genesis-3d_engine/Engine/foundation/meshbuilder/meshbuilder.h

/****************************************************************************
Copyright (c) 2011-2013,WebJet Business Division,CYOU
 
http://www.genesis-3d.com.cn

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
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The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

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IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
****************************************************************************/
#ifndef __MESH_BUILDER_H__
#define __MESH_BUILDER_H__

#ifdef __OSX__
#include "core/types.h"
#include "math/matrix44.h"
#else
#include "foundation/core/types.h"
#include "foundation/math/matrix44.h"
#endif

namespace MeshBuilder
{
	inline unsigned char* _bias_in_bytes(void* ptr, size_t bias)
	{
		return reinterpret_cast<unsigned char*>(ptr) + bias;
	}

	void _transforms(ubyte* buffer, SizeT vertexCount, SizeT vertexSize, SizeT posBias, const Math::matrix44& trans);

	// buffer: vertex buffer, vertexSize: a vertex element's size, posBias: the starting location(in bytes) of position data in a vertex element
	// trans: transform matrix
	template<typename T>
	inline void TransformPositions(T* buffer, SizeT vertexCount, SizeT vertexSize, SizeT posBias, const Math::matrix44& trans)
	{
		_transforms(reinterpret_cast<ubyte*>(buffer), vertexCount, vertexSize, posBias, trans);
	}

	// buffer: vertex buffer, vertexSize: a vertex element's size, normBias: the starting location(in bytes) of normal data in a vertex element
	// trans: transform matrix
	template<typename T>
	inline void TransformNormals(T* buffer, SizeT vertexCount, SizeT vertexSize, SizeT normBias, const Math::matrix44& trans)
	{
		Math::matrix44 Inverse      = Math::matrix44::inverse(trans);
		Math::matrix44 InvTranspose = Math::matrix44::transpose(Inverse);
		InvTranspose.set_position(Math::float4(0, 0, 0, 1));
		_transforms(reinterpret_cast<ubyte*>(buffer), vertexCount, vertexSize, normBias, InvTranspose);
	}


	// ----------------------------------------------------------------------------------------
	// const iterator
	template<typename TYPE>
	class elem_iterator_const
	{
	public:
		elem_iterator_const(const ubyte* begin, SizeT vertex_size);
		elem_iterator_const(ubyte* begin, SizeT vertex_size);
		void operator ++();
		void operator --();
		const TYPE& operator *() const;
		const TYPE* operator->() const;
		const TYPE* get() const;
		const TYPE* get(SizeT elem_bias) const;
	protected:
		union
		{
			mutable ubyte* ptr;
			TYPE* elem_ptr;
		};
		SizeT vertex_size;
	};

	template<typename TYPE>
	inline elem_iterator_const<TYPE>::elem_iterator_const(const ubyte* begin, SizeT vertex_size)
	{
		n_assert(NULL != begin);
		this->ptr = const_cast<ubyte*>(begin);
		this->vertex_size = vertex_size;
	}

	template<typename TYPE>
	inline elem_iterator_const<TYPE>::elem_iterator_const(ubyte* begin, SizeT vertex_size)
	{
		n_assert(NULL != begin);
		this->ptr = begin;
		this->vertex_size = vertex_size;
	}

	template<typename TYPE>
	inline void elem_iterator_const<TYPE>::operator ++()
	{
		this->ptr += vertex_size;
	}	

	template<typename TYPE>
	inline void elem_iterator_const<TYPE>::operator --()
	{
		this->ptr -= vertex_size;
	}

	template<typename TYPE>
	inline const TYPE& elem_iterator_const<TYPE>::operator *() const
	{
		return *(this->elem_ptr);
	}

	template<typename TYPE>
	inline const TYPE* elem_iterator_const<TYPE>::operator->() const
	{
		return this->elem_ptr;
	}

	template<typename TYPE>
	inline const TYPE* elem_iterator_const<TYPE>::get() const
	{
		return this->elem_ptr;
	}

	template<typename TYPE>
	inline const TYPE* elem_iterator_const<TYPE>::get(SizeT elem_bias) const
	{
		return reinterpret_cast <TYPE*>(this->ptr + elem_bias * vertex_size);
	}
	// ===================================================================================================
	// unconst iterator
	template<typename TYPE>
	class elem_iterator : public elem_iterator_const<TYPE>
	{
	public:
		typedef elem_iterator<TYPE> self;
		elem_iterator(ubyte* begin, SizeT vertex_size);
		TYPE& operator *() const;
		TYPE* operator->() const;
		self& operator ++ () const;
		const self& operator ++ (int) const;

		TYPE* get() const;		
		TYPE* get(SizeT elem_bias) const;
		void set(const TYPE& info);
	protected:
		typedef elem_iterator_const<TYPE> super;

	};

	template<typename TYPE>
	inline elem_iterator<TYPE>::elem_iterator(ubyte* begin, SizeT vertex_size)
		: super(begin, vertex_size)
	{
	}

	template<typename TYPE>
	inline TYPE& elem_iterator<TYPE>::operator *() const
	{
		return *(this->elem_ptr);
	}

	template<typename TYPE>
	inline TYPE* elem_iterator<TYPE>::operator->() const
	{
		return this->elem_ptr;
	}

	template<typename TYPE>
	inline elem_iterator<TYPE>& elem_iterator<TYPE>::operator ++ () const
	{
		this->ptr += this->vertex_size;
		return *((self*)this);
	}
	template<typename TYPE>
	inline const elem_iterator<TYPE>& elem_iterator<TYPE>::operator ++ (int) const
	{
		this->ptr += this->vertex_size;
		return *((self*)this);
	}


	template<typename TYPE>
	inline TYPE* elem_iterator<TYPE>::get() const
	{
		return this->elem_ptr;
	}

	template<typename TYPE>
	inline TYPE* elem_iterator<TYPE>::get(SizeT elem_bias) const
	{
		return reinterpret_cast <TYPE*>(this->ptr + elem_bias * this->vertex_size);
	}

	template<typename TYPE>
	inline void elem_iterator<TYPE>::set(const TYPE& info)
	{
		*(this->elem_ptr) = info;
	}
}

#endif //__MESH_BUILDER_H__