polyadvent

A game engine from scratch in C
git clone git://jb55.com/polyadvent
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terrain.h (1988B)

      1 
      2 
      3 #ifndef POLYADVENT_TERRAIN_H
      4 #define POLYADVENT_TERRAIN_H
      5 
      6 #include "entity.h"
      7 #include "model.h"
      8 #include "debug.h"
      9 
     10 #define MAX_CELL_VERTS 4
     11 #define MAX_VERT_TRIS 20
     12 
     13 struct point;
     14 
     15 struct perlin_settings {
     16     double freq;
     17     int depth;
     18     int seed;
     19     double amplitude;
     20     double ox, oy;
     21     double o1, o1s;
     22     double o2, o2s;
     23     double scale;
     24     double exp;
     25 };
     26 
     27 struct tri {
     28 #ifdef DEBUG
     29     struct entity_id debug_id;
     30 #endif
     31     int vert_indices[3];
     32 };
     33 
     34 struct vert_tris {
     35     u8 tri_count;
     36     struct tri tris[MAX_VERT_TRIS];
     37 };
     38 
     39 struct terrain_cell {
     40     u8 vert_count;
     41     int verts_index[MAX_CELL_VERTS];
     42 #ifdef DEBUG
     43     struct entity_id debug_ent[MAX_CELL_VERTS];
     44 #endif
     45 };
     46 
     47 struct terrain {
     48     struct entity_id entity_id;
     49     struct terrain_cell *grid;
     50     struct vert_tris *vtris;
     51     int n_cells; // all cells = grid_cells^2
     52     float cell_size;
     53     float *verts;
     54     int n_verts;
     55     struct perlin_settings settings;
     56     struct point *samples;
     57     double (*fn)(struct terrain *, double, double);
     58     int n_samples;
     59     float pdist;
     60     double size;
     61 };
     62 
     63 double old_noisy_boi(struct terrain *, double x, double y);
     64 
     65 
     66 void update_terrain(struct terrain *terrain, const double pdist);
     67 void gen_terrain_samples(struct terrain *terrain, float scale, const double pdist);
     68 void init_terrain(struct terrain *terrain, float size);
     69 void reset_terrain(struct terrain *terrain, float size);
     70 void create_terrain(struct terrain *terrain, float scale, int seed);
     71 void destroy_terrain(struct terrain *terrain);
     72 void query_terrain_grid(struct terrain *terrain, float x, float y, struct terrain_cell *cells[9]);
     73 
     74 static inline int grid_index(struct terrain *terrain, float x) {
     75     return x / terrain->cell_size;
     76 }
     77 
     78 static inline void grid_pos_debug(const char *thing, struct terrain *terrain, float *pos) {
     79     int gx = grid_index(terrain, pos[0]);
     80     int gy = grid_index(terrain, pos[1]);
     81     debug("%s grid pos (%d, %d)\n", thing, gx, gy);
     82 }
     83 
     84 #endif /* POLYADVENT_TERRAIN_H */