text: #include <stddef.h>
  #include <stdlib.h>
  
  #include "fontdesc.h"
  #include "renderer.h"
  
  
  int font_desc_alloc_size(const char *filename) {
    return offsetof(FontDesc, filename) + strlen(filename) + 1;
  }
  
  void font_desc_init(FontDesc *font_desc, const char *filename, float size, unsigned int font_options) {
    memcpy(font_desc->filename, filename, strlen(filename) + 1);
    font_desc->size = size;
    font_desc->options = font_options;
    font_desc->tab_size = 4;
    font_desc->cache_length = 0;
    font_desc->cache_last_index = 0; /* Normally no need to initialize. */
  }
  
  void font_desc_free(FontDesc *font_desc) {
    for (int i = 0; i < font_desc->cache_length; i++) {
      ren_free_font(font_desc->cache[i].font);
    }
    font_desc->cache_length = 0;
  }
  
  void font_desc_set_tab_size(FontDesc *font_desc, int tab_size) {
    font_desc->tab_size = tab_size;
    for (int i = 0; i < font_desc->cache_length; i++) {
      ren_set_font_tab_size(font_desc->cache[i].font, tab_size);
    }
  }
  
  int font_desc_get_tab_size(FontDesc *font_desc) {
    return font_desc->tab_size;
  }
  
  static void load_scaled_font(FontDesc *font_desc, int index, int scale) {
    RenFont *font = ren_load_font(font_desc->filename, scale * font_desc->size, font_desc->options);
    if (!font) {
      /* The font was able to load when initially loaded using renderer.load.font.
         If now is no longer available we just abort the application. */
      fprintf(stderr, "Fatal error: unable to load font %s. Application will abort.\n",
        font_desc->filename);
      exit(1);
    }
    font_desc->cache[index].font = font;
    font_desc->cache[index].scale = scale;
  }
  
  RenFont *font_desc_get_font_at_scale(FontDesc *font_desc, int scale) {
    int index = -1;
    for (int i = 0; i < font_desc->cache_length; i++) {
      if (font_desc->cache[i].scale == scale) {
        index = i;
        break;
      }
    }
    if (index < 0) {
      index = font_desc->cache_length;
      if (index < FONT_CACHE_ARRAY_MAX) {
        load_scaled_font(font_desc, index, scale);
        font_desc->cache_length = index + 1;
      } else {
        // FIXME: should not print into the stderr or stdout.
        fprintf(stderr, "Warning: max array of font scale reached.\n");
        index = (font_desc->cache_last_index == 0 ? 1 : 0);
        ren_free_font(font_desc->cache[index].font);
        load_scaled_font(font_desc, index, scale);
      }
    }
    font_desc->cache_last_index = index;
    return font_desc->cache[index].font;
  }
  
  