#include "U8glib.h"
U8GLIB_SSD1306_128X64 u8g(U8G_I2C_OPT_DEV_0); // Add " | U8G_I2C_OPT_NO_ACK | U8G_I2C_OPT_FAST" if the screen isn't working

// Classes
#include "bitmaps.h"

// Pins
#define jsXPin 0
#define jsYPin 1
#define jsSWPin 2

// Screen
#define screenWidth 128
#define screenHeight 64

// Joystick
float jsX = 0.0;
float jsY = 0.0;
bool jsSW = false;
bool jsSWD = false;

// Cursor
int cursorX = 0;
int cursorY = 0;
#define cursorSpeed 10

// Application Class
typedef struct
{
  unsigned char* bits;
  int width;
  int height;
} application;

// Home
application apps[] =
{
  {notesBMP_bits, notesBMP_width, notesBMP_height},
  {drawBMP_bits, drawBMP_width, drawBMP_height},
  {snakeBMP_bits, snakeBMP_width, snakeBMP_height}
};

void setup()
{
  // Joystick
  digitalWrite(jsSWPin, HIGH);

  // Screen
  u8g.setFont(u8g_font_tpssb);
  u8g.setColorIndex(1);
}

void loop()
{
  // Joystick
  getJoystickInput();

  // Cursor
  cursorX = constrain(cursorX + round(jsX * cursorSpeed), 0, screenWidth - 1);
  cursorY = constrain(cursorY - round(jsY * cursorSpeed), 0, screenHeight - 1);

  // Screen
  u8g.firstPage();
  do { draw(); jsSWD = false; } while ( u8g.nextPage() );
}

void draw()
{
  // Cursor
  u8g.drawXBM(cursorX, cursorY, cursorBMP_width, cursorBMP_height, cursorBMP_bits);

  // Applications
  int x = 1, y = 1;
  for (int i = 0; i < (sizeof apps / sizeof apps[0]); i++)
  {
    application app = apps[i];
    u8g.drawXBM(x, y, app.width, app.height, app.bits);

    x += app.width + 1;

    if (x > screenWidth)
    {
      x = 1;
      y += app.height + 1;
    }
  }
}

void getJoystickInput()
{
  jsX = 0.0 - (analogRead(jsXPin) / 1023.0 * 2 - 1);
  jsY = analogRead(jsYPin) / 1023.0 * 2 - 1;

  bool reading = !digitalRead(jsSWPin);

  if (jsSW != reading)
  {
    jsSW = reading;

    if (jsSW == true)
      jsSWD = true;
  }
  else
    jsSWD = false;
}