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

#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64

Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);

const int JOY_X = 26;  // HORZ
const int JOY_Y = 27;  // VERT
const int JOY_SW = 16; // SEL

void setup() {
  Wire.setSDA(0);
  Wire.setSCL(1);
  Wire.begin();

  pinMode(JOY_SW, INPUT_PULLUP);

  display.begin(SSD1306_SWITCHCAPVCC, 0x3C);
  display.clearDisplay();
}

void loop() {
  int rawX = analogRead(JOY_X);
  int rawY = analogRead(JOY_Y);

  // Map 12-bit ADC (0-4095) to OLED coordinates
  int x = map(rawX, 0, 4095, 0, 127);
  int y = map(rawY, 0, 4095, 63, 0); // invert Y if desired

  display.clearDisplay();

  // Draw a 4x4 square as the cursor
  display.fillRect(x, y, 4, 4, SSD1306_WHITE);

  // If joystick button is pressed, draw a border
  if (digitalRead(JOY_SW) == LOW) {
    display.drawRect(0, 0, 128, 64, SSD1306_WHITE);
  }

  display.display();
  delay(20);
}