diff options
Diffstat (limited to 'lib/pure/math.nim')
| -rw-r--r-- | lib/pure/math.nim | 21 |
1 files changed, 14 insertions, 7 deletions
diff --git a/lib/pure/math.nim b/lib/pure/math.nim index e4aecd272..78ea02cbf 100644 --- a/lib/pure/math.nim +++ b/lib/pure/math.nim @@ -135,12 +135,12 @@ proc random*(max: int): int {.gcsafe.} ## which initializes the random number generator with a "random" ## number, i.e. a tickcount. -when not defined(windows): - proc random*(max: float): float {.gcsafe.} - ## returns a random number in the range 0..<max. The sequence of - ## random number is always the same, unless `randomize` is called - ## which initializes the random number generator with a "random" - ## number, i.e. a tickcount. This is currently not supported for windows. +proc random*(max: float): float {.gcsafe.} + ## returns a random number in the range 0..<max. The sequence of + ## random number is always the same, unless `randomize` is called + ## which initializes the random number generator with a "random" + ## number, i.e. a tickcount. This has a 16-bit resolution on windows + ## and a 48-bit resolution on other platforms. proc randomize*() {.gcsafe.} ## initializes the random number generator with a "random" @@ -205,7 +205,14 @@ when not defined(JS): proc drand48(): float {.importc: "drand48", header: "<stdlib.h>".} proc random(max: float): float = result = drand48() * max - + when defined(windows): + proc random(max: float): float = + # we are hardcodeing this because + # importcing macros is extremely problematic + # and because the value is publicly documented + # on MSDN and very unlikely to change + const rand_max = 32767 + result = (float(rand()) / float(rand_max)) * max proc randomize() = randomize(cast[int](epochTime())) |