HI Juan, Clamping to 0.0 to 1.0 range is standard for OpenGL texturing. I believe this now a new GL extension for a float format that isn't clamped to the 0.0 to 1.0 range, so have a look on OpenGL .org and other places online for further info.
Robert. On Mon, Sep 20, 2010 at 6:14 PM, Juan Hernando <[email protected]> wrote: > Dear all, > I'm writing some GLSL code that needs to access a 1D floating point texture > as input in a vertex shader. My problem is that I'm getting > clamped/normalized (not sure which one) values inside GLSL instead of the > full range values. > > For debug purposes I've setup a dummy texture like this: > osg::Image *image = new osg::Image; > float *tmp = new float; > image->setImage(1, 1, 1, GL_R32F, GL_RED, GL_FLOAT, > (unsigned char*)tmp, osg::Image::USE_NEW_DELETE); > tmp[0] = 2 > osg::Texture1D *texture = new osg::Texture1D(); > texture->setFilter(osg::Texture::MIN_FILTER, osg::Texture::NEAREST); > texture->setFilter(osg::Texture::MAG_FILTER, osg::Texture::NEAREST); > texture->setImage(image); > > In this case, the following GLSL expression: > texture1D(the_texture, 0.0).r > returns 1. > > But if I change the image setup to: > float *tmp = new float[4]; > image->setImage(1, 1, 1, GL_RGBA32F, GL_RGBA, GL_FLOAT, > (unsigned char*)tmp, osg::Image::USE_NEW_DELETE); > it works fine. > > Looking at the source code from Texture.cpp I've found that > Texture::computeInternalFormatType() does not deal with GL_R32F, GL_RG32F, > GL_R32UI, ... they all fall into the default clause of the switch statement > which assigns _internalFormatType to NORMALIZED. At the same time I've found > no member function to change that attribute manually. > Is that an omission or am I doing something wrong in the initialization? > If that's an omission, is there an easy workaround that doesn't require > recompiling the library? > > Thanks and best regards, > Juan > _______________________________________________ > osg-users mailing list > [email protected] > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org > _______________________________________________ osg-users mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
