On Tue, Sep 9, 2014 at 8:26 PM, Kenneth Graunke <kenn...@whitecape.org> wrote: > On Tuesday, September 09, 2014 10:30:16 AM Ian Romanick wrote: >> On 09/08/2014 01:10 AM, Tapani Pälli wrote: >> > From: Kalyan Kondapally <kalyan.kondapa...@intel.com> >> > >> > According to GLSL-ES Spec(i.e. 1.0, 3.0), gl_Position value is undefined >> > after the vertex processing stage if we don't write gl_Position. However, >> > GLSL 1.10 Spec mentions that writing to gl_Position is mandatory. In case >> > of GLSL-ES, it's not an error and atleast the linking should pass. >> > Currently, Mesa throws an linker error in case we dont write to gl_position >> > and Version is less then 140(GLSL) and 300(GLSL-ES). This patch changes >> > it so that we don't report an error in case of GLSL-ES. >> >> Wow. We can add this to the list of ways OpenGL ES is just plain >> broken. Since there is absolutely NO WAY this shader can produce any >> useful results, we should at least do the courtesy of generating a >> warning. So, keep the first if-condistion the same, but do >> linker_warning instead of linker_error if prog->IsES. > > I like that idea. But what about 1.40 or 1.50? I'm having a hard time > imagining how 1.40 would let you produce any useful results, either (so maybe > we should issue a warning there too). With 1.50, you at least have geometry > shaders, so you can produce real output later...
If you are using transform feedback or store instructions with rasterization disabled, gl_Position is useless. Marek _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
