iPad 2 Graphics: Will anti-aliasing and AF be supported?

Discussion in 'iPad' started by BergerFan, Mar 3, 2011.

  1. BergerFan macrumors 68020

    BergerFan

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  2. GnillGnoll macrumors member

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    #2
    AA and AF have been supported since iOS 4.0 on all devices (AF actually has been available even earlier on pre-3GS devices).

    However, these features have seen little use so far because of the performance cost and because of a lack of developer awareness. iPad 2 should easily be fast enough to use both, so let the developers know if you think an app would benefit from AA and/or AF.
     
  3. MRU macrumors demi-god

    MRU

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    #3
    A GnillGnoll says, it depends whether developers implement it or not.

    What we may see is updates to existing games with AA enabled for iPad 2.
     
  4. maflynn Moderator

    maflynn

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    #4
    The risk there is then fragmenting the iOS platform further. People complain about android being fragmented but the iOS platform isn't all that better.
     
  5. GnillGnoll macrumors member

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    #5
    For most developers there are just two iOS device families, updated each year – the differences between iPad WiFi and 3G or iPod Touch and iPhone are often irrelevant. If you want the platform to progress then some fragmentation is unavoidable.

    Adding AA and AF is a simple image quality improvement that requires almost no effort from developers (no additional assets needed, just a few lines of code + testing) and has no impact on the application's functionality. For light graphical loads even the older devices would benefit.
     
  6. mikethebigo macrumors 68000

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    #6
    Does anyone know if safari on the iPad 2 uses AA for text?
     
  7. BergerFan thread starter macrumors 68020

    BergerFan

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    #7
    I guess the answer to my op, is yes! :D
    Real Racing 2, Infinity Blade, Pinball HD, War Pinball HD all support at least AA, Real Racing 2 definitely supports both.

    I've noticed zero change, so far.
     
  8. Krevnik macrumors 68040

    Krevnik

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    #8
    iOS and OS X have been using AA for text for a very long time (10 years). The catch is that the AA algorithm that Apple uses is different than the one that say, Microsoft uses in Windows. ClearType aims to produce crisp text, even if it slightly distorts the typeface used, and Microsoft picks default fonts in Windows based on minimizing that distortion effect. Apple's AA algorithm aims at more accurate typeface display, even if it winds up a bit fuzzy as a result. The catch is that with a PPI only in the 130 PPI range, there aren't enough pixels to make a typeface look crisp, and Apple likes to use curvy fonts that require AA to look right, producing the fuzzy text on the iPad.

    Without the AA, the iPhone 4's display of text would not look anywhere near as good as it does.
     
  9. goMac macrumors 603

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    #9
    What? No fragmenting here at all. All that will happen is an app will run prettier on one device than another.

    Stuff like AA doesn't break the app on older devices, it just won't look as pretty.
     
  10. Pressure macrumors 68040

    Pressure

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    #10
    With the ImgTec SGX543 Anti-Aliasing is basically free, so it would be silly not to use it.
     
  11. mikethebigo macrumors 68000

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    #11
    Very interesting. Thanks for the explanation. I am confused however, because my MBP has a lower PPI than the iPad, and yet the text looks much nicer and clearer than on the iPad. Is there a reason for this?
     
  12. Krevnik macrumors 68040

    Krevnik

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    #12
    There are a few different things that can be at play:

    - How the text is anti-aliased. This even includes how it is rendered onto the display (CoreGraphics vs CoreAnimation for example). There was an ugly bug in the 10.5 betas for example where if you put text on a CA layer, it would render terribly due to bad scaling by the GPU. I've noticed that iOS uses CoreAnimation more heavily, which has a lot of dependency on the GPU not doing weird bilinear filtering on your 2D bitmaps. Subpixel AA doesn't work so well in this situation either unless you can get the GPU to do it for you.
    - How far from the screen do you normally use the MBP versus the iPad? The MBP's default of 110 PPI isn't much lower than the 126 PPI, so they are actually pretty comparable. Anyone with the high-res 15" display has 127 PPI there as well.
    - Font size. A UI that displays larger fonts versus smaller fonts will appear to be anti-aliased differently.
    - Font typeface. Any difference in the font typeface will change how it looks when anti-aliased. While Apple uses Helvetica in both cases, I do believe they are different typefaces within the Helvetica family.

    Put simply, because the text is fuzzy, that your sign that AA is being used. Without AA it would look pixelated and distorted from the original shape. Depending on how you render things, and the quality of the GPU (if you use the 3D rasterizer like Apple does now), you can drastically change the quality of the AA.
     

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