#version 450 core
layout(points) in;
layout(triangle_strip, max_vertices = 18) out;
layout(std140, binding = 0) uniform TheMat { mat4 theMat; };
layout(location=0) uniform vec3 lightPos;
layout(location=1) uniform float rad;
float rad2 = rad;
// Preprocessed to include ../functions.glsl
float closestPointOnLineParam (vec2 a, vec2 b, vec2 p) {
  return dot(p - a,b-a) / dot(b-a,b-a);
}
vec2 closestPointOnSeg (vec2 a,vec2 b, vec2 p) {
  float x = closestPointOnLineParam(a,b,p);
  if (x < 0) {
      return a;
  } else{ if (x > 1) { return b; }
      { return a + (x * (b- a));}
  }
}
// End include 2023-03-13 15:33:44.438312149 UTC
vec2 shift(vec2 p) {
  return vec2(lightPos.xy + (rad2 * normalize(p - lightPos.xy)));
}
float isLHS(vec2 startV, vec2 testV) {
  return sign(-startV.x * testV.y + startV.y * testV.x);
}
// construct a box with openings on bottom face and face away from wall
void main() {
  vec2 p1 = gl_in[0].gl_Position.xy;
  vec2 p2 = gl_in[0].gl_Position.zw;
  vec2 closepoint = closestPointOnSeg(p1,p2,lightPos.xy);
  if (isLHS(p1 - lightPos.xy, p2 - lightPos.xy) < 0 && distance(closepoint,lightPos.xy) < rad2) {
    vec2 closeshift = (rad2 * normalize(closepoint - lightPos.xy)) + lightPos.xy - closepoint;
    vec2 p1cs = p1 + closeshift;
    vec2 p1o = vec2( distance(p1,lightPos.xy) > rad2 ? p1cs : shift(p1) );
    vec2 p2cs = p2 + closeshift;
    vec2 p2o = vec2( distance(p2,lightPos.xy) > rad2 ? p2cs : shift(p2) );

    gl_Position = theMat * vec4(p1o,-500,1); EmitVertex();
    gl_Position = theMat * vec4(p1,-500,1); EmitVertex();
    gl_Position = theMat * vec4(p1o,100,1); EmitVertex();
    gl_Position = theMat * vec4(p1,100,1); EmitVertex();
    gl_Position = theMat * vec4(p1cs,100,1); EmitVertex();
    gl_Position = theMat * vec4(p2,100,1); EmitVertex();
    gl_Position = theMat * vec4(p2cs,100,1); EmitVertex();
    gl_Position = theMat * vec4(p2o,100,1); EmitVertex();
    EndPrimitive();

//    gl_Position = theMat * vec4(p2o,100,1); EmitVertex();
//    gl_Position = theMat * vec4(p2,100,1); EmitVertex();
//    gl_Position = theMat * vec4(p2o,0,1); EmitVertex();
//    gl_Position = theMat * vec4(p2,0,1); EmitVertex();
    
    gl_Position = theMat * vec4(p2,100,1); EmitVertex();
    gl_Position = theMat * vec4(p2,-500,1); EmitVertex();
    gl_Position = theMat * vec4(p2o,100,1); EmitVertex();
    gl_Position = theMat * vec4(p2o,-500,1); EmitVertex();
    gl_Position = theMat * vec4(p2cs,100,1); EmitVertex();
    gl_Position = theMat * vec4(p2cs,-500,1); EmitVertex();
    gl_Position = theMat * vec4(p1cs,100,1); EmitVertex();
    gl_Position = theMat * vec4(p1cs,-500,1); EmitVertex();
    gl_Position = theMat * vec4(p1o,100,1); EmitVertex();
    gl_Position = theMat * vec4(p1o,-500,1); EmitVertex();
    
    EndPrimitive();
  } else {
  }
}