public void ProcessRequest(HttpContext context)
{
uint x, y, z;
//Parse request parameters
if (!uint.TryParse(context.Request.Params["x"], out x))
{
throw (new ArgumentException("Invalid parameter"));
}
if (!uint.TryParse(context.Request.Params["y"], out y))
{
throw (new ArgumentException("Invalid parameter"));
}
if (!uint.TryParse(context.Request.Params["z"], out z))
{
throw (new ArgumentException("Invalid parameter"));
}
// Create a bitmap of size 256x256
using (var bmp = new Bitmap(256, 256))
// get graphics from bitmap
using (var graphics = Graphics.FromImage(bmp))
{
// calc rect from tile key
var queryWindow = TransformTools.TileToWgs(x, y, z);
// build the sql
string sx1 = Convert.ToString(queryWindow.Left, CultureInfo.InvariantCulture);
string sy1 = Convert.ToString(queryWindow.Top, CultureInfo.InvariantCulture);
string sx2 = Convert.ToString(queryWindow.Right, CultureInfo.InvariantCulture);
string sy2 = Convert.ToString(queryWindow.Bottom, CultureInfo.InvariantCulture);
var strSql = string.Format("SELECT Id, AsBinary(Geometry) FROM WorldGeom WHERE MBRIntersects(Geometry, BuildMbr({0}, {1}, {2}, {3}));",
sx1, sy2, sx2, sy1);
using (SQLiteCommand command = new SQLiteCommand(strSql, Global.cn))
using (SQLiteDataReader reader = command.ExecuteReader())
{
while (reader.Read())
{
int id = reader.GetInt32(0);
byte[] wkb = reader[1] as byte[];
// create GDI path from wkb
var path = WkbToGdi.Parse(wkb, p => TransformTools.WgsToTile(x, y, z, p));
// fill polygon
var fill = new SolidBrush(Color.FromArgb(168, 0, 0, 255));
graphics.FillPath(fill, path);
fill.Dispose();
// draw outline
graphics.DrawPath(Pens.Black, path);
}
reader.Close();
}
//Stream the image to the client
using (var memoryStream = new System.IO.MemoryStream())
{
// Saving a PNG image requires a seekable stream, first save to memory stream
// http://forums.asp.net/p/975883/3646110.aspx#1291641
bmp.Save(memoryStream, System.Drawing.Imaging.ImageFormat.Png);
var buffer = memoryStream.ToArray();
context.Response.ContentType = "image/png";
context.Response.OutputStream.Write(buffer, 0, buffer.Length);
}
}
}
public void ProcessRequest(HttpContext context)
{
uint x, y, z;
//Parse request parameters
if (!uint.TryParse(context.Request.Params["x"], out x))
{
throw (new ArgumentException("Invalid parameter"));
}
if (!uint.TryParse(context.Request.Params["y"], out y))
{
throw (new ArgumentException("Invalid parameter"));
}
if (!uint.TryParse(context.Request.Params["z"], out z))
{
throw (new ArgumentException("Invalid parameter"));
}
// Create a bitmap of size 256x256
using (var bmp = new Bitmap(256, 256))
// get graphics from bitmap
using (var graphics = Graphics.FromImage(bmp))
{
// calc rect from tile key
var queryWindow = TransformTools.TileToWgs(x, y, z);
// build the sql
var strSql = string.Format(CultureInfo.InvariantCulture,
@"SELECT WorldGeom.Id, AsBinary(Geometry), Pop/Area as PopDens FROM WorldGeom " +
@"JOIN WorldData on WorldData.Id = WorldGeom.Id " +
@"WHERE MBRIntersects(Geometry, BuildMbr({0}, {1}, {2}, {3}));",
queryWindow.Left, queryWindow.Top, queryWindow.Right, queryWindow.Bottom);
var choropleth = new Classification <double, Color>
{
MinValue = 0, // lower border for classification
DefaultAttribute = Color.White, // color if key hits no class
Values = new SortedList <double, Color> { // the classes
{ 50, Color.Green },
{ 100, Color.LightGreen },
{ 250, Color.Yellow },
{ 500, Color.Orange },
