// Copyright (c) 2017-2018 Xiamen Yaji Software Co., Ltd.

CCEffect %{
  techniques:
  - passes:
    - vert: vs
      frag: fs
      blendState:
        targets:
        - blend: true
      rasterizerState:
        cullMode: none
      properties:
        texture: { value: white }
        alphaThreshold: { value: 0.5 }
        u_fluxayTexture: { value: white }
}%


CCProgram vs %{
  precision highp float;

  #include <cc-global>
  #include <cc-local>

  in vec3 a_position;
  in vec4 a_color;
  out vec4 v_color;

  #if USE_TEXTURE
  in vec2 a_uv0;
  out vec2 v_uv0;
  #endif

  void main () {
    vec4 pos = vec4(a_position, 1);

    #if CC_USE_MODEL
    pos = cc_matViewProj * cc_matWorld * pos;
    #else
    pos = cc_matViewProj * pos;
    #endif

    #if USE_TEXTURE
    v_uv0 = a_uv0;
    #endif

    v_color = a_color;

    gl_Position = pos;
  }
}%


CCProgram fs %{
  precision highp float;

  #include <alpha-test>
  #include <texture>
  #include <cc-global>
  in vec4 v_color;

  #if USE_TEXTURE
  in vec2 v_uv0;
  uniform sampler2D texture;
  #endif

  uniform sampler2D u_fluxayTexture;  //流光纹理
  // 自定义属性
  // 所有非 sampler 的 uniform 都必须以 UBO 形式声明
  // UBO 成员声明类型和顺序有严格的校验机制，以排除 GL 标准下隐式布局对齐带来的内存消耗
  uniform ARGS {
    float u_time;
  };
  void main () {
    vec4 o = vec4(1, 1, 1, 1);

    #if USE_TEXTURE
      CCTexture(texture, v_uv0, o);
    #endif

    o *= v_color;

    #if USE_BGRA
      gl_FragColor = o.bgra;
    #else
      gl_FragColor = o.rgba;
    #endif

    ALPHA_TEST(o);
    // 使用 sin 函数模拟时间变化，周期为 2.0 秒
    float simulatedTime = tan(cc_time.x);
    // 在底图不透明的地方叠加流光纹理的颜色
    vec2 fluxayUV = vec2(v_uv0.x, v_uv0.y);
    // 根据时间控制流光纹理的UV
    fluxayUV.x -= simulatedTime;
    // 获取流光纹理上UV的颜色
    vec4 fluxay = texture2D(u_fluxayTexture, fluxayUV);
    if(o.a<= 0.8 && simulatedTime > -1.0 && simulatedTime < 1.0 && v_uv0.x > 0.1 && v_uv0.x < 0.9 && v_uv0.y > 0.1 && v_uv0.y < 0.9) {
      gl_FragColor = o + fluxay;
    } else {
      gl_FragColor = o;
    }
  }
}%