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

#define SCREEN_WIDTH 128 // OLED display width, in pixels
#define SCREEN_HEIGHT 64 // OLED display height, in pixels

// Declaration for an SSD1306 display connected to I2C (SDA, SCL pins)
// On an arduino UNO:       A4(SDA), A5(SCL)

#define OLED_RESET     4 // Reset pin # (or -1 if sharing Arduino reset pin)
#define SCREEN_ADDRESS 0x3c ///< See datasheet for Address; 0x3D for 128x64, 0x3C for 128x32
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);


int x = display.width() / 2; int y = display.height() / 2;
float xspeed = 1; float yspeed = 1.6;
int circRad = 4;
byte udly;


void setup() {
  Serial.begin(9600);

  // SSD1306_SWITCHCAPVCC = generate display voltage from 3.3V internally
  if(!display.begin(SSD1306_SWITCHCAPVCC, SCREEN_ADDRESS)) {
    Serial.println(F("SSD1306 allocation failed"));
    for(;;); // Don't proceed, loop forever
  }

  

  // Clear the buffer
  display.clearDisplay();

  
}

void loop() {
  bounceXY(udly);
}

void bounceXY(byte udly) {
  display.drawCircle(x, y, circRad, SSD1306_WHITE);
    // display.drawCircle(display.width()/2, display.height()/2, i, SSD1306_WHITE);
    display.display();

  delay(udly);
  //delay(5);
  display.drawCircle(x, y, circRad, SSD1306_BLACK);
  //display.drawPixel(x,y,BLACK);
  x = x + xspeed;
  y = y + yspeed;

  if (x > display.width() - (circRad+2) || (x < circRad+2) ) {
    xspeed = xspeed * -1; //reverse
  }
  if (y > display.height() - (circRad+2) || (y < circRad+2) ) {
    yspeed = yspeed * -1; //reverse
  }
}