{ 1000, Color.Red },
{ 2500, Color.DarkRed },
{ double.MaxValue, Color.Purple }
}
};
using (SQLiteCommand command = new SQLiteCommand(strSql, Global.cn))
using (SQLiteDataReader reader = command.ExecuteReader())
{
while (reader.Read())
{
int id = reader.GetInt32(0);
byte[] wkb = reader[1] as byte[];
double popDens = reader.IsDBNull(2)? -1 : reader.GetDouble(2);
// create GDI path from wkb
var path = WkbToGdi.Parse(wkb, p => TransformTools.WgsToTile(x, y, z, p));
// fill polygon
var color = choropleth.GetValue(popDens);
var fill = new SolidBrush(Color.FromArgb(168, color.R, color.G, color.B));
graphics.FillPath(fill, path);
fill.Dispose();
// draw outline
graphics.DrawPath(Pens.Black, path);
}
reader.Close();
}
//Stream the image to the client
using (var memoryStream = new System.IO.MemoryStream())
{
// Saving a PNG image requires a seekable stream, first save to memory stream
// http://forums.asp.net/p/975883/3646110.aspx#1291641
bmp.Save(memoryStream, System.Drawing.Imaging.ImageFormat.Png);
var buffer = memoryStream.ToArray();
context.Response.ContentType = "image/png";
context.Response.OutputStream.Write(buffer, 0, buffer.Length);
}
}
}
// http://msdn.microsoft.com/en-us/library/bb259689.aspx
public void ProcessRequest(HttpContext context)
{
uint x, y, z;
//Parse request parameters
if (!uint.TryParse(context.Request.Params["x"], out x))
{
throw (new ArgumentException("Invalid parameter"));
}
if (!uint.TryParse(context.Request.Params["y"], out y))
{
throw (new ArgumentException("Invalid parameter"));
}
if (!uint.TryParse(context.Request.Params["z"], out z))
{
throw (new ArgumentException("Invalid parameter"));
}
// Create a bitmap of size 256x256
using (var bmp = new Bitmap(256, 256))
// get graphics from bitmap
using (var graphics = Graphics.FromImage(bmp))
{
int symbolSize = 16; // the size of our symbol in pixel
// calculate geo rect, taking the bleeding into account
// = the maximum number of pixels a symbol can "bleed" into a neighbouring tile
// see tile tile http://80.146.239.139/SpatialTutorial/04-TilesAndLabelsHandler.ashx?x=69&y=44&z=7
var rect = TransformTools.TileToWgs(x, y, z, symbolSize / 2);
int left = (int)Math.Floor(rect.Left);
int right = (int)Math.Floor(rect.Right);
int top = (int)Math.Floor(rect.Top);
int bottom = (int)Math.Floor(rect.Bottom);
// draw text
var font = new Font("Arial", symbolSize - 4);
var format = new StringFormat {
Alignment = StringAlignment.Center, LineAlignment = StringAlignment.Center
};
for (double lon = left; lon <= right; lon++)
{
for (double lat = top; lat <= bottom; lat++)
{
var g1 = new System.Windows.Point(lon, lat);
var g2 = new System.Windows.Point(lon + 1, lat + 1);
var p1 = TransformTools.WgsToTile(x, y, z, g1);
var p2 = TransformTools.WgsToTile(x, y, z, g2);
graphics.DrawLine(Pens.Black, new System.Drawing.Point((int)p1.X, (int)p1.Y), new System.Drawing.Point((int)p2.X, (int)p1.Y));
graphics.DrawLine(Pens.Black, new System.Drawing.Point((int)p1.X, (int)p1.Y), new System.Drawing.Point((int)p1.X, (int)p2.Y));
if (z < 6) // no symbols for levels < 6
{
continue;
}
// draw symbol for latitude
graphics.FillEllipse(Brushes.LightGray, (int)(p1.X + p2.X) / 2 - symbolSize, (int)p1.Y - symbolSize, symbolSize * 2, symbolSize * 2);
graphics.DrawEllipse(Pens.Black, (int)(p1.X + p2.X) / 2 - symbolSize, (int)p1.Y - symbolSize, symbolSize * 2, symbolSize * 2);
graphics.DrawString(string.Format("{0}°", lat), font, Brushes.Black, (int)(p1.X + p2.X) / 2, (int)p1.Y, format);
