Mercurial > hg > openttd
changeset 18999:081eb943326c draft
(svn r23855) -Fix [FS#5007]: out of bounds read for slowdown parameter caused desync when railtype >= 4, vehicles were fast, and the original acceleration model was used
| author | rubidium <rubidium@openttd.org> |
|---|---|
| date | Thu, 26 Jan 2012 17:48:23 +0000 |
| parents | 66b191c02555 |
| children | 991dd42d980e |
| files | src/train_cmd.cpp |
| diffstat | 1 files changed, 9 insertions(+), 10 deletions(-) [+] |
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--- a/src/train_cmd.cpp +++ b/src/train_cmd.cpp @@ -2794,19 +2794,18 @@ (!v->IsFrontEngine() || HasBit(v->compatible_railtypes, GetRailType(tile))); } -/** Data structure for storing engine speed changes of a rail type. */ -struct RailtypeSlowdownParams { +/** Data structure for storing engine speed changes of an acceleration type. */ +struct AccelerationSlowdownParams { byte small_turn; ///< Speed change due to a small turn. byte large_turn; ///< Speed change due to a large turn. byte z_up; ///< Fraction to remove when moving up. byte z_down; ///< Fraction to add when moving down. }; -/** Speed update fractions for each rail type. */ -static const RailtypeSlowdownParams _railtype_slowdown[] = { +/** Speed update fractions for each acceleration type. */ +static const AccelerationSlowdownParams _accel_slowdown[] = { /* normal accel */ {256 / 4, 256 / 2, 256 / 4, 2}, ///< normal - {256 / 4, 256 / 2, 256 / 4, 2}, ///< electrified {256 / 4, 256 / 2, 256 / 4, 2}, ///< monorail {0, 256 / 2, 256 / 4, 2}, ///< maglev }; @@ -2820,12 +2819,12 @@ { if (old_z == v->z_pos || _settings_game.vehicle.train_acceleration_model != AM_ORIGINAL) return; - const RailtypeSlowdownParams *rsp = &_railtype_slowdown[v->railtype]; + const AccelerationSlowdownParams *asp = &_accel_slowdown[GetRailTypeInfo(v->railtype)->acceleration_type]; if (old_z < v->z_pos) { - v->cur_speed -= (v->cur_speed * rsp->z_up >> 8); + v->cur_speed -= (v->cur_speed * asp->z_up >> 8); } else { - uint16 spd = v->cur_speed + rsp->z_down; + uint16 spd = v->cur_speed + asp->z_down; if (spd <= v->gcache.cached_max_track_speed) v->cur_speed = spd; } } @@ -3242,9 +3241,9 @@ if (chosen_dir != v->direction) { if (prev == NULL && _settings_game.vehicle.train_acceleration_model == AM_ORIGINAL) { - const RailtypeSlowdownParams *rsp = &_railtype_slowdown[v->railtype]; + const AccelerationSlowdownParams *asp = &_accel_slowdown[GetRailTypeInfo(v->railtype)->acceleration_type]; DirDiff diff = DirDifference(v->direction, chosen_dir); - v->cur_speed -= (diff == DIRDIFF_45RIGHT || diff == DIRDIFF_45LEFT ? rsp->small_turn : rsp->large_turn) * v->cur_speed >> 8; + v->cur_speed -= (diff == DIRDIFF_45RIGHT || diff == DIRDIFF_45LEFT ? asp->small_turn : asp->large_turn) * v->cur_speed >> 8; } direction_changed = true; v->direction = chosen_dir;