From b2dc4d9c1dcd7c49191005e0a533ca926126eb87 Mon Sep 17 00:00:00 2001 From: rubidium Date: Sun, 4 Dec 2011 12:07:19 +0000 Subject: [PATCH] (svn r23425) -Document [FS#4815]: why vehicles might be continuously changing speed up and down --- known-bugs.txt | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/known-bugs.txt b/known-bugs.txt index c1a87d7be5..04bef6a908 100644 --- a/known-bugs.txt +++ b/known-bugs.txt @@ -338,3 +338,23 @@ Train does not crash with itself [FS#4635]: it does not add anything to gameplay. Nevertheless trains shall not crash in normal operation, so making a train not crash with itself is the best solution for everyone. + +Vehicles not keeping their "maximum" speed [FS#4815]: + Vehicles that have not enough power to reach and maintain their + advertised maximum speed might be constantly jumping between two + speeds. This is due to the fact that speed and its calculations + are done with integral numbers instead of floating point numbers. + As a result of this a vehicle will never reach its equilibrium + between the drag/friction and propulsion. So in effect it will be + in a vicious circle of speeding up and slowing down due to being + just at the other side of the equilibrium. + + Not speeding up when near the equilibrium will cause the vehicle + to never come in the neighbourhood of the equilibrium and not + slowing down when near the equilibrium will cause the vehicle + to never slow down towards the equilibrium once it has come down + a hill. + + It is possible to calculate whether the equilibrium will be + passed, but then all acceleration calculations need to be done + twice.