// draw symbol for longitude
graphics.FillEllipse(Brushes.LightGray, (int)(p1.X) - symbolSize, (int)(p1.Y + p2.Y) / 2 - symbolSize, symbolSize * 2, symbolSize * 2);
graphics.DrawEllipse(Pens.Black, (int)(p1.X) - symbolSize, (int)(p1.Y + p2.Y) / 2 - symbolSize, symbolSize * 2, symbolSize * 2);
graphics.DrawString(string.Format("{0}°", lon), font, Brushes.Black, (int)(p1.X), (int)(p1.Y + p2.Y) / 2, format);
}
}
font.Dispose();
//Stream the image to the client
using (var memoryStream = new System.IO.MemoryStream())
{
// Saving a PNG image requires a seekable stream, first save to memory stream
// http://forums.asp.net/p/975883/3646110.aspx#1291641
bmp.Save(memoryStream, System.Drawing.Imaging.ImageFormat.Png);
var buffer = memoryStream.ToArray();
context.Response.ContentType = "image/png";
context.Response.OutputStream.Write(buffer, 0, buffer.Length);
}
}
}
// http://msdn.microsoft.com/en-us/library/bb259689.aspx
public void ProcessRequest(HttpContext context)
{
uint x, y, z;
//Parse request parameters
if (!uint.TryParse(context.Request.Params["x"], out x))
{
throw (new ArgumentException("Invalid parameter"));
}
if (!uint.TryParse(context.Request.Params["y"], out y))
{
throw (new ArgumentException("Invalid parameter"));
}
if (!uint.TryParse(context.Request.Params["z"], out z))
{
throw (new ArgumentException("Invalid parameter"));
}
// Create a bitmap of size 256x256
using (var bmp = new Bitmap(256, 256))
// get graphics from bitmap
using (var graphics = Graphics.FromImage(bmp))
{
// widen stroke width based on zoom
int strokeSize = (z > 15) ? 4 : (z > 10) ? 3 : (z > 5) ? 2 : 1;
// calculate map scale
var mapSize = 256 * Math.Pow(2, z); // size of the map in pixel
double earthCircumfence = 2.0 * Math.PI * 6378137.0; // circumfence of earth
var scale = mapSize / earthCircumfence; // pixel per mercator unit
// Calculate the symbol sizes with 3 different scaling modes
// 1 - constant scaling - radius is always 16 pixels
int sz1 = (int)(16 * Math.Pow(scale, 0.0));
// 2 - linear scaling - the symbol has a size of 10000 merctor units (=meter at equator, equals sz = 10000 * scale)
int sz2 = (int)(10000 * Math.Pow(scale, 1.0));
// 2 - logarithmic scaling - the size is adapted with a base size (64) and a scaling factor (0.25)
int sz3 = (int)(64 * Math.Pow(scale, 0.25));
// the maximum number of pixels a symbol can "bleed" into a neighbouring tile
var bleedingPixels = (Math.Max(Math.Max(sz1, sz2), sz3) + strokeSize) / 2;
var rect = TransformTools.TileToWgs(x, y, z, bleedingPixels);
int left = (int)Math.Floor(rect.Left);
int right = (int)Math.Floor(rect.Right);
int top = (int)Math.Floor(rect.Top);
int bottom = (int)Math.Floor(rect.Bottom);
var pen = new System.Drawing.Pen(System.Drawing.Color.Black, strokeSize);
var format = new StringFormat {
Alignment = StringAlignment.Center, LineAlignment = StringAlignment.Center
};
for (int lon = left; lon <= right; lon++)
{
for (int lat = top; lat <= bottom; lat++)
{
var g1 = new System.Windows.Point(lon, lat);
var g2 = new System.Windows.Point(lon + 1, lat + 1);
var p1 = TransformTools.WgsToTile(x, y, z, g1);
var p2 = TransformTools.WgsToTile(x, y, z, g2);
graphics.DrawLine(pen, new System.Drawing.Point((int)p1.X, (int)p1.Y), new System.Drawing.Point((int)p2.X, (int)p1.Y));
graphics.DrawLine(pen, new System.Drawing.Point((int)p1.X, (int)p1.Y), new System.Drawing.Point((int)p1.X, (int)p2.Y));
