raze/polymer/jfaud/inc/memfile.hpp
terminx 7b0104e9a1 JFAud
git-svn-id: https://svn.eduke32.com/eduke32@452 1a8010ca-5511-0410-912e-c29ae57300e0
2007-01-12 22:42:19 +00:00

101 lines
2.5 KiB
C++
Executable file

#ifndef __memfile_hpp__
#define __memfile_hpp__
#include <cstdlib>
#include <cstring>
#include "file.hpp"
#include "sysdefs.h"
class MemFile : public JFAudFile {
private:
unsigned char *dataptr, *posn;
long datalen;
void (*disposalfunc)(void*);
public:
MemFile(void *ptr, long len, void (*dispose)(void*))
{
dataptr = posn = (unsigned char *)ptr;
datalen = len;
disposalfunc = dispose;
}
virtual ~MemFile()
{
if (disposalfunc) disposalfunc((void*)dataptr);
else free((void*)dataptr);
}
virtual bool IsOpen(void) const { return dataptr != NULL && datalen >= 0; }
virtual long Read(long nbytes, void *buf)
{
long toread = datalen - ((intptr_t)posn - (intptr_t)dataptr);
if (toread > nbytes) toread = nbytes;
memcpy(buf, posn, toread);
posn = (unsigned char *)((intptr_t)posn + toread);
return toread;
}
virtual bool ReadByte(char *c)
{
if ((intptr_t)posn - (intptr_t)dataptr >= datalen) return false;
*c = *(posn++);
return true;
}
virtual bool ReadShort(short *s, bool big=false)
{
short ss = 0;
if ((intptr_t)posn - (intptr_t)dataptr >= datalen-1) return false;
if (B_LITTLE_ENDIAN == 1) {
ss = ((short)*(posn++));
ss |= ((short)*(posn++)) << 8;
} else {
ss = ((short)*(posn++)) << 8;
ss |= ((short)*(posn++));
}
*s = ss;
return true;
}
virtual bool ReadLong(int *l, bool big=false)
{
short ll = 0;
if ((intptr_t)posn - (intptr_t)dataptr >= datalen-3) return false;
if (B_LITTLE_ENDIAN == 1) {
ll = ((int)*(posn++));
ll |= ((int)*(posn++)) << 8;
ll |= ((int)*(posn++)) << 16;
ll |= ((int)*(posn++)) << 24;
} else {
ll = ((int)*(posn++)) << 24;
ll |= ((int)*(posn++)) << 16;
ll |= ((int)*(posn++)) << 8;
ll |= ((int)*(posn++));
}
*l = ll;
return true;
}
virtual long Seek(long pos, SeekFrom where)
{
if (where == JFAudFile::Set) {
posn = (unsigned char *)((intptr_t)dataptr + pos);
} else if (where == JFAudFile::Cur) {
posn = (unsigned char *)((intptr_t)posn + pos);
} else if (where == JFAudFile::End) {
posn = (unsigned char *)((intptr_t)dataptr + datalen + pos);
} else return -1;
if ((intptr_t)posn < (intptr_t)dataptr)
posn = dataptr;
else if ((intptr_t)posn > ((intptr_t)dataptr + datalen))
posn = (unsigned char *)((intptr_t)dataptr + datalen);
return (intptr_t)posn - (intptr_t)dataptr;
}
virtual long Tell(void) const { return (intptr_t)posn - (intptr_t)dataptr; }
virtual long Length(void) const { return datalen; }
virtual int Rewind(void) { posn = dataptr; return 0; }
};
#endif