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authorrubidium <rubidium@openttd.org>2011-02-06 16:45:27 +0000
committerrubidium <rubidium@openttd.org>2011-02-06 16:45:27 +0000
commitfd86b0608d051d14d5c1eba2a9730d94f4c505d2 (patch)
tree85cd7e8da10629fde7b6310ab1e318cf368ec0d0 /src
parentfd94ed3009ab4a3f1016d32c6884b696412ec152 (diff)
downloadopenttd-fd86b0608d051d14d5c1eba2a9730d94f4c505d2.tar.xz
(svn r21997) -Fix [FS#4473]: when the difference between force and resistance is smaller than the mass(*4) there would be no acceleration anymore, even when at higher (or lower) speed the force and resistance balance out better
Diffstat (limited to 'src')
-rw-r--r--src/ground_vehicle.cpp12
1 files changed, 10 insertions, 2 deletions
diff --git a/src/ground_vehicle.cpp b/src/ground_vehicle.cpp
index cc2360d3f..1c706b5c6 100644
--- a/src/ground_vehicle.cpp
+++ b/src/ground_vehicle.cpp
@@ -151,8 +151,16 @@ int GroundVehicle<T, Type>::GetAcceleration() const
}
if (mode == AS_ACCEL) {
- /* Divide by 4 to compensate for the wacky game scale. */
- return (force - resistance) / (mass * 4);
+ /* Easy way out when there is no acceleration. */
+ if (force == resistance) return 0;
+
+ /* When we accelerate, make sure we always keep doing that, even when
+ * the excess force is more than the mass. Otherwise a vehicle going
+ * down hill will never slow down enough, and a vehicle that came up
+ * a hill will never speed up enough to (eventually) get back to the
+ * same (maximum) speed. */
+ int accel = (force - resistance) / (mass * 4);
+ return force < resistance ? min(-1, accel) : max(1, accel);
} else {
return min(-force - resistance, -10000) / mass;
}