Initiual commit: AssetImporter source moved from ZFXCE repository to its own repository. PLease do not use the ZFXCE repo any more.

git-svn-id: https://assimp.svn.sourceforge.net/svnroot/assimp/trunk@1 67173fc5-114c-0410-ac8e-9d2fd5bffc1f

code/ConvertToLHProcess.cpp

@@ -0,0 +1,155 @@
+/** @file Implementation of the post processing step to convert all imported data
+ * to a left-handed coordinate system.
+ */
+#include "ConvertToLHProcess.h"
+#include "../include/aiPostProcess.h"
+#include "../include/aiMesh.h"
+#include "../include/aiAnim.h"
+#include "../include/aiScene.h"
+
+
+using namespace Assimp;
+
+// The transformation matrix to convert from DirectX coordinates to OpenGL coordinates.
+const aiMatrix3x3 Assimp::ConvertToLHProcess::sToOGLTransform(
+	1.0f, 0.0f, 0.0f, 0.0f, 0.0f, -1.0f, 0.0f, 1.0f, 0.0f
+	);
+// The transformation matrix to convert from OpenGL coordinates to DirectX coordinates.
+const aiMatrix3x3 Assimp::ConvertToLHProcess::sToDXTransform(
+	1.0f, 0.0f, 0.0f, 0.0f, 0.0f, 1.0f, 0.0f, -1.0f, 0.0f
+	);
+
+// ------------------------------------------------------------------------------------------------
+// Constructor to be privately used by Importer
+ConvertToLHProcess::ConvertToLHProcess()
+{
+	// nothing to do here
+}
+
+// ------------------------------------------------------------------------------------------------
+// Destructor, private as well
+ConvertToLHProcess::~ConvertToLHProcess()
+{
+	// nothing to do here
+}
+
+// ------------------------------------------------------------------------------------------------
+// Returns whether the processing step is present in the given flag field.
+bool ConvertToLHProcess::IsActive( unsigned int pFlags) const
+{
+	return (pFlags & aiProcess_ConvertToLeftHanded) != 0;
+}
+
+// ------------------------------------------------------------------------------------------------
+// Executes the post processing step on the given imported data.
+void ConvertToLHProcess::Execute( aiScene* pScene)
+{
+	// Check for an existent root node to proceed
+	if (NULL == pScene->mRootNode)
+		return;
+
+	// transform the root node of the scene, the other nodes will follow then
+	ConvertToDX( pScene->mRootNode->mTransformation);
+
+	// transform all meshes accordingly
+	for( unsigned int a = 0; a < pScene->mNumMeshes; a++)
+		ProcessMesh( pScene->mMeshes[a]);
+
+	// transform all animation channels affecting the root node as well
+	for( unsigned int a = 0; a < pScene->mNumAnimations; a++)
+	{
+		aiAnimation* anim = pScene->mAnimations[a];
+		for( unsigned int b = 0; b < anim->mNumBones; b++)
+		{
+			aiBoneAnim* boneAnim = anim->mBones[b];
+			if( strcmp( boneAnim->mBoneName.data, pScene->mRootNode->mName.data) == 0)
+				ProcessAnimation( boneAnim);
+		}
+	}
+}
+
+// ------------------------------------------------------------------------------------------------
+// Converts a single mesh to left handed coordinates. 
+void ConvertToLHProcess::ProcessMesh( aiMesh* pMesh)
+{
+	// invert the order of all faces in this mesh
+	for( unsigned int a = 0; a < pMesh->mNumFaces; a++)
+	{
+		aiFace& face = pMesh->mFaces[a];
+		for( unsigned int b = 0; b < face.mNumIndices / 2; b++)
+			std::swap( face.mIndices[b], face.mIndices[ face.mNumIndices - 1 - b]);
+	}
+
+	// mirror texture y coordinate
+	for( unsigned int a = 0; a < AI_MAX_NUMBER_OF_TEXTURECOORDS; a++)
+	{
+		if( pMesh->HasTextureCoords( a))
+		{
+			for( unsigned int b = 0; b < pMesh->mNumVertices; b++)
+				pMesh->mTextureCoords[a][b].y = 1.0f - pMesh->mTextureCoords[a][b].y;
+		}
+	}
+
+	// mirror bitangents as well as they're derived from the texture coords
+	if( pMesh->HasTangentsAndBitangents())
+	{
+		for( unsigned int a = 0; a < pMesh->mNumVertices; a++)
+			pMesh->mBitangents[a] = -pMesh->mBitangents[a];
+	}
+}
+
+// ------------------------------------------------------------------------------------------------
+// Converts the given animation to LH coordinates. 
+void ConvertToLHProcess::ProcessAnimation( aiBoneAnim* pAnim)
+{
+	// position keys
+	for( unsigned int a = 0; a < pAnim->mNumPositionKeys; a++)
+		ConvertToDX( pAnim->mPositionKeys[a].mValue);
+
+	// rotation keys
+	for( unsigned int a = 0; a < pAnim->mNumRotationKeys; a++)
+	{
+		aiMatrix3x3 rotmat = pAnim->mRotationKeys[a].mValue.GetMatrix();
+		ConvertToDX( rotmat);
+		pAnim->mRotationKeys[a].mValue = aiQuaternion( rotmat);
+	}
+}
+
+// ------------------------------------------------------------------------------------------------
+// Static helper function to convert a vector/matrix from DX to OGL coords
+void ConvertToLHProcess::ConvertToOGL( aiVector3D& poVector)
+{
+	poVector = sToOGLTransform * poVector;
+}
+
+// ------------------------------------------------------------------------------------------------
+void ConvertToLHProcess::ConvertToOGL( aiMatrix3x3& poMatrix)
+{
+	poMatrix *= sToOGLTransform;
+}
+
+// ------------------------------------------------------------------------------------------------
+void ConvertToLHProcess::ConvertToOGL( aiMatrix4x4& poMatrix)
+{
+	poMatrix *= aiMatrix4x4( sToOGLTransform);
+}
+
+// ------------------------------------------------------------------------------------------------
+// Static helper function to convert a vector/matrix from OGL back to DX coords
+void ConvertToLHProcess::ConvertToDX( aiVector3D& poVector)
+{
+	poVector = sToDXTransform * poVector;
+}
+
+// ------------------------------------------------------------------------------------------------
+void ConvertToLHProcess::ConvertToDX( aiMatrix3x3& poMatrix)
+{
+	poMatrix *= sToDXTransform;
+}
+
+// ------------------------------------------------------------------------------------------------
+void ConvertToLHProcess::ConvertToDX( aiMatrix4x4& poMatrix)
+{
+	aiMatrix4x4 temp(sToDXTransform);
+	poMatrix *= temp;
+}