/////////////////////////////////////////////////////////
// FXAA effect

#ifdef GL_ES
precision mediump float;
#endif

uniform mediump sampler2D samplerFront;
varying vec2 vTex;
uniform mediump float pixelWidth;
uniform mediump float pixelHeight;
vec2 iResolution = vec2( 1./pixelWidth, 1./pixelHeight);
 

//uniform lowp sampler2D tex;
//uniform mediump vec2 fragCoord;
uniform mediump float WindowWidth;
uniform mediump float WindowHeight;

#ifndef FXAA_REDUCE_MIN
    #define FXAA_REDUCE_MIN   (1.0/ 128.0)
#endif
#ifndef FXAA_REDUCE_MUL
    #define FXAA_REDUCE_MUL   (1.0 / 8.0)
#endif
#ifndef FXAA_SPAN_MAX
    #define FXAA_SPAN_MAX     8.0
#endif

vec4 fxaa_2_0(sampler2D tex, vec2 fragCoord, vec2 resolution,
            vec2 v_rgbNW, vec2 v_rgbNE, 
            vec2 v_rgbSW, vec2 v_rgbSE, 
            vec2 v_rgbM) {
    vec4 color;
    mediump vec2 inverseVP = vec2(1.0 / resolution.x, 1.0 / resolution.y);
    vec3 rgbNW = texture2D(tex, v_rgbNW).xyz;
    vec3 rgbNE = texture2D(tex, v_rgbNE).xyz;
    vec3 rgbSW = texture2D(tex, v_rgbSW).xyz;
    vec3 rgbSE = texture2D(tex, v_rgbSE).xyz;
    vec4 texColor = texture2D(tex, v_rgbM);
    vec3 rgbM  = texColor.xyz;
    vec3 luma = vec3(0.299, 0.587, 0.114);
    float lumaNW = dot(rgbNW, luma);
    float lumaNE = dot(rgbNE, luma);
    float lumaSW = dot(rgbSW, luma);
    float lumaSE = dot(rgbSE, luma);
    float lumaM  = dot(rgbM,  luma);
    float lumaMin = min(lumaM, min(min(lumaNW, lumaNE), min(lumaSW, lumaSE)));
    float lumaMax = max(lumaM, max(max(lumaNW, lumaNE), max(lumaSW, lumaSE)));
    
    mediump vec2 dir;
    dir.x = -((lumaNW + lumaNE) - (lumaSW + lumaSE));
    dir.y =  ((lumaNW + lumaSW) - (lumaNE + lumaSE));
    
    float dirReduce = max((lumaNW + lumaNE + lumaSW + lumaSE) *
                          (0.25 * FXAA_REDUCE_MUL), FXAA_REDUCE_MIN);
    
    float rcpDirMin = 1.0 / (min(abs(dir.x), abs(dir.y)) + dirReduce);
    dir = min(vec2(FXAA_SPAN_MAX, FXAA_SPAN_MAX),
              max(vec2(-FXAA_SPAN_MAX, -FXAA_SPAN_MAX),
              dir * rcpDirMin)) * inverseVP;
    
    vec3 rgbA = 0.5 * (
        texture2D(tex, fragCoord * inverseVP + dir * (1.0 / 3.0 - 0.5)).xyz +
        texture2D(tex, fragCoord * inverseVP + dir * (2.0 / 3.0 - 0.5)).xyz);
    vec3 rgbB = rgbA * 0.5 + 0.25 * (
        texture2D(tex, fragCoord * inverseVP + dir * -0.5).xyz +
        texture2D(tex, fragCoord * inverseVP + dir * 0.5).xyz);

    float lumaB = dot(rgbB, luma);
    if ((lumaB < lumaMin) || (lumaB > lumaMax))
        color = vec4(rgbA, texColor.a);
    else
        color = vec4(rgbB, texColor.a);
    return color;
}

//To save 9 dependent texture reads, you can compute
//these in the vertex shader and use the optimized
//frag.glsl function in your frag shader. 

//This is best suited for mobile devices, like iOS.

void texcoords_3_1(vec2 fragCoord, vec2 resolution,
			out vec2 v_rgbNW, out vec2 v_rgbNE,
			out vec2 v_rgbSW, out vec2 v_rgbSE,
			out vec2 v_rgbM) {
	vec2 inverseVP = 1.0 / resolution.xy;
	v_rgbNW = (fragCoord + vec2(-1.0, -1.0)) * inverseVP;
	v_rgbNE = (fragCoord + vec2(1.0, -1.0)) * inverseVP;
	v_rgbSW = (fragCoord + vec2(-1.0, 1.0)) * inverseVP;
	v_rgbSE = (fragCoord + vec2(1.0, 1.0)) * inverseVP;
	v_rgbM = vec2(fragCoord * inverseVP);
}

vec4 apply_1_2(sampler2D tex, vec2 fragCoord, vec2 resolution) {
	mediump vec2 v_rgbNW;
	mediump vec2 v_rgbNE;
	mediump vec2 v_rgbSW;
	mediump vec2 v_rgbSE;
	mediump vec2 v_rgbM;

	//compute the texture coords
	texcoords_3_1(fragCoord, resolution, v_rgbNW, v_rgbNE, v_rgbSW, v_rgbSE, v_rgbM);
	
	//compute FXAA
	return fxaa_2_0(tex, fragCoord, resolution, v_rgbNW, v_rgbNE, v_rgbSW, v_rgbSE, v_rgbM);
}

void main() {
  vec2 uv = 1.*vTex;
 // uv.y = 1.0 - uv.y;

  //can also use gl_FragCoord.xy
  vec2 fragCoord = uv * iResolution; 

  vec4 color;
  // if (enabled) {
       color = apply_1_2(samplerFront, fragCoord, iResolution);
  // } else {
    //  color = texture2D(samplerFront, uv);
  // }

  gl_FragColor = color;
}
[/code:17ngs3nv] 

.xml file is not accepting int or boolean variable; just percent or float ;
So look the original source and converted source ..and meditate or play with online editor like glslsandbox... 
good luck
when you want learn something .. 
allow time minimum 4   hour/day during 30day you will become beginner
allow time minimum 8   hour/day during 60day you will become confirmed
allow time minimum 12 hour/day during 120day you will become expert
allow time minimum 16 hour/day during 365day you will become master
I am BEGINNER ;