glsl boom

<-vertex->

  #version 120

  varying vec2 uv;

  void main(void)
  {

  uv = gl_MultiTexCoord0.st;
  gl_Position = ftransform();
  }






<-fragment->


  #version 120

  uniform sampler2D RTBlur;
  uniform float  rt_w;
  uniform float  rt_h;
  uniform int blurType;

  varying vec2 uv;

  const int g_iFilterTime = 9; // 过滤次数
  const float g_fGene = (1.0/(1.0 + 2.0*(0.93 + 0.8 + 0.7 + 0.6 + 0.5 + 0.4 + 0.3 + 0.2 + 0.1))); // 衰减因子

  void main(void)
  {

  float aryAttenuation[g_iFilterTime];
  aryAttenuation[0] = 0.93;
  aryAttenuation[1] = 0.8;
  aryAttenuation[2] = 0.7;
  aryAttenuation[3] = 0.6;
  aryAttenuation[4] = 0.5;
  aryAttenuation[5] = 0.4;
  aryAttenuation[6] = 0.3;
  aryAttenuation[7] = 0.2;
  aryAttenuation[8] = 0.1;

  vec4 sum =  texture2D(RTBlur, uv)*g_fGene;
  float blurStep =0.01;


  if(1 == blurType)
  {
  // blur in y (vertical)


  blurStep = 1.0 / rt_h;
  vec2 vec2Step =vec2(0,blurStep);
  for(int i = 0; i < g_iFilterTime; ++i)
    {
    sum += texture2D(RTBlur, uv + vec2Step)*aryAttenuation[i]*g_fGene;
    sum += texture2D(RTBlur, uv - vec2Step)*aryAttenuation[i]*g_fGene;
    vec2Step += vec2(0,blurStep);
    }
  
  }
  else
  {
    // blur in y (vertical)
  
   
   blurStep = 1.0 / rt_w;
   
    vec2 vec2Step =vec2(blurStep,0);
   for(int i = 0; i < g_iFilterTime; ++i)
    {
    sum += texture2D(RTBlur, uv + vec2Step)*aryAttenuation[i]*g_fGene;
    sum += texture2D(RTBlur, uv - vec2Step)*aryAttenuation[i]*g_fGene;
    vec2Step += vec2(blurStep,0);
    }
  
  
  }
   
 
   gl_FragColor = sum;
}