assimp/code/ScenePreprocessor.cpp

/*
Open Asset Import Library (assimp)
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All rights reserved.

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  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
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* Neither the name of the assimp team, nor the names of its
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  derived from this software without specific prior
  written permission of the assimp team.

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"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 
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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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*/

#include "ScenePreprocessor.h"
#include "../include/assimp/ai_assert.h"
#include "../include/assimp/scene.h"
#include "../include/assimp/DefaultLogger.hpp"


using namespace Assimp;

// ---------------------------------------------------------------------------------------------
void ScenePreprocessor::ProcessScene ()
{
	ai_assert(scene != NULL);

	// Process all meshes
	for (unsigned int i = 0; i < scene->mNumMeshes;++i)
		ProcessMesh(scene->mMeshes[i]);

	// - nothing to do for nodes for the moment
	// - nothing to do for textures for the moment
	// - nothing to do for lights for the moment
	// - nothing to do for cameras for the moment

	// Process all animations
	for (unsigned int i = 0; i < scene->mNumAnimations;++i)
		ProcessAnimation(scene->mAnimations[i]);

	// Generate a default material if none was specified
	if (!scene->mNumMaterials && scene->mNumMeshes)	{
		scene->mMaterials      = new aiMaterial*[2];
		aiMaterial* helper;

		aiString name;

		scene->mMaterials[scene->mNumMaterials] = helper = new aiMaterial();
		aiColor3D clr(0.6f,0.6f,0.6f);
		helper->AddProperty(&clr,1,AI_MATKEY_COLOR_DIFFUSE);

		// setup the default name to make this material identifiable
		name.Set(AI_DEFAULT_MATERIAL_NAME);
		helper->AddProperty(&name,AI_MATKEY_NAME);

		DefaultLogger::get()->debug("ScenePreprocessor: Adding default material \'" AI_DEFAULT_MATERIAL_NAME  "\'");

		for (unsigned int i = 0; i < scene->mNumMeshes;++i) {
			scene->mMeshes[i]->mMaterialIndex = scene->mNumMaterials;
		}

		scene->mNumMaterials++;
	}
}

// ---------------------------------------------------------------------------------------------
void ScenePreprocessor::ProcessMesh (aiMesh* mesh)
{
	// If aiMesh::mNumUVComponents is *not* set assign the default value of 2
	for (unsigned int i = 0; i < AI_MAX_NUMBER_OF_TEXTURECOORDS; ++i)	{
		if (!mesh->mTextureCoords[i]) {
			mesh->mNumUVComponents[i] = 0;
		} else {
			if (!mesh->mNumUVComponents[i])
				mesh->mNumUVComponents[i] = 2;

			aiVector3D* p = mesh->mTextureCoords[i], *end = p+mesh->mNumVertices;

			// Ensure unsued components are zeroed. This will make 1D texture channels work
			// as if they were 2D channels .. just in case an application doesn't handle
			// this case
			if (2 == mesh->mNumUVComponents[i]) {
				for (; p != end; ++p)
					p->z = 0.f;
			}
			else if (1 == mesh->mNumUVComponents[i]) {
				for (; p != end; ++p)
					p->z = p->y = 0.f;
			}
			else if (3 == mesh->mNumUVComponents[i]) {
				// Really 3D coordinates? Check whether the third coordinate is != 0 for at least one element
				for (; p != end; ++p) {
					if (p->z != 0)
						break;
				}
				if (p == end) {
					DefaultLogger::get()->warn("ScenePreprocessor: UVs are declared to be 3D but they're obviously not. Reverting to 2D.");
					mesh->mNumUVComponents[i] = 2;
				}
			}
		}
	}

	// If the information which primitive types are there in the
	// mesh is currently not available, compute it.
	if (!mesh->mPrimitiveTypes)	{
		for (unsigned int a = 0; a < mesh->mNumFaces; ++a)	{
			aiFace& face = mesh->mFaces[a];
			switch (face.mNumIndices)
			{
			case 3u:
				mesh->mPrimitiveTypes |= aiPrimitiveType_TRIANGLE;
				break;

			case 2u:
				mesh->mPrimitiveTypes |= aiPrimitiveType_LINE;
				break;

			case 1u:
				mesh->mPrimitiveTypes |= aiPrimitiveType_POINT;
				break;

			default:
				mesh->mPrimitiveTypes |= aiPrimitiveType_POLYGON;
				break;
			}
		}
	}

