Support loading of SD for other architectures

Plus improved explanatory comments

examples/Other libraries/Mega and Due/TFT_SDcard_jpg/TFT_SDcard_jpg.ino

@@ -34,6 +34,10 @@
 
 // Images on SD Card must be put in the root folder (top level) to be found
 // Use the SdFat or SD library examples to verify your SD Card interface works!
+
+// Uncomment the #define LOAD_SDFAT_LIBRARY in User_Config.h in the JPEGDecoder src folder
+// if the Due is used with the SdFat library. SdFat allows bit bashing the SPI if needed.
+
 // The example images used to test this sketch can be found in the library
 // JPEGDecoder/extras folder
 //----------------------------------------------------------------------------------------------------
@@ -53,7 +57,7 @@
   TFT_HX8357 tft = TFT_HX8357(); // Invoke custom Mega library
 #elif defined (ARDUINO_ARCH_SAM)
   // Due libraries
-  #include <SdFat.h>             // Use the SdFat library for the Due
+  #include <SdFat.h>             // Use the SdFat library for the Due, see sketch header notes above
   SdFat SD;                      // Permit SD function call for the Due
   #include <TFT_HX8357_Due.h>    // Hardware-specific Due library
   TFT_HX8357_Due tft = TFT_HX8357_Due(); // Invoke custom Due library

library.json

@@ -1,6 +1,6 @@
 {
   "name": "JPEGDecoder",
-  "version": "1.7.3",
+  "version": "1.7.4",
   "keywords": "jpeg, jpg, decoder, TFT",
   "description": "A JPEG decoder library, tested on Mega, Due and ESP8266",
   "repository":

library.properties

@@ -1,5 +1,5 @@
 name=JPEGDecoder
-version=1.7.3
+version=1.7.4
 author=Bodmer <bodmer@anola.net>, Makoto Kurauchi, Rich Geldreich
 maintainer=Bodmer
 sentence= Jpeg decoder tested with Arduino Mega, Arduino Due and ESP8266 based NodeMCU 1.0

src/JPEGDecoder.cpp

@@ -80,7 +80,7 @@ uint8_t JPEGDecoder::pjpeg_need_bytes_callback(uint8_t* pBuf, uint8_t buf_size,
 	if (jpg_source == JPEG_FS_FILE) g_pInFileFs.read(pBuf,n); // else we are handling a file
 #endif
 
-#ifdef LOAD_SD_LIBRARY
+#if defined (LOAD_SD_LIBRARY) || defined (LOAD_SDFAT_LIBRARY)
 	if (jpg_source == JPEG_SD_FILE) g_pInFileSd.read(pBuf,n); // else we are handling a file
 #endif
 
@@ -274,13 +274,13 @@ int JPEGDecoder::readSwappedBytes(void) {
 int JPEGDecoder::decodeFile(const char *pFilename){
 
 #ifdef ESP8266
-#ifdef LOAD_SD_LIBRARY
+#if defined (LOAD_SD_LIBRARY) || defined (LOAD_SDFAT_LIBRARY)
 	if (*pFilename == '/')
 #endif
 	return decodeFsFile(pFilename);
 #endif
 
-#ifdef LOAD_SD_LIBRARY
+#if defined (LOAD_SD_LIBRARY) || defined (LOAD_SDFAT_LIBRARY)
 	return decodeSdFile(pFilename);
 #endif
 
@@ -290,13 +290,13 @@ int JPEGDecoder::decodeFile(const char *pFilename){
 int JPEGDecoder::decodeFile(const String& pFilename){
 
 #ifdef ESP8266
-#ifdef LOAD_SD_LIBRARY
+#if defined (LOAD_SD_LIBRARY) || defined (LOAD_SDFAT_LIBRARY)
 	if (pFilename.charAt(0) == '/')
 #endif
 	return decodeFsFile(pFilename);
 #endif
 
-#ifdef LOAD_SD_LIBRARY
+#if defined (LOAD_SD_LIBRARY) || defined (LOAD_SDFAT_LIBRARY)
 	return decodeSdFile(pFilename);
 #endif
 
@@ -345,7 +345,7 @@ int JPEGDecoder::decodeFsFile(fs::File jpgFile) { // This is for the SPIFFS libr
 #endif
 
 
-#ifdef LOAD_SD_LIBRARY
+#if defined (LOAD_SD_LIBRARY) || defined (LOAD_SDFAT_LIBRARY)
 
 // Call specific to SD filing system in case leading / is used
 int JPEGDecoder::decodeSdFile(const char *pFilename) {
@@ -465,7 +465,7 @@ void JPEGDecoder::abort(void) {
 	if (jpg_source == JPEG_FS_FILE) if (g_pInFileFs) g_pInFileFs.close();
 #endif
 
