billboard

import QtQuick 2.6

Item {
    width: 794
    height: 602

    Column {
        Image {
            id: logo
            width: 794
            height: 301
            source: 'https://s3-eu-west-1.amazonaws.com/qt-brand/uploads/2015/04/PrimaryLogo.png'
        }
        ShaderEffect {
            width: 794
            height: 301
            property var source: ShaderEffectSource {
                sourceItem: logo
            }

            property real grid: 10.0

            property real step_x: 0.001
            property real step_y: step_x * width / height

            fragmentShader: '
                uniform float grid;
                uniform float step_x;
                uniform float step_y;

                uniform sampler2D source;
                uniform lowp float qt_Opacity;
                varying vec2 qt_TexCoord0;

                void main()
                {
                    vec2 uv = qt_TexCoord0.xy;
                    float offx = floor(uv.x  / (grid * step_x));
                    float offy = floor(uv.y  / (grid * step_y));
                    vec3 res = texture2D(source, vec2(offx * grid * step_x , offy * grid * step_y)).rgb;
                    vec2 prc = fract(uv / vec2(grid * step_x, grid * step_y));
                    vec2 pw = pow(abs(prc - 0.5), vec2(2.0));
                    float  rs = pow(0.45, 2.0);
                    float gr = smoothstep(rs - 0.1, rs + 0.1, pw.x + pw.y);
                    float y = (res.r + res.g + res.b) / 3.0;
                    vec3 ra = res / y;
                    float ls = 0.3;
                    float lb = ceil(y / ls);
                    float lf = ls * lb + 0.3;
                    res = lf * res;
                    vec3 col = mix(res, vec3(0.1, 0.1, 0.1), gr);
                    gl_FragColor = qt_Opacity * vec4(col, 1.0);
                }'
        }
    }
}