const char *textlabelbase_fs =
  "#version 400\n"
  "precision highp float;\n"
  "uniform sampler2D u_texture;\n"
  "in vec2 texc;\n"
  "\n"
  "out vec4 outColor;\n"
  "\n"
  "void main(void)\n"
  "{\n"
  "  outColor = texture(u_texture, texc);\n"
  "  if (outColor.a == 0.)\n"
  "    discard;\n"
  "}\n"
  "\n";
