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*/

/** @file A helper class that processes texture transformations */



#include <assimp/Importer.hpp>
#include <assimp/postprocess.h>
#include <assimp/DefaultLogger.hpp>
#include <assimp/scene.h>

#include "TextureTransform.h"
#include <assimp/StringUtils.h>

using namespace Assimp;

// ------------------------------------------------------------------------------------------------
// Constructor to be privately used by Importer
TextureTransformStep::TextureTransformStep() :
 configFlags()
{
 // nothing to do here
}

// ------------------------------------------------------------------------------------------------
// Destructor, private as well
TextureTransformStep::~TextureTransformStep() = default;

// ------------------------------------------------------------------------------------------------
// Returns whether the processing step is present in the given flag field.
bool TextureTransformStep::IsActive( unsigned int pFlags) const
{
 return (pFlags & aiProcess_TransformUVCoords) != 0;
}

// ------------------------------------------------------------------------------------------------
// Setup properties
void TextureTransformStep::SetupProperties(const Importer* pImp)
{
 configFlags = pImp->GetPropertyInteger(AI_CONFIG_PP_TUV_EVALUATE,AI_UVTRAFO_ALL);
}

// ------------------------------------------------------------------------------------------------
void TextureTransformStep::PreProcessUVTransform(STransformVecInfo& info)
{
 /* This function tries to simplify the input UV transformation.
 * That's very important as it allows us to reduce the number
 * of output UV channels. The order in which the transformations
 * are applied is - as always - scaling, rotation, translation.
 */

	int rounded;
	char szTemp[512];

 /* Optimize the rotation angle. That's slightly difficult as
 * we have an inprecise floating-point number (when comparing
 * UV transformations we'll take that into account by using
 * an epsilon of 5 degrees). If there is a rotation value, we can't
 * perform any further optimizations.
 */
 if (info.mRotation)
 {
 float out = info.mRotation;
 rounded = static_cast<int>((info.mRotation / static_cast<float>(AI_MATH_TWO_PI)));
 if (rounded)
 {
 out -= rounded * static_cast<float>(AI_MATH_PI);
 ASSIMP_LOG_INFO("Texture coordinate rotation ", info.mRotation, " can be simplified to ", out);
 }

 // Next step - convert negative rotation angles to positives
 if (out < 0.f)
 out = (float)AI_MATH_TWO_PI * 2 + out;

 info.mRotation = out;
 return;
 }


 /* Optimize UV translation in the U direction. To determine whether
 * or not we can optimize we need to look at the requested mapping
 * type (e.g. if mirroring is active there IS a difference between
 * offset 2 and 3)
 */
 rounded = (int)info.mTranslation.x;
 if (rounded) {
 float out = 0.0f;
 szTemp[0] = 0;
 if (aiTextureMapMode_Wrap == info.mapU) {
 // Wrap - simple take the fraction of the field
 out = info.mTranslation.x-(float)rounded;
			ai_snprintf(szTemp, 512, "[w] UV U offset %f can be simplified to %f", info.mTranslation.x, out);
 }
 else if (aiTextureMapMode_Mirror == info.mapU && 1 != rounded) {
 // Mirror
 if (rounded % 2)
 rounded--;
 out = info.mTranslation.x-(float)rounded;

 ai_snprintf(szTemp,512,"[m/d] UV U offset %f can be simplified to %f",info.mTranslation.x,out);
 }
 else if (aiTextureMapMode_Clamp == info.mapU || aiTextureMapMode_Decal == info.mapU) {
 // Clamp - translations beyond 1,1 are senseless
 ai_snprintf(szTemp,512,"[c] UV U offset %f can be clamped to 1.0f",info.mTranslation.x);

 out = 1.f;
 }
 if (szTemp[0]) {
 ASSIMP_LOG_INFO(szTemp);
 info.mTranslation.x = out;
 }
 }

 /* Optimize UV translation in the V direction. To determine whether
 * or not we can optimize we need to look at the requested mapping
 * type (e.g. if mirroring is active there IS a difference between
 * offset 2 and 3)
 */
 rounded = (int)info.mTranslation.y;
 if (rounded) {
 float out = 0.0f;
 szTemp[0] = 0;
 if (aiTextureMapMode_Wrap == info.mapV) {
 // Wrap - simple take the fraction of the field
 out = info.mTranslation.y-(float)rounded;
 ::ai_snprintf(szTemp,512,"[w] UV V offset %f can be simplified to %f",info.mTranslation.y,out);
 }
 else if (aiTextureMapMode_Mirror == info.mapV && 1 != rounded) {
 // Mirror
 if (rounded % 2)
 rounded--;
 out = info.mTranslation.x-(float)rounded;

