349 lines
12 KiB
C++
349 lines
12 KiB
C++
/*
|
|
---------------------------------------------------------------------------
|
|
Open Asset Import Library (assimp)
|
|
---------------------------------------------------------------------------
|
|
|
|
Copyright (c) 2006-2018, assimp team
|
|
|
|
|
|
|
|
All rights reserved.
|
|
|
|
Redistribution and use of this software in source and binary forms,
|
|
with or without modification, are permitted provided that the following
|
|
conditions are met:
|
|
|
|
* Redistributions of source code must retain the above
|
|
copyright notice, this list of conditions and the
|
|
following disclaimer.
|
|
|
|
* Redistributions in binary form must reproduce the above
|
|
copyright notice, this list of conditions and the
|
|
following disclaimer in the documentation and/or other
|
|
materials provided with the distribution.
|
|
|
|
* Neither the name of the assimp team, nor the names of its
|
|
contributors may be used to endorse or promote products
|
|
derived from this software without specific prior
|
|
written permission of the assimp team.
|
|
|
|
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
|
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
|
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
|
|
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
|
|
OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
|
|
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
|
|
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
|
|
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
|
|
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
|
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
|
|
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
---------------------------------------------------------------------------
|
|
*/
|
|
|
|
/** @file Defines the StreamReader class which reads data from
|
|
* a binary stream with a well-defined endianness.
|
|
*/
|
|
|
|
#ifndef AI_STREAMREADER_H_INCLUDED
|
|
#define AI_STREAMREADER_H_INCLUDED
|
|
|
|
#include "ByteSwapper.h"
|
|
#include "Exceptional.h"
|
|
#include <memory>
|
|
#include <assimp/IOStream.hpp>
|
|
#include <assimp/Defines.h>
|
|
|
|
namespace Assimp {
|
|
|
|
// --------------------------------------------------------------------------------------------
|
|
/** Wrapper class around IOStream to allow for consistent reading of binary data in both
|
|
* little and big endian format. Don't attempt to instance the template directly. Use
|
|
* StreamReaderLE to read from a little-endian stream and StreamReaderBE to read from a
|
|
* BE stream. The class expects that the endianness of any input data is known at
|
|
* compile-time, which should usually be true (#BaseImporter::ConvertToUTF8 implements
|
|
* runtime endianness conversions for text files).
|
|
*
|
|
* XXX switch from unsigned int for size types to size_t? or ptrdiff_t?*/
|
|
// --------------------------------------------------------------------------------------------
|
|
template <bool SwapEndianess = false, bool RuntimeSwitch = false>
|
|
class StreamReader
|
|
{
|
|
public:
|
|
// FIXME: use these data types throughout the whole library,
|
|
// then change them to 64 bit values :-)
|
|
|
|
typedef int diff;
|
|
typedef unsigned int pos;
|
|
|
|
public:
|
|
// ---------------------------------------------------------------------
|
|
/** Construction from a given stream with a well-defined endianness.
|
|
*
|
|
* The StreamReader holds a permanent strong reference to the
|
|
* stream, which is released upon destruction.
|
|
* @param stream Input stream. The stream is not restarted if
|
|
* its file pointer is not at 0. Instead, the stream reader
|
|
* reads from the current position to the end of the stream.
