watershade.fs

// Viewport dimensions
const vec2 viewport = vec2(1080.0, 720.0);

// Pixel scaling
const vec2 pixelScale = vec2(2.0, 2.0);

void mainImage( out vec4 fragColor, in vec2 fragCoord )
{    
    // Calculate the distance to merge pixels
    float dx = pixelScale.x * (1.0 / viewport.x);
    float dy = pixelScale.y * (1.0 / viewport.y);

    // Get the base UV coordinate of the pixel
    vec2 baseUV = fragCoord/iResolution.xy;
    
    // Use a wave function to translate the pixel UV
    float X = baseUV.x*0.5+iTime;
    float Y = baseUV.y*0.25+iTime;
    baseUV.y += cos(X+Y)*0.0025*cos(Y);
    baseUV.x += sin(X-Y)*0.012*sin(Y);

    // Calculate a UV for this new blocky pixel
    vec2 pixelatedUV = vec2(dx * floor(baseUV.x / dx), dy * floor(baseUV.y / dy));

    // Rebuild the texture with the new UVs
    vec3 tc = texture(iChannel0, pixelatedUV).rgb;

    // Apply a color filter
    tc = tc + vec3(0, 0.05, 0.15);

    // Build the final pixel
    fragColor = vec4(tc, 1.0);
    
}