[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

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



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?