add new enums: RenderLayer, EngineValueID, eNullFont, FileSortStyle and SortDirection

[ericoporto]

https://github.com/adventuregamestudio/ags-manual/wiki/StandardEnums

eNullFont

This can be used instead of an existing font, and instead will draw no text, and return 0 size for the text.

---

enum RenderLayer
{
  eRenderLayerNone      = 0x00000000,
  eRenderLayerEngine    = 0x00000001,
  eRenderLayerCursor    = 0x00000002,
  eRenderLayerUI        = 0x00000004,
  eRenderLayerRoom      = 0x00000008,
  eRenderLayerAll       = 0xFFFFFFFF
};

Used in functions that take a screenshot. It allows to be specific to what elements should be rendered in the screen capture, so you can for example, create a screenshot of only the room layer and not include any GUI or cursor on top. The Engine layer is for things like the in-engine FPS counter.

---

enum FileSortStyle
{
  eFileSort_None = 0,
  eFileSort_Name = 1,
  eFileSort_Time = 2
};

enum SortDirection
{
  eSortNoDirection = 0,
  eSortAscending   = 1,
  eSortDescending  = 2
};

These are used when sorting files or save slots, in functions that returns lists, and give you some configuration on how these lists should be sorted.

---

// Engine value constant name pattern:
// ENGINE_VALUE_<I,II,S,SI>_NAME, where
//   I - integer, II - indexed integer, S - string, SI - indexed string.
enum EngineValueID
{
  ENGINE_VALUE_UNDEFINED = 0,            // formality...
  ENGINE_VALUE_SI_VALUENAME,             // get engine value's own name, by its index
  ENGINE_VALUE_S_ENGINE_NAME,
  ENGINE_VALUE_S_ENGINE_VERSION,         // N.N.N.N (with an optional custom tag)
  ENGINE_VALUE_S_ENGINE_VERSION_FULL,    // full, with bitness, endianess and any tag list
  ENGINE_VALUE_S_DISPLAY_MODE_STR,
  ENGINE_VALUE_S_GFXRENDERER,
  ENGINE_VALUE_S_GFXFILTER,
  ENGINE_VALUE_I_SPRCACHE_MAXNORMAL,   // sprite cache capacity limit (in KB)
  ENGINE_VALUE_I_SPRCACHE_NORMAL,  // sprite cache capacity filled (in KB)
  ENGINE_VALUE_I_SPRCACHE_LOCKED,  // amount of locked sprites (in KB)
  ENGINE_VALUE_I_SPRCACHE_EXTERNAL, // amount of external sprites, that means dynamic sprites (in KB)
  ENGINE_VALUE_I_TEXCACHE_MAXNORMAL,   // texture cache capacity limit (in KB)
  ENGINE_VALUE_I_TEXCACHE_NORMAL,  // texture cache capacity filled (in KB)
  ENGINE_VALUE_I_FPS_MAX,    // max fps, this is set by SetGameSpeed
  ENGINE_VALUE_I_FPS,      // real average fps (updates along with the game run)
  ENGINE_VALUE_LAST                      // in case user wants to iterate them
};