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// ==========================================================
// Classified FreeImageIO handler
//
// Design and implementation by
// - schickb (schickb@hotmail.com)
//
// This file is part of FreeImage 3
//
// COVERED CODE IS PROVIDED UNDER THIS LICENSE ON AN "AS IS" BASIS, WITHOUT WARRANTY
// OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, WITHOUT LIMITATION, WARRANTIES
// THAT THE COVERED CODE IS FREE OF DEFECTS, MERCHANTABLE, FIT FOR A PARTICULAR PURPOSE
// OR NON-INFRINGING. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE COVERED
// CODE IS WITH YOU. SHOULD ANY COVERED CODE PROVE DEFECTIVE IN ANY RESPECT, YOU (NOT
// THE INITIAL DEVELOPER OR ANY OTHER CONTRIBUTOR) ASSUME THE COST OF ANY NECESSARY
// SERVICING, REPAIR OR CORRECTION. THIS DISCLAIMER OF WARRANTY CONSTITUTES AN ESSENTIAL
// PART OF THIS LICENSE. NO USE OF ANY COVERED CODE IS AUTHORIZED HEREUNDER EXCEPT UNDER
// THIS DISCLAIMER.
//
// Use at your own risk!
// ==========================================================
class MemIO : public FreeImageIO {
public :
MemIO( BYTE *data ) : _start(data), _cp(data) {
read_proc = _ReadProc;
write_proc = _WriteProc;
tell_proc = _TellProc;
seek_proc = _SeekProc;
}
void Reset() {
_cp = _start;
}
static unsigned _ReadProc(void *buffer, unsigned size, unsigned count, fi_handle handle);
static unsigned _WriteProc(void *buffer, unsigned size, unsigned count, fi_handle handle);
static int _SeekProc(fi_handle handle, long offset, int origin);
static long _TellProc(fi_handle handle);
private:
BYTE * const _start;
BYTE *_cp;
};
unsigned
MemIO::_ReadProc(void *buffer, unsigned size, unsigned count, fi_handle handle) {
MemIO *memIO = (MemIO*)handle;
BYTE *tmp = (BYTE *)buffer;
for (unsigned c = 0; c < count; c++) {
memcpy(tmp, memIO->_cp, size);
memIO->_cp = memIO->_cp + size;
tmp += size;
}
return count;
}
unsigned
MemIO::_WriteProc(void *buffer, unsigned size, unsigned count, fi_handle handle) {
ASSERT( false );
return size;
}
int
MemIO::_SeekProc(fi_handle handle, long offset, int origin) {
ASSERT(origin != SEEK_END);
MemIO *memIO = (MemIO*)handle;
if (origin == SEEK_SET)
memIO->_cp = memIO->_start + offset;
else
memIO->_cp = memIO->_cp + offset;
return 0;
}
long
MemIO::_TellProc(fi_handle handle) {
MemIO *memIO = (MemIO*)handle;
return memIO->_cp - memIO->_start;
}
// ----------------------------------------------------------
// PSEUDOCODE... HELPS TO UNDERSTAND HOW THE MEMIO CLASS WORKS
// ----------------------------------------------------------
int
main(int argc, char *argv[]) {
BYTE *data = loadimagesomehow();
MemIO memIO(data);
FIBITMAP *fbmp = FreeImage_LoadFromHandle( fif, &memIO, (fi_handle)&memIO );
}
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