server/src/kernel/resources.c

/* vi: set ts=2:
 +-------------------+  Christian Schlittchen <corwin@amber.kn-bremen.de>
 |                   |  Enno Rehling <enno@eressea.de>
 | Eressea PBEM host |  Katja Zedel <katze@felidae.kn-bremen.de>
 | (c) 1998 - 2003   |  Henning Peters <faroul@beyond.kn-bremen.de>
 |                   |  Ingo Wilken <Ingo.Wilken@informatik.uni-oldenburg.de>
 +-------------------+  Stefan Reich <reich@halbling.de>

 This program may not be used, modified or distributed
 without prior permission by the authors of Eressea.
*/

#include <platform.h>
#include <kernel/config.h>
#include "resources.h"

/* kernel includes */
#include "build.h"
#include "item.h"
#include "region.h"
#include "terrain.h"

#include <util/rand.h>
#include <util/rng.h>

#include <stdlib.h>
#include <assert.h>
#include <string.h>

static double ResourceFactor(void)
{
  static double value = -1.0;
  if (value < 0) {
    const char *str = get_param(global.parameters, "resource.factor");
    value = str ? atof(str) : 1.0;
  }
  return value;
}

void update_resources(region * r)
{
  struct rawmaterial *res = r->resources;
  while (res) {
    if (res->type->update)
      res->type->update(res, r);
    res = res->next;
  }
}

extern int dice_rand(const char *s);

static void update_resource(struct rawmaterial *res, double modifier)
{
  double amount = 1 + (res->level - res->startlevel) * res->divisor / 100.0;
  amount = ResourceFactor() * res->base * amount * modifier;
  if (amount < 1.0)
    res->amount = 1;
  else
    res->amount = (int)amount;
  assert(res->amount > 0);
}

void
add_resource(region * r, int level, int base, int divisor,
  const resource_type * rtype)
{
  struct rawmaterial *rm = calloc(sizeof(struct rawmaterial), 1);

  rm->next = r->resources;
  r->resources = rm;
  rm->level = level;
  rm->startlevel = level;
  rm->base = base;
  rm->divisor = divisor;
  rm->flags = 0;
  rm->type = rmt_get(rtype);
  update_resource(rm, 1.0);
  rm->type->terraform(rm, r);
}

void terraform_resources(region * r)
{
  int i;
  const terrain_type *terrain = r->terrain;

  if (terrain->production == NULL)
    return;
  for (i = 0; terrain->production[i].type; ++i) {
    rawmaterial *rm;
    const terrain_production *production = terrain->production + i;
    const resource_type *rtype = production->type;

    for (rm = r->resources; rm; rm = rm->next) {
      if (rm->type->rtype == rtype)
        break;
    }
    if (rm)
      continue;

    if (chance(production->chance)) {
      add_resource(r, dice_rand(production->startlevel),
        dice_rand(production->base), dice_rand(production->divisor),
        production->type);
    }
  }
}

static void terraform_default(struct rawmaterial *res, const region * r)
{
#define SHIFT 70
  double modifier =
    1.0 + ((rng_int() % (SHIFT * 2 + 1)) - SHIFT) * ((rng_int() % (SHIFT * 2 +
        1)) - SHIFT) / 10000.0;
  res->amount = (int)(res->amount * modifier);  /* random adjustment, +/- 91% */
  if (res->amount < 1)
    res->amount = 1;
  unused(r);
}

#ifdef RANDOM_CHANGE
static void resource_random_change(int *pvalue, boolean used)
{
  int split = 5;
  int rnd = rng_int() % 100;

  if (pvalue == 0 || rnd % 10 >= 10)
    return;
  if (used)
    split = 4;
  /* if a resource was mined this round, there is a 6% probability
   * of a decline and a 4% probability of a raise. */
  /* if it wasn't mined this round, there is an equal probability
   * of 5% for a decline or a raise. */
  if (rnd < split) {
    (*pvalue)++;
  } else {
    (*pvalue)--;
  }
  if ((*pvalue) < 0)
    (*pvalue) = 0;
}
#endif

static int visible_default(const rawmaterial * res, int skilllevel)
/* resources are visible, if skill equals minimum skill to mine them
 * plus current level of difficulty */
{
  const struct item_type *itype = res->type->rtype->itype;
  if (res->level <= 1
    && res->level + itype->construction->minskill <= skilllevel + 1) {
    assert(res->amount > 0);
    return res->amount;
  } else if (res->level + itype->construction->minskill <= skilllevel + 2) {
    assert(res->amount > 0);
    return res->amount;
  }
  return -1;
}

static void use_default(rawmaterial * res, const region * r, int amount)
{
  assert(res->amount > 0 && amount >= 0 && amount <= res->amount);
  res->amount -= amount;
  while (res->amount == 0) {
    double modifier =
      1.0 + ((rng_int() % (SHIFT * 2 + 1)) - SHIFT) * ((rng_int() % (SHIFT * 2 +
          1)) - SHIFT) / 10000.0;
    int i;

    for (i = 0; r->terrain->production[i].type; ++i) {
      if (res->type->rtype == r->terrain->production[i].type)
        break;
    }

    ++res->level;
    update_resource(res, modifier);
  }
}

struct rawmaterial *rm_get(region * r, const struct resource_type *rtype)
{
  struct rawmaterial *rm = r->resources;
  while (rm && rm->type->rtype != rtype)
    rm = rm->next;
  return rm;
}

struct rawmaterial_type *rawmaterialtypes = 0;

struct rawmaterial_type *rmt_find(const char *str)
{
  rawmaterial_type *rmt = rawmaterialtypes;
  while (rmt && strcmp(rmt->name, str) != 0)
    rmt = rmt->next;
  return rmt;
}

struct rawmaterial_type *rmt_get(const struct resource_type *rtype)
{
  rawmaterial_type *rmt = rawmaterialtypes;
  while (rmt && rmt->rtype != rtype)
    rmt = rmt->next;
  return rmt;
}

struct rawmaterial_type *rmt_create(const struct resource_type *rtype,
  const char *name)
{
  rawmaterial_type *rmtype = malloc(sizeof(rawmaterial_type));
  rmtype->name = strdup(name);
  rmtype->rtype = rtype;
  rmtype->terraform = terraform_default;
  rmtype->update = NULL;
  rmtype->use = use_default;
  rmtype->visible = visible_default;
  rmtype->next = rawmaterialtypes;
  rawmaterialtypes = rmtype;
  return rmtype;
}