Partial update / draw, Garmin Connect IQ watch face Monkey C

function onShow() {
    redraw = true;
}

function onUpdate(dc) {
    dc.clearClip();
    redraw = true;
    fullUpdate();
    partialUpdate();
    draw(dc);
}

function onPartialUpdate(dc) {
    partialUpdate();
    dc.setClip(clipMin[0], clipMin[1], clipMax[0] - clipMin[0], clipMax[1] - clipMin[1]);
    draw(dc);
}

function draw(dc) {
    if (redraw) {
        // Full redraw, 1x per minute (or when he is looking on his watch)
        var dc2 = backgroundBitmap.getDc();
        dc2.draw(...)
        redraw = false;
    }

    dc.drawBitmap(0, 0, backgroundBitmap);

    // Second hand, drawn every second
    dc.draw(...)
}