+#define RETRO_ENVIRONMENT_GET_HW_RENDER_INTERFACE (41 | RETRO_ENVIRONMENT_EXPERIMENTAL)
+ /* const struct retro_hw_render_interface ** --
+ * Returns an API specific rendering interface for accessing API specific data.
+ * Not all HW rendering APIs support or need this.
+ * The contents of the returned pointer is specific to the rendering API
+ * being used. See the various headers like libretro_vulkan.h, etc.
+ *
+ * GET_HW_RENDER_INTERFACE cannot be called before context_reset has been called.
+ * Similarly, after context_destroyed callback returns,
+ * the contents of the HW_RENDER_INTERFACE are invalidated.
+ */
+#define RETRO_ENVIRONMENT_SET_SUPPORT_ACHIEVEMENTS (42 | RETRO_ENVIRONMENT_EXPERIMENTAL)
+ /* const bool * --
+ * If true, the libretro implementation supports achievements
+ * either via memory descriptors set with RETRO_ENVIRONMENT_SET_MEMORY_MAPS
+ * or via retro_get_memory_data/retro_get_memory_size.
+ *
+ * This must be called before the first call to retro_run.
+ */
+#define RETRO_ENVIRONMENT_SET_HW_RENDER_CONTEXT_NEGOTIATION_INTERFACE (43 | RETRO_ENVIRONMENT_EXPERIMENTAL)
+ /* const struct retro_hw_render_context_negotiation_interface * --
+ * Sets an interface which lets the libretro core negotiate with frontend how a context is created.
+ * The semantics of this interface depends on which API is used in SET_HW_RENDER earlier.
+ * This interface will be used when the frontend is trying to create a HW rendering context,
+ * so it will be used after SET_HW_RENDER, but before the context_reset callback.
+ */
+#define RETRO_ENVIRONMENT_SET_SERIALIZATION_QUIRKS 44
+ /* uint64_t * --
+ * Sets quirk flags associated with serialization. The frontend will zero any flags it doesn't
+ * recognize or support. Should be set in either retro_init or retro_load_game, but not both.
+ */
+#define RETRO_ENVIRONMENT_SET_HW_SHARED_CONTEXT (44 | RETRO_ENVIRONMENT_EXPERIMENTAL)
+ /* N/A (null) * --
+ * The frontend will try to use a 'shared' hardware context (mostly applicable
+ * to OpenGL) when a hardware context is being set up.
+ *
+ * Returns true if the frontend supports shared hardware contexts and false
+ * if the frontend does not support shared hardware contexts.
+ *
+ * This will do nothing on its own until SET_HW_RENDER env callbacks are
+ * being used.
+ */
+#define RETRO_ENVIRONMENT_GET_VFS_INTERFACE (45 | RETRO_ENVIRONMENT_EXPERIMENTAL)
+ /* struct retro_vfs_interface_info * --
+ * Gets access to the VFS interface.
+ * VFS presence needs to be queried prior to load_game or any
+ * get_system/save/other_directory being called to let front end know
+ * core supports VFS before it starts handing out paths.
+ * It is recomended to do so in retro_set_environment
+ */
+#define RETRO_ENVIRONMENT_GET_LED_INTERFACE (46 | RETRO_ENVIRONMENT_EXPERIMENTAL)
+ /* struct retro_led_interface * --
+ * Gets an interface which is used by a libretro core to set
+ * state of LEDs.
+ */
+#define RETRO_ENVIRONMENT_GET_AUDIO_VIDEO_ENABLE (47 | RETRO_ENVIRONMENT_EXPERIMENTAL)
+ /* int * --
+ * Tells the core if the frontend wants audio or video.
+ * If disabled, the frontend will discard the audio or video,
+ * so the core may decide to skip generating a frame or generating audio.
+ * This is mainly used for increasing performance.
+ * Bit 0 (value 1): Enable Video
+ * Bit 1 (value 2): Enable Audio
+ * Bit 2 (value 4): Use Fast Savestates.
+ * Bit 3 (value 8): Hard Disable Audio
+ * Other bits are reserved for future use and will default to zero.
+ * If video is disabled:
+ * * The frontend wants the core to not generate any video,
+ * including presenting frames via hardware acceleration.
+ * * The frontend's video frame callback will do nothing.
+ * * After running the frame, the video output of the next frame should be
+ * no different than if video was enabled, and saving and loading state
+ * should have no issues.
