// Copyright (c) 2017-2020 Xiamen Yaji Software Co., Ltd.
CCEffect %{
  temporaries:
    s1: &s1 {
      minFilter: linear,
      magFilter: linear,
      addressU: clamp,
      addressV: clamp,
    }
  techniques:
  - name: tonemap
    passes:
    - vert: tonemap-vs:vert
      frag: tonemap-fs:frag
      depthStencilState:
        depthTest: false
        depthWrite: false
      properties:
        u_texSampler: { sampler: *s1 }
        u_blendTexSampler: { sampler: *s1 }
}%

CCProgram tonemap-vs %{
  precision highp float;
  #include <common/common-define>
  #include <builtin/uniforms/cc-global>

  in vec2 a_position;
  in vec2 a_texCoord;
  out vec2 v_uv;
  out vec4 v_offset;

  vec4 vert () {
    vec4 pos = vec4(a_position, 0, 1);
    v_uv = a_texCoord * cc_screenScale.xy;
    v_offset = v_uv.xyxy + cc_nativeSize.zwzw * vec4(1.0, 0.0, 0.0, -1.0);

    return pos;
  }
}%

CCProgram tonemap-fs %{
  precision highp float;
  #include <builtin/uniforms/cc-global>
  #include <common/common-define>
  #include <common/color/gamma>
  #include <common/color/aces>

  in vec2 v_uv;
  in vec4 v_offset;

  uniform sampler2D u_texSampler;
  uniform sampler2D u_blendTexSampler;

  vec3 ToLDR(vec3 color) {
    #if CC_USE_HDR
      color *= cc_exposure.x * FP_SCALE_INV;
      color = ACESToneMap(color);
      color = LinearToSRGB(color);
    #endif
    return color;
  }

  vec4 frag () {
    #if CC_USE_SMAA
      // Fetch the blending weights for current pixel:
      vec4 a;
      a.rb = texture(u_blendTexSampler, v_uv).rb; // Bottom / Left
      a.g = texture(u_blendTexSampler, v_offset.zw).g; // Top
      a.a = texture(u_blendTexSampler, v_offset.xy).a; // Right

      // Is there any blending weight with a value greater than 0.0?
      if (dot(a, vec4(1.0)) < 1e-5) {
        vec4 o = texture(u_texSampler, v_uv);
        o.rgb = ToLDR(o.rgb);
        return o;
      } else {
        vec2 offset;
        offset.x = a.a > a.b ? a.a : -a.b;
        offset.y = a.g > a.r ? -a.g : a.r;
        if (abs(offset.x) > abs(offset.y)) {
          offset.y = 0.0;
        } else {
          offset.x = 0.0;
        }
        vec4 C = texture(u_texSampler, v_uv);
        C.rgb = ToLDR(C.rgb);

        vec2 uv = v_uv + sign(offset) * cc_nativeSize.zw;
        vec4 Cop = texture(u_texSampler, uv);
        Cop.rgb = ToLDR(Cop.rgb);

        float s = abs(offset.x) > abs(offset.y) ? abs(offset.x) : abs(offset.y);
        C.rgb = pow(C.rgb, vec3(2.2));
        Cop.rgb = pow(Cop.rgb, vec3(2.2));
        vec4 mixed = mix(C, Cop, s);
        mixed.rgb = pow(mixed.rgb, vec3(1.0 / 2.2));
        return mixed;
      }
    #else
      vec4 o = texture(u_texSampler, v_uv);
      //o = texture(u_blendTexSampler, v_uv);
      o.rgb = ToLDR(o.rgb);
      return o;
    #endif
  }
}%