//in method for casting single ray
 //where
 perpendicularDistToWall = distToWallByRay*Math.Cos((Player.me().worldViewAngle-rayAngle).rad);

 double stripHeight = (64.0d / perpendicularDistToWall) * Player.me().worldDistToProjectionPlane;
 //

 int stripPosY = (ProjectionPlane.me().sizeInWorld.Y/2 - (int)(stripHeight / 2));
 stripPosY += (int)stripHeight-1;
 int startPixel = stripPosY;

 while (startPixel != ProjectionPlane.me().sizeInWorld.Y){
  float curdist = ProjectionPlane.me().sizeInWorld.Y / (2.0f * startPixel - ProjectionPlane.me().sizeInWorld.Y);

  float weight = curdist / (float)(perpendicularDistToWall);

  float floorX = weight * minimalIntersection.X + (1.0f - weight) *  Player.me().worldPosition.X;
  float floorY = weight * minimalIntersection.Y + (1.0f - weight) *  Player.me().worldPosition.Y;

  int textureX = (int)(floorX * 32) % 32;
  int textureY = (int)(floorY * 32) % 32;

  textureX = Math.Abs(textureX);
  textureY = Math.Abs(textureY);

  b = new SolidBrush(ProjectionPlane.imageFloor1.GetPixel(textureX, textureY));
  //draw current floor pixel directly in buffer
  //stripX from 0 to projection_plane width
  g.FillRectangle(b, stripX, startPixel, 1, 1);

  startPixel++;