|
|
* @param le If @c RuntimeSwitch is true: specifies whether the
|
|
* stream is in little endian byte order. Otherwise the
|
|
* endianness information is contained in the @c SwapEndianess
|
|
* template parameter and this parameter is meaningless. */
|
|
StreamReader(std::shared_ptr<IOStream> stream, bool le = false)
|
|
: stream(stream)
|
|
, le(le)
|
|
{
|
|
ai_assert(stream);
|
|
InternBegin();
|
|
}
|
|
|
|
// ---------------------------------------------------------------------
|
|
StreamReader(IOStream* stream, bool le = false)
|
|
: stream(std::shared_ptr<IOStream>(stream))
|
|
, le(le)
|
|
{
|
|
ai_assert(stream);
|
|
InternBegin();
|
|
}
|
|
|
|
// ---------------------------------------------------------------------
|
|
~StreamReader() {
|
|
delete[] buffer;
|
|
}
|
|
|
|
public:
|
|
|
|
// deprecated, use overloaded operator>> instead
|
|
|
|
// ---------------------------------------------------------------------
|
|
/** Read a float from the stream */
|
|
float GetF4()
|
|
{
|
|
return Get<float>();
|
|
}
|
|
|
|
// ---------------------------------------------------------------------
|
|
/** Read a double from the stream */
|
|
double GetF8() {
|
|
return Get<double>();
|
|
}
|
|
|
|
// ---------------------------------------------------------------------
|
|
/** Read a signed 16 bit integer from the stream */
|
|
int16_t GetI2() {
|
|
return Get<int16_t>();
|
|
}
|
|
|
|
// ---------------------------------------------------------------------
|
|
/** Read a signed 8 bit integer from the stream */
|
|
int8_t GetI1() {
|
|
return Get<int8_t>();
|
|
}
|
|
|
|
// ---------------------------------------------------------------------
|
|
/** Read an signed 32 bit integer from the stream */
|
|
int32_t GetI4() {
|
|
return Get<int32_t>();
|
|
}
|
|
|
|
// ---------------------------------------------------------------------
|
|
/** Read a signed 64 bit integer from the stream */
|
|
int64_t GetI8() {
|
|
return Get<int64_t>();
|
|
}
|
|
|
|
// ---------------------------------------------------------------------
|
|
/** Read a unsigned 16 bit integer from the stream */
|
|
uint16_t GetU2() {
|
|
return Get<uint16_t>();
|
|
}
|
|
|
|
// ---------------------------------------------------------------------
|
|
/** Read a unsigned 8 bit integer from the stream */
|
|
uint8_t GetU1() {
|
|
return Get<uint8_t>();
|
|
}
|
|
|
|
// ---------------------------------------------------------------------
|
|
/** Read an unsigned 32 bit integer from the stream */
|
|
uint32_t GetU4() {
|
|
return Get<uint32_t>();
|
|
}
|
|
|
|
// ---------------------------------------------------------------------
|
|
/** Read a unsigned 64 bit integer from the stream */
|
|
uint64_t GetU8() {
|
|
return Get<uint64_t>();
|
|
}
|
|
|
|
public:
|
|
// ---------------------------------------------------------------------
|
|
/** Get the remaining stream size (to the end of the stream) */
|
|
unsigned int GetRemainingSize() const {
|
|
return (unsigned int)(end - current);
|
|
}
|
|
|
|
// ---------------------------------------------------------------------
|
|
/** Get the remaining stream size (to the current read limit). The
|
|
* return value is the remaining size of the stream if no custom
|
|
* read limit has been set. */
|
|
unsigned int GetRemainingSizeToLimit() const {
|
|
return (unsigned int)(limit - current);
|
|
}
|
|
|
|
// ---------------------------------------------------------------------
|
|
/** Increase the file pointer (relative seeking) */
|
|
void IncPtr(intptr_t plus) {
|
|
current += plus;
|
|
if (current > limit) {
|
|
throw DeadlyImportError("End of file or read limit was reached");
|
|
}
|
|
}
|
|
|
|
// ---------------------------------------------------------------------
|
|
/** Get the current file pointer */
|
|
int8_t* GetPtr() const {
|
|
return current;
|
|
}
|
|
|
|
// ---------------------------------------------------------------------
|
|
/** Set current file pointer (Get it from #GetPtr). This is if you
|
|
* prefer to do pointer arithmetics on your own or want to copy
|
|
* large chunks of data at once.
|
|
* @param p The new pointer, which is validated against the size
|
|
* limit and buffer boundaries. */
|
|
void SetPtr(int8_t* p) {
|
|
current = p;
|
|
if (current > limit || current < buffer) {
|
|
throw DeadlyImportError("End of file or read limit was reached");
|
|
}
|
|
}
|
|
|
|
// ---------------------------------------------------------------------
|
|
/** Copy n bytes to an external buffer
|
|
* @param out Destination for copying
|
|
* @param bytes Number of bytes to copy */
|
|
void CopyAndAdvance(void* out, size_t bytes) {
|
|
int8_t* ur = GetPtr();
|
|
SetPtr(ur+bytes); // fire exception if eof
|
|
|
|
::memcpy(out,ur,bytes);
|
|
}
|
|
|
|
// ---------------------------------------------------------------------
|
|
/** Get the current offset from the beginning of the file */
|
|
int GetCurrentPos() const {
|
|
return (unsigned int)(current - buffer);
|
|
}
|
|
|
|
void SetCurrentPos(size_t pos) {
|
|
SetPtr(buffer + pos);
|
|
}
|
|
|
|
// ---------------------------------------------------------------------
|
|
/** Setup a temporary read limit
|
|
*
|
|
* @param limit Maximum number of bytes to be read from
|
|
* the beginning of the file. Specifying UINT_MAX
|
|
* resets the limit to the original end of the stream.