 ::ai_snprintf(szTemp,512,"[m/d] UV V offset %f can be simplified to %f",info.mTranslation.y,out);
 }
 else if (aiTextureMapMode_Clamp == info.mapV || aiTextureMapMode_Decal == info.mapV) {
 // Clamp - translations beyond 1,1 are senseless
 ::ai_snprintf(szTemp,512,"[c] UV V offset %f can be clamped to 1.0f",info.mTranslation.y);

 out = 1.f;
 }
 if (szTemp[0]) {
 ASSIMP_LOG_INFO(szTemp);
 info.mTranslation.y = out;
 }
 }
}

// ------------------------------------------------------------------------------------------------
void UpdateUVIndex(const std::list<TTUpdateInfo>& l, unsigned int n)
{
 // Don't set if == 0 && wasn't set before
 for (std::list<TTUpdateInfo>::const_iterator it = l.begin();it != l.end(); ++it) {
 const TTUpdateInfo& info = *it;

 if (info.directShortcut)
 *info.directShortcut = n;
 else if (!n)
 {
 info.mat->AddProperty<int>((int*)&n,1,AI_MATKEY_UVWSRC(info.semantic,info.index));
 }
 }
}

// ------------------------------------------------------------------------------------------------
inline const char* MappingModeToChar(aiTextureMapMode map)
{
 if (aiTextureMapMode_Wrap == map)
 return "-w";

 if (aiTextureMapMode_Mirror == map)
 return "-m";

 return "-c";
}

// ------------------------------------------------------------------------------------------------
void TextureTransformStep::Execute( aiScene* pScene)
{
 ASSIMP_LOG_DEBUG("TransformUVCoordsProcess begin");


 /* We build a per-mesh list of texture transformations we'll need
 * to apply. To achieve this, we iterate through all materials,
 * find all textures and get their transformations and UV indices.
 * Then we search for all meshes using this material.
 */
 typedef std::list<STransformVecInfo> MeshTrafoList;
 std::vector<MeshTrafoList> meshLists(pScene->mNumMeshes);

 for (unsigned int i = 0; i < pScene->mNumMaterials;++i) {

 aiMaterial* mat = pScene->mMaterials[i];
 for (unsigned int a = 0; a < mat->mNumProperties;++a) {

 aiMaterialProperty* prop = mat->mProperties[a];
 if (!::strcmp( prop->mKey.data, "$tex.file")) {
 STransformVecInfo info;

 // Setup a shortcut structure to allow for a fast updating
 // of the UV index later
 TTUpdateInfo update;
 update.mat = (aiMaterial*) mat;
 update.semantic = prop->mSemantic;
 update.index = prop->mIndex;

 // Get textured properties and transform
 for (unsigned int a2 = 0; a2 < mat->mNumProperties;++a2) {
 aiMaterialProperty* prop2 = mat->mProperties[a2];
 if (prop2->mSemantic != prop->mSemantic || prop2->mIndex != prop->mIndex) {
 continue;
 }

 if ( !::strcmp( prop2->mKey.data, "$tex.uvwsrc")) {
 info.uvIndex = *((int*)prop2->mData);

 // Store a direct pointer for later use
 update.directShortcut = (unsigned int*) prop2->mData;
 }

 else if ( !::strcmp( prop2->mKey.data, "$tex.mapmodeu")) {
 info.mapU = *((aiTextureMapMode*)prop2->mData);
 }
 else if ( !::strcmp( prop2->mKey.data, "$tex.mapmodev")) {
 info.mapV = *((aiTextureMapMode*)prop2->mData);
 }
 else if ( !::strcmp( prop2->mKey.data, "$tex.uvtrafo")) {
 // ValidateDS should check this
 ai_assert(prop2->mDataLength >= 20);
 ::memcpy(&info.mTranslation.x,prop2->mData,sizeof(float)*5);

 // Directly remove this property from the list
 mat->mNumProperties--;
 for (unsigned int a3 = a2; a3 < mat->mNumProperties;++a3) {
 mat->mProperties[a3] = mat->mProperties[a3+1];
 }

 delete prop2;

 // Warn: could be an underflow, but this does not invoke undefined behaviour
 --a2;
 }
 }

 // Find out which transformations are to be evaluated
 if (!(configFlags & AI_UVTRAFO_ROTATION)) {
 info.mRotation = 0.f;
 }
 if (!(configFlags & AI_UVTRAFO_SCALING)) {
 info.mScaling = aiVector2D(1.f,1.f);
 }
 if (!(configFlags & AI_UVTRAFO_TRANSLATION)) {
 info.mTranslation = aiVector2D(0.f,0.f);
 }

