Method SetupTargetCount

src/industry_cmd.cpp:2632–2672

Decide how many industries of each type are needed. */

/** Decide how many industries of each type are needed. */
void IndustryBuildData::SetupTargetCount()
{
	bool changed = false;
	uint num_planned = 0; // Number of industries planned in the industry build data.
	for (IndustryType it = 0; it < NUM_INDUSTRYTYPES; it++) {
		changed |= this->builddata[it].GetIndustryTypeData(it);
		num_planned += this->builddata[it].target_count;
	}
	uint total_amount = this->wanted_inds >> 16; // Desired total number of industries.
	changed |= num_planned != total_amount;
	if (!changed) return; // All industries are still the same, no need to re-randomize.

	/* Initialize the target counts. */
	uint force_build = 0;  // Number of industries that should always be available.
	uint32_t total_prob = 0; // Sum of probabilities.
	for (IndustryType it = 0; it < NUM_INDUSTRYTYPES; it++) {
		IndustryTypeBuildData *ibd = this->builddata + it;
		force_build += ibd->min_number;
		ibd->target_count = ibd->min_number;
		total_prob += ibd->probability;
	}

	if (total_prob == 0) return; // No buildable industries.

	/* Subtract forced industries from the number of industries available for construction. */
	total_amount = (total_amount <= force_build) ? 0 : total_amount - force_build;

	/* Assign number of industries that should be aimed for, by using the probability as a weight. */
	while (total_amount > 0) {
		uint32_t r = RandomRange(total_prob);
		IndustryType it = 0;
		while (r >= this->builddata[it].probability) {
			r -= this->builddata[it].probability;
			it++;
			assert(it < NUM_INDUSTRYTYPES);
		}
		assert(this->builddata[it].probability > 0);
		this->builddata[it].target_count++;
		total_amount--;
	}
}

/**
 * Try to create a random industry, during gameplay