#version 300 es

in  highp vec2 uv;
out highp vec4 color;

uniform sampler2D sampler1;
uniform int nv;
uniform highp float nvGain;

void main()
{
  color = texture(sampler1, uv);

  if (nv == 1)
  {
    highp float lumi = 1.0 - (0.2126 * color.r + 0.7152 * color.g + 0.0722 * color.b);
    color *= 1.0 + lumi;
    color *= nvGain;
  }
}