+ * If audio is disabled:
+ * * The frontend wants the core to not generate any audio.
+ * * The frontend's audio callbacks will do nothing.
+ * * After running the frame, the audio output of the next frame should be
+ * no different than if audio was enabled, and saving and loading state
+ * should have no issues.
+ * Fast Savestates:
+ * * Guaranteed to be created by the same binary that will load them.
+ * * Will not be written to or read from the disk.
+ * * Suggest that the core assumes loading state will succeed.
+ * * Suggest that the core updates its memory buffers in-place if possible.
+ * * Suggest that the core skips clearing memory.
+ * * Suggest that the core skips resetting the system.
+ * * Suggest that the core may skip validation steps.
+ * Hard Disable Audio:
+ * * Used for a secondary core when running ahead.
+ * * Indicates that the frontend will never need audio from the core.
+ * * Suggests that the core may stop synthesizing audio, but this should not
+ * compromise emulation accuracy.
+ * * Audio output for the next frame does not matter, and the frontend will
+ * never need an accurate audio state in the future.
+ * * State will never be saved when using Hard Disable Audio.
+ */
+#define RETRO_ENVIRONMENT_GET_MIDI_INTERFACE (48 | RETRO_ENVIRONMENT_EXPERIMENTAL)
+ /* struct retro_midi_interface ** --
+ * Returns a MIDI interface that can be used for raw data I/O.
+ */
+
+#define RETRO_ENVIRONMENT_GET_FASTFORWARDING (49 | RETRO_ENVIRONMENT_EXPERIMENTAL)
+ /* bool * --
+ * Boolean value that indicates whether or not the frontend is in
+ * fastforwarding mode.
+ */
+
+#define RETRO_ENVIRONMENT_GET_TARGET_REFRESH_RATE (50 | RETRO_ENVIRONMENT_EXPERIMENTAL)
+ /* float * --
+ * Float value that lets us know what target refresh rate
+ * is curently in use by the frontend.
+ *
+ * The core can use the returned value to set an ideal
+ * refresh rate/framerate.
+ */
+
+#define RETRO_ENVIRONMENT_GET_INPUT_BITMASKS (51 | RETRO_ENVIRONMENT_EXPERIMENTAL)
+ /* bool * --
+ * Boolean value that indicates whether or not the frontend supports
+ * input bitmasks being returned by retro_input_state_t. The advantage
+ * of this is that retro_input_state_t has to be only called once to
+ * grab all button states instead of multiple times.
+ *
+ * If it returns true, you can pass RETRO_DEVICE_ID_JOYPAD_MASK as 'id'
+ * to retro_input_state_t (make sure 'device' is set to RETRO_DEVICE_JOYPAD).
+ * It will return a bitmask of all the digital buttons.
+ */
+
+/* VFS functionality */
+
+/* File paths:
+ * File paths passed as parameters when using this API shall be well formed UNIX-style,
+ * using "/" (unquoted forward slash) as directory separator regardless of the platform's native separator.
+ * Paths shall also include at least one forward slash ("game.bin" is an invalid path, use "./game.bin" instead).
+ * Other than the directory separator, cores shall not make assumptions about path format:
+ * "C:/path/game.bin", "http://example.com/game.bin", "#game/game.bin", "./game.bin" (without quotes) are all valid paths.
+ * Cores may replace the basename or remove path components from the end, and/or add new components;
+ * however, cores shall not append "./", "../" or multiple consecutive forward slashes ("//") to paths they request to front end.
+ * The frontend is encouraged to make such paths work as well as it can, but is allowed to give up if the core alters paths too much.
+ * Frontends are encouraged, but not required, to support native file system paths (modulo replacing the directory separator, if applicable).
+ * Cores are allowed to try using them, but must remain functional if the front rejects such requests.
