Glyph artifacts when using glyph cache

Created by: Boscop

When I render glyphs like in the gpu_cache example, I get artifacts like this:

It looks like it's caused by glyphs being tightly packed in the texture and OpenGL trying to interpolate because of self.cache_tex.sampled().magnify_filter(glium::uniforms::MagnifySamplerFilter::Nearest). But the problem persists when I change that to Linear. Maybe it could be solved by leaving 1 pixel space between glyphs horizontally and vertically? Or maybe there is a better solution by choosing a different way for OpenGL to access the texture data?