The unrandomness of a simple modulus becomes glaringly obvious in a game or other program where you're invoking random numbers continuously and doing stuff based on them.
And please, read the thread first.
[edited by - Promit on April 14, 2004 7:13:13 PM]
C++ Random?
I havn't read the other posts but this is how I use random-numbers in C++
// Last Attacker \\---=( LA )=---// LA Extreme \\
[edited by - Last Attacker on April 15, 2004 3:53:31 AM]
#define RANDOMIZE() (srand(static_cast<unsigned int>(time(0))))#define RANDOM_INT(MIN, MAX) (MIN + rand() % (MAX - MIN + 1))#define RANDOM_FLOAT(MIN, MAX) (MIN + (static_cast<float>(rand())) / 0x7fff * (MAX - MIN))// Last Attacker \\---=( LA )=---// LA Extreme \\
ICQ Number : 120585863
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laextr@icqmail.com[edited by - Last Attacker on April 15, 2004 3:53:31 AM]
quote:Original post by Last Attacker
I havn''t read the other posts but this is how I use random-numbers in C++
Your code has macro creation mistakes that are almost textbook example worthy.
quote:
#define RANDOM_INT(MIN, MAX) (MIN + rand() % (MAX - MIN + 1))
Here is the classic insufficient number of parethesis error. A call to RANDOM_INT(2 + 1, 2 + 6) will give strange results. In particular it would give results in the range of 3 to 10 instead of the expected 3 to 8 range. Also, it suffers from symbol duplication on the MIN parameter.
quote:
#define RANDOM_FLOAT(MIN, MAX) (MIN + (static_cast<float>(rand())) / 0x7fff * (MAX - MIN))
Again, symbol repeat issue on the MIN parameter, and the insufficient parenthesis error. Also add in the fact that you''re dividing by 0x7fff which makes your code non-portable. A implmentation of rand() returns numbers in the range 0 to RAND_MAX, where RAND_MAX is at least 0x7fff, but may be more. If you brought your code to a different compiler your random floats may suddenly be whole orders of magnitude greater than your MAX value.
You''re obviously using C++, so why not switch over to inline functions?
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