// 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 }     
        sys_time: { value: 0.1, editor: { tooltip: '频率' } }
       
}%
 
 
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 <cc-global>
  #include <texture>
  #include <alpha-test>

  in vec4 v_color;
 
  in vec2 v_uv0;
  uniform sampler2D texture;
  
  // 自定义属性
  uniform Properties {
    float sys_time;		// 频率
  };
  
  float inFlash(float angle, vec2 uv, float xLength, float interval, float beginTime, float offX, float loopTime){
  
        //亮度值
		float brightness = 0.0;			
		//倾斜角
		float angleInRed = 0.0174444 * angle;
		
		//当前时间
	    float currentTime = sys_time/interval;
		
		//获取本次光照的起始时间
	    //float currentTimeInt = floor(currentTime/interval) -1.0;
	    //currentTimeInt *= interval;
		
		//获取本次光照的流逝时间 = 当前时间 - 起始时间
		//float currentTimePassed = currentTime - currentTimeInt;
		
		if(currentTime > beginTime)
		{
		    //底部左边界和右边界
			float xBottomLeftBound;
			float xBottomRightBound;
			
			//此点边界
			float xPointLeftBound;
		    float xPointRightBound;
			
			float x0 = currentTime - beginTime;
		    x0 /= loopTime;
			
			//设置右边界
			xBottomRightBound = x0;

			//设置左边界
			xBottomLeftBound = x0 - xLength;
			
			//投影至x的长度 = y/tan（angle）
			float xProjL = (uv.y)/tan(angleInRed);
			
			//此点的左边界 = 底部左边界 - 投影至x的长度
			xPointLeftBound = xBottomLeftBound - xProjL;
			//此点的右边界 = 底部右边界 - 投影至x的长度
			xPointRightBound = xBottomRightBound - xProjL;

			//边界加上一个偏移
			xPointLeftBound += offX;
			xPointRightBound += offX;
			
			//如果该点在区域内
			if(uv.x > xPointLeftBound && uv.x < xPointRightBound)
			{
				//得到发光区域的中心点
				float midness = (xPointLeftBound + xPointRightBound)/2.0;

				//趋近中心点的程度，0表示位于边缘， 1 表示位于中心点
				float rate = (xLength - 2.0 * abs(uv.x - midness)) / (xLength);
				brightness = rate;
			}

		}
		
		brightness = max(brightness, 0.0);

		//返回颜色 = 纯白色 * 亮度
		//vec4 col = vec4 (1,1,1,1) * brightness;
		return brightness;
  
  
  }
  	
  void main () {
    // 保存顶点颜色
    vec4 color = v_color;
    
    // 叠加纹理颜色
    color *= texture(texture, v_uv0);
	
	vec4 outp;
	//传进i.uv等参数，得到亮度值
	float tmpBrightness;
	tmpBrightness = inFlash(60.0, v_uv0, 4.0, 0.25, 1.0, 0.15, 0.5);


	//图像区域，判定设置为颜色的A >0.5， 输出为材质颜色 + 光亮值
	if(color.w >0.5)
	{
		outp = color + vec4(1,1,1,1) * tmpBrightness/1.5;
	}
	else
	{
		outp = vec4(0,0,0,0);
	}
					
	gl_FragColor = outp;
  }
}%