​

varying vec2 vTexCoord;

​

uniform sampler2D u_maskTexture;

​

void main() {

  vec2 texCoord = vec2(vTexCoord.x, 1.0 - vTexCoord.y);

  vec4 maskColor = texture2D(u_maskTexture, texCoord);

  //gl_FragColor = color;

  gl_FragColor = maskColor;

  float a = maskColor.a ;

  a = a - 1.0/a*0.0035;

  if (a < 0.059) {

    a = 0.0;

  }

  gl_FragColor.a = a;

}