 // Do some preprocessing
 PreProcessUVTransform(info);
 info.uvIndex = std::min(info.uvIndex,AI_MAX_NUMBER_OF_TEXTURECOORDS -1u);

 // Find out whether this material is used by more than
 // one mesh. This will make our task much, much more difficult!
 unsigned int cnt = 0;
 for (unsigned int n = 0; n < pScene->mNumMeshes;++n) {
 if (pScene->mMeshes[n]->mMaterialIndex == i)
 ++cnt;
 }

 if (!cnt)
 continue;
 else if (1 != cnt) {
 // This material is referenced by more than one mesh!
 // So we need to make sure the UV index for the texture
 // is identical for each of it ...
 info.lockedPos = AI_TT_UV_IDX_LOCK_TBD;
 }

 // Get all corresponding meshes
 for (unsigned int n = 0; n < pScene->mNumMeshes;++n) {
 aiMesh* mesh = pScene->mMeshes[n];
 if (mesh->mMaterialIndex != i || !mesh->mTextureCoords[0])
 continue;

 unsigned int uv = info.uvIndex;
 if (!mesh->mTextureCoords[uv]) {
 // If the requested UV index is not available, take the first one instead.
 uv = 0;
 }

 if (mesh->mNumUVComponents[info.uvIndex] >= 3){
 ASSIMP_LOG_WARN("UV transformations on 3D mapping channels are not supported");
 continue;
 }

 MeshTrafoList::iterator it;

 // Check whether we have this transform setup already
 for (it = meshLists[n].begin();it != meshLists[n].end(); ++it) {

 if ((*it) == info && (*it).uvIndex == uv) {
 (*it).updateList.push_back(update);
 break;
 }
 }

 if (it == meshLists[n].end()) {
 meshLists[n].push_back(info);
 meshLists[n].back().uvIndex = uv;
 meshLists[n].back().updateList.push_back(update);
 }
 }
 }
 }
 }

 char buffer[1024]; // should be sufficiently large
 unsigned int outChannels = 0, inChannels = 0, transformedChannels = 0;

 // Now process all meshes. Important: we don't remove unreferenced UV channels.
 // This is a job for the RemoveUnreferencedData-Step.
 for (unsigned int q = 0; q < pScene->mNumMeshes;++q) {

 aiMesh* mesh = pScene->mMeshes[q];
 MeshTrafoList& trafo = meshLists[q];

 inChannels += mesh->GetNumUVChannels();

 if (!mesh->mTextureCoords[0] || trafo.empty() || (trafo.size() == 1 && trafo.begin()->IsUntransformed())) {
 outChannels += mesh->GetNumUVChannels();
 continue;
 }

 // Move untransformed UV channels to the first position in the list ....
 // except if we need a new locked index which should be as small as possible
 bool veto = false, need = false;
 unsigned int cnt = 0;
 unsigned int untransformed = 0;

 MeshTrafoList::iterator it,it2;
 for (it = trafo.begin();it != trafo.end(); ++it,++cnt) {

 if (!(*it).IsUntransformed()) {
 need = true;
 }

 if ((*it).lockedPos == AI_TT_UV_IDX_LOCK_TBD) {
 // Lock this index and make sure it won't be changed
 (*it).lockedPos = cnt;
 veto = true;
 continue;
 }

 if (!veto && it != trafo.begin() && (*it).IsUntransformed()) {
 for (it2 = trafo.begin();it2 != it; ++it2) {
 if (!(*it2).IsUntransformed())
 break;
 }
 trafo.insert(it2,*it);
 trafo.erase(it);
 break;
 }
 }
 if (!need)
 continue;

 // Find all that are not at their 'locked' position and move them to it.
 // Conflicts are possible but quite unlikely.
 cnt = 0;
 for (it = trafo.begin();it != trafo.end(); ++it,++cnt) {
 if ((*it).lockedPos != AI_TT_UV_IDX_LOCK_NONE && (*it).lockedPos != cnt) {
 it2 = trafo.begin();unsigned int t = 0;
 while (t != (*it).lockedPos)
 ++it2;

 if ((*it2).lockedPos != AI_TT_UV_IDX_LOCK_NONE) {
 ASSIMP_LOG_ERROR("Channel mismatch, can't compute all transformations properly [design bug]");
 continue;
 }

 std::swap(*it2,*it);
 if ((*it).lockedPos == untransformed)
 untransformed = cnt;
 }
 }

 // ... and add dummies for all unreferenced channels
 // at the end of the list
 bool ref[AI_MAX_NUMBER_OF_TEXTURECOORDS];
 for (unsigned int n = 0; n < AI_MAX_NUMBER_OF_TEXTURECOORDS;++n)
 ref[n] = !mesh->mTextureCoords[n];

 for (it = trafo.begin();it != trafo.end(); ++it)
 ref[(*it).uvIndex] = true;

 for (unsigned int n = 0; n < AI_MAX_NUMBER_OF_TEXTURECOORDS;++n) {
 if (ref[n])
 continue;
 trafo.emplace_back();
 trafo.back().uvIndex = n;
 }

