// This sketch if for an ESP32, it draws Jpeg images pulled from an SD Card
 // onto the TFT.
 
 // As well as the TFT_eSPI library you will need the JPEG Decoder library.
 // A copy can be downloaded here, it is based on the library by Makoto Kurauchi.
 // https://github.com/Bodmer/JPEGDecoder
 
 // Images on SD Card must be put in the root folder (top level) to be found
 // Use the SD library examples to verify your SD Card interface works!
 
 // The example images used to test this sketch can be found in the library
 // JPEGDecoder/extras folder
 //----------------------------------------------------------------------------------------------------
 
 #include <SPI.h>
 
 #include <FS.h>
 #include <SD.h>
 
 #include <TFT_eSPI.h>
 TFT_eSPI tft = TFT_eSPI();
 
 // JPEG decoder library
 #include <JPEGDecoder.h>
 
 //####################################################################################################
 // Setup
 //####################################################################################################
 void setup() {
   Serial.begin(115200);
 
   // Set all chip selects high to avoid bus contention during initialisation of each peripheral
   digitalWrite(22, HIGH); // Touch controller chip select (if used)
   digitalWrite(15, HIGH); // TFT screen chip select
   digitalWrite( 5, HIGH); // SD card chips select, must use GPIO 5 (ESP32 SS)
 
   tft.begin();
 
   if (!SD.begin()) {
     Serial.println("Card Mount Failed");
     return;
   }
   uint8_t cardType = SD.cardType();
 
   if (cardType == CARD_NONE) {
     Serial.println("No SD card attached");
     return;
   }
 
   Serial.print("SD Card Type: ");
   if (cardType == CARD_MMC) {
     Serial.println("MMC");
   } else if (cardType == CARD_SD) {
     Serial.println("SDSC");
   } else if (cardType == CARD_SDHC) {
     Serial.println("SDHC");
   } else {
     Serial.println("UNKNOWN");
   }
 
   uint64_t cardSize = SD.cardSize() / (1024 * 1024);
   Serial.printf("SD Card Size: %lluMB\n", cardSize);
 
   Serial.println("initialisation done.");
 }
 
 //####################################################################################################
 // Main loop
 //####################################################################################################
 void loop() {
 
   tft.setRotation(2);  // portrait
   tft.fillScreen(random(0xFFFF));
 
   // The image is 300 x 300 pixels so we do some sums to position image in the middle of the screen!
   // Doing this by reading the image width and height from the jpeg info is left as an exercise!
   int x = (tft.width()  - 300) / 2 - 1;
   int y = (tft.height() - 300) / 2 - 1;
 
   drawSdJpeg("/EagleEye.jpg", x, y);     // This draws a jpeg pulled off the SD Card
   delay(2000);
 
   tft.setRotation(2);  // portrait
   tft.fillScreen(random(0xFFFF));
   drawSdJpeg("/Baboon40.jpg", 0, 0);     // This draws a jpeg pulled off the SD Card
   delay(2000);
 
   tft.setRotation(2);  // portrait
   tft.fillScreen(random(0xFFFF));
   drawSdJpeg("/lena20k.jpg", 0, 0);     // This draws a jpeg pulled off the SD Card
   delay(2000);
 
   tft.setRotation(1);  // landscape
   tft.fillScreen(random(0xFFFF));
   drawSdJpeg("/Mouse480.jpg", 0, 0);     // This draws a jpeg pulled off the SD Card
 
   delay(2000);
 
   while(1); // Wait here
 }
 
 //####################################################################################################
 // Draw a JPEG on the TFT pulled from SD Card
 //####################################################################################################
 // xpos, ypos is top left corner of plotted image
 void drawSdJpeg(const char *filename, int xpos, int ypos) {
 
   // Open the named file (the Jpeg decoder library will close it)
   File jpegFile = SD.open( filename, FILE_READ);  // or, file handle reference for SD library
  
   if ( !jpegFile ) {
     Serial.print("ERROR: File \""); Serial.print(filename); Serial.println ("\" not found!");
     return;
   }
 
   Serial.println("===========================");
   Serial.print("Drawing file: "); Serial.println(filename);
   Serial.println("===========================");
 
   // Use one of the following methods to initialise the decoder:
   bool decoded = JpegDec.decodeSdFile(jpegFile);  // Pass the SD file handle to the decoder,
   //bool decoded = JpegDec.decodeSdFile(filename);  // or pass the filename (String or character array)
 
   if (decoded) {
     // print information about the image to the serial port
     jpegInfo();
     // render the image onto the screen at given coordinates
     jpegRender(xpos, ypos);
   }
   else {
     Serial.println("Jpeg file format not supported!");
   }
 }
 
 //####################################################################################################
 // Draw a JPEG on the TFT, images will be cropped on the right/bottom sides if they do not fit
 //####################################################################################################
 // This function assumes xpos,ypos is a valid screen coordinate. For convenience images that do not
 // fit totally on the screen are cropped to the nearest MCU size and may leave right/bottom borders.
 void jpegRender(int xpos, int ypos) {
 
