glslangvalidator -V offscreen.vert -o offscreen.vert.spv
glslangvalidator -V offscreen.frag -o offscreen.frag.spv
glslangvalidator -V quad.vert -o quad.vert.spv
glslangvalidator -V quad.frag -o quad.frag.spv
glslangvalidator -V mirror.vert -o mirror.vert.spv
glslangvalidator -V mirror.frag -o mirror.frag.spv