Updated on 15/07/2009 to Silverlight 3 RTW

Inspired by old school MS DOS demos and this Flash Alchemy experiment.
Found out that someone already ported some code from the Alchemy experiment to C#.
So after some tweaking and some help of my colleague Frederik it’s up and running in Silverlight 3 beta.

I’m using two threads to speed up the plasma calculation when moving the dots, since everybody has a duo,triple,quad,octa … core CPU these days,
One thread does even lines and the other odd lines (interlacing).

 public static void GeneratePlasmaEvenLines()
     {
       int index = 0;

       for (var x = 0; x < width; x +=2)
       {
         for (var y = 0; y < height ; y+=1)
         {
           uint color = CalculatePixel(x, y);
           plasma[index++] = color % 255;
         }
         index += width;
       }
     }

     public static void GeneratePlasmaOddLines()
     {
         int index = width;
         for (var x = 1; x < width; x+=2)
         {
             for (var y = 0; y < height; y+=1)
             {
                 uint color = CalculatePixel(x, y);
                 plasma[index++] = color % 255;
             }
             index += height;
         }
     }

  private static uint CalculatePixel(int x, int y)
     {
         int w = (int) param6;
         int h = (int)param5;
         uint color = (uint)
        (
              128.0 + (param3 * Math.Sin(x / param1))
            + 128.0 + (param4 * Math.Sin(y / param2))
            + 128.0 + ((param5/4) * Math.Sin(Math.Sqrt((double)((x - w)* (x - w) + (y - h ) * (y - h))) / 9.0))
            + 128.0 + ((param6/4)* Math.Sin(Math.Sqrt((double)(x * x + y * y)) / 9.0))
        ) / 4;

         // Add shift position to sync the color
         color +=  LastShift;
         return color;
     }

Placing the pixels on the canvas with the our brand new bitmap api

private void BuildBitmap(uint[] data)
        {
            uint colorValue=0;
                for (int x = 0; x < imageWidth; x++)
                {
                    for (int y = 0; y < imageHeight; y++)
                    {
                        // set the pixel value
                        int palletIndex = (int)data[y * imageWidth + x];
                        colorValue = GeneratePlasma.palette[palletIndex];
                        writeableBitmap.Pixels[y * imageWidth + x] = (int)colorValue;
                    }
                }

            writeableBitmap.Invalidate();
            btImage.Source = writeableBitmap;
            GC.Collect();
        }

To view the full code download the project below.

Silverlight 3 is required

This entry was posted on Thursday, June 4th, 2009 at 08:11 and is filed under Animation, Silverlight. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.