assimp.assimp/code/SceneCombiner.cpp

/*
Open Asset Import Library (ASSIMP)
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*/

/** @file Implements Assimp::SceneCombiner. This is a smart utility
 *    class that can be used to combine several scenes, meshes, ...
 *    in one.
 */

#include "AssimpPCH.h"
#include "SceneCombiner.h"
#include "fast_atof.h"

namespace Assimp
{

// ------------------------------------------------------------------------------------------------
// Add a prefix to a string
inline void PrefixString(aiString& string,const char* prefix, unsigned int len)
{
	// Add the prefix
	::memmove(string.data+len,string.data,string.length+1);
	::memcpy (string.data, prefix, len);

	// And update the string's length
	string.length += len;
}

// ------------------------------------------------------------------------------------------------
// Add a name prefix to all nodes in a hierarchy
void SceneCombiner::AddNodePrefixes(aiNode* node, const char* prefix, unsigned int len)
{
	ai_assert(NULL != prefix);

	PrefixString(node->mName,prefix,len);

	// Process all children recursively
	for (unsigned int i = 0; i < node->mNumChildren;++i)
		AddNodePrefixes(node->mChildren[i],prefix,len);
}

// ------------------------------------------------------------------------------------------------
// Merges two scenes. Currently only used by the LWS loader.
void SceneCombiner::MergeScenes(aiScene* dest,std::vector<aiScene*>& src,
	unsigned int flags)
{
	ai_assert(NULL != dest);
	ai_assert(0 == dest->mNumTextures);
	ai_assert(0 == dest->mNumLights);
	ai_assert(0 == dest->mNumCameras);
	ai_assert(0 == dest->mNumMeshes);
	ai_assert(0 == dest->mNumMaterials);

	if (src.empty())return;

	// some iterators will be needed multiple times
	std::vector<aiScene*>::iterator begin = src.begin(),
		end = src.end(), cur;

	// this helper array is used as lookup table several times
	std::vector<unsigned int> offset(src.size());
	std::vector<unsigned int>::iterator ofsbegin = offset.begin(),
		offend = offset.end(), ofscur;
	
	unsigned int cnt;
	bool bNeedPrefix = false;

	// First find out how large the respective output arrays must be
	for ( cur = begin; cur != end; ++cur)
	{
		dest->mNumTextures   += (*cur)->mNumTextures;
		dest->mNumMaterials  += (*cur)->mNumMaterials;
		dest->mNumMeshes     += (*cur)->mNumMeshes;
		dest->mNumLights     += (*cur)->mNumLights;
		dest->mNumCameras    += (*cur)->mNumCameras;
		dest->mNumAnimations += (*cur)->mNumAnimations;

		if ((*cur)->mNumAnimations > 0 ||
			(*cur)->mNumCameras    > 0 ||
			(*cur)->mNumLights     > 0)
		{
			bNeedPrefix = true;
		}
	}

	// generate the output texture list + an offset table
	if (dest->mNumTextures)
	{
		aiTexture** pip = dest->mTextures = new aiTexture*[dest->mNumMaterials];
		for ( cur = begin, ofscur = ofsbegin,cnt = 0; cur != end; ++cur,++ofscur)
		{
			for (unsigned int i = 0; i < (*cur)->mNumTextures;++i,++pip)
				*pip = (*cur)->mTextures[i];

			*ofscur = cnt;
			cnt += (*cur)->mNumTextures;
		}
	}

	// generate the output material list + an offset table
	if (dest->mNumMaterials)
	{
		aiMaterial** pip = dest->mMaterials = new aiMaterial*[dest->mNumMaterials];
		for ( cur = begin, ofscur = ofsbegin,cnt = 0; cur != end; ++cur,++ofscur)
		{
			for (unsigned int i = 0; i < (*cur)->mNumMaterials;++i,++pip)
			{
				*pip = (*cur)->mMaterials[i];

				if ((*cur)->mNumTextures != dest->mNumTextures)
				{
					// We need to update all texture indices of the mesh.
					// So we need to search for a material property like 
					// that follows the following pattern: "$tex.file.<s>.<n>"
					// where s is the texture type (i.e. diffuse) and n is 
					// the index of the texture.

