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Revision as of 15:41, 21 February 2016 by Criezy (talk | contribs) (Fix link to bug (it was giving a404 error). I also changed it to use the new bug ID.)
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Name SAGA Engine TODO
Technical Contact(s) SAGA Engine Team
Subsystem Engine



  • ITE is completable
  • The Amiga version is not supported yet
  • Demo versions:
    • The older non-interactive demos are supported
    • The newer interactive demo versions of the game are supported
    • The original DOS demo is not supported yet, as it is based on very early version of engine, so many structures are different. Most of the resources have been mapped but they're still untested. The actors and objects list needs to be moved to our code. They've been found but not processed yet


  • The demo has two parts, an interactive and a non-interactive one. It's playable and probably completable
  • The full game is completable, with some small glitches



  • [ITE] There's a slight pause (about a second or less) when a digital music track loops, when using compressed music. This pause does not exist when the music tracks are not compressed
  • [IHNM/ITE] The first frame of animations is not shown when changing scenes. Perhaps a problem with the rendering pipeline. Currently, there's a hack to show it correctly. This issue is apparent in IHNM in Nimdok's chapter, with the mob of prisoners, when the prisoners break loose and take the prison. Note that there is currently a hack that fixes it, but the prisoner animation itself is problematic as well, and will look incorrect if the player hasn't put the jar in the box and tries to leave the prison. In this case, a video is shown, and after the video is done and the game returns back to the scene, the prisoner animation is wrong, because the animation is paused and then resumed, and it doesn't resume from the first frame (thus showing incorrectly)
  • [IHNM] The (dis)appearing compact disk in Ellen's chapter is currently handled with a hack
  • [IHNM] Pathfinding bugs: When a character moves over an exit zone while doing an action, he stops his action and exits the room instead. The known places where this occurs are:
    • Chapter 2 (Ellen): When trying to interact with the monitor on the right in the monitors room, Ellen enters the next room instead. The character interacts correctly with the monitor in the IHNM demo, but there the monitor has a corresponding hitzone, which does not exist in the full version. [Bug #{{{id}}}]
    • Chapter 4 (Nimdok): When Nimdok is moved to the patient's table in the recovery room, he doesn't stop at the table and enters the back room instead
    • A workaround has been installed by commit c825cc41a57b40a9af6ca51a3674b90e5f17e00f. As this fix causes regressions if used globally, it is limited to IHNM and the two rooms (chapter/scene) listed above.
  • [IHNM] Chapter 1 (Gorrister): In the engine room if you pick up the bloody key and re-enter the room another key is there (seems the corresponding hitzone is not disabled correctly)
  • [IHNM] Chapter 2 (Ellen): When Ellen picks up the chalice, the phrase she says "Now I got the cup, but what do I do with it?" is cut off prematurely, as she exits the scene
  • [IHNM] When clicking on Gorrister in the character selection screen, it seems that it doesn't play the entire animation. He should disappear completely (he does in the original), but in ScummVM he doesn't. Not always, at least.
  • [IHNM] When clicking on the right side of a screen in Nimdok's chapter, a masking issue occurs sometimes. Here's a screenshot:
Masking bug in Nimdok's chapter

compress_saga tool

  • [IHNM] Currently, the SFX.RES file in IHNM cannot be compressed
  • [ITE] MacBinary files are not supported yet (used by the Mac CD Guild version)


  • [ITE] We need to find out where following script functions are called:
    • SF_cycleColors -- all implementation bits sit in palanim.cpp
    • sfPlayVoice -- used in ITE CD

Long-term ToDos for the SAGA engine


  • Make actor animation Event-driven. See FIXME in actor.cpp. Maybe it should be INTERVAL_EVENT
  • In many places RSC_LoadResource() is called but memory is not freed afterwards, i.e. there is a huge leak
  • Optimize screen output. Now we blit whole screen for each frame. Use "dirty rectangles" instead
  • Remove use of floating point, especially doubles.
  • The text is not always positioned like in the original (can be seen in ITE, but it's more apparent in IHNM, where text that should be on the top of the screen is in the bottom)

MIDI related

  • When using the original XMIDI music resources, some songs play at the wrong speed. The worst example I've heard of this is the "Elk Fanfare" during the intro. It could be the meta events we don't handle, but at least the tempo event doesn't seem to make any difference. Maybe something in the data header instead...?

Bugs in the original games

Check about bugs that occured in the original games (some of which have been fixed in ScummVM) in the SAGA Bugs page