function limitBounds(b, maxWidth, maxHeight) {
    var w = b[1][0] - b[0][0];

    if (w > maxWidth) {
        var c = (b[1][0] + b[0][0]) / 2;

        maxWidth /= 2;
        b[0][0] = c - maxWidth;
        b[1][0] = c + maxWidth;
    }

    var h = b[1][1] - b[0][1];

    if (h > maxHeight) {
        var ch = (b[1][1] + b[0][1]) / 2;

        maxHeight /= 2;
        b[0][1] = ch - maxHeight;
        b[1][1] = ch + maxHeight;
    }
}

function visualBounds(path, feature) {
    if (feature._visualBounds) {
        return feature._visualBounds;
    }

    var bb = feature._bounds || (feature._bounds = path.bounds(feature));
    var c = feature._centroid || (feature._centroid = path.centroid(feature));
    var d = 0.366;
    var b = [[bb[0][0], bb[0][1]], [bb[1][0], bb[1][1]]];
    var sx = d3.scale.linear().domain([b[0][0], b[1][0]]).range([0, 1]);
    var sy = d3.scale.linear().domain([b[0][1], b[1][1]]).range([0, 1]);

    if (Math.abs(0.5 - sx(c[0])) > d || Math.abs(0.5 - sy(c[1])) > d) {
        var h = Math.min(c[0] - b[0][0], b[1][0] - c[0], c[1] - b[0][1], b[1][1] - c[1]);
        b[0][0] = c[0] - h;
        b[1][0] = c[0] + h;
        b[0][1] = c[1] - h;
        b[1][1] = c[1] + h;
    }

    if (feature.id === 'AUS') {
        b[1][1] = d3.interpolate(b[0][1], b[1][1])(0.75);
    } else if (feature.id === 'USA') {
        b[1][0] = d3.interpolate(b[0][0], b[1][0])(0.28);
    }

    feature._visualBounds = b;

    return b;
}

function groupBounds(path, features, width, height, maxWidth, maxHeight) {
    var r = features.length ? [[[], []], [[], []]] : [[[0], [0]], [[width], [height]]];

    features.forEach(function (feature) {
        var b = visualBounds(path, feature);

        //limitBounds(b, maxWidth, maxHeight);

        r[0][0].push(b[0][0]);
        r[0][1].push(b[0][1]);
        r[1][0].push(b[1][0]);
        r[1][1].push(b[1][1]);
    });

    r[0][0] = Math.min.apply(this, r[0][0]);
    r[0][1] = Math.min.apply(this, r[0][1]);
    r[1][0] = Math.max.apply(this, r[1][0]);
    r[1][1] = Math.max.apply(this, r[1][1]);

    return r;
}


function getScale(size, width, height, scaleMargin, maxScale) {
    var marginSize = [(size[0] + width * scaleMargin * 2), (size[1] + width * scaleMargin * 2)];
    var sizeRatio = marginSize[0] / marginSize[1];
    var boxRatio = width / height;
    var r;

    if (sizeRatio >= boxRatio) {
        r = width / marginSize[0];
    } else {
        r = height / marginSize[1];
    }

    if (r < 1) {
        r = 1;
    } else if (r > maxScale) {
        r = maxScale;
    }

    return r;
}