Hi Juan, I have now had a chance to do a first pass review of your changes for GL_EXT_shader_image_load_store and for now I'd like to hold back from merging any changes as I'm not yet comfortable on how best to provide support for this feature in the OSG. Your proposed solution feels a bit awkward to me and I'm afraid I don't yet have a suggestion of to address it, to be able to do this I'll need to spend more time studying the GL feature and reflecting on how it'll be used in the context of the OSG and how we might support it class wise.
To help in this process could you provide a few examples of where you see this feature being used? Thanks, Robert. On 17 October 2011 10:49, Juan Hernando <[email protected]> wrote: > Dear all, > Some months ago I wrote a simple extension to support > GL_EXT_shader_image_load_store in the GL3 version of OSG. > What I've done is to provide a new StateAttribute which is called > ImageTextureBinding. This state attribute binds a texture to a shader "image > unit" identified by the number passed in the constructor. The current > interface is rather simple, providing the minimum set of functions to make > it usable. > The implementation does not worry about synchronization issues, being the > user who takes the responsibility of invoking glMemoryBarrier as needed. > > In the diff file included I've also added suppport for symbolic names for > texture formats present in GL_ARB_texture_rg. > > The example included shows the result of rasterizing 100 overlapping > screen-aligned quads while doing atomic increments of a single channel > integer texture at the raster positions. In my hardware (NVidia), it's > curious to see how the quad is decomposed in 2 triangles that overlap at the > diagonal. The example has a command line option (--early-test) to show the > difference between enabling early z-tests or not in the fragment shader. > > Please, feel free to make any comments or suggestions. > > Best regards, > Juan > > _______________________________________________ > osg-submissions mailing list > [email protected] > http://lists.openscenegraph.org/listinfo.cgi/osg-submissions-openscenegraph.org > _______________________________________________ osg-submissions mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-submissions-openscenegraph.org
