uniform sampler2D _MainTex;
void main ()
{
  float x;
  x = (texture2D (_MainTex, gl_TexCoord[0].xy).w - 0.001);
  if ((x < 0.0)) {
    discard;
  };
  gl_FragData[0] = vec4(0.0, 0.0, 0.0, 0.0);
}