- Constructor
Create a fix size array, say “bool pix[MAX_WIDTH*MAX_HEIGHT];”, that represent the state of all the pixels on the screen.

- OnMouseMove
Set the state of that (x,y) pixel, say “pix[x+y*MAX_WIDTH] = true;”
Refresh screen (Invalidate)

- To export the signature map to visible string
foreach pix[xi+yi*MAX_WIDTH] that is true, append to string as value of (xi+yi*MAX_WIDTH) and also separate with any separator (e.g. “,)

- To import visible string and convert into signature map
Reset the pix array (set all element to false). Read string and throw away the separators, convert the value into integer. Set “pix[value] = true”. Make sure validate the value to avoid buffer over/underflow

- Draw the signature
foreach pix[xi+yi*MAX_WIDTH] that is true, set the screen pixel to a color. if you want the signature looks “bold”er, u can draw a circle with larger radius around the pixel.