WriteableBitmapEx from codeplex

The WriteableBitmapEx library is a collection of extension methods for Silverlight’s WriteableBitmap. The WriteableBitmap class that was added in Silverlight 3, allows the direct manipulation of a bitmap and could be used to generate fast procedural images by drawing directly to a bitmap. The WriteableBitmap API is very minimalistic and there’s only the raw Pixels array for such operations. The WriteableBitmapEx library tries to compensate that with extensions methods that are easy to use like built in methods. The library extends the WriteableBitmap class with elementary and fast (2D drawing) functionality, conversion methods and functions to combine (blit) WriteableBitmaps.
The extension methods are grouped into different CS files with a partial class. It is possible to include just a few methods by using the specific source CS files directly or all extension methods through the built library assembly.


  • Base
    • Support for the Color structure
    • SetPixel method with various overloads
    • Fast Clear methods
    • ForEach method to apply a given function to all pixels of the bitmap
  • Shapes
    • Fast line drawing algorithms
    • Ellipse, polyline, quad, rectangle and triangle
  • Blitting
    • Different blend modes including alpha, additive, subtractive, multiply, mask and none
    • Optimized fast path for non blended blitting
  • Conversion
    • Convert a WriteableBitmap to a byte array
    • Create a WriteableBitmap from a byte array

Sample Code

// Initialize the WriteableBitmap with size 512x512 and set it as source of an Image control
WriteableBitmap writeableBmp = new WriteableBitmap(512, 512);
ImageControl.Source = writeableBmp;

// Clear the WriteableBitmap with white color

// Green line from P1(1, 2) to P2(30, 40)
writeableBmp.DrawLine(1, 2, 30, 40, Colors.Green);

// Black triangle with the points P1(10, 5), P2(20, 40) and P3(30, 10)
writeableBmp.DrawTriangle(10, 5, 20, 40, 30, 10, Colors.Black);

// Red rectangle from the point P1(2, 4) that is 10px wide and 6px high
writeableBmp.DrawRectangle(2, 4, 12, 10, Colors.Red);

// Blue ellipse with the center point P1(2, 2) that is 8px wide and 5px high
writeableBmp.DrawEllipseCentered(2, 2, 8, 5, Colors.Blue);

// Closed green polyline with P1(10, 5), P2(20, 40), P3(30, 30) and P4(7, 8)
int[] p = new int[] { 10, 5, 20, 40, 30, 30, 7, 8, 10, 5 };
writeableBmp.DrawPolyline(p, Colors.Green);

// Present the WriteableBitmap!

For more visit: http://writeablebitmapex.codeplex.com/


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