   //jpegInfo(); // Print information from the JPEG file (could comment this line out)
 
   uint16_t *pImg;
   uint16_t mcu_w = JpegDec.MCUWidth;
   uint16_t mcu_h = JpegDec.MCUHeight;
   uint32_t max_x = JpegDec.width;
   uint32_t max_y = JpegDec.height;
 
   bool swapBytes = tft.getSwapBytes();
   tft.setSwapBytes(true);
   
   // Jpeg images are draw as a set of image block (tiles) called Minimum Coding Units (MCUs)
   // Typically these MCUs are 16x16 pixel blocks
   // Determine the width and height of the right and bottom edge image blocks
   uint32_t min_w = jpg_min(mcu_w, max_x % mcu_w);
   uint32_t min_h = jpg_min(mcu_h, max_y % mcu_h);
 
   // save the current image block size
   uint32_t win_w = mcu_w;
   uint32_t win_h = mcu_h;
 
   // record the current time so we can measure how long it takes to draw an image
   uint32_t drawTime = millis();
 
   // save the coordinate of the right and bottom edges to assist image cropping
   // to the screen size
   max_x += xpos;
   max_y += ypos;
 
   // Fetch data from the file, decode and display
   while (JpegDec.read()) {    // While there is more data in the file
     pImg = JpegDec.pImage ;   // Decode a MCU (Minimum Coding Unit, typically a 8x8 or 16x16 pixel block)
 
     // Calculate coordinates of top left corner of current MCU
     int mcu_x = JpegDec.MCUx * mcu_w + xpos;
     int mcu_y = JpegDec.MCUy * mcu_h + ypos;
 
     // check if the image block size needs to be changed for the right edge
     if (mcu_x + mcu_w <= max_x) win_w = mcu_w;
     else win_w = min_w;
 
     // check if the image block size needs to be changed for the bottom edge
     if (mcu_y + mcu_h <= max_y) win_h = mcu_h;
     else win_h = min_h;
 
     // copy pixels into a contiguous block
     if (win_w != mcu_w)
     {
       uint16_t *cImg;
       int p = 0;
       cImg = pImg + win_w;
       for (int h = 1; h < win_h; h++)
       {
         p += mcu_w;
         for (int w = 0; w < win_w; w++)
         {
           *cImg = *(pImg + w + p);
           cImg++;
         }
       }
     }
 
     // calculate how many pixels must be drawn
     uint32_t mcu_pixels = win_w * win_h;
 
     // draw image MCU block only if it will fit on the screen
     if (( mcu_x + win_w ) <= tft.width() && ( mcu_y + win_h ) <= tft.height())
       tft.pushImage(mcu_x, mcu_y, win_w, win_h, pImg);
     else if ( (mcu_y + win_h) >= tft.height())
       JpegDec.abort(); // Image has run off bottom of screen so abort decoding
   }
 
   tft.setSwapBytes(swapBytes);
 
   showTime(millis() - drawTime); // These lines are for sketch testing only
 }
 
 //####################################################################################################
 // Print image information to the serial port (optional)
 //####################################################################################################
 // JpegDec.decodeFile(...) or JpegDec.decodeArray(...) must be called before this info is available!
 void jpegInfo() {
 
   // Print information extracted from the JPEG file
   Serial.println("JPEG image info");
   Serial.println("===============");
   Serial.print("Width      :");
   Serial.println(JpegDec.width);
   Serial.print("Height     :");
   Serial.println(JpegDec.height);
   Serial.print("Components :");
   Serial.println(JpegDec.comps);
   Serial.print("MCU / row  :");
   Serial.println(JpegDec.MCUSPerRow);
   Serial.print("MCU / col  :");
   Serial.println(JpegDec.MCUSPerCol);
   Serial.print("Scan type  :");
   Serial.println(JpegDec.scanType);
   Serial.print("MCU width  :");
   Serial.println(JpegDec.MCUWidth);
   Serial.print("MCU height :");
   Serial.println(JpegDec.MCUHeight);
   Serial.println("===============");
   Serial.println("");
 }
 
 //####################################################################################################
 // Show the execution time (optional)
 //####################################################################################################
 // WARNING: for UNO/AVR legacy reasons printing text to the screen with the Mega might not work for
 // sketch sizes greater than ~70KBytes because 16 bit address pointers are used in some libraries.
 
 // The Due will work fine with the HX8357_Due library.
 
 void showTime(uint32_t msTime) {
   //tft.setCursor(0, 0);
   //tft.setTextFont(1);
   //tft.setTextSize(2);
   //tft.setTextColor(TFT_WHITE, TFT_BLACK);
   //tft.print(F(" JPEG drawn in "));
   //tft.print(msTime);
   //tft.println(F(" ms "));
   Serial.print(F(" JPEG drawn in "));
   Serial.print(msTime);
   Serial.println(F(" ms "));
 }
 

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