if (z < 6) // no symbols for levels < 6
{
continue;
}
int sz;
Brush brush;
switch ((lat + lon) % 3) // switch between the 3 size modes
{
case 0: sz = sz1; brush = Brushes.LightGreen; break;
case 1: sz = sz2; brush = Brushes.LightYellow; break;
default: sz = sz3; brush = Brushes.LightBlue; break;
}
graphics.FillEllipse(brush, (int)(p1.X + p2.X) / 2 - sz, (int)p1.Y - sz, sz * 2, sz * 2);
graphics.FillEllipse(brush, (int)(p1.X) - sz, (int)(p1.Y + p2.Y) / 2 - sz, sz * 2, sz * 2);
graphics.DrawEllipse(pen, (int)(p1.X + p2.X) / 2 - sz, (int)p1.Y - sz, sz * 2, sz * 2);
graphics.DrawEllipse(pen, (int)(p1.X) - sz, (int)(p1.Y + p2.Y) / 2 - sz, sz * 2, sz * 2);
if (sz > 4)
{
var font = new Font("Arial", sz - 4);
graphics.DrawString(string.Format("{0}°", lat), font, Brushes.Black, (int)(p1.X + p2.X) / 2, (int)p1.Y, format);
graphics.DrawString(string.Format("{0}°", lon), font, Brushes.Black, (int)(p1.X), (int)(p1.Y + p2.Y) / 2, format);
font.Dispose();
}
}
}
//Stream the image to the client
using (var memoryStream = new System.IO.MemoryStream())
{
// Saving a PNG image requires a seekable stream, first save to memory stream
// http://forums.asp.net/p/975883/3646110.aspx#1291641
bmp.Save(memoryStream, System.Drawing.Imaging.ImageFormat.Png);
var buffer = memoryStream.ToArray();
context.Response.ContentType = "image/png";
context.Response.OutputStream.Write(buffer, 0, buffer.Length);
}
}
}
// http://msdn.microsoft.com/en-us/library/bb259689.aspx
public void ProcessRequest(HttpContext context)
{
uint x, y, z;
//Parse request parameters
if (!uint.TryParse(context.Request.Params["x"], out x))
{
throw (new ArgumentException("Invalid parameter"));
}
if (!uint.TryParse(context.Request.Params["y"], out y))
{
throw (new ArgumentException("Invalid parameter"));
}
if (!uint.TryParse(context.Request.Params["z"], out z))
{
throw (new ArgumentException("Invalid parameter"));
}
// Create a bitmap of size 256x256
using (var bmp = new Bitmap(256, 256))
// get graphics from bitmap
using (var graphics = Graphics.FromImage(bmp))
{
// draw background
//var brush = new LinearGradientBrush(new Point(0, 0), new Point(256, 256),
// Color.LightBlue, Color.Transparent);
//graphics.FillRectangle(brush, new Rectangle(0, 0, 256, 256));
//brush.Dispose();
var rect = TransformTools.TileToWgs(x, y, z);
int left = (int)Math.Floor(rect.Left);
int right = (int)Math.Floor(rect.Right);
int top = (int)Math.Floor(rect.Top);
int bottom = (int)Math.Floor(rect.Bottom);
for (int lon = left; lon <= right; lon++)
{
for (int lat = top; lat <= bottom; lat++)
{
var g1 = new System.Windows.Point(lon, lat);
var g2 = new System.Windows.Point(lon + 1, lat + 1);
var p1 = TransformTools.WgsToTile(x, y, z, g1);
var p2 = TransformTools.WgsToTile(x, y, z, g2);
graphics.DrawLine(Pens.Black, new System.Drawing.Point((int)p1.X, (int)p1.Y), new System.Drawing.Point((int)p2.X, (int)p1.Y));
graphics.DrawLine(Pens.Black, new System.Drawing.Point((int)p1.X, (int)p1.Y), new System.Drawing.Point((int)p1.X, (int)p2.Y));
}
}
//Stream the image to the client
using (var memoryStream = new System.IO.MemoryStream())
{
// Saving a PNG image requires a seekable stream, first save to memory stream
// http://forums.asp.net/p/975883/3646110.aspx#1291641
bmp.Save(memoryStream, System.Drawing.Imaging.ImageFormat.Png);
var buffer = memoryStream.ToArray();
context.Response.ContentType = "image/png";
context.Response.OutputStream.Write(buffer, 0, buffer.Length);
}
}
}
