#include <SPI.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>

// SETUP OLED SCREEN
const byte SCREEN_WIDTH = 128; // OLED display width, in pixels
const byte SCREEN_HEIGHT = 64; // OLED display height, in pixels
const int OLED_RESET = -1; // Reset pin # (or -1 if sharing Arduino reset pin)
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);


// Used to rotate bitmap
#define DEG2RAD 0.0174532925 
int angle = 0;

// Battery Icon 
const static uint8_t PROGMEM  batteryH []  = 
{ 16, 8,
	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xff, 0x80, 0xff, 0xc0, 0xff, 0xc0, 0xff, 0x80, 0x00, 0x00, 
	0x00, 0x00, 0x00, 0x00
};
// Battery Icon 
const static uint8_t PROGMEM  batteryV []  = 
{ 8, 16,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff
};


void setup()   {

  // Need to hardware reset my display manually via pin 7
  digitalWrite(7, LOW);
  pinMode(7, OUTPUT);
  delay(200);
  pinMode(7, INPUT);
  delay(5);
  
  // by default, we'll generate the high voltage from the 3.3v line
  display.begin(SSD1306_SWITCHCAPVCC, 0x3C);  // initialize
}

void loop() {
    display.clearDisplay(); // Clear the display buffer
    display.setTextSize(1);
    display.setTextColor(WHITE);
    // drawRotatedBitmap(1, 0, batteryH, 270);
    display.drawBitmap(0, 0,  batteryV, 4, 8, 1);
    display.setCursor(10,0);
    display.println("34%");
    
    
    display.display();     
    delay(100); // Pause so we see it
}


void drawRotatedBitmap(int16_t x, int16_t y, const uint8_t *bitmap, uint16_t angle) {
    // example of use:
    // drawRotatedBitmap(1, 0, batteryH, 270);

  uint8_t w = pgm_read_byte(bitmap++);
  uint8_t h = pgm_read_byte(bitmap++);

  int16_t newx, newy;
  uint8_t data = 0;

  float  cosa = cos(angle * DEG2RAD), sina = sin(angle * DEG2RAD);

  x = x - ((w * cosa / 2) - (h * sina / 2));
  y = y - ((h * cosa / 2) + (w * sina / 2));

  for (int16_t j = 0; j < h; j++) {
    for (int16_t i = 0; i < w; i++ ) {
      if ((j * w + i) & 7) data <<= 1;
      else      data   = pgm_read_byte(bitmap++);

      newx = 0.5 + x + ((i * cosa) - (j * sina));
      newy = 0.5 + y + ((j * cosa) + (i * sina));

      if (data & 0x80) display.drawPixel(newx, newy, 1);
      //else            display.drawPixel(newx, newy, 0);
    }
  }
}