-#ifdef LOAD_SD_LIBRARY
+#if defined (LOAD_SD_LIBRARY) || defined (LOAD_SDFAT_LIBRARY)
 	if (jpg_source == JPEG_SD_FILE) if (g_pInFileSd) g_pInFileSd.close();
 #endif
 }

src/JPEGDecoder.h

@@ -23,19 +23,17 @@ Latest version here:
 		#include "arduino.h"
 		#include <pgmspace.h>
 
-// If the sketch has included FS.h without setting FS_NO_GLOBALS then it is likely
+// If the sketch has included FS.h without setting FS_NO_GLOBALS first then it is likely
 // there will be a redefinition of 'class fs::File' error due to conflict with the
 // SD library, so we can't load the SD library.
 		#if !defined (FS_NO_GLOBALS) && defined (FS_H)
 			#undef LOAD_SD_LIBRARY
+			#undef LOAD_SDFAT_LIBRARY
 		#endif
 
 		#ifdef ESP32  // SD library not compatible with ESP32
 			#undef LOAD_SD_LIBRARY
-		#endif
-
-		#ifdef LOAD_SD_LIBRARY
-			#include <SD.h>
+			#undef LOAD_SDFAT_LIBRARY // Compatibility untested
 		#endif
 
 		#ifndef ESP32  // ESP32 does not support SPIFFS yet
@@ -44,18 +42,16 @@ Latest version here:
 			#include <FS.h>
 		#endif
 
-	#else
+	#endif
 
-		#ifdef LOAD_SD_LIBRARY
-			#if defined (ARDUINO_ARCH_AVR)
-				#include <SD.h>    // For the Mega
-			#elif defined (ARDUINO_ARCH_SAM)
-				//#include <SdFat.h> // For Due etc where we might need to bit bash the SPI
-			    #include <SD.h>    // Alternative
-			#endif
+	#if defined (LOAD_SD_LIBRARY) || defined (LOAD_SDFAT_LIBRARY)
+		#ifdef LOAD_SDFAT_LIBRARY
+			#include <SdFat.h> // Alternative where we might need to bit bash the SPI
+		#else
+			#include <SD.h>    // Default
 		#endif
-
 	#endif
+
 
 #include "picojpeg.h"
 

src/User_Config.h

@@ -1,14 +1,42 @@
-// Comment out the next #define if you are not using an SD Card to store the JPEGs
+// Comment out the next #defines if you are not using an SD Card to store the JPEGs
 // Commenting out the line is NOT essential but will save some FLASH space if
-// SD Card access is not needed.
+// SD Card access is not needed. Note: use of SdFat is currently untested!
 
-#define LOAD_SD_LIBRARY
+#define LOAD_SD_LIBRARY // Default SD Card library
+//#define LOAD_SDFAT_LIBRARY // Use SdFat library instead, so SD Card SPI can be bit bashed
+
+
+// Note for ESP8266 users:
+// If the sketch uses SPIFFS and has included FS.h without defining FS_NO_GLOBALS first
+// then the JPEGDecoder library will NOT load the SD or SdFat libraries. Use lines thus
+// in your sketch (see the examples included in the JPEGDecoder library):
+/*
+#define FS_NO_GLOBALS
+#include <FS.h>
+
+// You will then need to directly reference the SPIFFS File type thus in the sketch, e.g.:
+
+fs::File jpegFile = SPIFFS.open( filename, "r"); // Example
+
+// This will then allow the default method of using the SD library File type to be used
+// in the same sketch, e.g.:
+
+File jpegFile = SD.open( filename, FILE_READ);
+
+*/
+
+// This is all to avoid a redefinition of 'class fs::File' error due to a conflict between the
+// duplicate definitions in the SD library and the SPIFFS library.
+
 
 #ifdef ESP8266
-    // Comment out the next #define if you do not want the bytes swapped in the
-	// the image blocks returned by read(). Swapping the bytes does mean pixel blocks can be
-	// written to the screen faster using the ESP8266 SPI library writePattern()
-	// member function. Comment out for "normal" byte order. Images will look pyscodelic
-    // with wrong colours if the byte order is not right for your sketch!
-	// #define SWAP_BYTES
+    // Unomment out the next #define if you want the bytes swapped in the image blocks
+	// returned by read(). 
+
+	// Swapping the bytes is only needed to use the ESP8266 SPI library writePattern()
+	// member function and it is better to use readSwappedBytes() instead of read() in
+	// the sketch. Images will look pyscodelic with wrong colours if the SPI transmit byte
+	// order is not right for your sketch!
+
+	// #define SWAP_BYTES // Deprecated, only included for backwards compatibility
 #endif