mesh index array size limitations?

Comments

• ar2rsawseen Maintainer

  April 2014

  wow that sounds like a lot of indices.
  Unfortunately I don't know, it may be internal limitation, it may be device limitation (GPU, etc) will forward to @atilim

  http://appcodingeasy.com/Gideros-Mobile

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• keszegh Member

  April 2014

  thanks, it is for my drawing app 'fragmenter' and so this limit poses a limit on the number of strokes one can draw on a single frame. and on pc (but on android too) the above mentioned limit comes much earlier than other cpu etc resource limits.
  
  i did not notice that earlier but now with new drawing methods i'm implementing the triangle-generation can be multiplied by x32, so now i can reach the above limit quite easily with few seconds of drawing. and that's too early.
  
  i can go around it by splitting a mesh into submeshes but that's annoying, i have complicated/hierarchical enough data structures without this already (layers, in each layer frames and now in each frame i would need to handle subframes).

  Longtitle Productions, creator of
  Fragmenter - animated loop machine and IKONOMIKON - the memory game

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• atilim Maintainer

  April 2014 edited April 2014 Accepted Answer

  Hi,
  
  Unfortunately, it's OpenGL ES limitation and 2^16 is the limit.
  
  (Extra info: glDrawElements https://www.khronos.org/opengles/sdk/docs/man/xhtml/glDrawElements.xml only accepts GL_UNSIGNED_BYTE or GL_UNSIGNED_SHORT and not GL_UNSIGNED_INT)
  

  http://en.wikipedia.org/wiki/Cytorus

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• keszegh Member

  April 2014 edited April 2014

  thanks for the info @atilim,
  is/will it be the same in opengl es 2?
  also on pc there is normal opengl, couldn't that make a difference? (in gideros player or win export whenever it comes)

  Longtitle Productions, creator of
  Fragmenter - animated loop machine and IKONOMIKON - the memory game

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• atilim Maintainer

  April 2014

  Desktop OpenGL already doesn't have this limitation (2^32 is the limit) and OpenGL ES 3 has lifted this limitation. You can see the difference by looking at the 'type' parameter:
  
  OpenGL ES 2: http://www.khronos.org/opengles/sdk/docs/man/xhtml/glDrawElements.xml
  OpenGL ES 3: http://www.khronos.org/opengles/sdk/docs/man3/html/glDrawElements.xhtml
  OpenGL Desktop: http://www.opengl.org/sdk/docs/man4/html/glDrawElements.xhtml
  
  But I'm not sure whether we'll lift this limitation with Gideros desktop version.

  http://en.wikipedia.org/wiki/Cytorus

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• keszegh Member

  April 2014

  thanks for the details,
  "But I'm not sure whether we'll lift this limitation with Gideros desktop version. " ... at least now you know that there is a need for it (from one person, heh), so if there will be a chance to do so, you can decide better.
  

  Longtitle Productions, creator of
  Fragmenter - animated loop machine and IKONOMIKON - the memory game

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• atilim Maintainer

  April 2014

  Most probably desktop Gideros will use https://code.google.com/p/angleproject/ and therefore we will have same limitations with OpenGL ES 2.0. (Using Angle means better compatibility between mobile and desktop versions.)
  

  Likes: SinisterSoft

  http://en.wikipedia.org/wiki/Cytorus

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• keszegh Member

  April 2014

  i see, well, i'm not that expert, so if that's the way, then ok. although it is surprising for me that the opengl es code is translated to directx and not to opengl, seems weird. also, as dx is win only, translating to opengl wouldn't make unified win, mac and linux desktop support easier?
  
  as this limitation persists on mobile anyway, probably i will also need a solution that works everywhere.

  Longtitle Productions, creator of
  Fragmenter - animated loop machine and IKONOMIKON - the memory game

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• SinisterSoft Maintainer

  April 2014 edited April 2014

  OpenGL isn't built into windows from 7 onwards. So there would be no point doing an OpenGL version for desktop as modern Windows machines wouldn't play the game unless the user had installed OpenGL drivers from the gfx manufacturer. That's why it's easier to use angleproject as a converter than make a directx specific version. (that's what I think anyhow).
  
  This gives me confidence that it should be perfect for Gideros:
  
  "ANGLE is used as the default WebGL backend for both Google Chrome and Mozilla Firefox on Windows platforms. Chrome uses ANGLE for all graphics rendering on Windows, including the accelerated Canvas2D implementation and the Native Client sandbox environment."
  

  Coder, video game industry veteran (since the '80s, ❤'s assembler), arrested - never convicted hacker (in the '90s), dad of five, he/him (if that even matters!).
  https://deluxepixel.com

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• keszegh Member

  April 2014

  i see. also i read now a bit about different solutions for open gl es support on desktop and it seemed that angleproject is the best option.
  but it already feels so good talking about the 'hows' of desktop support and not the 'ifs' (although we can still talk about the 'whens').

  Longtitle Productions, creator of
  Fragmenter - animated loop machine and IKONOMIKON - the memory game

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