From Tim George, "Currently there is a problem with using a camera with a viewport with a non 0 offset and also using an FBO. The problem is that only area made up of the viewports width and height is drawn based on an offset of 0,0 instead of using the viewports offset.

It is caused by line 991 in RenderStage.cpp:


Code:
fbo_ext->glBlitFramebuffer(
0, 0, static_cast<GLint>(_viewport->width()), static_cast<GLint>(_viewport->height()),
0, 0, static_cast<GLint>(_viewport->width()), static_cast<GLint>(_viewport->height()),
blitMask, GL_NEAREST);



which is not taking into account the viewport x and y when performing the blit. It probably should be:


Code:
fbo_ext->glBlitFramebuffer(
static_cast<GLint>(_viewport->x()), static_cast<GLint>(_viewport->y()),
static_cast<GLint>(_viewport->width()) + static_cast<GLint>(_viewport->x()), static_cast<GLint>(_viewport->height()) + static_cast<GLint>(_viewport->y()),
static_cast<GLint>(_viewport->x()), static_cast<GLint>(_viewport->y()),
static_cast<GLint>(_viewport->width()) + static_cast<GLint>(_viewport->x()), static_cast<GLint>(_viewport->height()) + static_cast<GLint>(_viewport->y()),
blitMask, GL_NEAREST);
"

Note from Robert Osfield, made small tweak to above on merge, changing the width+x to x+width to make it read more naturally.



git-svn-id: http://svn.openscenegraph.org/osg/OpenSceneGraph/branches/OpenSceneGraph-3.2@14404 16af8721-9629-0410-8352-f15c8da7e697