[games] Implement in-game saves #11380

fetzerch · 2017-01-05T22:42:12Z

Implement in-game (save ram) saves.

Description

This implements in-game saves where the frontend accesses the game's memory and saves/loads it to/from disk. This is mostly used in emulators for SRAM (battery backed up ram on cartridges) or memory cards.

For reference, these are the other ways how saving is implemented in the Game API:

Savestates (Savestate manager #11034)
The game saves it directly (already implemented and used for example by ScummVM)

Differences to save states:

Works only for supported games (e.g. emulated games with SRAM support)
Often works emulator independent (and can be used to start a game with one emulator and continue with another)
Visible in-game (e.g. in-game save game selection menus)
Closer to how saving in the good old days worked where one could only save at certain points where the game allowed it.

Previously PRed to the retroplayer banch in garbear#73
API-Change: Merging has to be synced with kodi-game/game.libretro#10.

Motivation and Context

Save games.

How Has This Been Tested?

Best tested with 2048 or SNES/GBA emulators.

Types of change

Bug fix (non-breaking change which fixes an issue)
New feature (non-breaking change which adds functionality)
Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

My code follows the Code guidelines of this project
My change requires a change to the documentation, either Doxygen or wiki
I have updated the documentation accordingly
I have read the CONTRIBUTING document
I have added tests to cover my change
All new and existing tests passed

xbmc/games/addons/GameClient.h

@@ -161,6 +162,9 @@ class CGameClient : public ADDON::CAddonDll
  std::unique_ptr<IGameClientPlayback> m_playback; // Interface to control playback
  GAME_REGION           m_region;              // Region of the loaded game

+  // In-game saves
+  std::unique_ptr<CGameClientInGameSaves> m_inGameSaves;


xbmc/games/addons/GameClientInGameSaves.cpp

+
+void CGameClientInGameSaves::Load()
+{
+    Load(GAME_MEMORY_SAVE_RAM);


xbmc/games/addons/GameClientInGameSaves.cpp

+
+void CGameClientInGameSaves::Save()
+{
+    Save(GAME_MEMORY_SAVE_RAM);


xbmc/games/addons/GameClientInGameSaves.cpp

+  if (size > 0)
+  {
+    const std::string path = GetPath(memoryType);
+


xbmc/games/addons/GameClientInGameSaves.h

+  /*!
+   * \brief This class implements in-game saves.
+   *
+   * Some games do not implement state persistence on their own, but rely on the frontend for saving their current


akva2 · 2017-01-06T08:43:19Z

https://imgflip.com/i/1h66wu

akva2 · 2017-01-06T08:48:14Z

(and it looks all good to me now).

Change GetMemory to use a non-const pointer. This is necessary for in-game (SRAM) saves that need to write into the memory.

fetzerch · 2017-01-06T13:01:48Z

Thanks!

Does it make sense to save periodically (maybe every minute)? We don't control cores and they might crash before we're able to stop a game. Guess that could easily be implemented with a CTimer in CGameClient and could even be reused later for savestates. If it makes sense this can however come in a separate PR.

akva2 · 2017-01-06T13:03:51Z

maybe, but then we'd definitely need to ping-pong on the sram file, or you may end up dumping corrupted data (either because the core has stomped ram, or because of timing, core may be busy updating sram).

garbear · 2017-01-07T00:40:30Z

I would like to abstract the various software and hardware details of managing one's saved data.

I think the best interface would be a "Saved game" concept associated with a single game/file. The saved game would include the player's current progress, including awards/achievements (scraped from a ROM achievements service) and a history of saved data. The saved data would include all forms of the game's storage at a point in time, and we could eventually allow more fine-grained memory management like loading/saving/importing/exporting SRAM saves (per-file) or savestates (per-emulator).

xbmc/games/addons/GameClientInGameSaves.cpp

+
+#define INGAME_SAVES_DIRECTORY          "InGameSaves"
+#define INGAME_SAVES_EXTENSION_SAVE_RAM ".sav"
+#define INGAME_SAVES_EXTENSION_RTC      ".rtc"


garbear · 2017-02-04T22:38:31Z

@fetzerch is this ready to go in?

xbmc/games/addons/GameClient.cpp

@@ -276,6 +277,9 @@ bool CGameClient::OpenFile(const CFileItem& file, IGameAudioCallback* audio, IGa
  if (!InitializeGameplay(file.GetPath(), audio, video))
    return false;

+  m_inGameSaves.reset(new CGameClientInGameSaves(this, &m_struct));


fetzerch · 2017-02-05T09:35:37Z

From my side it's ready - but I thought you don't want it in its current from (without the abstraction).
Imho it would be nice to have save games working in nightly-builds and we can refactor it to a more fancy solution afterwards, but then at least the code doing the actual saving/loading is there.
Another advantage would be that we don't have to sync the game.libretro API change any more. It's always something you have to remember when rebasing the retroplayer branches.

