assimp/code/PostProcessing/OptimizeGraph.cpp

359 lines
12 KiB
C++

/*
---------------------------------------------------------------------------
Open Asset Import Library (assimp)
---------------------------------------------------------------------------
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All rights reserved.
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* Redistributions in binary form must reproduce the above
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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
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"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,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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*/
/** @file OptimizeGraph.cpp
* @brief Implementation of the aiProcess_OptimizGraph step
*/
#ifndef ASSIMP_BUILD_NO_OPTIMIZEGRAPH_PROCESS
#include "OptimizeGraph.h"
#include "ProcessHelper.h"
#include "ConvertToLHProcess.h"
#include <assimp/Exceptional.h>
#include <assimp/SceneCombiner.h>
#include <stdio.h>
using namespace Assimp;
#define AI_RESERVED_NODE_NAME "$Reserved_And_Evil"
/* AI_OG_USE_HASHING enables the use of hashing to speed-up std::set lookups.
* The unhashed variant should be faster, except for *very* large data sets
*/
#ifdef AI_OG_USE_HASHING
// Use our standard hashing function to compute the hash
#define AI_OG_GETKEY(str) SuperFastHash(str.data, str.length)
#else
// Otherwise hope that std::string will utilize a static buffer
// for shorter node names. This would avoid endless heap copying.
#define AI_OG_GETKEY(str) std::string(str.data)
#endif
// ------------------------------------------------------------------------------------------------
// Constructor to be privately used by Importer
OptimizeGraphProcess::OptimizeGraphProcess() :
mScene(),
nodes_in(),
nodes_out(),
count_merged() {
// empty
}
// ------------------------------------------------------------------------------------------------
// Destructor, private as well
OptimizeGraphProcess::~OptimizeGraphProcess() {
// empty
}
// ------------------------------------------------------------------------------------------------
// Returns whether the processing step is present in the given flag field.
bool OptimizeGraphProcess::IsActive(unsigned int pFlags) const {
return (0 != (pFlags & aiProcess_OptimizeGraph));
}
// ------------------------------------------------------------------------------------------------
// Setup properties for the post-processing step
void OptimizeGraphProcess::SetupProperties(const Importer *pImp) {
// Get value of AI_CONFIG_PP_OG_EXCLUDE_LIST
std::string tmp = pImp->GetPropertyString(AI_CONFIG_PP_OG_EXCLUDE_LIST, "");
AddLockedNodeList(tmp);
}
// ------------------------------------------------------------------------------------------------
// Collect new children
void OptimizeGraphProcess::CollectNewChildren(aiNode *nd, std::list<aiNode *> &nodes) {
nodes_in += nd->mNumChildren;
// Process children
std::list<aiNode *> child_nodes;
for (unsigned int i = 0; i < nd->mNumChildren; ++i) {
CollectNewChildren(nd->mChildren[i], child_nodes);
nd->mChildren[i] = nullptr;
}
// Check whether we need this node; if not we can replace it by our own children (warn, danger of incest).
if (locked.find(AI_OG_GETKEY(nd->mName)) == locked.end()) {
for (std::list<aiNode *>::iterator it = child_nodes.begin(); it != child_nodes.end();) {
if (locked.find(AI_OG_GETKEY((*it)->mName)) == locked.end()) {
(*it)->mTransformation = nd->mTransformation * (*it)->mTransformation;
nodes.push_back(*it);
it = child_nodes.erase(it);
continue;
}
++it;
}
if (nd->mNumMeshes || !child_nodes.empty()) {
nodes.push_back(nd);
} else {
delete nd; /* bye, node */
return;
}
} else {
// Retain our current position in the hierarchy
nodes.push_back(nd);
// Now check for possible optimizations in our list of child nodes. join as many as possible
aiNode *join_master = nullptr;
aiMatrix4x4 inv;
const LockedSetType::const_iterator end = locked.end();
std::list<aiNode *> join;
for (std::list<aiNode *>::iterator it = child_nodes.begin(); it != child_nodes.end();) {
aiNode *child = *it;
if (child->mNumChildren == 0 && locked.find(AI_OG_GETKEY(child->mName)) == end) {
// There may be no instanced meshes
unsigned int n = 0;
for (; n < child->mNumMeshes; ++n) {
if (meshes[child->mMeshes[n]] > 1) {
break;
}
}
if (n == child->mNumMeshes) {
if (!join_master) {
join_master = child;
inv = join_master->mTransformation;
inv.Inverse();
} else {
child->mTransformation = inv * child->mTransformation;
join.push_back(child);
it = child_nodes.erase(it);
continue;
}
}
}
++it;
}
if (join_master && !join.empty()) {
join_master->mName.length = ::ai_snprintf(join_master->mName.data, MAXLEN, "$MergedNode_%i", count_merged++);
unsigned int out_meshes = 0;
for (std::list<aiNode *>::const_iterator it = join.cbegin(); it != join.cend(); ++it) {
out_meshes += (*it)->mNumMeshes;
}
// copy all mesh references in one array
if (out_meshes) {
unsigned int *meshIdxs = new unsigned int[out_meshes + join_master->mNumMeshes], *tmp = meshIdxs;
