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

#define TFT_CS   10
#define TFT_DC   9
#define TFT_RST  8

#define BLACK   0x0000
#define RED     0xF800
#define ORANGE  0xFD20
#define YELLOW  0xFFE0
#define GREEN   0x07E0
#define BLUE    0x001F
#define INDIGO  0x4810
#define VIOLET  0x9010
#define WHITE   0xFFFF

Adafruit_ILI9341 tft = Adafruit_ILI9341(TFT_CS, TFT_DC, TFT_RST);

void setup() {
  Serial.begin(9600);
  
  // Initializing TFT display:
  tft.begin();
}

void loop() {
  // Fill TFT Screen with a color:
  tft.fillScreen(BLACK);
  delay(500);

  // Draw a rainbow square with reducing side length:
  for (int side = 680; side > 0; side -= 25) {
    drawRainbowSquare(20, 480, side);
    delay(1000);
  }

  delay(2000);

  // Fill the entire screen with white:
  tft.fillScreen(WHITE);
  delay(500);

  // Draw a rainbow triangle with reducing side length:
  for (int side = 220; side > 0; side -= 25) {
    drawRainbowTriangle(20, 300, side);
    delay(200);
  }

  delay(2000);
}

void drawRainbowSquare(int x, int y, int side) {
  int colorArray[] = {RED, ORANGE, YELLOW, GREEN, BLUE, INDIGO, VIOLET};
  int numColors = sizeof(colorArray) / sizeof(colorArray[0]);
  
  for (int i = 0; i < numColors; ++i) {
    tft.fillRect(x - side / 2, y - side / 2, side, side, colorArray[i]);
    delay(100);
  }
}

void drawRainbowTriangle(int x, int y, int side) {
  int colorArray[] = {RED, ORANGE, YELLOW, GREEN, BLUE, INDIGO, VIOLET};
  int numColors = sizeof(colorArray) / sizeof(colorArray[0]);
  
  for (int i = 0; i < numColors; ++i) {
    int x0 = x;
    int y0 = y - side / 2;
    int x1 = x - side / 2;
    int y1 = y + side / 2;
    int x2 = x + side / 2;
    int y2 = y + side / 2;

    tft.fillTriangle(x0, y0, x1, y1, x2, y2, colorArray[i]);
    delay(1000);
  }
}