glsl boom

原理：

1.渲染场景到fbo

2.对fbo进行高斯横向，纵向模糊，到新的fbo

3.对两张图进行叠加

模糊后的

效果就这样

给数据加大

<-vertex->
 
  #version 
 
  varying vec2 uv;
 
  void main(void)
  {
 
  uv = gl_MultiTexCoord0.st;
  gl_Position = ftransform();
  }
 
<-fragment->
 
  #version 
 
  uniform sampler2D RTBlur;
  uniform float  rt_w;
  uniform float  rt_h;
  uniform int blurType;
 
  varying vec2 uv;
 
  const int g_iFilterTime = ; // 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[] = 0.93;
  aryAttenuation[] = 0.8;
  aryAttenuation[] = 0.7;
  aryAttenuation[] = 0.6;
  aryAttenuation[] = 0.5;
  aryAttenuation[] = 0.4;
  aryAttenuation[] = 0.3;
  aryAttenuation[] = 0.2;
  aryAttenuation[] = 0.1;
 
  vec4 sum =  texture2D(RTBlur, uv)*g_fGene;
  float blurStep =0.01;
 
  if( == blurType)
  {
  // blur in y (vertical)
 
  blurStep = 1.0 / rt_h;
  vec2 vec2Step =vec2(,blurStep);
  for(int i = ; 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);
    }
 
  }
  else
  {
    // blur in y (vertical)
 
   blurStep = 1.0 / rt_w;
 
    vec2 vec2Step =vec2(blurStep,);
   for(int i = ; 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,);
    }
 
  }
 
   gl_FragColor = sum;
}

应该把需要发光的物体绘制boom，然后融合，这样才行，框架又得改。。。