Game Rates , Spawn ,fire ,drop ,etc

[egizz983]

generating random number between 0-10 i got 9 only 3 times in 200 generation tries . I am not very happy with a result of this :

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std::random_device rnum;
			std::mt19937 rnd(rnum());
			std::normal_distribution<> mlvl(5.0, 2.0);
			if (level < 3) {
				meteorlvl = 1;
			}
			if (level >= 3 && level < 8) {
				if (mlvl(rnd) <= (6.0-(((float)level)/10)*1.5)) {
					meteorlvl = 1;
				}
				else {
					meteorlvl = 2;
				}
			}

i already have tried , cuz i was able to get like 6 in a a row meteors by lvl 2 , i am not sure if its because of a rate or its because of a generated numbers . and i was checking a reference abou uniform_real and int distribution and and if you generating a number between 1-10(or any other) all of the numbers have same chance to be generated . its like

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0-1: *
1-2: ****
2-3: *********
3-4: ***************
4-5: ******************
5-6: *******************
6-7: ***************
7-8: ********
8-9: ****
9-10: *

shouldn't i use just int or real distribution instead ?

[albinopapa]

You could try it and see if it gives you the results you are after.

[Lorth]

I have created this "chance" function in a game i am working on. dunno if it might be useful for you.

i created this Before chili introduced the other way to use a random funcktion.

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bool Chances(float procent) { 
	float x = procent / 100;
	int random = (1 / x);
	
	if (rand() % random == 0)
		return true;
	return false; }

example how this works....

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bool returnTrue = Chances(25.0f);

it returns an true or false, depending on what percent value that is inputted.... let's say you want 25% to return true, than you input 25 in the function. and the function will use rand() and return either true or false with a 25% chance to return true....

remember to set srand(time(NULL)); in the code Before using the funciton

[egizz983]

This looks nice for a drop rate , i will use this in a future for sure ,that seems to be nice function i change a bit but result should be same

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bool Game::Chance(float p)
{
	float x = p / 100;
	int random = (1 / x);
	std::random_device rnum;
	std::mt19937 rnd(rnum());
	std::uniform_int_distribution<int> r(0, (random-1));
	if (r(rnd) == 0) {
		return true;
	}
	else {
		return false;
	}
}

i changed just because as chili said by using a rand() some numbers have higher chance to by generated and with uniform_int_distribution all numbers have same chance

[egizz983]

btw there is a bug in this code , example take 60 or75 and you will get 100% chance any way
60/100 = 0.6
1/0.6 = 1.666 = 1
std::uniform_int_distribution<int> r(0, (random-1));
0-(1-1) = 0
its works with 25,50or 100% but others will give you wrong chance
i made this like this but not sure if i still get accurate results :

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bool Game::Chance(int p)
{
	std::random_device rnum;
	std::mt19937 rnd(rnum());
	std::uniform_int_distribution<int> r(1, 100);
	if (r(rnd) <= p) {
		return true;
	}
	else {
		return false;
	}
}