Support for manual probabilities in item blend

[Amun 1832]

Hello, good people!

 

I was writing something to validate the server data(like blend.txt, cube, etc) and stumbled upon this lovely comment:

Quote

// Choong Ki-hwan's probability table
// It would be neat if we fix it so that it also receives the probability from blend.txt
// by rtsummit

So then I asked myself "Why not?"

Anyhow, here's the code(everything is in blend_item.cpp):

// after the last #include, add
#include <random>
  
// Optional: You can add this after the last import if you want.
// I've replaced the "Token" thing because Visual Studio was playing tricks with the tabs and it was too annoying.
#define str_match(s1,s2) _stricmp(s1,s2)==0
// or, if you want, you can just completely replace the Token stuff, like I did. Up to you, it's just optional stuff..

// Anyhow, now edit this struct:
struct BLEND_ITEM_INFO
{
	DWORD	item_vnum;
	int		apply_type;
	int		apply_value[MAX_BLEND_ITEM_VALUE];
	int		apply_duration[MAX_BLEND_ITEM_VALUE];
  
  // add these
	int     apply_prob[MAX_BLEND_ITEM_VALUE];
	int     duration_prob[MAX_BLEND_ITEM_VALUE];
	int     apply_prob_sum;// we'll just do the sum straight away
	int     duration_prob_sum;// since we have to check if it has probability or not
};

 

// search for
static int FN_random_index()

// add these before(or after.. whatever)
// You don't really have to add this, you can just use number(min, max) if you want to
int Randomi(int minx, int maxx) {
	std::random_device rd; // obtain a random number from hardware
	std::mt19937 gen(rd()); // seed the generator
	std::uniform_int_distribution<> distr(minx, maxx); // define the range

	return distr(gen);
}

int RandomFromProbs(int probs[], int probsSum)
{
	int rand = Randomi(1, probsSum);
	int accumulated = 0;
	
	for (int i = 0; i < MAX_BLEND_ITEM_VALUE; i++)
	{
		// this is just a fallback in case someone puts 0 for all of them
		// or maybe we should call FN_random_index from here instead?
        // up to you..
		if (i == MAX_BLEND_ITEM_VALUE - 1)
			return i;

		// if the probability is 0, then it's disabled, skip it
		if (!probs[i])
			continue;

		accumulated += probs[i];
		if (rand <= accumulated)
			return i;
	}
}

 

// search for 
else Token("end")

// Add this before
// if you didn't add that define, change these to Token
// here: else Token("apply_prob")
// and the second one: else Token("duration_prob")

		else if (0 == strcmp(key, "apply_prob"))
			{
				for (int i = 0; i < MAX_BLEND_ITEM_VALUE; ++i)
				{
					v = strtok(NULL, delim);
					if (!v)
					{
						fclose(fp);
						return false;
					}

					blend_item_info->apply_prob_sum += std::stoi(v);
					str_to_number(blend_item_info->apply_prob[i], v);
				}
			}
			else if (0 == strcmp(key, "duration_prob"))
			{
				for (int i = 0; i < MAX_BLEND_ITEM_VALUE; ++i)
				{
					v = strtok(NULL, delim);
					if (!v)
					{
						fclose(fp);
						return false;
					}

					blend_item_info->duration_prob_sum += std::stoi(v);
					str_to_number(blend_item_info->duration_prob[i], v);
				}
			}

 

// Search for
bool	Blend_Item_set_value(LPITEM item)

// Inside look for:
			if (item->GetVnum() == 51002) // energy crystal
			{
				apply_type = blend_info->apply_type;
				apply_value = blend_info->apply_value[FN_ECS_random_index()];
				apply_duration = blend_info->apply_duration[FN_ECS_random_index()];
			}
			else
			{
				apply_type = blend_info->apply_type;
				apply_value = blend_info->apply_value[FN_random_index()];
				apply_duration = blend_info->apply_duration[FN_random_index()];
			}


// Comment them or just replace them with this:
			apply_type = blend_info->apply_type;

			if (blend_info->apply_prob_sum)
			{
				apply_value = blend_info->apply_value[RandomFromProbs(blend_info->apply_prob, blend_info->apply_prob_sum)];
			}
			else
			{
				if (item->GetVnum() == 51002) // energy crystal
					apply_value = blend_info->apply_value[FN_ECS_random_index()];
				else
					apply_value = blend_info->apply_value[FN_random_index()];
			}

			if (blend_info->duration_prob_sum)
			{
				apply_duration = blend_info->apply_value[RandomFromProbs(blend_info->duration_prob, blend_info->duration_prob_sum)];
			}
			else
			{
				if (item->GetVnum() == 51002) // energy crystal
					apply_duration = blend_info->apply_duration[FN_ECS_random_index()];
				else
					apply_duration = blend_info->apply_duration[FN_random_index()];
			}

 

That's it, you're good to go.

I should mention that I didn't try it on the live server, just in the validation app, but everything should work just fine.

 

Example usage:

# this is just to prove that you don't have to add the probability stuff in all of them
# you can just add where you want to
#Blue Dew
section
	item_vnum	50825
	apply_type	ATT_BONUS
	apply_value	30	50	70	90	120
	apply_duration	60	120	180	300	600
end

#white dew
section
	item_vnum	50826
	apply_type	DEF_BONUS
	apply_value	40	70	100	150	200
# you can also add values like 0 1000 20 500 0
# it will just ignore the 0 and do the math for the other ones
	apply_prob	0	1000	200	150	90
# if you have something like this it will ignore the 0 
# and just give the one with a "valid" probability(the fifth, in this case - apply_value 200)
#	apply_prob 0 0 0 0 1
	apply_duration	60	120	180	300	600
	duration_prob	1	2	3	4	5
end

#energy crystal
section
	item_vnum	51002
	apply_type	ENERGY
	apply_value	1	3	5	7	10
	apply_duration	7200	7200	7200	7200	7200
# and you don't have to add both probabilities(for duration and apply), you can just use one.. or none!
	apply_prob	10	50	10	20	10
end

 

Have fun and let me know if you have any problems with it!

Cheers!

 

Edited April 14, 2022 by Amun
More details about Randomi function