void PathSimplificationApp::drawLine(cairo::Context &ctx, Vec2f const &pt1, Vec2f const &pt2, float thickness, Color col)
{
    ctx.setLineWidth(thickness);
    ctx.setSource(col);
    ctx.newSubPath();
    ctx.moveTo(pt1.x, pt1.y);
    ctx.lineTo(pt2.x, pt2.y);
    
    ctx.closePath();
    ctx.stroke();
}