Constant webxr::glwindow::PASSTHROUGH_FRAGMENT_SHADER

const PASSTHROUGH_FRAGMENT_SHADER: &[u8] = b"
  #version 330 core
  layout(location=0) out vec4 color;
  uniform sampler2D image;
  in vec2 vTexCoord;
  void main() {
    color = texture(image, vTexCoord);
  }
";