+ * Cores are encouraged to use the libretro-common filestream functions for file I/O,
+ * as they seamlessly integrate with VFS, deal with directory separator replacement as appropriate
+ * and provide platform-specific fallbacks in cases where front ends do not support VFS. */
+
+/* Opaque file handle
+ * Introduced in VFS API v1 */
+struct retro_vfs_file_handle;
+
+/* Opaque directory handle
+ * Introduced in VFS API v3 */
+struct retro_vfs_dir_handle;
+
+/* File open flags
+ * Introduced in VFS API v1 */
+#define RETRO_VFS_FILE_ACCESS_READ (1 << 0) /* Read only mode */
+#define RETRO_VFS_FILE_ACCESS_WRITE (1 << 1) /* Write only mode, discard contents and overwrites existing file unless RETRO_VFS_FILE_ACCESS_UPDATE is also specified */
+#define RETRO_VFS_FILE_ACCESS_READ_WRITE (RETRO_VFS_FILE_ACCESS_READ | RETRO_VFS_FILE_ACCESS_WRITE) /* Read-write mode, discard contents and overwrites existing file unless RETRO_VFS_FILE_ACCESS_UPDATE is also specified*/
+#define RETRO_VFS_FILE_ACCESS_UPDATE_EXISTING (1 << 2) /* Prevents discarding content of existing files opened for writing */
+
+/* These are only hints. The frontend may choose to ignore them. Other than RAM/CPU/etc use,
+ and how they react to unlikely external interference (for example someone else writing to that file,
+ or the file's server going down), behavior will not change. */
+#define RETRO_VFS_FILE_ACCESS_HINT_NONE (0)
+/* Indicate that the file will be accessed many times. The frontend should aggressively cache everything. */
+#define RETRO_VFS_FILE_ACCESS_HINT_FREQUENT_ACCESS (1 << 0)
+
+/* Seek positions */
+#define RETRO_VFS_SEEK_POSITION_START 0
+#define RETRO_VFS_SEEK_POSITION_CURRENT 1
+#define RETRO_VFS_SEEK_POSITION_END 2
+
+/* stat() result flags
+ * Introduced in VFS API v3 */
+#define RETRO_VFS_STAT_IS_VALID (1 << 0)
+#define RETRO_VFS_STAT_IS_DIRECTORY (1 << 1)
+#define RETRO_VFS_STAT_IS_CHARACTER_SPECIAL (1 << 2)
+
+/* Get path from opaque handle. Returns the exact same path passed to file_open when getting the handle
+ * Introduced in VFS API v1 */
+typedef const char *(RETRO_CALLCONV *retro_vfs_get_path_t)(struct retro_vfs_file_handle *stream);
+
+/* Open a file for reading or writing. If path points to a directory, this will
+ * fail. Returns the opaque file handle, or NULL for error.
+ * Introduced in VFS API v1 */
+typedef struct retro_vfs_file_handle *(RETRO_CALLCONV *retro_vfs_open_t)(const char *path, unsigned mode, unsigned hints);
+
+/* Close the file and release its resources. Must be called if open_file returns non-NULL. Returns 0 on success, -1 on failure.
+ * Whether the call succeeds ot not, the handle passed as parameter becomes invalid and should no longer be used.
+ * Introduced in VFS API v1 */
+typedef int (RETRO_CALLCONV *retro_vfs_close_t)(struct retro_vfs_file_handle *stream);
+
+/* Return the size of the file in bytes, or -1 for error.
+ * Introduced in VFS API v1 */
+typedef int64_t (RETRO_CALLCONV *retro_vfs_size_t)(struct retro_vfs_file_handle *stream);
+
+/* Truncate file to specified size. Returns 0 on success or -1 on error
+ * Introduced in VFS API v2 */
+typedef int64_t (RETRO_CALLCONV *retro_vfs_truncate_t)(struct retro_vfs_file_handle *stream, int64_t length);
+
+/* Get the current read / write position for the file. Returns -1 for error.
+ * Introduced in VFS API v1 */
+typedef int64_t (RETRO_CALLCONV *retro_vfs_tell_t)(struct retro_vfs_file_handle *stream);
+
+/* Set the current read/write position for the file. Returns the new position, -1 for error.
+ * Introduced in VFS API v1 */
+typedef int64_t (RETRO_CALLCONV *retro_vfs_seek_t)(struct retro_vfs_file_handle *stream, int64_t offset, int seek_position);
+
+/* Read data from a file. Returns the number of bytes read, or -1 for error.
+ * Introduced in VFS API v1 */
+typedef int64_t (RETRO_CALLCONV *retro_vfs_read_t)(struct retro_vfs_file_handle *stream, void *s, uint64_t len);
+
+/* Write data to a file. Returns the number of bytes written, or -1 for error.
+ * Introduced in VFS API v1 */
+typedef int64_t (RETRO_CALLCONV *retro_vfs_write_t)(struct retro_vfs_file_handle *stream, const void *s, uint64_t len);
+
+/* Flush pending writes to file, if using buffered IO. Returns 0 on sucess, or -1 on failure.
