test_swirl.scd

(
// By James McCartney
var w, h = 1080, v = 720, seed, run = true, phase = 0;

var text_radius = 300; // pixels
var text_angle_increment = 7.degrad; // 7 degrees converted to radians
var text_start_angle = 0;
var text_center_x = 0;
var text_center_y = 0;
var text_font = Font("Helvetica", 48);

a = rrand(60,300);
~history = (lines: ["this is a test string for swirling"]);
w = Window("wedge", Rect(40, 40, h, v), false);
w.view.background = Color.rand(0,0.3);
w.onClose = { run = false }; // stop the thread on close
w.front;
// store an initial seed value for the random generator
seed = Date.seed;
w.drawFunc = {
    Pen.width = 2;
    Pen.use {
        // reset this thread's seed for a moment
        thisThread.randSeed = Date.seed;
        // now a slight chance of a new seed or background color
        if (0.006.coin) { seed = Date.seed; };
        if (0.02.coin) { w.view.background = Color.rand(0,0.3); };
        // either revert to the stored seed or set the new one
        thisThread.randSeed = seed;
        // the random values below will be the same each time if the seed has not changed
        // only the phase value has advanced
        Pen.translate(h/2, v/2);
        // rotate the whole image
        // negative random values rotate one direction, positive the other
Pen.rotate(phase * 1.0.rand2);
        // scale the rotated y axis in a sine pattern
        Pen.scale(1, 0.3 * sin(phase * 1.0.rand2 + 2pi.rand) + 0.5 );
        // create a random number of annular wedges
        rrand(6,24).do {
            Pen.color = Color.rand(0.0,1.0).alpha_(rrand(0.1,0.7));
            Pen.beginPath;
            ~history.lines[0].asString.do({ |chr, idx |
                // iterate over all letters and draw them on the calculated position
                var sx = text_center_x + (text_radius * sin(text_start_angle + (idx * text_angle_increment)));
                var sy = text_center_y + (text_radius * cos(text_start_angle + (idx * text_angle_increment)));
                Pen.stringAtPoint(chr.asString, sx@sy, text_font);
            });
            Pen.addAnnularWedge(Point(0,0), a = rrand(60,300), a + 50.rand2, 2pi.rand
                + (phase * 2.0.rand2), 2pi.rand);
            if (0.5.coin) {Pen.stroke}{Pen.fill};
        };
    };
};

// fork a thread to update 20 times a second, and advance the phase each time
{ while { run } { w.refresh; 0.05.wait; phase = phase + 0.01pi;} }.fork(AppClock)

)