Brightness Increasing...

I got this distance blur 2D filter,done by MARTINSH (THANKS!), but the problem is that when i activate it game brightness increases. I have no idea what wrong with it.

uniform sampler2D bgl_RenderedTexture;
uniform sampler2D bgl_DepthTexture;
uniform float bgl_RenderedTextureWidth;
uniform float bgl_RenderedTextureHeight;
#define PI  3.14159265
float width = bgl_RenderedTextureWidth; //texture width
float height = bgl_RenderedTextureHeight; //texture height
//general stuff
make sure that these two values are the same for your camera, otherwise distances will be wrong.
float znear = 0.05; //camera clipping start
float zfar = 3000.0; //camera clipping end
//user variables
int samples = 2; //blur sample count 
float blurstart = 450.0; //blur starting distance in Blender units
float range = 5.0; //blur fading distance in Blender units
float maxblur = 1.0; //maximum radius of blur
bool noise = false; //use noise instead of pattern dithering?
float namount = 0.0002; //sample dithering amount
vec2 rand(in vec2 coord) //generating noise/pattern texture for dithering
 float noiseX = ((fract(1.0-coord.s*(width/2.0))*0.25)+(fract(coord.t*(height/2.0))*0.75))*2.0-1.0;
 float noiseY = ((fract(1.0-coord.s*(width/2.0))*0.75)+(fract(coord.t*(height/2.0))*0.25))*2.0-1.0;
 if (noise)
  noiseX = clamp(fract(sin(dot(coord ,vec2(12.9898,78.233))) * 43758.5453),0.0,1.0)*2.0-1.0;
  noiseY = clamp(fract(sin(dot(coord ,vec2(12.9898,78.233)*2.0)) * 43758.5453),0.0,1.0)*2.0-1.0;
 return vec2(noiseX,noiseY);
void main() 
 vec3 col = vec3(0.0);
 float zdepth = texture2D(bgl_DepthTexture,gl_TexCoord[0].xy).x;
 float depth = -zfar * znear / (zdepth * (zfar - znear) - zfar);
 float blur = (depth-blurstart)/range*0.5;
 blur = clamp(blur*maxblur,0.0,maxblur);
 vec2 noise = rand(gl_TexCoord[0].xy)*namount*blur;
 float w = (1.0/width)*blur+noise.x;
 float h = (1.0/height)*blur+noise.y;
 float ss = 3.6/sqrt(float(samples));
 float dz = 2.0/float(samples);
 float l = 0.0;
 float z = 1.0 - dz/2.0;
 float s = 1.0;
 for (int k = 0; k <= samples; k += 1)
 float r = sqrt(1.0-z);
 vec2 wh = vec2(cos(l)*r, sin(l)*r);
 col += texture2D(bgl_RenderedTexture,gl_TexCoord[0].xy+vec2(wh.x*w, wh.y*h)).rgb;
 z -= dz;
 l += ss/r;
 gl_FragColor.rgb = col/float(samples);
 gl_FragColor.a = 1.0;

:confused: ive had the same problem ocuring with other 2d filthers its the little button called shadeless (a shity problem) also the problem is when the (wire) in the materials menu is selected

I haven’t tried it out but I know the Problem too well, and it’s simple, very simple: At »col« several Layers get added to each other, and logically 1+1 gives 2, equally the Screen gets brighter with every »sample« added. Usually, that should be corrected right at the Equation »col += …« at the very End between ».rgb« and Semicolon, but here the Correction is done when the »col« gets called into the gl_FragColor – I guess that’s okay, but you might try taking away the »/float(samples)« and instead put it at the End of the col-Equation. I also would try just using »/samples« or maybe »/int(samples)« because one does not simply use 2.5 Samples, a Float seems of no Necessity to me.