// Effect Syntax Guide: https://docs.cocos.com/creator/manual/zh/shader/index.html

CCEffect %{
  techniques:
  - name: opaque
    passes:
    - vert: unlit-vs:vert # builtin header
      frag: unlit-fs
      properties: &props
        mainTexture:    { value: black }
        mainColor:      { value: [1, 1, 1, 1], editor: { type: color } }
  - name: transparent
    passes:
    - vert: unlit-vs:vert # builtin header
      frag: unlit-fs
      blendState:
        targets:
        - blend: true
          blendSrc: src_alpha
          blendDst: one_minus_src_alpha
          blendSrcAlpha: src_alpha
          blendDstAlpha: one_minus_src_alpha
      properties: *props
}%

CCProgram unlit-vs %{
  
precision highp float;
#include <legacy/input-standard>
#include <builtin/uniforms/cc-global>
#include <legacy/local-batch>
#include <legacy/input-standard>
#include <legacy/fog-vs>
#include <legacy/shadow-map-vs>

in vec4 a_color;
#if HAS_SECOND_UV
  in vec2 a_texCoord1;
#endif

out vec3 v_position;
out vec3 v_normal;
out vec3 v_tangent;
out vec3 v_bitangent;
out vec2 v_uv;
out vec2 v_uv1;
out vec4 v_color;

vec4 vert () {
  StandardVertInput In;
  CCVertInput(In);

  mat4 matWorld, matWorldIT;
  CCGetWorldMatrixFull(matWorld, matWorldIT);

  vec4 pos = matWorld * In.position;

  v_position = pos.xyz;
  v_normal = normalize((matWorldIT * vec4(In.normal, 0.0)).xyz);
  v_tangent = normalize((matWorld * vec4(In.tangent.xyz, 0.0)).xyz);
  v_bitangent = cross(v_normal, v_tangent) * In.tangent.w; // note the cross order

  v_uv = a_texCoord;
  #if HAS_SECOND_UV
    v_uv1 = a_texCoord1;
  #endif
  v_color = a_color;

  CC_TRANSFER_FOG(pos);
  CC_TRANSFER_SHADOW(pos);

  return cc_matProj * (cc_matView * matWorld) * In.position;
}

}%

CCProgram unlit-fs %{
  precision highp float;
  #include <legacy/output>
  #include <legacy/fog-fs>

  #include <unpack>

  in vec2 v_uv;
  in vec3 v_position;
  in vec3 v_normal;

  uniform samplerCube mainTexture;

  uniform Constant {
    vec4 mainColor;
  };

  #if CC_FORWARD_ADD
    layout(location = 0) out vec4 fragColorX;                        
                                                                   
    void main () {
      fragColorX = vec4(0.);                                            
    } 
  #elif (CC_PIPELINE_TYPE == CC_PIPELINE_TYPE_FORWARD) 
                                                                   
    layout(location = 0) out vec4 fragColorX;                        
                                                                    
    void main () {                                                   
      vec3 uv = normalize(v_position);
      vec4 col = texture(mainTexture, uv);

      col.rgb = unpackRGBE(col);
      
      // CC_APPLY_FOG(col, v_position);
      fragColorX = CCFragOutput(col);                                            
    }                                                                
                                                                   
  #else           
    #include <common/math/octahedron-transform>                                  
                                                                    
    layout(location = 0) out vec4 fragColor0;                        
    layout(location = 1) out vec4 fragColor1;                        
    layout(location = 2) out vec4 fragColor2;         
    layout(location = 3) out vec4 fragColor3;         

    
  vec3 GetLookupVectorForSphereCapture(vec3 ReflectionVector, vec3 WorldPosition, vec4 SphereCapturePositionAndRadius, float NormalizedDistanceToCapture, vec3 LocalCaptureOffset, inout float DistanceAlpha)
  {
    vec3 ProjectedCaptureVector = ReflectionVector;
    float ProjectionSphereRadius = SphereCapturePositionAndRadius.w;
    float SphereRadiusSquared = ProjectionSphereRadius * ProjectionSphereRadius;

    vec3 LocalPosition = WorldPosition - SphereCapturePositionAndRadius.xyz;
    float LocalPositionSqr = dot(LocalPosition, LocalPosition);

    // Find the intersection between the ray along the reflection vector and the capture's sphere
    vec3 QuadraticCoef;
    QuadraticCoef.x = 1.;
    QuadraticCoef.y = dot(ReflectionVector, LocalPosition);
    QuadraticCoef.z = LocalPositionSqr - SphereRadiusSquared;

    float Determinant = QuadraticCoef.y * QuadraticCoef.y - QuadraticCoef.z;

    // Only continue if the ray intersects the sphere
    // FLATTEN
    if (Determinant >= 0.)
    {
      float FarIntersection = sqrt(Determinant) - QuadraticCoef.y;

      vec3 LocalIntersectionPosition = LocalPosition + FarIntersection * ReflectionVector;
      ProjectedCaptureVector = normalize(LocalIntersectionPosition - LocalCaptureOffset);
      // Note: some compilers don't handle smoothstep min > max (this was 1, .6)
      //DistanceAlpha = 1.0 - smoothstep(.6, 1, NormalizedDistanceToCapture);

      float x = clamp( 2.5 * NormalizedDistanceToCapture - 1.5, 0., 1. );
      DistanceAlpha = 1. - x*x*(3. - 2.*x);
    }
    return ProjectedCaptureVector;
  }               

    float raySphere (vec3 o, vec3 d, vec3 center, float radius) {
        float rSq = radius * radius;
        vec3 e = center - o;
        float eSq = dot(e, e);

        float aLength = dot(e, d); // assume ray direction already normalized
        float fSq = rSq - (eSq - aLength * aLength);
        if (fSq < 0.) { return 0.; }

        float f = sqrt(fSq);
        float t = eSq < rSq ? aLength + f : aLength - f;
        if (t < 0.) { return 0.; }
        return t;
    }
                                                                    
    void main () {
      fragColor0 = vec4(vec3(0.), 1.);
      fragColor1 = vec4(vec3(0.), 1.);

      vec3 V = normalize(cc_cameraPos.xyz - v_position);
      vec3 ref = normalize(reflect(-V, v_normal));

      // vec4 cubePosRadius = vec4(5.27, 1.512, -6.648, 30.);
      // float DistanceAlpha = 1.;
      // ref = GetLookupVectorForSphereCapture(ref, v_position, cubePosRadius, length(v_position - cubePosRadius.xyz) / cubePosRadius.w, vec3(0.), DistanceAlpha);

      // float t = raySphere(v_position, ref, cubePosRadius.xyz, cubePosRadius.w);
      // vec3 intersectionPos = v_position + ref * t;
      // ref = normalize(intersectionPos - cubePosRadius.xyz);

      vec4 col = texture(mainTexture, ref);
      col.rgb = unpackRGBE(col);
      fragColor2 = vec4(col.rgb, 0.);
      fragColor3 = vec4(v_position, 1.);
    }                                                                
                                                                    
  #endif
}%