jenesis - resize screen

Discussion in 'NDS - Emulation and Homebrew' started by evoo1, Aug 7, 2008.

Aug 7, 2008

jenesis - resize screen by evoo1 at 5:16 PM (2,060 Views / 0 Likes) 5 replies

  1. evoo1
    OP

    Member evoo1 GBAtemp Regular

    Joined:
    Jul 25, 2008
    Messages:
    109
    Location:
    Vienna
    Country:
    Austria
    Is there any way to configure jenesis in a way that it fits the whole game on the screen of the DS? As of now, I have to navigate the picture to the left/right with my shoulder buttons if i want to see all of it.

    any ideas? thanks!
     
  2. Destructobot

    Member Destructobot Crave the Hammer

    Joined:
    Oct 15, 2006
    Messages:
    5,005
    Location:
    Portland, OR
    Country:
    United States
    It's not possible, and according to the author it never will be. Something about how the emulator uses the DS's video hardware to render the Genesis graphics.

    There was an older version (I forget which) that had a software renderer with full scaling, but it didn't run nearly as fast and it didn't have sound.
     
  3. evoo1
    OP

    Member evoo1 GBAtemp Regular

    Joined:
    Jul 25, 2008
    Messages:
    109
    Location:
    Vienna
    Country:
    Austria
    Well no sound and fps drops are probably not worth the fullscreen.
    thanks though [​IMG]
     
  4. DanTheManMS

    Member DanTheManMS aka Ricochet Otter

    Joined:
    Jun 2, 2007
    Messages:
    4,325
    Location:
    Georgia
    Country:
    United States
    Right, here's a slightly more technical explanation. Emulators for the DS have two options. They can either take advantage of the DS's fast dedicated 2D hardware for drawing to the screen, using DS sprites and tiles (this is called hardware rendering), or they can function like emulators for the PC operate, that is, figure out what the screen should look like in memory and then paint the image to the screen pixel by pixel (called software rendering).

    Hardware rendering is faster, and due to this jEnesisDS uses hardware rendering, but because of the way the DS renders the screen you can only scale vertically, not horizontally. The reason is because the DS draws row-by-row, so you can simply skip a few rows here and there to squish the screen vertically. You cannot however skip a column of pixels when drawing. Thus, horizontal scaling is not possible with hardware emulation.

    With software emulation, since the emulator determines what the screen should look like before painting it to the screen, the image can be modified before being drawn to the screen, thus allowing horizontal scaling to be possible. This is unlike hardware emulation in which the DS doesn't really know what it's displaying on the screen, it's just blindly drawing it (not really "blindly" but more blind than software emulation at least).

    jEnesisDS v0.4a has a software renderer version, as does PicoDriveDS, but because software rendering is much slower, you'll have to use frameskip to maintain full speed, and you won't have any sound.
     
  5. evoo1
    OP

    Member evoo1 GBAtemp Regular

    Joined:
    Jul 25, 2008
    Messages:
    109
    Location:
    Vienna
    Country:
    Austria
    Oh I thought jenesis still uses software rendering and I was amazed by how smooth it runs xD
    Thanks for clearing that up for me [​IMG]
     
  6. DanTheManMS

    Member DanTheManMS aka Ricochet Otter

    Joined:
    Jun 2, 2007
    Messages:
    4,325
    Location:
    Georgia
    Country:
    United States
    Nope, v0.4a is the only released version to ever use software rendering. All other versions use hardware rendering, hence the full speed with no frameskip.

    Just on a side note, frameskip isn't even an option in the hardware build because it would do no good. With hardware rendering, less than 5% of the CPU time is spent drawing to the screen. With software rendering this figure shoots up closer to 50%, hence why frameskip has an effect there.
     

Share This Page