+/* 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;
+};
+
+enum retro_hw_render_interface_type
+{
+ RETRO_HW_RENDER_INTERFACE_VULKAN = 0,
+ RETRO_HW_RENDER_INTERFACE_D3D9 = 1,
+ RETRO_HW_RENDER_INTERFACE_D3D10 = 2,
+ RETRO_HW_RENDER_INTERFACE_D3D11 = 3,
+ RETRO_HW_RENDER_INTERFACE_D3D12 = 4,
+ RETRO_HW_RENDER_INTERFACE_GSKIT_PS2 = 5,
+ RETRO_HW_RENDER_INTERFACE_DUMMY = INT_MAX
+};
+
+/* Base struct. All retro_hw_render_interface_* types
+ * contain at least these fields. */
+struct retro_hw_render_interface
+{
+ enum retro_hw_render_interface_type interface_type;
+ unsigned interface_version;
+};
+
+typedef void (RETRO_CALLCONV *retro_set_led_state_t)(int led, int state);
+struct retro_led_interface
+{
+ retro_set_led_state_t set_led_state;
+};
+
+/* Retrieves the current state of the MIDI input.
+ * Returns true if it's enabled, false otherwise. */
+typedef bool (RETRO_CALLCONV *retro_midi_input_enabled_t)(void);
+
+/* Retrieves the current state of the MIDI output.
+ * Returns true if it's enabled, false otherwise */
+typedef bool (RETRO_CALLCONV *retro_midi_output_enabled_t)(void);
+
+/* Reads next byte from the input stream.
+ * Returns true if byte is read, false otherwise. */
+typedef bool (RETRO_CALLCONV *retro_midi_read_t)(uint8_t *byte);
+
+/* Writes byte to the output stream.
+ * 'delta_time' is in microseconds and represent time elapsed since previous write.
+ * Returns true if byte is written, false otherwise. */
+typedef bool (RETRO_CALLCONV *retro_midi_write_t)(uint8_t byte, uint32_t delta_time);
+
+/* Flushes previously written data.
+ * Returns true if successful, false otherwise. */
+typedef bool (RETRO_CALLCONV *retro_midi_flush_t)(void);
+
+struct retro_midi_interface
+{
+ retro_midi_input_enabled_t input_enabled;
+ retro_midi_output_enabled_t output_enabled;
+ retro_midi_read_t read;
+ retro_midi_write_t write;
+ retro_midi_flush_t flush;
+};
+
+enum retro_hw_render_context_negotiation_interface_type
+{
+ RETRO_HW_RENDER_CONTEXT_NEGOTIATION_INTERFACE_VULKAN = 0,
+ RETRO_HW_RENDER_CONTEXT_NEGOTIATION_INTERFACE_DUMMY = INT_MAX
+};
+
+/* Base struct. All retro_hw_render_context_negotiation_interface_* types
+ * contain at least these fields. */
+struct retro_hw_render_context_negotiation_interface
+{
+ enum retro_hw_render_context_negotiation_interface_type interface_type;
+ unsigned interface_version;
+};
+
+/* Serialized state is incomplete in some way. Set if serialization is
+ * usable in typical end-user cases but should not be relied upon to
+ * implement frame-sensitive frontend features such as netplay or
+ * rerecording. */
+#define RETRO_SERIALIZATION_QUIRK_INCOMPLETE (1 << 0)
+/* The core must spend some time initializing before serialization is
+ * supported. retro_serialize() will initially fail; retro_unserialize()
+ * and retro_serialize_size() may or may not work correctly either. */
+#define RETRO_SERIALIZATION_QUIRK_MUST_INITIALIZE (1 << 1)
+/* Serialization size may change within a session. */
+#define RETRO_SERIALIZATION_QUIRK_CORE_VARIABLE_SIZE (1 << 2)
+/* Set by the frontend to acknowledge that it supports variable-sized
+ * states. */
+#define RETRO_SERIALIZATION_QUIRK_FRONT_VARIABLE_SIZE (1 << 3)
+/* Serialized state can only be loaded during the same session. */
+#define RETRO_SERIALIZATION_QUIRK_SINGLE_SESSION (1 << 4)
+/* Serialized state cannot be loaded on an architecture with a different
+ * endianness from the one it was saved on. */
+#define RETRO_SERIALIZATION_QUIRK_ENDIAN_DEPENDENT (1 << 5)
+/* Serialized state cannot be loaded on a different platform from the one it
+ * was saved on for reasons other than endianness, such as word size
+ * dependence */
+#define RETRO_SERIALIZATION_QUIRK_PLATFORM_DEPENDENT (1 << 6)
+
+#define RETRO_MEMDESC_CONST (1 << 0) /* The frontend will never change this memory area once retro_load_game has returned. */
+#define RETRO_MEMDESC_BIGENDIAN (1 << 1) /* The memory area contains big endian data. Default is little endian. */
+#define RETRO_MEMDESC_SYSTEM_RAM (1 << 2) /* The memory area is system RAM. This is main RAM of the gaming system. */
+#define RETRO_MEMDESC_SAVE_RAM (1 << 3) /* The memory area is save RAM. This RAM is usually found on a game cartridge, backed up by a battery. */
+#define RETRO_MEMDESC_VIDEO_RAM (1 << 4) /* The memory area is video RAM (VRAM) */
+#define RETRO_MEMDESC_ALIGN_2 (1 << 16) /* All memory access in this area is aligned to their own size, or 2, whichever is smaller. */
+#define RETRO_MEMDESC_ALIGN_4 (2 << 16)
+#define RETRO_MEMDESC_ALIGN_8 (3 << 16)
+#define RETRO_MEMDESC_MINSIZE_2 (1 << 24) /* All memory in this region is accessed at least 2 bytes at the time. */
+#define RETRO_MEMDESC_MINSIZE_4 (2 << 24)
+#define RETRO_MEMDESC_MINSIZE_8 (3 << 24)