/*
 * This file is part of Deliantra, the Roguelike Realtime MMORPG.
 * 
 * Copyright (©) 2011 Marc Alexander Lehmann / Robin Redeker / the Deliantra team
 * 
 * Deliantra is free software: you can redistribute it and/or modify it under
 * the terms of the Affero GNU General Public License as published by the
 * Free Software Foundation, either version 3 of the License, or (at your
 * option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the Affero GNU General Public License
 * and the GNU General Public License along with this program. If not, see
 * <http://www.gnu.org/licenses/>.
 * 
 * The authors can be reached via e-mail to <support@deliantra.net>
 */

#include <global.h>

#include "noise.h"

#define FANCY_GRAPHICS 1

static void
gen_quadspace (int x, int y, int z)
{
  vec2d P = vec2d (x, y);

  const int deep_sea_z = -200;

  static frac2d gen(13);

  static frac2d vec_gen1 (6, 2, 0.5, 1);
  static frac2d vec_gen2 (6, 2, 0.5, 2);

  const float continent_scale = 0.00008;

  vec2d perturb_pos = pow (P, 1.4) * 1e-5;

  vec2d perturb (
     vec_gen1.fBm (perturb_pos),
     vec_gen2.fBm (perturb_pos)
  );

  float perturb_perturb = 1 - (P[1] - P[0]) * (1. / 25000 / 2);
  perturb_perturb = perturb_perturb * perturb_perturb * 0.4;
  perturb *= perturb_perturb;

  vec2d P_continent = P * continent_scale + perturb;

  static frac2d continent_gen (13, 2.13, 0.5);
  float continent = continent_gen.fBm (P_continent) + 0.05f;

  float x_gradient    = P[0] * (1. / 25000);
  float y_gradient    = P[1] * (1. / 25000);
  float xy_gradient   = (P[0] + P[1]) * (0.5 / 25000);

  const float N = (25000 - 1) * continent_scale;

  // we clip a large border on the perturbed shape, to get irregular coastline
  // and then clip a smaller border around the real shape
  continent = border_blend (-1.f, continent, P_continent                        , N, 400 * continent_scale);
  continent = border_blend (-1.f, continent, P * continent_scale + perturb * 0.1, N, 100 * continent_scale);

  enum {
    T_NONE,
    T_OCEAN,
    T_RIVER,
    T_VALLEY,
    T_MOUNTAIN,
    T_UNDERGROUND,
    T_ACQUIFER,
  } t = T_NONE;

  vec3d c;
  int h = 1000000; // height form heightmap

  // the continent increases in height from 0 to ~700 levels in the absence of anything else
  // thats about one step every 7 maps.
  int base_height  = blend (0, 300, xy_gradient, 0.2f, 0.9f);
  int river_height = base_height * 9 / 10;

  // add this to rivers to "dry them out"
  float dry_out = max (0.f, lerp (xy_gradient, 0.7f, 1.f, 0.f, 0.3f));

  static frac2d river_gen (2);
  float river1 = abs (river_gen.fBm (P * 0.001 + perturb * 4))                              + dry_out;
  float river2 = river_gen.ridgedmultifractal (P * 0.04, 0.8, 10) - y_gradient * 0.2 - 0.16 - dry_out;

  float valley = river1 - 0.2f;

  static frac2d mountain_gen (8, 2.14, 0.5);
  float mountain = mountain_gen.ridgedmultifractal (P * 0.004);

  //TODO: mountains should not lower the height, should they?
  t = valley < 0 ? T_VALLEY : T_MOUNTAIN;
  c = blend0 (vec3d (0, 0.8, 0), vec3d (0.8, 0, 0), valley, 0.1f);
  h = blend0 (base_height + continent * 300, base_height + mountain * xy_gradient * 400, valley, 0.1f);

  if (river1 < 0.01f)
    {
      // main rivers - they cut deeply into the mountains (base_height * 0.9f)
      t = T_RIVER;
      c = vec3d (0.2, 0.2, 1);
      min_it (h, river_height + lerp<float> (river1, 0.f, 0.01f, -20, -1));
    }

  if (river2 > 0)
    {
      t = T_RIVER;
      c = vec3d (0.2, 0.2, 1);
      min_it (h, river_height + lerp<float> (river1, 0.f, 0.01f, -5, -1));
    }

  if (continent < 0)
    {
      t = T_OCEAN;
      min_it (h, min (continent * 200, -1));
      c = vec3d (0, 0, 1);
    }

  // now we have the base height, and base terrain

#if FANCY_GRAPHICS
  z = h; // show the surface, not the given z layer
#endif

  // everything below the surface is underground, or a variant
  if (z < h)
    {
      t = T_UNDERGROUND;
    }

