#include <Adafruit_GFX.h>
#include <Adafruit_ILI9341.h>
#include <SPI.h>
#include <math.h>

#define TFT_DC 2
#define TFT_CS 15
#define TFT_WIDTH 320
#define TFT_HEIGHT 240

Adafruit_ILI9341 tft = Adafruit_ILI9341(TFT_CS, TFT_DC);

void setup() {
  tft.begin();
  tft.setRotation(1);
  tft.fillScreen(ILI9341_BLACK);
  tft.setTextColor(ILI9341_WHITE);
  tft.setTextSize(2);
}

void loop() {
  while (true) {
    drawCombinedSignalSmooth();
    delay(100);
    tft.fillRect(0, 0, tft.width(), tft.height(), ILI9341_BLACK);
  }
}

void drawCombinedSignalSmooth() {
  float xStart = 0; // Start x-coordinate
  float xEnd = TFT_WIDTH; // End x-coordinate
  float step = 0.01; // Step size for drawing

  float xPrev = xStart;
  float yPrev = calculateCombinedSignal(xStart);

  for (float x = xStart + step; x <= xEnd; x += step) {
    float yCurr = calculateCombinedSignal(x);
    
    // Draw a line segment from previous point to current point
    tft.drawLine(xPrev, yPrev, x, yCurr, ILI9341_YELLOW);
    
    // Update previous point
    xPrev = x;
    yPrev = yCurr;
  }
}

float calculateCombinedSignal(float x) {
  float onde_P = -(1 / 0.4) * exp(-pow((x - 20), 2) / pow(8, 2));
  float onde_Q = (1.4 / 0.4) * exp(-pow((x - 42), 2) / 1.5);
  float onde_R = -(4 / 0.2) * exp(-pow((x - 47.35), 2) / pow(2.5, 2));
  float onde_S = (1 / 0.2) * exp(-pow((x - 50.9), 2) / pow(1.5, 2));
  float onde_T= -(1 / 0.3) * exp(-pow((x - 85), 2) / 80);
  return (onde_P+onde_Q+onde_R+onde_S+onde_T)*6 + TFT_HEIGHT / 2+20;
}