for (unsigned int n = 0; n < join_master->mNumMeshes; ++n) {
*tmp++ = join_master->mMeshes[n];
}
for (const aiNode *join_node : join) {
for (unsigned int n = 0; n < join_node->mNumMeshes; ++n) {
*tmp = join_node->mMeshes[n];
aiMesh *mesh = mScene->mMeshes[*tmp++];
// Assume the transformation is affine
// manually move the mesh into the right coordinate system
// Check for odd negative scale (mirror)
if (join_node->mTransformation.Determinant() < 0) {
// Reverse the mesh face winding order
FlipWindingOrderProcess::ProcessMesh(mesh);
}
// Update positions, normals and tangents
const aiMatrix3x3 IT = aiMatrix3x3(join_node->mTransformation).Inverse().Transpose();
for (unsigned int a = 0; a < mesh->mNumVertices; ++a) {
mesh->mVertices[a] *= join_node->mTransformation;
if (mesh->HasNormals())
mesh->mNormals[a] *= IT;
if (mesh->HasTangentsAndBitangents()) {
mesh->mTangents[a] *= IT;
mesh->mBitangents[a] *= IT;
}
}
}
delete join_node; // bye, node
}
delete[] join_master->mMeshes;
join_master->mMeshes = meshIdxs;
join_master->mNumMeshes += out_meshes;
}
}
}
// reassign children if something changed
if (child_nodes.empty() || child_nodes.size() > nd->mNumChildren) {
delete[] nd->mChildren;
if (!child_nodes.empty()) {
nd->mChildren = new aiNode *[child_nodes.size()];
} else
nd->mChildren = nullptr;
}
nd->mNumChildren = static_cast<unsigned int>(child_nodes.size());
if (nd->mChildren) {
aiNode **tmp = nd->mChildren;
for (std::list<aiNode *>::iterator it = child_nodes.begin(); it != child_nodes.end(); ++it) {
aiNode *node = *tmp++ = *it;
node->mParent = nd;
}
}
nodes_out += static_cast<unsigned int>(child_nodes.size());
}
// ------------------------------------------------------------------------------------------------
// Execute the post-processing step on the given scene
void OptimizeGraphProcess::Execute(aiScene *pScene) {
ASSIMP_LOG_DEBUG("OptimizeGraphProcess begin");
nodes_in = nodes_out = count_merged = 0;
mScene = pScene;
meshes.resize(pScene->mNumMeshes, 0);
FindInstancedMeshes(pScene->mRootNode);
// build a blacklist of identifiers. If the name of a node matches one of these, we won't touch it
locked.clear();
for (std::list<std::string>::const_iterator it = locked_nodes.begin(); it != locked_nodes.end(); ++it) {
#ifdef AI_OG_USE_HASHING
locked.insert(SuperFastHash((*it).c_str()));
#else
locked.insert(*it);
#endif
}
for (unsigned int i = 0; i < pScene->mNumAnimations; ++i) {
for (unsigned int a = 0; a < pScene->mAnimations[i]->mNumChannels; ++a) {
aiNodeAnim *anim = pScene->mAnimations[i]->mChannels[a];
locked.insert(AI_OG_GETKEY(anim->mNodeName));
}
}
for (unsigned int i = 0; i < pScene->mNumMeshes; ++i) {
for (unsigned int a = 0; a < pScene->mMeshes[i]->mNumBones; ++a) {
aiBone *bone = pScene->mMeshes[i]->mBones[a];
locked.insert(AI_OG_GETKEY(bone->mName));
// HACK: Meshes referencing bones may not be transformed; we need to look them.
// The easiest way to do this is to increase their reference counters ...
meshes[i] += 2;
}
}
for (unsigned int i = 0; i < pScene->mNumCameras; ++i) {
aiCamera *cam = pScene->mCameras[i];
locked.insert(AI_OG_GETKEY(cam->mName));
}
for (unsigned int i = 0; i < pScene->mNumLights; ++i) {
aiLight *lgh = pScene->mLights[i];
locked.insert(AI_OG_GETKEY(lgh->mName));
}
// Insert a dummy master node and make it read-only
aiNode *dummy_root = new aiNode(AI_RESERVED_NODE_NAME);
locked.insert(AI_OG_GETKEY(dummy_root->mName));
const aiString prev = pScene->mRootNode->mName;
pScene->mRootNode->mParent = dummy_root;
dummy_root->mChildren = new aiNode *[dummy_root->mNumChildren = 1];
dummy_root->mChildren[0] = pScene->mRootNode;
// Do our recursive processing of scenegraph nodes. For each node collect
// a fully new list of children and allow their children to place themselves
// on the same hierarchy layer as their parents.
std::list<aiNode *> nodes;
CollectNewChildren(dummy_root, nodes);
ai_assert(nodes.size() == 1);
if (dummy_root->mNumChildren == 0) {
pScene->mRootNode = nullptr;
throw DeadlyImportError("After optimizing the scene graph, no data remains");
}
if (dummy_root->mNumChildren > 1) {
pScene->mRootNode = dummy_root;
// Keep the dummy node but assign the name of the old root node to it
pScene->mRootNode->mName = prev;
} else {
// Remove the dummy root node again.
pScene->mRootNode = dummy_root->mChildren[0];
dummy_root->mChildren[0] = nullptr;
delete dummy_root;
}
pScene->mRootNode->mParent = nullptr;
if (!DefaultLogger::isNullLogger()) {
if (nodes_in != nodes_out) {
ASSIMP_LOG_INFO_F("OptimizeGraphProcess finished; Input nodes: ", nodes_in, ", Output nodes: ", nodes_out);
} else {
ASSIMP_LOG_DEBUG("OptimizeGraphProcess finished");
}
}
meshes.clear();
locked.clear();
}
// ------------------------------------------------------------------------------------------------
// Build a LUT of all instanced meshes
void OptimizeGraphProcess::FindInstancedMeshes(aiNode *pNode) {
for (unsigned int i = 0; i < pNode->mNumMeshes; ++i) {
++meshes[pNode->mMeshes[i]];
}
for (unsigned int i = 0; i < pNode->mNumChildren; ++i)
FindInstancedMeshes(pNode->mChildren[i]);
}
#endif // !! ASSIMP_BUILD_NO_OPTIMIZEGRAPH_PROCESS