libakgl/include/akgl/tilemap.h

#ifndef _TILEMAP_H_
#define _TILEMAP_H_

#include "actor.h"
#include "staticstring.h"
#include <jansson.h>

#define AKGL_TILEMAP_MAX_WIDTH                        512
#define AKGL_TILEMAP_MAX_HEIGHT                       512
#define AKGL_TILEMAP_MAX_LAYERS                       16
#define AKGL_TILEMAP_MAX_TILESETS                     16
#define AKGL_TILEMAP_MAX_TILES_PER_IMAGE              65536
#define AKGL_TILEMAP_MAX_TILESET_NAME_SIZE            512
#define AKGL_TILEMAP_MAX_TILESET_FILENAME_SIZE        512
#define AKGL_TILEMAP_MAX_OBJECT_NAME_SIZE             512
#define AKGL_TILEMAP_MAX_OBJECTS_PER_LAYER            128

#define AKGL_TILEMAP_OBJECT_TYPE_ACTOR                1

#define AKGL_TILEMAP_LAYER_TYPE_TILES                 1
#define AKGL_TILEMAP_LAYER_TYPE_OBJECTS               2

typedef struct {
    float x;
    float y;
    int gid;
    int id;
    int height;
    int width;
    int rotation;
    int type;
    bool visible;
    akgl_Actor *actorptr;
    char name[AKGL_TILEMAP_MAX_OBJECT_NAME_SIZE];
} akgl_TilemapObject;

typedef struct {
    short type;
    float opacity;
    bool visible;
    int height;
    int width;
    int x;
    int y;
    int id;
    int data[AKGL_TILEMAP_MAX_WIDTH * AKGL_TILEMAP_MAX_HEIGHT];
    akgl_TilemapObject objects[AKGL_TILEMAP_MAX_OBJECTS_PER_LAYER];
} akgl_TilemapLayer;

typedef struct {
    int columns;
    int firstgid;
    char imagefilename[AKGL_TILEMAP_MAX_TILESET_FILENAME_SIZE];
    int imageheight;
    int imagewidth;
    char name[AKGL_TILEMAP_MAX_TILESET_NAME_SIZE];
    SDL_Texture *texture;
    // Use this as a lookup table instead of storing tiles
    // in individual textures to blit them from a single
    // texture at runtime
    // FIXME: This is probably not very efficient. For a map
    // with a single tileset it makes sense. For a map with
    // multiple tilesets you may have set A start at firstgid 1
    // and have 1728 tiles. Set B may start at firstgid 1729 and
    // have 1728 more tiles. This means Set B has 1728 empty
    // tile_offsets[] entries before firstgid 1729 because of the
    // way akgl_tilemap_load_tilesets() works. This is really inefficient
    // and should be improved in the future, and will eventually
    // lead to premature exhaustion of AKGL_TILEMAP_MAX_TILES_PER_IMAGE
    // because set D or E may only have 64 tiles but they may be
    // at the upper end of the array bound already because of this.
    int tile_offsets[AKGL_TILEMAP_MAX_TILES_PER_IMAGE][2];
    int tilecount;
    int tileheight;
    int tilewidth;
    int spacing;
    int margin;
} akgl_Tileset;

typedef struct {
    int tilewidth;
    int tileheight;
    int width;
    int height;
    int numlayers;
    int orientation; // 0 = orthogonal, 1 = isometric
    int numtilesets;
    akgl_Tileset tilesets[AKGL_TILEMAP_MAX_TILESETS];
    akgl_TilemapLayer layers[AKGL_TILEMAP_MAX_LAYERS];
} akgl_Tilemap;

akerr_ErrorContext AKERR_NOIGNORE *akgl_tilemap_load(char *fname, akgl_Tilemap *dest);
akerr_ErrorContext AKERR_NOIGNORE *akgl_tilemap_draw(SDL_Renderer *renderer, akgl_Tilemap *dest, SDL_FRect *viewport, int layeridx);
akerr_ErrorContext AKERR_NOIGNORE *akgl_tilemap_draw_tileset(SDL_Renderer *renderer, akgl_Tilemap *dest, int tilesetidx);

/*
 * These functions are part of the internal API and should not be called by the user.
 * They are only exposed here for unit testing.
 */

akerr_ErrorContext AKERR_NOIGNORE *akgl_get_json_tilemap_property(json_t *obj, char *key, char *type, json_t **dest);
akerr_ErrorContext AKERR_NOIGNORE *akgl_get_json_properties_string(json_t *obj, char *key, akgl_String **dest);
akerr_ErrorContext AKERR_NOIGNORE *akgl_get_json_properties_integer(json_t *obj, char *key, int *dest);
akerr_ErrorContext AKERR_NOIGNORE *akgl_tilemap_compute_tileset_offsets(akgl_Tilemap *dest, int tilesetidx);
akerr_ErrorContext AKERR_NOIGNORE *akgl_tilemap_load_layer_objects(akgl_Tilemap *dest, json_t *root, int layerid);
akerr_ErrorContext AKERR_NOIGNORE *akgl_tilemap_load_layer_tile(akgl_Tilemap *dest, json_t *root, int layerid);
akerr_ErrorContext AKERR_NOIGNORE *akgl_tilemap_load_layers(akgl_Tilemap *dest, json_t *root);
akerr_ErrorContext AKERR_NOIGNORE *akgl_tilemap_load_tilesets_each(json_t *tileset, akgl_Tilemap *dest, int tsidx);
akerr_ErrorContext AKERR_NOIGNORE *akgl_tilemap_load_tilesets(akgl_Tilemap *dest, json_t *root);


#endif //_TILEMAP_H_