Time for action – the buildIndexBuffer() method

1. 1. Add the Index Buffer region to the Terrain class:

   #region Index Buffer
   private void BuildIndexBuffer(int width, int height)
   {
       int indexCount = (width-1) * (height-1) * 6;
       short[] indices = new short[indexCount];
       int counter = 0;
   
       for (short z = 0; z < height - 1; z++)
           for (short x = 0; x < height - 1; x++)
           {
               short upperLeft = (short)(x + (z * width));
               short upperRight = (short)(upperLeft + 1);
               short lowerLeft = (short)(upperLeft + width);
               short lowerRight = (short)(upperLeft + width + 1);
   
               indices[counter++] = upperLeft;
               indices[counter++] = lowerRight;
               indices[counter++] = lowerLeft;
               indices[counter++] = upperLeft;
               indices[counter++] = upperRight;
               indices[counter++] = lowerRight;
           }
   
       indexBuffer = new IndexBuffer(
           device, 
           IndexElementSize.SixteenBits, 
   ...