README.md

NameDrop

Water ripple effect written in SwiftUI/GLSL to replicate the NameDrop animation first demoed on iOS 17. Should be easier to add with the new .layerEffect modifier. The magic mostly happens in this little block of code:

        void main() {
            float offset = (u_time - floor(u_time))/u_time;
            float currentTime = u_time*offset*0.5;
            vec3 waveParams = vec3(u_scale, u_sharpness, u_spread);
            vec2 waveCenter = vec2(0.5, 1.05);
        
            vec2 coord = v_tex_coord;
            float dist = distance(coord, waveCenter);
            vec4 current_color = texture2D(u_texture, coord);
        
            //Only distort the pixels within the parameter distance from the center
            if ((dist <= ((currentTime) + (waveParams.z))) &&
                (dist >= ((currentTime) - (waveParams.z)))) {
                float diff = (dist - currentTime);
                float scaleDiff = (1.0 - pow(abs(diff * waveParams.x), waveParams.y));
                float diffTime = (diff  * scaleDiff);
                vec2 diffTexCoord = normalize(coord - waveCenter);
                coord += ((diffTexCoord * diffTime) / (currentTime * dist * 10)); //40
                current_color = texture2D(u_texture, coord);
                current_color += (current_color * scaleDiff) / (currentTime * dist * 40.0);
            }
            
            gl_FragColor = current_color;

Give me a shoutout if you end up using it anywhere!

Twitter: @cyrilzakka