  // put acquifers a bit below the surface, to reduce them leaking out (will still happen)
  if (z < h - 3)
    {
      static frac3d acquifer_gen (4);
      float acquifer = acquifer_gen.ridgedmultifractal (vec3d (x * 0.001, y * 0.001, z * 0.01), 1.003, 2);

      if (acquifer > 0.48)
        {
          t = T_ACQUIFER;
          c = vec3d (1,1,1);
        }
    }

  // TODO: caves
  // TODO: chees areas
  // TODO: minerals
  // TODO: monsters

#if FANCY_GRAPHICS
  float v = clamp (lerp<float> (h, deep_sea_z, 800, 0.f, 1.f), 0.f, 1.f);
  c *= v;

  putc (clamp<int> (255 * c[0], 0, 255), stdout);
  putc (clamp<int> (255 * c[1], 0, 255), stdout);
  putc (clamp<int> (255 * c[2], 0, 255), stdout);
#endif
}

void noise_test ();
void noise_test ()
{
#if 0
  int Nw = 700;

  printf ("P6 %d %d 255\n", Nw * 3, Nw * 2);
  // pmake&&server/deliantra-server >x&&convert -depth 8 -size 512xx512 gray:x x.ppm&& cv x.ppm
  for (int y = 0; y < Nw; ++y)
    {
      if (!(y&63))fprintf (stderr, "y %d\n", y * 50 / Nw);//D

      for (int x = 0; x < Nw; ++x) gen_quadspace (x * 25000 / Nw, y * 25000 / Nw, 0);

      for (int x = 0; x < Nw; ++x) gen_quadspace (x +   400, y, 0);
      for (int x = 0; x < Nw; ++x) gen_quadspace (x + 22000, y +  2000, 0);
    }
  for (int y = 0; y < Nw; ++y)
    {
      if (!(y&63))fprintf (stderr, "y %d\n", y * 50 / Nw+50);//D

      for (int x = 0; x < Nw; ++x) gen_quadspace (x +  1000, y + 22000, 0);
      for (int x = 0; x < Nw; ++x) gen_quadspace (x + 12500, y + 12500, 0);
      for (int x = 0; x < Nw; ++x) gen_quadspace (x + 22000, y + 22500, 0);
    }

          //putc (127 * gen.noise (vec2d (x * 0.01, y * 0.01)) + 128, stdout);
          //putc (256 * gen.terrain2 (x * 0.004, y * 0.004, 8), stdout);
          //putc (256 * gen.fBm (vec2d(x * 0.01, y * 0.01), 16), stdout);
          //putc (256 * gen.turbulence (vec2d (x * 0.004 - 1, y * 0.004 - 1), 10), stdout);
          //putc (256 * gen.heterofractal (vec2d (x * 0.008, y * 0.008), 8, 0.9), stdout);
          //putc (256 * gen.hybridfractal (vec2d (x * 0.01, y * 0.01), 8, -.4, -4), stdout);
          //putc (256 * gen.fBm (vec2d (x * 0.002, y * 0.002), 2), stdout);
          //putc (127.49 * gen.billowfractal (vec2d (x * 0.01, y * 0.01), 9) + 128, stdout);
#elif 1
  int N = 25000;

  printf ("P6 %d %d 255\n", N, N);
  for (int y = 0; y < N; ++y)
    {
      if (!(y&63))fprintf (stderr, "y %d\n", y);//D

      for (int x = 0; x < N; ++x) gen_quadspace (x, y, 0);
    }
#else
  int N = 200;

  //printf ("P6 %d %d 255\n", N, N);
  // pmake&&server/deliantra-server >x&&convert -depth 8 -size 512xx512 gray:x x.ppm&& cv x.ppm
  for (int z = 0; z < N; ++z)
    {
      if (!(z&7))fprintf (stderr, "z %d\n", z);//D
  for (int y = 0; y < N; ++y)
    for (int x = 0; x < N; ++x)
      {
#if 0
        float v = gen3.ridgedmultifractal (vec3d (x * 0.001 + 0.2, y * 0.001 + 0.2, z * 0.01 + 0.2), 1.03, 2) * 2;

        if (z < 64)
          v = v * (z * z) / (64 * 64);

        if (v <= 0.9)
          continue;
#endif
        static frac3d gen3 (10);
        //float v = gen3.turbulence (vec3d (x * 0.01, y * 0.01, z * 0.01));
        float v = gen3.ridgedmultifractal (vec3d (x * 0.001, y * 0.001, z * 0.001), 1.003, 2);

        if (v <= 0.48) continue;

        float r[4];
        int i[4];

        r[0] = x;
        r[1] = y;
        r[2] = z;
        r[3] = v;

        memcpy (i, r, 16);

        i[0] = htonl (i[0]);
        i[1] = htonl (i[1]);
        i[2] = htonl (i[2]);
        i[3] = htonl (i[3]);

        fwrite (i, 4*4, 1, stdout);
      }
    }
#endif

  exit (0);
}