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

Fix 2183fd4d: [NewGRF] Use divide instead of right shift for signed numbers. (#9480) 

"For negative a, the value of a >> b is implementation-defined (in most implementations, this performs arithmetic right shift, so that the result remains negative)."
pull/9481/head
Michael Lutz 2021-08-15 12:14:53 +02:00 committed by GitHub
parent 2183fd4dab
commit ee333a9549
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
2 changed files with 2 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
src/newgrf_engine.cpp
View File

@ -1189,7 +1189,7 @@ int GetEngineProperty(EngineID engine, PropertyID property, int orig_value, cons
if (callback != CALLBACK_FAILED) {
if (is_signed) {
/* Sign extend 15 bit integer */
return static_cast<int16>(callback << 1) >> 1;
return static_cast<int16>(callback << 1) / 2;
} else {
return callback;
}

2
src/train_cmd.cpp
View File

@ -363,7 +363,7 @@ int Train::GetCurveSpeedLimit() const
/* Apply max_speed modifier (cached value is fixed-point binary with 8 fractional bits)
* and clamp the result to an acceptable range. */
max_speed += (max_speed * this->tcache.cached_curve_speed_mod) >> 8;
max_speed += (max_speed * this->tcache.cached_curve_speed_mod) / 256;
max_speed = Clamp(max_speed, 2, absolute_max_speed);
}