On 07/11/2013 10:18 PM, Paul Berry wrote:
On 11 July 2013 16:30, Ian Romanick <i...@freedesktop.org> wrote:
I believe you're right, that there's a bug in our implementation--it would successfully compile this shader, and it shouldn't. In fact, based on my discussion with Chad today, it sounds like we don't have any code at all to modify Mesa's behaviour when the forward-compatible flag is in effect--my understanding is that the EGL and GLX DRI front-ends just drop that flag on the floor. So to fix the bug we would have to do some plumbing work to get the flag through DRI to Mesa's gl_context.
I just verified this with an example EGL program. Mesa's EGL layer passes the forward-compatible flag to the DRI layer, and DRI ignores it.
Another possibility that Chad suggested when I was talking to him this afternoon is to just just return BAD_MATCH if the client supplies the forward-compatibility flag when requesting a 3.0+ context. Rationale: Mesa doesn't really support the forward-compatibility flag anyhow (since the EGL and GLX front-ends just drop it on the floor), and besides we don't know of any shipping apps that require it (the flag is intended as a developer aid, so it's unlikely that published apps rely on it). I don't have a really strong opinion about is, so I'll let Chad weigh in if he wants to champion this alternative.
Let's fix Mesa to simply emit EGL_BAD_MATCH if the user requests a forward- compatible context. I don't believe we have the right balance of resources and interest to properly implement and test support for the forward-compatible flag. No one users are asking for it, and it's likely nearly no one will use it. The future may change this situation, but that's a big 'may'. _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
