/*
  Forum: https://forum.arduino.cc/t/displaying-rgb-bitmap-on-tft-from-c-file/1191496
  Wokwi: https://wokwi.com/projects/382087959061470209
*/
#include "hi.h"

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

#define TFT_DC 9
#define TFT_CS 10

Adafruit_ILI9341 tft = Adafruit_ILI9341(TFT_CS, TFT_DC);

constexpr int maxNoOfImgs {10};

int yTop = 0;
int xPos = 0;
int yPos = 0;
int step  = 4;
int noOfImgs = 1;

void setup() {
  Serial.begin(115200);
  Serial.println(image.width);
  Serial.println(image.height);
  tft.begin();
}

void loop() {
  move();
}

void move() {
  for (int n = 0; n < noOfImgs; n++) {
    decodeImageAt(xPos, yPos + n * 32, ILI9341_BLACK);
  }
  xPos += step;
  if (xPos >= tft.width() - image.width || xPos < 0) {
    step = -step;
    noOfImgs++;
    if (noOfImgs > maxNoOfImgs) {
      tft.fillScreen(ILI9341_BLACK);
      noOfImgs = 1;  
    }
  }
}



void decodeImageAt(int x, int y, uint16_t bkColor) {
  uint16_t a;
  uint16_t b;
  uint16_t color;
  int myX;
  deleteTail(x, y, bkColor);
  for (int row = yTop; row < image.height; row++) {
    for (int col = 0; col < image.width; col++) {
      a = pixil_frame[row * image.width * 2 + col * 2];
      b = pixil_frame[row * image.width * 2 + col * 2 + 1];
      color = b << 8 + a;
      if (color == 0) {
        color = bkColor;
      }
      else
      {
        if (yTop == 0) {
          yTop = row;
        };  // Forget the rows on top of yTop which are completely "zero"
      }
      if (step > 0) {
        myX = col + x;
      } else {
        myX = (image.width - col) + x;
      }
      tft.drawPixel(myX, row + y, color);
    }
  }
}

void deleteTail(int x, int y, uint16_t bkColor) {
  // This routine could be replaced by tft.drawRect() ...
  if (x == 0 || x == tft.width() - image.width) {
    return;
  };
  int myX;
  for (int row = yTop; row < image.height; row++) {
    for (int col = 0; col < abs(step); col++) {
      if (step < 0) 
      {
        myX = (image.width + col) + x +1;
      } 
      else 
      {
        myX = col + x -step;
      }
      tft.drawPixel(myX, row + y, bkColor);
    }
  }
}