#vertex

void main() {
    gl_TexCoord[0] = gl_MultiTexCoord0;
    gl_Position = ftransform();
}

#fragment

uniform vec2 scale;
uniform sampler2D img;
uniform sampler2D mvs;

void main() {
    vec2 tc = gl_TexCoord[0].xy;
    vec2 mv = texture2D(mvs, tc).xy - 0.5;
    gl_FragColor = 0.125 * (
        texture2D(img, tc - (0.125 * scale) * mv) +
        texture2D(img, tc - (0.250 * scale) * mv) +
        texture2D(img, tc - (0.375 * scale) * mv) +
        texture2D(img, tc - (0.500 * scale) * mv) +
        texture2D(img, tc - (0.625 * scale) * mv) +
        texture2D(img, tc - (0.750 * scale) * mv) +
        texture2D(img, tc - (0.875 * scale) * mv) +
        texture2D(img, tc - (1.000 * scale) * mv));
}