/// <summary>
/// Renders the polygon to a bitmap.
/// </summary>
/// <param name="poly">The polygon.</param>
/// <param name="width">The desired width (pixel) of the image.</param>
/// <returns>The bitmap.</returns>
/// <remarks>
/// The width has to be at least 2 * sqrt(n), n the number of vertices.
/// Otherwise, an empty bitmap
/// </remarks>
public Bitmap Render(Geometry.IPolygon poly, int width = 800)
{
Bitmap bitmap;
// Check if the specified width is reasonable
if (width < 2 * Math.Sqrt(poly.Points.Count))
{
return(new Bitmap(1, 1));
}
var bounds = poly.Bounds();
// World margin on each side
float margin = (float)bounds.Height * 0.05f;
float scale = width / ((float)bounds.Width + 2 * margin);
var target = new Rectangle(0, 0, width, (int)((bounds.Height + 2 * margin) * scale));
bitmap = new Bitmap(width, target.Height, PixelFormat.Format32bppPArgb);
using (var g = Graphics.FromImage(bitmap))
{
g.Clear(colors.Background);
g.SmoothingMode = SmoothingMode.HighQuality;
var context = new RenderContext(new Projection(target), colors);
context.Add(poly);
if (!EnablePoints)
{
context.Enable(3, false);
}
var renderer = new LayerRenderer();
renderer.Context = context;
renderer.RenderTarget = g;
renderer.Render();
}
return(bitmap);
}
/// <summary>
/// Exports a polygon to PNG format.
/// </summary>
/// <param name="poly">The polygon.</param>
/// <param name="width">The desired width (pixel) of the image.</param>
/// <param name="file">The PNG filename.</param>
/// <param name="regions">Enable rendering of regions.</param>
/// <param name="points">Enable rendering of points.</param>
public static void Save(Geometry.IPolygon poly, string file = null, int width = 800,
bool points = true)
{
// Check file name
if (string.IsNullOrWhiteSpace(file))
{
file = string.Format("poly-{0}.png", DateTime.Now.ToString("yyyy-M-d-hh-mm-ss"));
}
// Ensure .png extension.
if (file.EndsWith(".png", StringComparison.OrdinalIgnoreCase))
{
Path.ChangeExtension(file, ".png");
}
var renderer = new ImageRenderer();
renderer.EnableRegions = false;
renderer.EnablePoints = points;
var bitmap = renderer.Render(poly, width);
bitmap.Save(file, ImageFormat.Png);
}
