#define DISPLAY_WIDTH  4
#define DISPLAY_HEIGHT 5

unsigned long characterMap[3];
// set up a character in the characterMap
void Chr(char theChar, unsigned long value) {
 characterMap[theChar - 32] = value;
}

// The offset of our string in the display
int offset = 0;
unsigned long lastMillis = 0;
unsigned long currentMillis = 0;
unsigned int timeout;
int length = sizeof("FAV");
// render the string on the given offset
void renderString(char *theString, int offset) {
 int index = 0;
 while (theString[index]) {
   renderCharacter(theString[index], offset - index * (DISPLAY_WIDTH + 1));
   index++;
 }
}
// render a character on the given offset
void renderCharacter(char theChar, int charOffset) {
 if (charOffset <= -DISPLAY_WIDTH || charOffset > DISPLAY_WIDTH) {
   // off the 'screen' nothing to do
   return;
 }
 unsigned long graphic = characterMap[theChar - 32];
 for (byte y = 0; y < DISPLAY_HEIGHT; y++) {
   for (byte x = 0; x < DISPLAY_WIDTH; x++) {
     setPixel(3 - x + charOffset, y, graphic & 0x1);
     graphic = graphic >> 1;
   }
 }
}
// light a pixel at the given coordinates
void setPixel(byte x, byte y, boolean ledStatus) {
 if (x >= 0 && x < DISPLAY_WIDTH) {
   if (y <= x) {
     x++;
   }
   setLed(y, x, ledStatus);
 }
}
// turn on the pins to light a LED
void setLed(byte vin, byte gnd, boolean ledStatus) {
 delay(1);
 pinMode(0, INPUT); 
 pinMode(1, INPUT); 
 pinMode(2, INPUT); 
 pinMode(3, INPUT); 
 pinMode(4, INPUT); 
 if(!ledStatus) return;
 pinMode(vin, OUTPUT);   
 pinMode(gnd, OUTPUT); 
 digitalWrite(vin, HIGH);
 digitalWrite(gnd, LOW); 
}
// runs at start
void setup() {
 // set up render map
 // Rows:   1---2---3---4---5---
 Chr('A', 0b10011001111110010110);
 Chr('B', 0b01111001011110010111);
 Chr('F', 0b00010001011100011111);
 // how long to wait between shifting the display
 timeout = 1000 / 12;
}
// loops continuously
void loop() {
 currentMillis = millis();
 setLed(1,1, 0x1);
// renderString("FAB", offset);
// if (currentMillis - lastMillis > timeout) {
//   lastMillis = currentMillis;
//   // shift string over one "pixel"
//   offset++;
//   // if it's past the length of the string, start over from the beginning
//   if (offset > length * (DISPLAY_WIDTH + 1)) {
//     offset = -DISPLAY_WIDTH;
//   }
// }
  
}