Fork of Field Line Desinger by bit.craft

###Changes:

1. Added background image
2. Added saving result to disk
3. Changed initital setup

###Key Map

[SPACE] to switch the mouse charge
[TAB] or [#] switch between field types 
  
[q][w][e] [a][s][d] move the limits 
[l] limit on/off
  
Use cursor keys to rotate the field lines.
[SHIFT] cursor keys to change the line density
  
[b] blurred / soft mode
[m] moiree mode on/off
[-] line thickness
[f] filters
[t] tiled mode
[i] invert colors

[1] lores 
[2] hires
[g] grid style reset
[r] reset all
[R] reset all

[S] save image to data folder
[D] draw background or not