					for (unsigned int a = 0; a < (*pip)->mNumProperties;++a)
					{
						aiMaterialProperty* prop = (*pip)->mProperties[a];
						if (!strncmp(prop->mKey.data,"$tex.file",9))
						{
							// Check whether this texture is an embedded texture.
							// In this case the property looks like this: *<n>,
							// where n is the index of the texture.
							aiString& s = *((aiString*)prop->mData);
							if ('*' == s.data[0])
							{
								// Offset the index and write it back ..
								const unsigned int idx = strtol10(&s.data[1]) + *ofscur;
								itoa10(&s.data[1],sizeof(s.data)-1,idx);
							}
						}
					}
				}
			}

			*ofscur = cnt;
			cnt += (*cur)->mNumMaterials;
		}
	}

	// generate the output mesh list + again an offset table
	if (dest->mNumMeshes)
	{
		aiMesh** pip = dest->mMeshes = new aiMesh*[dest->mNumMeshes];
		for ( cur = begin, ofscur = ofsbegin,cnt = 0; cur != end; ++cur,++ofscur)
		{
			for (unsigned int i = 0; i < (*cur)->mNumMeshes;++i,++pip)
			{
				*pip = (*cur)->mMeshes[i];

				// update the material index of the mesh
				(*pip)->mMaterialIndex += *ofscur;
			}

			// reuse the offset array - store now the mesh offset in it
			*ofscur = cnt;
			cnt += (*cur)->mNumMeshes;
		}
	}

	// Now generate the output node graph. We need to make those
	// names in the graph that are referenced by anims or lights
	// or cameras unique. So we add a prefix to them ... $SC1_
	// First step for now: find out which nodes are referenced by
	// anim bones or cameras and add the prefix to their names.

	if (bNeedPrefix)
	{
		// Allocate space for light sources, cameras and animations
		aiLight** ppLights = dest->mLights = (dest->mNumLights 
			? new aiLight*[dest->mNumLights] : NULL);

		aiCamera** ppCameras = dest->mCameras = (dest->mNumCameras 
			? new aiCamera*[dest->mNumCameras] : NULL);

		aiAnimation** ppAnims = dest->mAnimations = (dest->mNumAnimations 
			? new aiAnimation*[dest->mNumAnimations] : NULL);


		for (cur = begin, cnt = 0; cur != end; ++cur)
		{
			char buffer[10];
			buffer[0] = '$';
			buffer[1] = 'S';
			buffer[2] = 'C';

			char* sz = &buffer[itoa10(&buffer[3],sizeof(buffer)-3, cnt++)+2];
			*sz++ = '_';
			*sz++ = '\0';

			const unsigned int len = (unsigned int)::strlen(buffer);
			AddNodePrefixes((*cur)->mRootNode,buffer,len);

			// Copy light sources, add the prefix to them, too
			for (unsigned int i = 0; i < (*cur)->mNumLights;++i,++ppLights)
			{
				*ppLights = (*cur)->mLights[i];
				PrefixString((*ppLights)->mName,buffer,len);
			}
			// Copy cameras, add the prefix to them, too
			for (unsigned int i = 0; i < (*cur)->mNumCameras;++i,++ppCameras)
			{
				*ppCameras = (*cur)->mCameras[i];
				PrefixString((*ppCameras)->mName,buffer,len);
			}

			// Copy animations, add the prefix to them, too
			for (unsigned int i = 0; i < (*cur)->mNumAnimations;++i,++ppAnims)
			{
				*ppAnims = (*cur)->mAnimations[i];
				PrefixString((*ppAnims)->mName,buffer,len);
			}
		}
	}

	// now delete all input scenes
	for (cur = begin; cur != end; ++cur)
	{
		aiScene* deleteMe = *cur;

		// We need to delete the arrays before the destructor is called -
		// we are reusing the array members
		delete[] deleteMe->mMeshes;     deleteMe->mMeshes     = NULL;
		delete[] deleteMe->mCameras;    deleteMe->mCameras    = NULL;
		delete[] deleteMe->mLights;     deleteMe->mLights     = NULL;
		delete[] deleteMe->mMaterials;  deleteMe->mMaterials  = NULL;
		delete[] deleteMe->mAnimations; deleteMe->mAnimations = NULL;

		delete[] deleteMe->mRootNode->mChildren;
		deleteMe->mRootNode->mChildren = NULL;

		// Now we can safely delete the scene
		delete[] deleteMe;
		AI_DEBUG_INVALIDATE_PTR(*cur);
	}
}


// ------------------------------------------------------------------------------------------------
void SceneCombiner::MergeMeshes(aiMesh* dest,std::vector<aiMesh*>& src,
	unsigned int flags)
{
}

}