I am wanting to generate the same random sequence (of numbers or characters) based on a given "seed" value.

Using the standard Randomize function does not seem to have such an option.

For example in C# you can initialize the Random function with a seed value (Random seed c#).

How can I achieve something similar in Delphi?

CodePudding user response：

You only need to assign a particular value to the RandSeed global variable.

Actually, I'm almost surprised you asked, because you clearly know of the Randomize function, the documentation for which states the following:

The random number generator should be initialized by making a call to Randomize, or by assigning a value to RandSeed.

CodePudding user response：

In general, pseudorandom number generators have internal state, in order to calculate the next number. So they are not thread-safe, and require an instance per thread. For encapsulated thread-safe random numbers, you can use a suitable hash function, such as xxHash, and pass it a seed and a counter that you increment after each call in the thread.

There is a Delphi implementation of xxHash here: https://github.com/Xor-el/xxHashPascal

For general use, it's easy to make several versions in 1, 2 or 3 dimensions as needed, and return either floating point in 0..1 or integers in a range.