module doodle.dia.layer_stack;

public {
    import doodle.dia.icanvas;
}

final class LayerStack {
    this(in Layer[] layers) {
        _layers = layers.dup;
    }

    Rectangle bounds() const {
        // Take the union of all layer bounds
        Rectangle bounds = Rectangle.DEFAULT;
        foreach (layer; _layers) { bounds = bounds | layer.bounds; }
        assert(bounds.valid);
        return bounds;
    }

    void draw(in Rectangle pixelDamage, scope Context pixelCr,
              in Rectangle modelDamage, scope Context modelCr) {
        foreach(layer; _layers) {
            layer.draw(pixelDamage, pixelCr, modelDamage, modelCr);
        }
    }

    private {
        Layer[] _layers;
    }
}