Hi, I have converted my fixed function OSG program to a shader pipeline (using setVertexAttribArray and shaders instead of the setVertexPointer et al) and did run into some issues when disabling "UseVertexAttributeAliasing", and OSG is compiled with OPENGL_PROFILE=GLCORE (So OSG_GL_VERTEX_FUNCS_AVAILABLE is unset). I tested the same code on a linux with OSG compiled for a FFP. And there, the code works as expected.
A simple test program is here: https://github.com/fwiesel/vertexarrayfunctest An API trace of the failing case shows the following interesting part: ... glEnableVertexAttribArray(0) glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, NULL) # NULL is okay, the Array has been bound before glDisableVertexAttribArray(0) glDisableVertexAttribArray(1) glDisableVertexAttribArray(2) glDisableVertexAttribArray(11) glDisableVertexAttribArray(12) glDrawArrays(GL_POINTS, 0, 500) ... No prior call to enable the array 1,2, 11, or 12 are issued. The glDisableVertexAttribArray calls are coming from osg::State::applyDisablingOfVertexAttributes() https://github.com/openscenegraph/OpenSceneGraph/blob/master/src/osg/State.cpp#L1296-L1304 as _useVertexAttributeAliasing is false, and each "<array>._lazy_disable" is true. The state of "<array>._enabled" is never checked, as "disable<array>Pointer" is unconditionally mapped to the aliased "disableVertexAttribArray" I think, the bug lies in the assumption of the lazy disabling, that if we do not use the aliasing, that there is a fixed function pipeline. But if OSG_GL_VERTEX_FUNCS_AVAILABLE the functions are unconditionally mapped to aliased vertex attributes. I think, the whole lazy disabling of aliased attributes is superfluous in that context, as each vertex attribute tracks its own state already, and have proposed a patch accordingly: https://github.com/openscenegraph/OpenSceneGraph/pull/125 With the patch applied, the code runs as expected. Does anyone have a different explanation or a better proposal for solving the issue? It doesn't seem to be the acceptable solution. Cheers, Fabian _______________________________________________ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
