OpenGL ES - Discussion/Problems Thread
Author
I'm pretty new at this, but after having played around with OpenGL ES for a little bit, I'm struck by what looks like some handicaps:
1. You can't call glGetIntegerv with either GL_MODELVIEW_MATRIX or GL_PROJECTION_MATRIX or GL_TEXTURE_MATRIX. Huh? I ran into this trying to implement billboarding for a particle system, which I don't think is possible to do without knowing the world matrix.
2. Point sprites seem to have a maximum size of 1, at least in the default setup. Why on earth have point sprites with a maximum size of 1?
Anyone else having issues with ES?
Quote:Original post by faseidmanThis is a limitation of OpenGL ES 1.0. Dynamic states can't be queried. For matrices, you can get around this by using the OES_query_matrix extension. This extension is optional, but it's supported in the QUALCOMM implementation (I'm the one who wrote it, actually).
1. You can't call glGetIntegerv with either GL_MODELVIEW_MATRIX or GL_PROJECTION_MATRIX or GL_TEXTURE_MATRIX. Huh? I ran into this trying to implement billboarding for a particle system, which I don't think is possible to do without knowing the world matrix.
Quote:Original post by faseidmanYou mean points? Point sprites aren't supported in 1.0.
2. Point sprites seem to have a maximum size of 1, at least in the default setup. Why on earth have point sprites with a maximum size of 1?
We didn't support a point size other than 1 because doing so requires that antialiasing, and we didn't want to do that in a software implementation. However, the phones that contest entries will run on will have some hardware support, and I believe that sizes greater than 1 will be supported.
Author
Thanks for clarifying that about point sprites. I read something about point sprite support on khronos' website, so I assumed it was implemented here.
As for the worldview matrix thing, would that be portable to a cell phone then if it's supported by QUALCOMM? It would be great if I could use it, but if it's going to cause a problem I'd rather do something that I know is going to work.
Thanks for your help.
As for the worldview matrix thing, would that be portable to a cell phone then if it's supported by QUALCOMM? It would be great if I could use it, but if it's going to cause a problem I'd rather do something that I know is going to work.
Thanks for your help.
Quote:Original post by faseidmanThey were added in 1.1, which was announced at SIGGRAPH last week. There aren't really any 1.1 implementations available yet, though.
Thanks for clarifying that about point sprites. I read something about point sprite support on khronos' website, so I assumed it was implemented here.
Quote:Original post by faseidmanIt's as portable as any OpenGL extension. In other words, as long as you check for the extension before using it, and provide a backup plan if it's not there, it'll be portable.
As for the worldview matrix thing, would that be portable to a cell phone then if it's supported by QUALCOMM? It would be great if I could use it, but if it's going to cause a problem I'd rather do something that I know is going to work.
For the purposes of this contest, though, the OES_query_matrix extension will be fully supported on the platforms used for judging, so feel free to use it.
Author
Thanks man, you rock.
Is the call slow? I read somewhere today that reading things back from the graphics hardware is a very slow operation. If that's true I'd rather just keep a copy of the world stack in memory.
Is the call slow? I read somewhere today that reading things back from the graphics hardware is a very slow operation. If that's true I'd rather just keep a copy of the world stack in memory.
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