//
// Happy Halloween
// by Hari Wiguna 2015
//
// 01 - modify to work with Chinese knockoff
// 02 - Draw Happy Halloween & Pumpkin Face

// Wiring:
// Arduino A4 --> OLED SDA
// Arduino A5 --> OLED SCL
// Arduino D2 --> OLED VCC
// Arduino Gnd--> OLED Gnd
//
// Potentiometers are on Gnd and +5V, wipers go to A0, A2, A2

/*********************************************************************
This is an example for our Monochrome OLEDs based on SSD1306 drivers

  Pick one up today in the adafruit shop!
  ------> http://www.adafruit.com/category/63_98

This example is for a 128x64 size display using I2C to communicate
3 pins are required to interface (2 I2C and one reset)

Adafruit invests time and resources providing this open source code,
please support Adafruit and open-source hardware by purchasing
products from Adafruit!

Written by Limor Fried/Ladyada  for Adafruit Industries.
BSD license, check license.txt for more information
All text above, and the splash screen must be included in any redistribution
*********************************************************************/

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

#define OLED_RESET 4
Adafruit_SSD1306 display(OLED_RESET);

int prevEyeSize = -1;
int prevEyeRotation = 0;
int prevMouthWidth = -1;
int eyeSep = 2;
int headR = 50;

#define LOGO16_GLCD_HEIGHT 16
#define LOGO16_GLCD_WIDTH  16
static const unsigned char PROGMEM logo16_glcd_bmp[] =
{ B00000000, B11000000,
  B00000001, B11000000,
  B00000001, B11000000,
  B00000011, B11100000,
  B11110011, B11100000,
  B11111110, B11111000,
  B01111110, B11111111,
  B00110011, B10011111,
  B00011111, B11111100,
  B00001101, B01110000,
  B00011011, B10100000,
  B00111111, B11100000,
  B00111111, B11110000,
  B01111100, B11110000,
  B01110000, B01110000,
  B00000000, B00110000
};

#if (SSD1306_LCDHEIGHT != 64)
#error("Height incorrect, please fix Adafruit_SSD1306.h!");
#endif

void setup()   {
  // This is a hack to get my Chinese OLED to work.
  // I power the OLED using D2 because my OLED does not have a reset pin.
  // Without this hack, my oled displays static random dots.
  pinMode(2, OUTPUT);
  digitalWrite(2, LOW);
  delay(100);
  digitalWrite(2, HIGH);

  // by default, we'll generate the high voltage from the 3.3v line internally! (neat!)
  display.begin(SSD1306_SWITCHCAPVCC, 0x3C);  // initialize with the I2C addr 0x3D (for the 128x64)
  display.clearDisplay();
}

void loop() {
  int eyeSize = map(analogRead(A0), 0, 1023, 0, display.height() / 2);
  int eyeRotation = map(analogRead(A1), 0, 1023, 0, 360);
  int mouthWidth = map(analogRead(A2), 0, 1023, 0, display.width() / 2);

  if (eyeSize != prevEyeSize || eyeRotation != prevEyeRotation || mouthWidth != prevMouthWidth)
  {
    display.setTextColor(WHITE);
    display.setCursor(8, 0);
    display.setTextSize(2);
    display.println("Halloween!");

    //-- Head --
    display.drawCircle(display.width() / 2, display.height() / 2, headR, WHITE);

    //-- Left Eye --
    DrawEye(display.width() / 2 - prevEyeSize - eyeSep, display.height() / 2, prevEyeSize, prevEyeRotation, BLACK);
    DrawEye(display.width() / 2 - eyeSize - eyeSep, display.height() / 2, eyeSize, eyeRotation, WHITE);

    //-- Right Eye --
    DrawEye(display.width() / 2 + prevEyeSize + eyeSep, display.height() / 2, prevEyeSize, prevEyeRotation, BLACK);
    DrawEye(display.width() / 2 + eyeSize + eyeSep, display.height() / 2, eyeSize, eyeRotation, WHITE);

    //-- Mouth --
    DrawMouth(prevMouthWidth, BLACK);
    DrawMouth(mouthWidth, WHITE);

    display.display();

    prevEyeSize = eyeSize;
    prevEyeRotation = eyeRotation;
    prevMouthWidth = mouthWidth;
  }
}

void DrawEye(int x0, int y0, int r, int rotation, int color)
{
  //    display.drawCircle(display.width() / 2 - r, display.height() / 2, r, WHITE);
  //    display.drawCircle(display.width() / 2 + r, display.height() / 2, r, WHITE);

  int x[3], y[3];
  for (int i = 0; i < 3; i++)
  {
    float angle = (rotation * 2 * PI / 360) + i * 2 * PI / 3;
    x[i] = x0 + sin(angle) * r;
    y[i] = y0 + cos(angle) * r;
  }
  display.drawTriangle(
    x[0], y[0],
    x[1], y[1],
    x[2], y[2],
    color);
}

void DrawMouth(byte width, int color)
{
  int xOrigin =  display.width() / 2;
  //display.drawLine( xOrigin - width, 61, xOrigin + width, 61, color);

  int eighth = width / 4;
  int x0 = xOrigin - width;
  int x1 = xOrigin - width + eighth;
  int x2 = xOrigin - width + eighth + eighth;
  int x3 = xOrigin - width + eighth + eighth + eighth;
  int x4 = xOrigin;
  int x5 = xOrigin + width - eighth - eighth - eighth;
  int x6 = xOrigin + width - eighth - eighth;
  int x7 = xOrigin + width - eighth;
  int x8 = xOrigin + width;

  int y0 = 55;
  int y1 = 63;
  display.drawLine( x0, y0, x1, y1, color);
  display.drawLine( x1, y1, x2, y0, color);
  display.drawLine( x2, y0, x3, y1, color);
  display.drawLine( x3, y1, x4, y0, color);
  display.drawLine( x4, y0, x5, y1, color);
  display.drawLine( x5, y1, x6, y0, color);
  display.drawLine( x6, y0, x7, y1, color);
  display.drawLine( x7, y1, x8, y0, color);
}