#version 450 core
layout(early_fragment_tests) in;
layout (std140, binding = 1) uniform TheLight { vec4 lightPos; vec4 lumRad; };
layout (binding = 0) uniform sampler2D posTexture;
layout (binding = 1) uniform sampler2D normals;
in vec2 vTexPos;
out vec4 fColor;
float rad = lumRad.a;
void main() {
  vec3 pos = texture(posTexture, vTexPos).xyz;
  vec3 distVec = pos - lightPos.xyz;
  float dist = dot(distVec, distVec);
//  float dist = dot(distVec.xy, distVec.xy);
//  if (dist > rad) {
//    discard;
//  }
  float t = texture(normals, vTexPos).w;
  vec3 norm = texture(normals, vTexPos).xyz;
  float y1 = dot(normalize(norm), normalize(distVec));
  float y2 = float(y1 > 0 ? 1 : 0);
  //float y2x = y2;
  float y4 = float(y1 > 0 && y1 < 0.5 ? 0.5 : y2);
  float y5 = max(0,y1);
  //float y4 = smoothstep(-1,1,y1);
  //float y4 = 0.25*pow(y1+1,2);
  float y3 = float(t > 0 
        ? y2 
        : (t == 0 ? y4 : y4));
  //float x = 1 - (dist / rad);
  //float x = 1;
  //float x = (dist > rad ? 0 : 1);
  float x = 1 - (pow(dist / rad,4));
  vec3 c = y3* x * lumRad.rgb;
  fColor = vec4(c, 0);
}