//Fiji Fractal by Johannes Schindelin

dim = 256; /* width / height */
frames = 20;

red = 101;
green = 164;
blue = 227;

zoomIntoX = 4;
zoomIntoY = 4;

newImage("Fiji Fractal", "RGB", dim, dim, frames);
id = getImageID();
setBatchMode(true);

bigdim = 9;

while (bigdim < 8 * dim)
    bigdim *= 8;
offset = bigdim / 9;

newImage("Fiji Fractal (the big picture)", "RGB", bigdim, bigdim, 1);
big = getImageID();
setPixel(offset, offset, (red << 16) | (green << 8) | blue);


for (scale = 1; 9 * scale <= bigdim; scale *= 8)
    fijiAtScale(scale);

for (frame = 1; frame <= frames; frame++) {
    factor = pow(8, frame / frames);
    dim2 = bigdim / factor;
    off2x = offset + (offset * 8 - dim2) * zoomIntoX / 7;
    off2y = offset + (offset * 8 - dim2) * zoomIntoY / 7;
    selectImage(big);
    makeRectangle(off2x, off2y, dim2, dim2);
    run("Duplicate...", "title=dup");
    run("Size...", "width=" + dim + " height=" + dim + " constrain average interpolation=Bicubic");
    /* 
     * Note: the fractal has holes in it, and we want the *downsampled* image to be Fiji blue.
     * Hence we adjust the contrast a little.
     */
    setMinAndMax(225 - 42 * frame / frames, 251 - 7 * frame / frames);
    makeRectangle(0, 0, dim, dim);
    run("Copy");
    run("Close");
    selectImage(id);
    setSlice(frame);
    makeRectangle(0, 0, dim, dim);
    run("Paste");
    run("Select None");
}
setOption("changes", false);
doCommand("Start Animation [\\]");
run("In [+]");
run("In [+]");

function pasteAtScale(x, y, scale) {
    makeRectangle(offset + x * scale, offset + y * scale, scale, scale);
    run("Paste");
}

function fijiAtScale(scale) {
    makeRectangle(offset, offset, scale, scale);
    run("Copy");
    for (i = 1; i < 7; i++) {
        // upper bar of the F
        pasteAtScale(i, 0, scale);
        // left bar of the F
        pasteAtScale(0, i, scale);
    }
    for (i = 0; i < 3; i++) {
        // left i
        pasteAtScale(2, 2 + i, scale);
        // vertical part of j
        pasteAtScale(4, 2 + i, scale);
        // horizontal part of j
        pasteAtScale(2 + i, 6, scale);
        // right i
        pasteAtScale(6, 2 + i, scale);
    }
    // remaining gap in j
    pasteAtScale(4, 5, scale);
    run("Select None");
}