uniform sampler2D tex;

void main()
{
	const float softness = 0.008;

	float alpha = texture2D(tex, gl_TexCoord[0].st).a;
	float mask = smoothstep(0.5 - softness, 0.5 + softness, alpha);

	gl_FragColor.rgb = gl_Color.rgb;
	gl_FragColor.a = mask;
}