/*
    Forum: https://forum.arduino.cc/t/problem-mit-tft-displays/1441876/30
    Wokwi: https://wokwi.com/projects/462736310567641089


  2026/04/30
  ec2021

   Basierend auf dem Adafruit Beispiel (ILI9341-Test)
   Demonstriert die online-Umrechnung von RGB 565 Konstanten in BGR mit der Funktion RGB2BGR()
   
*/


#include "SPI.h"
#include "Adafruit_GFX.h"
#include "Adafruit_ILI9341.h"

#define TFT_DC 9
#define TFT_CS 10

// VGA color palette from UTFT-Library
#define VGA_BLACK		0x0000
#define VGA_WHITE		0xFFFF
#define VGA_RED			0xF800
#define VGA_GREEN		0x0400
#define VGA_BLUE		0x001F
#define VGA_SILVER	0xC618
#define VGA_GRAY		0x8410
#define VGA_MAROON	0x8000
#define VGA_YELLOW	0xFFE0
#define VGA_OLIVE		0x8400
#define VGA_LIME		0x07E0
#define VGA_AQUA		0x07FF
#define VGA_TEAL		0x0410
#define VGA_NAVY		0x0010
#define VGA_FUCHSIA	0xF81F
#define VGA_PURPLE	0x8010

Adafruit_ILI9341 tft = Adafruit_ILI9341(TFT_CS, TFT_DC);

void setup() {
  Serial.begin(9600);
  Serial.println("Farbtest RGB versus BGR"); 
   tft.begin();
  Serial.println("RGB") ;
  testFillScreenRGB();
  Serial.println("BGR") ;
  testFillScreenBGR();
 }


void loop(void) {
}

void testFillScreenRGB() {
  yield();
  tft.fillScreen(VGA_RED);
  yield();
  tft.fillScreen(VGA_GREEN);
  yield();
  tft.fillScreen(VGA_BLUE);
  yield();
  tft.fillScreen(VGA_BLACK);
  yield();
}

void testFillScreenBGR() {
  yield();
  tft.fillScreen(RGB2BGR(VGA_RED));
  yield();
  tft.fillScreen(RGB2BGR(VGA_GREEN));
  yield();
  tft.fillScreen(RGB2BGR(VGA_BLUE));
  yield();
  tft.fillScreen(VGA_BLACK);
  yield();
}

uint16_t RGB2BGR(uint16_t rgb) {
    uint16_t r = (rgb >> 11) & 0x1F;
    uint16_t g = (rgb & 0x07E0);
    uint16_t b = (rgb & 0x1F);
    return (b << 11) | g | r;
}

/*
void setColorRGB(byte r, byte g, byte b){
  myGLCD.setColor(b,g,r);
}
*/