assimp.assimp/code/M3D/M3DWrapper.cpp

/*
Open Asset Import Library (assimp)
----------------------------------------------------------------------

Copyright (c) 2006-2019, assimp team
Copyright (c) 2019 bzt

All rights reserved.

Redistribution and use of this software in source and binary forms,
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* Redistributions of source code must retain the above
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following disclaimer.

* Redistributions in binary form must reproduce the above
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following disclaimer in the documentation and/or other
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* 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,
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LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

----------------------------------------------------------------------
*/

#if !(ASSIMP_BUILD_NO_EXPORT || ASSIMP_BUILD_NO_M3D_EXPORTER) && !ASSIMP_BUILD_NO_M3D_IMPORTER

#include "M3DWrapper.h"

#include <assimp/DefaultIOSystem.h>
#include <assimp/IOStreamBuffer.h>
#include <assimp/ai_assert.h>

#if (__cplusplus >= 201103L) || (_MSC_VER >= 1915) || defined(AI_M3D_USE_STDMUTEX) // C++11 and MSVC that mostly supports it
#define AI_M3D_USE_STDMUTEX
#include <mutex>
#endif

// workaround: the M3D SDK expects a C callback, but we want to use Assimp::IOSystem to implement that
// This makes it non-rentrant so lock a mutex (requires C++11)

std::mutex file_mutex;

extern "C" {
void *m3dimporter_pIOHandler;

unsigned char *m3dimporter_readfile(char *fn, unsigned int *size) {
	ai_assert(nullptr != fn);
	ai_assert(nullptr != size);
	std::string file(fn);
	std::unique_ptr<Assimp::IOStream> pStream(
			(reinterpret_cast<Assimp::IOSystem *>(m3dimporter_pIOHandler))->Open(file, "rb"));
	size_t fileSize = 0;
	unsigned char *data = NULL;
	// sometimes pStream is nullptr for some reason (should be an empty object returning nothing I guess)
	if (pStream) {
		fileSize = pStream->FileSize();
		// should be allocated with malloc(), because the library will call free() to deallocate
		data = (unsigned char *)malloc(fileSize);
		if (!data || !pStream.get() || !fileSize || fileSize != pStream->Read(data, 1, fileSize)) {
			pStream.reset();
			*size = 0;
			// don't throw a deadly exception, it's not fatal if we can't read an external asset
			return nullptr;
		}
		pStream.reset();
	}
	*size = (int)fileSize;
	return data;
}
}

namespace Assimp {
M3DWrapper::M3DWrapper() {
	// use malloc() here because m3d_free() will call free()
	m3d_ = (m3d_t *)calloc(1, sizeof(m3d_t));
}

M3DWrapper::M3DWrapper(IOSystem *pIOHandler, const std::vector<unsigned char> &buffer) {
#ifdef AI_M3D_USE_STDMUTEX
	// M3D is NOT thread-safe, so lock the global mutex
	const std::lock_guard<std::mutex> lock(file_mutex);
#endif
	// pass this IOHandler to the C callback
	m3dimporter_pIOHandler = pIOHandler;
	m3d_ = m3d_load(const_cast<unsigned char *>(buffer.data()), m3dimporter_readfile, free, nullptr);
	// Clear the C callback
	m3dimporter_pIOHandler = nullptr;
}

M3DWrapper::~M3DWrapper() {
	reset();
}

void M3DWrapper::reset() {
	ClearSave();
	if (m3d_)
		m3d_free(m3d_);
	m3d_ = nullptr;
}

unsigned char *M3DWrapper::Save(int quality, int flags, unsigned int &size) {
#if (!(ASSIMP_BUILD_NO_EXPORT || ASSIMP_BUILD_NO_M3D_EXPORTER))
	ClearSave();
	saved_output_ = m3d_save(m3d_, quality, flags, &size);
	return saved_output_;
#else
	return nullptr;
#endif
}

void M3DWrapper::ClearSave() {
	if (saved_output_)
		M3D_FREE(saved_output_);
	saved_output_ = nullptr;
}
} // namespace Assimp

#endif