jpg_loader: introduced jpg decode using libjpeg-turbo fix #1

Added bool open(const char* data, uint32_t size, bool copy);

src/loaders/jpg/tvgJpgLoader.cpp

@@ -20,9 +20,26 @@
  * SOFTWARE.
  */
 
+#include <memory.h>
 #include "tvgLoaderMgr.h"
 #include "tvgJpgLoader.h"
 
+/************************************************************************/
+/* Internal Class Implementation                                        */
+/************************************************************************/
+
+void JpgLoader::clear()
+{
+    tjFree(data);
+    data = NULL;
+    pointer = NULL;
+    size = 0;
+}
+
+/************************************************************************/
+/* External Class Implementation                                        */
+/************************************************************************/
+
 JpgLoader::JpgLoader()
 {
     jpegDecompressor = tjInitDecompress();
@@ -37,6 +54,8 @@ JpgLoader::~JpgLoader()
 
 bool JpgLoader::open(const string& path)
 {
+    clear();
+
     bool success = false;
     FILE *jpegFile = NULL;
     if ((jpegFile = fopen(path.c_str(), "rb")) == NULL) return false;
@@ -46,24 +65,40 @@ bool JpgLoader::open(const string& path)
     if (((size = ftell(jpegFile)) < 1)) goto finalize;
     if (fseek(jpegFile, 0, SEEK_SET)) goto finalize;
 
-    if (data) tjFree(data);
     data = (unsigned char *) tjAlloc(size);
     if (!data) goto finalize;
 
     if (fread(data, size, 1, jpegFile) < 1) goto failure;
 
+    pointer = data;
     success = true;
     goto finalize;
 
 failure:
-    tjFree(data);
+    clear();
-    data = NULL;
 
 finalize:
     fclose(jpegFile);
     return success;
 }
 
+bool JpgLoader::open(const char* data, uint32_t size, bool copy)
+{
+    clear();
+
+    if (copy) {
+        this->data = (unsigned char *) malloc(size);
+        if (!this->data) return false;
+        memcpy((unsigned char *)this->data, data, size);
+        this->pointer = this->data;
+    } else {
+        this->pointer = (unsigned char *)data;
+    }
+
+    this->size = size;
+    return true;
+}
+
 bool JpgLoader::read()
 {
     int width, height;
@@ -80,7 +115,7 @@ bool JpgLoader::read()
     //decompress jpg image
     if (tjDecompress2(jpegDecompressor, data, size, image, width, 0, height, TJPF_BGRX, 0) < 0) {
         tjFree(image);
-        data = NULL;
+        image = NULL;
         return false;
     }
 
@@ -91,8 +126,7 @@ bool JpgLoader::read()
 
 bool JpgLoader::close()
 {
-    tjFree(data);
+    clear();
-    data = NULL;
     return true;
 }
 

src/loaders/jpg/tvgJpgLoader.h

@@ -32,14 +32,18 @@ public:
 
     using Loader::open;
     bool open(const string& path) override;
+    bool open(const char* data, uint32_t size, bool copy) override;
     bool read() override;
     bool close() override;
 
     const uint32_t* pixels() override;
 
 private:
+    void clear();
+
     tjhandle jpegDecompressor;
     unsigned char* data = nullptr;
+    const unsigned char* pointer = nullptr;
     unsigned long size = 0;
     unsigned char *image = nullptr;
 };