(SLOPE_NE) : M(SLOPE_NW)), tileh)) return 0;
static int32 CheckBridgeSlopeNorth(Axis axis, Slope tileh)
{
uint32 valid;
// disallow certain start tiles to avoid certain crooked bridges
if (tileh == SLOPE_S) return CMD_ERROR;
} else {
/* check slope at end tile
- no extra cost
*/
if (HASBIT(M(SLOPE_FLAT) | (direction == AXIS_X ? M(SLOPE_SW) : M(SLOPE_SE)), tileh)) return 0;
#undef M
valid = M(SLOPE_FLAT) | (axis == AXIS_X ? M(SLOPE_NE) : M(SLOPE_NW));
if (HASBIT(valid, tileh)) return 0;
// disallow certain end tiles to avoid certain crooked bridges
if (tileh == SLOPE_N) return CMD_ERROR;
}
/* disallow common start/end tiles to avoid certain crooked bridges e.g.
* start-tile: X 2,1 Y 2,4 (2 was disabled before)
* end-tile: X 8,4 Y 8,1 (8 was disabled before)
*/
if ((tileh == SLOPE_W && is_start_tile != (direction != AXIS_X)) ||
(tileh == SLOPE_E && is_start_tile == (direction != AXIS_X))) {
return CMD_ERROR;
}
// slope foundations
if (HASBIT(BRIDGE_FULL_LEVELED_FOUNDATION | BRIDGE_PARTLY_LEVELED_FOUNDATION, tileh)) {
return _price.terraform;
}
valid =
BRIDGE_FULL_LEVELED_FOUNDATION | M(SLOPE_N) |
(axis == AXIS_X ? M(SLOPE_E) : M(SLOPE_W));
if (HASBIT(valid, tileh)) return _price.terraform;
return CMD_ERROR;
}
static int32 CheckBridgeSlopeSouth(Axis axis, Slope tileh)
{
uint32 valid;
valid = M(SLOPE_FLAT) | (axis == AXIS_X ? M(SLOPE_SW) : M(SLOPE_SE));
if (HASBIT(valid, tileh)) return 0;
valid =
BRIDGE_FULL_LEVELED_FOUNDATION | M(SLOPE_S) |
(axis == AXIS_X ? M(SLOPE_W) : M(SLOPE_E));
if (HASBIT(valid, tileh)) return _price.terraform;
return CMD_ERROR;
}
#undef M
uint32 GetBridgeLength(TileIndex begin, TileIndex end)
{
int x1 = TileX(begin);
@ -274,9 +267,8 @@ int32 CmdBuildBridge(TileIndex end_tile, uint32 flags, uint32 p1, uint32 p2)
if (CmdFailed(ret)) return ret;
cost = ret;
// true - bridge-start-tile, false - bridge-end-tile
terraformcost = CheckBridgeSlope(direction, tileh_start, true);
if (CmdFailed(terraformcost) || (terraformcost && !allow_on_slopes))
terraformcost = CheckBridgeSlopeNorth(direction, tileh_start);
if (CmdFailed(terraformcost) || (terraformcost != 0 && !allow_on_slopes))
return_cmd_error(STR_1000_LAND_SLOPED_IN_WRONG_DIRECTION);
cost += terraformcost;
@ -287,8 +279,8 @@ int32 CmdBuildBridge(TileIndex end_tile, uint32 flags, uint32 p1, uint32 p2)
cost += ret;
// false - end tile slope check
terraformcost = CheckBridgeSlope(direction, tileh_end, false);
if (CmdFailed(terraformcost) || (terraformcost && !allow_on_slopes))
terraformcost = CheckBridgeSlopeSouth(direction, tileh_end);
if (CmdFailed(terraformcost) || (terraformcost != 0 && !allow_on_slopes))
return_cmd_error(STR_1000_LAND_SLOPED_IN_WRONG_DIRECTION);
cost += terraformcost;