Therefore: Your button, (needs a merge of kodi-game/game.libretro#10 as well).

garbear · 2017-02-05T09:53:48Z

jenkins build this please

fetzerch added Type: Feature non-breaking change which adds functionality Component: Games labels Jan 5, 2017

fetzerch requested a review from garbear January 5, 2017 22:42

fetzerch mentioned this pull request Jan 5, 2017

Implement SRAM saves garbear/xbmc#73

Closed

5 tasks

notspiff reviewed Jan 6, 2017

View reviewed changes

fetzerch added 2 commits January 6, 2017 10:21

[Game API] Update to Game API v1.0.29 - GetMemory (non const)

ac41cb1

Change GetMemory to use a non-const pointer. This is necessary for in-game (SRAM) saves that need to write into the memory.

[GameClient] Implement in-game saves

9de6c02

fetzerch force-pushed the sram-master branch from f7c3bae to 9de6c02 Compare January 6, 2017 09:21

thebrid reviewed Jan 10, 2017

View reviewed changes

xbmc/games/addons/GameClientInGameSaves.cpp

#define INGAME_SAVES_DIRECTORY "InGameSaves"

#define INGAME_SAVES_EXTENSION_SAVE_RAM ".sav"

#define INGAME_SAVES_EXTENSION_RTC ".rtc"

This comment was marked as spam.

Sign in to view

garbear mentioned this pull request Jan 27, 2017

RetroPlayer Leia 18.0 issues garbear/xbmc#80

Open

70 tasks

garbear reviewed Feb 4, 2017

View reviewed changes

garbear approved these changes Feb 5, 2017

View reviewed changes

garbear merged commit 6b29488 into xbmc:master Feb 5, 2017

MartijnKaijser added the v18 Leia label Feb 9, 2017

MartijnKaijser added this to the L 18.0-alpha1 milestone Feb 9, 2017

garbear mentioned this pull request May 26, 2017

Fix crash when closing standalone games #12166

Merged

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

[games] Implement in-game saves #11380

[games] Implement in-game saves #11380

fetzerch commented Jan 5, 2017

This comment was marked as spam.

This comment was marked as spam.

This comment was marked as spam.

This comment was marked as spam.

This comment was marked as spam.

This comment was marked as spam.

This comment was marked as spam.

This comment was marked as spam.

This comment was marked as spam.

This comment was marked as spam.

This comment was marked as spam.

akva2 commented Jan 6, 2017

akva2 commented Jan 6, 2017

fetzerch commented Jan 6, 2017

akva2 commented Jan 6, 2017 •

edited

garbear commented Jan 7, 2017

This comment was marked as spam.

garbear commented Feb 4, 2017

This comment was marked as spam.

This comment was marked as spam.

fetzerch commented Feb 5, 2017

garbear commented Feb 5, 2017

[games] Implement in-game saves #11380

[games] Implement in-game saves #11380

Conversation

fetzerch commented Jan 5, 2017

Description

Motivation and Context

How Has This Been Tested?

Types of change

Checklist:

This comment was marked as spam.

This comment was marked as spam.

This comment was marked as spam.

This comment was marked as spam.

This comment was marked as spam.

This comment was marked as spam.

This comment was marked as spam.

This comment was marked as spam.

This comment was marked as spam.

This comment was marked as spam.

This comment was marked as spam.

akva2 commented Jan 6, 2017

akva2 commented Jan 6, 2017

fetzerch commented Jan 6, 2017

akva2 commented Jan 6, 2017 • edited

garbear commented Jan 7, 2017

This comment was marked as spam.

garbear commented Feb 4, 2017

This comment was marked as spam.

This comment was marked as spam.

fetzerch commented Feb 5, 2017

garbear commented Feb 5, 2017

akva2 commented Jan 6, 2017 •

edited