punchie-engine/src/AssetManager.c

#include "AssetManager.h"
#include "Renderer.h"
#include "SDL_image.h"
#include "SDL_mixer.h"
#include "SDL_render.h"
#include "constants.h"
#include "reusable_ids.h"
#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>

typedef struct asset {
  AssetType type;
  char *path;
  union {
    SDL_Texture *texture;
    Mix_Chunk *chunk;
    Mix_Music *music;
  } data;
} Asset;

struct asset_manager {
  size_t count;
  size_t deleted_count;
  AssetID reusable_ids[MAX_ASSET_COUNT];
  Asset assets[MAX_ASSET_COUNT];
};

AssetManager *create_asset_manager() {
  AssetManager *am = (AssetManager *)malloc(sizeof(AssetManager));
  if (!am) {
    return NULL;
  }

  am->count = 0;
  am->deleted_count = 0;
  memset(am->reusable_ids, 0, sizeof(am->reusable_ids));
  memset(am->assets, 0, sizeof(am->assets));

  return am;
}

AssetID load_asset_to_manager(AssetManager *am, const char *path,
                              AssetType type, Renderer *renderer) {
  if (!am || type == ASSET_TYPE_COUNT) {
    return -1;
  }

  Asset asset = {};
  bool loaded = true;

  // TODO (Abdelrahman): Implement a way to make sure that an asset with the
  // same path is not already loaded. If the user attempts to load an asset
  // that already exists, the function should return -1 to indicate an error

  switch (type) {
  case ASSET_TYPE_IMAGE:
    if (!renderer) {
      loaded = false;
      break;
    }

    asset.data.texture = load_texture(renderer, path);

    if (!(asset.data.texture)) {
      loaded = false;
    }

    break;
  case ASSET_TYPE_AUDIO_FX:
    // TODO (Abdelrahman): Implement loading audio chunks
    break;
  case ASSET_TYPE_MUSIC:
    // TODO (Abdelrahman): Implement loading music
    break;
  default:
    loaded = false;
    break;
  }

  if (!loaded) {
    return -1;
  }

  AssetID id;

  if (am->deleted_count > 0) {
    id = (AssetID)reuse_id((int32_t *)am->reusable_ids, am->deleted_count);
    am->deleted_count -= 1;
    am->count += 1;
  } else {
    id = (am->count)++;
  }

  am->assets[id].type = type;

  am->assets[id].path = (char *)malloc(strlen(path) + 1);
  strcpy(am->assets[id].path, path);

  am->assets[id].data = asset.data;

  switch (type) {
  case ASSET_TYPE_IMAGE:
    asset.data.texture = NULL;
    break;
  case ASSET_TYPE_AUDIO_FX:
    asset.data.chunk = NULL;
    break;
  case ASSET_TYPE_MUSIC:
    asset.data.music = NULL;
    break;
  default:
    break;
  }

  return id;
}

void remove_asset_from_manager(AssetManager *am, AssetID id) {
  if (!am || am->count == 0) {
    return;
  }

  free(am->assets[id].path);
  am->assets[id].path = 0;

  switch (am->assets[id].type) {
  case ASSET_TYPE_IMAGE:
    SDL_DestroyTexture(am->assets[id].data.texture);
    am->assets[id].data.texture = NULL;
    break;
  case ASSET_TYPE_AUDIO_FX:
    // TODO (Abdelrahman): Implement closing audio chunk
    break;
  case ASSET_TYPE_MUSIC:
    // TODO (Abdelrahman): Implement closing music
    break;
  default:
    break;
  }

  am->reusable_ids[(am->deleted_count)++] = id;

  am->count -= 1;
}

SDL_Texture *get_texture(AssetManager *am, AssetID id) {
  if (am->assets[id].type != ASSET_TYPE_IMAGE) {
    return NULL;
  }

  return am->assets[id].data.texture;
}

Mix_Chunk *get_audio_chunk(AssetManager *am, AssetID id) {
  if (am->assets[id].type != ASSET_TYPE_AUDIO_FX) {
    return NULL;
  }

  return am->assets[id].data.chunk;
}

Mix_Music *get_music(AssetManager *am, AssetID id) {
  if (am->assets[id].type != ASSET_TYPE_MUSIC) {
    return NULL;
  }

  return am->assets[id].data.music;
}

void destroy_asset_manager(AssetManager *am) {
  if (!am) {
    return;
  }

  for (size_t i = 0; i < am->count; ++i) {
    free(am->assets[i].path);
    am->assets[i].path = NULL;

    switch (am->assets[i].type) {
    case ASSET_TYPE_IMAGE:
      SDL_DestroyTexture(am->assets[i].data.texture);
      am->assets[i].data.texture = NULL;
      break;
    case ASSET_TYPE_AUDIO_FX:
      // TODO (Abdelrahman): Implement closing audio chunk
      break;
    case ASSET_TYPE_MUSIC:
      // TODO (Abdelrahman): Implement closing music
      break;
    default:
      break;
    }
  }

  am->count = 0;
  am->deleted_count = 0;

  free(am);
  am = NULL;
}