 // Then check whether this list breaks the channel limit.
 // The unimportant ones are at the end of the list, so
 // it shouldn't be too worse if we remove them.
 unsigned int size = (unsigned int)trafo.size();
 if (size > AI_MAX_NUMBER_OF_TEXTURECOORDS) {

 if (!DefaultLogger::isNullLogger()) {
 ASSIMP_LOG_ERROR(static_cast<unsigned int>(trafo.size()), " UV channels required but just ",
 AI_MAX_NUMBER_OF_TEXTURECOORDS, " available");
 }
 size = AI_MAX_NUMBER_OF_TEXTURECOORDS;
 }


 aiVector3D* old[AI_MAX_NUMBER_OF_TEXTURECOORDS];
 for (unsigned int n = 0; n < AI_MAX_NUMBER_OF_TEXTURECOORDS;++n)
 old[n] = mesh->mTextureCoords[n];

 // Now continue and generate the output channels. Channels
 // that we're not going to need later can be overridden.
 it = trafo.begin();
 for (unsigned int n = 0; n < trafo.size();++n,++it) {

 if (n >= size) {
 // Try to use an untransformed channel for all channels we threw over board
 UpdateUVIndex((*it).updateList,untransformed);
 continue;
 }

 outChannels++;

 // Write to the log
 if (!DefaultLogger::isNullLogger()) {
 ::ai_snprintf(buffer,1024,"Mesh %u, channel %u: t(%.3f,%.3f), s(%.3f,%.3f), r(%.3f), %s%s",
 q,n,
 (*it).mTranslation.x,
 (*it).mTranslation.y,
 (*it).mScaling.x,
 (*it).mScaling.y,
 AI_RAD_TO_DEG( (*it).mRotation),
 MappingModeToChar ((*it).mapU),
 MappingModeToChar ((*it).mapV));

 ASSIMP_LOG_INFO(buffer);
 }

 // Check whether we need a new buffer here
 if (mesh->mTextureCoords[n]) {

 it2 = it;++it2;
 for (unsigned int m = n+1; m < size;++m, ++it2) {

 if ((*it2).uvIndex == n){
 it2 = trafo.begin();
 break;
 }
 }
 if (it2 == trafo.begin()){
 mesh->mTextureCoords[n] = new aiVector3D[mesh->mNumVertices];
 }
 }
 else mesh->mTextureCoords[n] = new aiVector3D[mesh->mNumVertices];

 aiVector3D* src = old[(*it).uvIndex];
 aiVector3D* dest, *end;
 dest = mesh->mTextureCoords[n];

 ai_assert(nullptr != src);

 // Copy the data to the destination array
 if (dest != src)
 ::memcpy(dest,src,sizeof(aiVector3D)*mesh->mNumVertices);

 end = dest + mesh->mNumVertices;

 // Build a transformation matrix and transform all UV coords with it
 if (!(*it).IsUntransformed()) {
 const aiVector2D& trl = (*it).mTranslation;
 const aiVector2D& scl = (*it).mScaling;

 // fixme: simplify ..
 ++transformedChannels;
 aiMatrix3x3 matrix;

 aiMatrix3x3 m2,m3,m4,m5;

 m4.a1 = scl.x;
 m4.b2 = scl.y;

 m2.a3 = m2.b3 = 0.5f;
 m3.a3 = m3.b3 = -0.5f;

 if ((*it).mRotation > AI_TT_ROTATION_EPSILON )
 aiMatrix3x3::RotationZ((*it).mRotation,matrix);

 m5.a3 += trl.x; m5.b3 += trl.y;
 matrix = m2 * m4 * matrix * m3 * m5;

 for (src = dest; src != end; ++src) { /* manual homogeneous divide */
 src->z = 1.f;
 *src = matrix * *src;
 src->x /= src->z;
 src->y /= src->z;
 src->z = 0.f;
 }
 }

 // Update all UV indices
 UpdateUVIndex((*it).updateList,n);
 }
 }

 // Print some detailed statistics into the log
 if (!DefaultLogger::isNullLogger()) {

 if (transformedChannels) {
 ASSIMP_LOG_INFO("TransformUVCoordsProcess end: ", outChannels, " output channels (in: ", inChannels, ", modified: ", transformedChannels,")");
 } else {
 ASSIMP_LOG_DEBUG("TransformUVCoordsProcess finished");
 }
 }
}