eleni.mutantstargoat.com Git - demo/blob - src/terrain.cc

   1 #include <gmath/gmath.h>
   2
   3 #include "camera.h"
   4 #include "gfxapi.h"
   5 #include "image.h"
   6 #include "mesh.h"
   7 #include "meshgen.h"
   8 #include "object.h"
   9 #include "scene.h"
  10 #include "terrain.h"
  11
  12 static float calc_height(float u, float v, void *ptr);
  13
  14 Terrain::Terrain()
  15 {
  16         vis_scene = 0;
  17 }
  18
  19 Terrain::~Terrain()
  20 {
  21 }
  22
  23 bool Terrain::init()
  24 {
  25         vis_scene = new Scene;
  26
  27         return true;
  28 }
  29
  30 void Terrain::destroy()
  31 {
  32         delete vis_scene;
  33 }
  34
  35 struct GenData {
  36         const TerrainParams *tp;
  37         float xoffs;
  38         float yoffs;
  39 };
  40
  41 bool Terrain::generate(const TerrainParams &params)
  42 {
  43         tiles.clear();
  44
  45         float txsz = params.xsz / params.xtiles;
  46         float tysz = params.ysz / params.ytiles;
  47
  48         for(int i=0; i<params.ytiles; i++) {
  49                 for(int j=0; j<params.xtiles; j++) {
  50                         TerrainTile tile;
  51                         tile.mesh = gfx_create_mesh();
  52
  53                         GenData data;
  54                         data.tp = &params;
  55                         data.xoffs = (float)j / (float)params.xtiles;
  56                         data.yoffs = (float)i / (float)params.ytiles;
  57
  58                         gen_heightfield(tile.mesh, txsz, tysz, params.max_height,
  59                                         params.tile_usub, params.tile_vsub, calc_height,
  60                                         (void*)&data);
  61
  62                         float xoffs = j * txsz - params.xsz / 2.0 + txsz / 2.0;
  63                         float yoffs = i * tysz - params.ysz / 2.0 + tysz / 2.0;
  64
  65                         Mat4 offmat;
  66                         offmat.translation(xoffs, 0, yoffs);
  67                         tile.mesh->transform(offmat);
  68
  69                         tiles.push_back(tile);
  70
  71 /*
  72         the terrain scene stores objects only
  73         no need to fill the mat, mesh std::vectors
  74 */
  75                         Object *o = new Object;
  76                         o->mesh = tile.mesh;
  77                         o->material = &material;
  78                         o->transform = Mat4::identity;
  79
  80                         vis_scene->objects.push_back(o);
  81                 }
  82         }
  83         return true;
  84 }
  85
  86 Scene *Terrain::get_visible(const Camera *camera) const
  87 {
  88         return vis_scene;
  89 }
  90
  91 static float calc_height(float u, float v, void *ptr)
  92 {
  93         if(!ptr) {
  94                 fprintf(stderr, "Terrain parameters not found.\n");
  95                 return 0;
  96         }
  97
  98         GenData *data = (GenData*)ptr;
  99         const TerrainParams *tp = data->tp;
 100
 101         u = u / tp->xtiles + data->xoffs;
 102         v = v / tp->ytiles + data->yoffs;
 103
 104         float sn = gph::fbm(u * tp->noise_freq, v * tp->noise_freq, tp->num_octaves);
 105
 106         if(tp->coarse_heightmap) {
 107                 Vec4 texel = tp->coarse_heightmap->lookup_nearest(u, v);
 108                 sn *= texel.x;
 109         }
 110         return sn;
 111 }