//波纹流光
CCEffect %{
  techniques:
  - passes:
    - vert: vs
      frag: fs
      blendState:
        targets:
        - blend: true
      rasterizerState:
        cullMode: none
      properties:
        texture: { value: white }
        u_time: { value: 0.5 }
}%

CCProgram vs %{ // 顶点Shader模块开始
  #include <cc-global>
  precision highp float;	  //定义float高精度
	in vec3 a_position; // 顶点Shader 从渲染管道里面获取的顶点信息,使用attribute来修饰;
	in vec2 a_uv0;   // 纹理坐标;
	out vec2 uv0;     // 传递给着色Shader，varying 来修饰，进行插值
	void main () {
		gl_Position = cc_matViewProj * vec4(a_position, 1);
		uv0 = a_uv0;
	}
}%

CCProgram fs %{
  #define TAU 6.12
  #define MAX_ITER 5
  precision highp float;

  in vec2 uv0;
  uniform sampler2D texture;
  uniform ARGS {
    vec4 UVoffset;
    float u_time;
    float rotated;
  };

  void main()
  {
    float u_time = u_time * .5+5.;
    vec2 UVnormalize;
    UVnormalize.x = (uv0.x-UVoffset.x)/(UVoffset.z-UVoffset.x);
    UVnormalize.y = (uv0.y-UVoffset.y)/(UVoffset.w-UVoffset.y);
    if(rotated > 0.5)
    {
      float temp = UVnormalize.x;
      UVnormalize.x = UVnormalize.y;
      UVnormalize.y = 1.0 - temp;
    }

    vec2 uv = uv0.xy;//fragCoord.xy / iResolution.xy;
    
    vec2 p = mod(uv*TAU, TAU)-250.0;

    vec2 i = vec2(p);
    float c = 1.0;
    float inten = .0065;

    for (int n = 0; n < MAX_ITER; n++) 
    {
      float t =  u_time * (1.0 - (3.5 / float(n+1)));
      i = p + vec2(cos(t - i.x) + sin(t + i.y), sin(t - i.y) + cos(1.5*t + i.x));
      c += 1.0/length(vec2(p.x / (cos(i.x+t)/inten),p.y / (cos(i.y+t)/inten)));
    }
    c /= float(MAX_ITER);
    c = 1.17-pow(c, 1.4);
    vec4 tex = texture2D(texture,uv0);
    vec3 colour = vec3(pow(abs(c), 20.0));
    colour = clamp(colour + vec3(0.0, 0.0, .0), 0.0, tex.a);

    // 混合波光
    float alpha = c*tex[3];  
    tex[0] = tex[0] + colour[0]*alpha; 
    tex[1] = tex[1] + colour[1]*alpha; 
    tex[2] = tex[2] + colour[2]*alpha; 
    gl_FragColor = vec4(1,1,1,1) * tex;
  }
}%