sharpen shader

gistfile1.cpp

varying vec2  TexCoord;  
void main(void)  
{  
   TexCoord = gl_MultiTexCoord0.st;  
   gl_Position = ftransform();     
}

///////
varying vec2  TexCoord;

uniform sampler2D s_texture;
uniform float Sharpenfactor;

void main()                                            
{
   vec4 Color = texture2D( s_texture, TexCoord.xy );
   //float Sharpenfactor = 30.0; //Make this between 10 and 50;

   Color -= texture2D( s_texture, TexCoord.xy+0.0001)*Sharpenfactor;
   Color += texture2D( s_texture, TexCoord.xy-0.0001)*Sharpenfactor;

   Color.a = 1.0;
   
   gl_FragColor = Color;
}


    shader.begin();
    shader.setUniform1f("Sharpenfactor", 10.0);
    camara.draw(0, 0);
    shader.end();