+ * Introduced in VFS API v1 */
+typedef int (RETRO_CALLCONV *retro_vfs_flush_t)(struct retro_vfs_file_handle *stream);
+
+/* Delete the specified file. Returns 0 on success, -1 on failure
+ * Introduced in VFS API v1 */
+typedef int (RETRO_CALLCONV *retro_vfs_remove_t)(const char *path);
+
+/* Rename the specified file. Returns 0 on success, -1 on failure
+ * Introduced in VFS API v1 */
+typedef int (RETRO_CALLCONV *retro_vfs_rename_t)(const char *old_path, const char *new_path);
+
+/* Stat the specified file. Retruns a bitmask of RETRO_VFS_STAT_* flags, none are set if path was not valid.
+ * Additionally stores file size in given variable, unless NULL is given.
+ * Introduced in VFS API v3 */
+typedef int (RETRO_CALLCONV *retro_vfs_stat_t)(const char *path, int32_t *size);
+
+/* Create the specified directory. Returns 0 on success, -1 on unknown failure, -2 if already exists.
+ * Introduced in VFS API v3 */
+typedef int (RETRO_CALLCONV *retro_vfs_mkdir_t)(const char *dir);
+
+/* Open the specified directory for listing. Returns the opaque dir handle, or NULL for error.
+ * Support for the include_hidden argument may vary depending on the platform.
+ * Introduced in VFS API v3 */
+typedef struct retro_vfs_dir_handle *(RETRO_CALLCONV *retro_vfs_opendir_t)(const char *dir, bool include_hidden);
+
+/* Read the directory entry at the current position, and move the read pointer to the next position.
+ * Returns true on success, false if already on the last entry.
+ * Introduced in VFS API v3 */
+typedef bool (RETRO_CALLCONV *retro_vfs_readdir_t)(struct retro_vfs_dir_handle *dirstream);
+
+/* Get the name of the last entry read. Returns a string on success, or NULL for error.
+ * The returned string pointer is valid until the next call to readdir or closedir.
+ * Introduced in VFS API v3 */
+typedef const char *(RETRO_CALLCONV *retro_vfs_dirent_get_name_t)(struct retro_vfs_dir_handle *dirstream);
+
+/* Check if the last entry read was a directory. Returns true if it was, false otherwise (or on error).
+ * Introduced in VFS API v3 */
+typedef bool (RETRO_CALLCONV *retro_vfs_dirent_is_dir_t)(struct retro_vfs_dir_handle *dirstream);
+
+/* Close the directory and release its resources. Must be called if opendir returns non-NULL. Returns 0 on success, -1 on failure.
+ * Whether the call succeeds ot not, the handle passed as parameter becomes invalid and should no longer be used.
+ * Introduced in VFS API v3 */
+typedef int (RETRO_CALLCONV *retro_vfs_closedir_t)(struct retro_vfs_dir_handle *dirstream);
+
+struct retro_vfs_interface
+{
+ /* VFS API v1 */
+ retro_vfs_get_path_t get_path;
+ retro_vfs_open_t open;
+ retro_vfs_close_t close;
+ retro_vfs_size_t size;
+ retro_vfs_tell_t tell;
+ retro_vfs_seek_t seek;
+ retro_vfs_read_t read;
+ retro_vfs_write_t write;
+ retro_vfs_flush_t flush;
+ retro_vfs_remove_t remove;
+ retro_vfs_rename_t rename;
+ /* VFS API v2 */
+ retro_vfs_truncate_t truncate;
+ /* VFS API v3 */
+ retro_vfs_stat_t stat;
+ retro_vfs_mkdir_t mkdir;
+ retro_vfs_opendir_t opendir;
+ retro_vfs_readdir_t readdir;
+ retro_vfs_dirent_get_name_t dirent_get_name;
+ retro_vfs_dirent_is_dir_t dirent_is_dir;
+ retro_vfs_closedir_t closedir;
+};
+
+struct retro_vfs_interface_info
+{
+ /* Set by core: should this be higher than the version the front end supports,
+ * front end will return false in the RETRO_ENVIRONMENT_GET_VFS_INTERFACE call
+ * Introduced in VFS API v1 */
+ uint32_t required_interface_version;
+
+ /* Frontend writes interface pointer here. The frontend also sets the actual
+ * version, must be at least required_interface_version.
+ * Introduced in VFS API v1 */
+ struct retro_vfs_interface *iface;
+};