SDL_Renderer backend and SDL_image texture loader

src/Resources/Resources.cpp

@@ -1,7 +1,7 @@
 #include <unordered_map>
 #include <fstream>
 #include <sstream>
-#include "../UsefulException.hpp"
+#include "../exceptions.hpp"
 #include "../format.hpp"
 #include "Resources.hpp"
 #include "embedded_resources.h"
@@ -19,16 +19,27 @@ MemoryStreamBuf::MemoryStreamBuf(void* _p, const std::size_t n){
     setp(p, p + n);
 }
 
-class MemoryStreamRead : public std::istream {
-public:
-    MemoryStreamRead(const void* p, const std::size_t n)
-        : std::istream(new MemoryStreamBuf((void*)p, n))
-    {}
+std::istream::pos_type MemoryStreamBuf::seekoff(
+    std::istream::off_type off,
+    std::ios_base::seekdir dir,
+    std::ios_base::openmode which)
+{
+    if (dir == std::ios_base::cur)
+        gbump(off);
+    else if (dir == std::ios_base::end)
+        setg(eback(), egptr() + off, egptr());
+    else if (dir == std::ios_base::beg)
+        setg(eback(), eback() + off, egptr());
+    return gptr() - eback();
+}
 
-    virtual ~MemoryStreamRead(){
-        delete rdbuf();
-    }
-};
+MemoryStreamRead::MemoryStreamRead(const void* p, const std::size_t n)
+    : std::istream(new MemoryStreamBuf((void*)p, n))
+{}
+
+MemoryStreamRead::~MemoryStreamRead(){
+    delete rdbuf();
+}
 
 static std::unordered_map<std::string, Resource>* _resourceMap = nullptr;