	// If tangents and normals are given but no bitangents compute them
	if (mesh->mTangents && mesh->mNormals && !mesh->mBitangents)	{

		mesh->mBitangents = new aiVector3D[mesh->mNumVertices];
		for (unsigned int i = 0; i < mesh->mNumVertices;++i)	{
			mesh->mBitangents[i] = mesh->mNormals[i] ^ mesh->mTangents[i];
		}
	}
}

// ---------------------------------------------------------------------------------------------
void ScenePreprocessor::ProcessAnimation (aiAnimation* anim)
{
	double first = 10e10, last = -10e10;
	for (unsigned int i = 0; i < anim->mNumChannels;++i)	{
		aiNodeAnim* channel = anim->mChannels[i];

		/*  If the exact duration of the animation is not given
		 *  compute it now.
		 */
		if (anim->mDuration == -1.)	{

			// Position keys
			for (unsigned int i = 0; i < channel->mNumPositionKeys;++i)	{
				aiVectorKey& key = channel->mPositionKeys[i];
				first = std::min (first, key.mTime);
				last  = std::max (last,  key.mTime);
			}

			// Scaling keys
			for (unsigned int i = 0; i < channel->mNumScalingKeys;++i)	{
				aiVectorKey& key = channel->mScalingKeys[i];
				first = std::min (first, key.mTime);
				last  = std::max (last,  key.mTime);
			}

			// Rotation keys
			for (unsigned int i = 0; i < channel->mNumRotationKeys;++i)	{
				aiQuatKey& key = channel->mRotationKeys[i];
				first = std::min (first, key.mTime);
				last  = std::max (last,  key.mTime);
			}
		}

		/*  Check whether the animation channel has no rotation
		 *  or position tracks. In this case we generate a dummy
		 *  track from the information we have in the transformation
		 *  matrix of the corresponding node.
		 */
		if (!channel->mNumRotationKeys || !channel->mNumPositionKeys || !channel->mNumScalingKeys)	{
			// Find the node that belongs to this animation
			aiNode* node = scene->mRootNode->FindNode(channel->mNodeName);
			if (node) // ValidateDS will complain later if 'node' is NULL
			{
				// Decompose the transformation matrix of the node
				aiVector3D scaling, position;
				aiQuaternion rotation;

				node->mTransformation.Decompose(scaling, rotation,position);

				// No rotation keys? Generate a dummy track
				if (!channel->mNumRotationKeys)	{
					channel->mNumRotationKeys = 1;
					channel->mRotationKeys = new aiQuatKey[1];
					aiQuatKey& q = channel->mRotationKeys[0];

					q.mTime  = 0.;
					q.mValue = rotation;

					DefaultLogger::get()->debug("ScenePreprocessor: Dummy rotation track has been generated");
				}

				// No scaling keys? Generate a dummy track
				if (!channel->mNumScalingKeys)	{
					channel->mNumScalingKeys = 1;
					channel->mScalingKeys = new aiVectorKey[1];
					aiVectorKey& q = channel->mScalingKeys[0];

					q.mTime  = 0.;
					q.mValue = scaling;

					DefaultLogger::get()->debug("ScenePreprocessor: Dummy scaling track has been generated");
				}

				// No position keys? Generate a dummy track
				if (!channel->mNumPositionKeys)	{
					channel->mNumPositionKeys = 1;
					channel->mPositionKeys = new aiVectorKey[1];
					aiVectorKey& q = channel->mPositionKeys[0];

					q.mTime  = 0.;
					q.mValue = position;

					DefaultLogger::get()->debug("ScenePreprocessor: Dummy position track has been generated");
				}
			}
		}
	}

	if (anim->mDuration == -1.)		{
		DefaultLogger::get()->debug("ScenePreprocessor: Setting animation duration");
		anim->mDuration = last - std::min( first, 0. );
	}
}