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Re: [Public WebGL] Re: maximum length of identifiers in WebGL GLSL



I would be fine with a 128 character limit; 64 might also be fine, but I worry that someone making extensive use of structs could end up with some fairly lengthy identifiers.  64 is still a good bit even with structs though; does anyone have any experience with long identifiers in actual real-world GLSL?

    - Vlad

----- Original Message -----
> ping.
> 
> 
> Anyone have an opinion on this?
> 
> 
> There are 2 issues.
> 
> 
> Issue #1: It's possible a GL driver could be exploited by passing it
> giant identifiers. Examples.
> 
> 
> ctx.bindAttribLocation(program, 4MegIdentifier, location);
> ctx.shaderSource(shader, shaderWith4MegIdentifiers, ...);
> 
> 
> Issue #2: Having a Min/Max identifier size of WebGL means programs
> will be more likely to work across platforms.
> 
> 
> Right now one platform might have a 64 character limit, another a 128
> character limit. If you're developing on the 128 character limit
> system you won't know your WebGL program is not going to work on some
> other system. If instead the spec says it must support 128 characters
> to be WebGL conformance than an system who's OpenGL driver does not
> support 128 character will either need a new driver or the WebGL
> implementation will need to alias the ids. In either case WebGL
> becomes more compatible across system.
> 
> 
> Note that the GLSL translator everyone is currently using already has
> a 128 character limit but it would be nice if that limit (or some
> limit) was formalized in the spec.
> 
> 
> 
> 
> 
> 
> 
> On Thu, Jul 29, 2010 at 3:11 PM, Gregg Tavares (wrk) < gman@google.com
> > wrote:
> 
> 
> Do we want to specify a maximum identifier length for WebGL GLSL?
> 
> 
> I didn't see one in the GLSL spec. I was going to write a test with
> really long identifiers (4meg) to see if I could find some drivers
> that had problems with them but it might be better to just require
> WebGL to enforce some maximum length. 64 chars? 128 chars? 256 chars
> which will make shaders less likely to fail on some drivers.
> 
> 
> Thoughts?
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