Look up into texture seems complicated. http://oss.sgi.com/projects/ogl-sample/registry/ARB/GLSLangSpec.Full.1.10.59.pdf show function as : vec4 texture1DProj (sampler1D sampler, vec4 coord [, float bias] )
That's quite complexe. Inside http://www.lighthouse3d.com/opengl/glsl/index.php?texture we see : uniform sampler2D tex; void main() { vec4 color = texture2D(tex,gl_TexCoord[0].st); gl_FragColor = color; } So, texture2D take a pointer and a vector. That's a lot more simple than previous function. But what is used today ? GLSL propose a lot of functionalities. What is needed is real world example. I need to know what is performance critical in current shader. Nicolas Boulay Le lundi 17 Avril 2006 17:03, Timothy Miller a écrit : > I've been thinking about programmable shaders and what we should > implement. If we have some reasonable way to load immediate values > into vectors, then we can subsume all of the following into a single > dot product primitive: > - scalar adds and subtracts > - scalar multiplies > - vector dot product > - matrix multiply > > We'll need a few other things like computing reciprocols (for > divides), vector sums and vector multiplies. (Later today, when I > have time, I'll produce a more formal and precise description of the > primitives I have in mind.) > > Anyhow, it seems to me that we should look at some examples. There > are two things we can do here. Some people with experience can write > out, in high-level pseudo-code, some simple shader programs. And > someone else could look at the OGA "model" and convert that into the > pseudo code corresponding to how it would be fully implemented in a > programmable shader (some details can be left out). > > This will help us figure out which primitives we need. And from > experience later, we can figure out where we might benefit from adding > a few more and optimizing some things. > _______________________________________________ > Open-graphics mailing list > [email protected] > http://lists.duskglow.com/mailman/listinfo/open-graphics > List service provided by Duskglow Consulting, LLC (www.duskglow.com) _______________________________________________ Open-graphics mailing list [email protected] http://lists.duskglow.com/mailman/listinfo/open-graphics List service provided by Duskglow Consulting, LLC (www.duskglow.com)
