text: export default `\
  #define SHADER_NAME experimentalshader-layer-fragment-shader
  
  #ifdef GL_ES
  precision highp float;
  #endif
  
  varying vec4 vColor;
  varying vec2 unitPosition;
  varying float innerUnitRadius;
  
  void main(void) {
    float distToCenter = length(unitPosition);
  
    if (distToCenter <= 1.0 && distToCenter >= innerUnitRadius) {
      gl_FragColor = vColor;
      gl_FragColor.a *= exp(-pow(distToCenter, 2.0)/0.3);
    } else {
      discard;
    }
  }
  `
  