|
|
* Returns the previously set limit. */
|
|
unsigned int SetReadLimit(unsigned int _limit) {
|
|
unsigned int prev = GetReadLimit();
|
|
if (UINT_MAX == _limit) {
|
|
limit = end;
|
|
return prev;
|
|
}
|
|
|
|
limit = buffer + _limit;
|
|
if (limit > end) {
|
|
throw DeadlyImportError("StreamReader: Invalid read limit");
|
|
}
|
|
return prev;
|
|
}
|
|
|
|
// ---------------------------------------------------------------------
|
|
/** Get the current read limit in bytes. Reading over this limit
|
|
* accidentally raises an exception. */
|
|
unsigned int GetReadLimit() const {
|
|
return (unsigned int)(limit - buffer);
|
|
}
|
|
|
|
// ---------------------------------------------------------------------
|
|
/** Skip to the read limit in bytes. Reading over this limit
|
|
* accidentally raises an exception. */
|
|
void SkipToReadLimit() {
|
|
current = limit;
|
|
}
|
|
|
|
// ---------------------------------------------------------------------
|
|
/** overload operator>> and allow chaining of >> ops. */
|
|
template <typename T>
|
|
StreamReader& operator >> (T& f) {
|
|
f = Get<T>();
|
|
return *this;
|
|
}
|
|
|
|
// ---------------------------------------------------------------------
|
|
/** Generic read method. ByteSwap::Swap(T*) *must* be defined */
|
|
template <typename T>
|
|
T Get() {
|
|
if ( current + sizeof(T) > limit) {
|
|
throw DeadlyImportError("End of file or stream limit was reached");
|
|
}
|
|
|
|
T f;
|
|
::memcpy (&f, current, sizeof(T));
|
|
Intern::Getter<SwapEndianess,T,RuntimeSwitch>() (&f,le);
|
|
current += sizeof(T);
|
|
|
|
return f;
|
|
}
|
|
|
|
private:
|
|
// ---------------------------------------------------------------------
|
|
void InternBegin() {
|
|
if (!stream) {
|
|
// in case someone wonders: StreamReader is frequently invoked with
|
|
// no prior validation whether the input stream is valid. Since
|
|
// no one bothers changing the error message, this message here
|
|
// is passed down to the caller and 'unable to open file'
|
|
// simply describes best what happened.
|
|
throw DeadlyImportError("StreamReader: Unable to open file");
|
|
}
|
|
|
|
const size_t s = stream->FileSize() - stream->Tell();
|
|
if (!s) {
|
|
throw DeadlyImportError("StreamReader: File is empty or EOF is already reached");
|
|
}
|
|
|
|
current = buffer = new int8_t[s];
|
|
const size_t read = stream->Read(current,1,s);
|
|
// (read < s) can only happen if the stream was opened in text mode, in which case FileSize() is not reliable
|
|
ai_assert(read <= s);
|
|
end = limit = &buffer[read];
|
|
}
|
|
|
|
private:
|
|
std::shared_ptr<IOStream> stream;
|
|
int8_t *buffer, *current, *end, *limit;
|
|
bool le;
|
|
};
|
|
|
|
// --------------------------------------------------------------------------------------------
|
|
// `static` StreamReaders. Their byte order is fixed and they might be a little bit faster.
|
|
#ifdef AI_BUILD_BIG_ENDIAN
|
|
typedef StreamReader<true> StreamReaderLE;
|
|
typedef StreamReader<false> StreamReaderBE;
|
|
#else
|
|
typedef StreamReader<true> StreamReaderBE;
|
|
typedef StreamReader<false> StreamReaderLE;
|
|
#endif
|
|
|
|
// `dynamic` StreamReader. The byte order of the input data is specified in the
|
|
// c'tor. This involves runtime branching and might be a little bit slower.
|
|
typedef StreamReader<true,true> StreamReaderAny;
|
|
|
|
} // end namespace Assimp
|
|
|
|
#endif // !! AI_STREAMREADER_H_INCLUDED
|