Downsample when blurring bloom

shader/texture/bloomBlur.frag

@@ -3,10 +3,12 @@ in vec2 vTexPos;
 out vec4 fColor;
 const vec2 winSize = vec2 (300,300);
 // note that the above opening bracket should be the first in this file
+// this is so that the window size can be extracted and the shader recompiled on
+// the fly
 uniform sampler2D screenTexture;
 
-const float hOff = 4.0 / winSize.x;
-const float vOff = 4.0 / winSize.y;
+const float hOff = 3.0 / winSize.x;
+const float vOff = 3.0 / winSize.y;
 const float frac = 1.0 / 9;
 const vec2 off[9] = vec2[]
     ( vec2( vOff,hOff )