assimp/code/TriangulateProcess.cpp

84 lines
2.7 KiB
C++

/** @file Implementation of the post processing step to split up
* all faces with more than three indices into triangles.
*/
#include <vector>
#include <assert.h>
#include "TriangulateProcess.h"
#include "../include/aiPostProcess.h"
#include "../include/aiMesh.h"
#include "../include/aiScene.h"
using namespace Assimp;
// ------------------------------------------------------------------------------------------------
// Constructor to be privately used by Importer
TriangulateProcess::TriangulateProcess()
{
// nothing to do here
}
// ------------------------------------------------------------------------------------------------
// Destructor, private as well
TriangulateProcess::~TriangulateProcess()
{
// nothing to do here
}
// ------------------------------------------------------------------------------------------------
// Returns whether the processing step is present in the given flag field.
bool TriangulateProcess::IsActive( unsigned int pFlags) const
{
return (pFlags & aiProcess_Triangulate) != 0;
}
// ------------------------------------------------------------------------------------------------
// Executes the post processing step on the given imported data.
void TriangulateProcess::Execute( aiScene* pScene)
{
for( unsigned int a = 0; a < pScene->mNumMeshes; a++)
TriangulateMesh( pScene->mMeshes[a]);
}
// ------------------------------------------------------------------------------------------------
// Triangulates the given mesh.
void TriangulateProcess::TriangulateMesh( aiMesh* pMesh)
{
std::vector<aiFace> newFaces;
newFaces.reserve( pMesh->mNumFaces*2);
for( unsigned int a = 0; a < pMesh->mNumFaces; a++)
{
const aiFace& face = pMesh->mFaces[a];
// if it's a simple primitive, just copy it
if( face.mNumIndices == 3)
{
newFaces.push_back( aiFace());
aiFace& nface = newFaces.back();
nface.mNumIndices = face.mNumIndices;
nface.mIndices = new unsigned int[nface.mNumIndices];
memcpy( nface.mIndices, face.mIndices, nface.mNumIndices * sizeof( unsigned int));
} else
{
assert( face.mNumIndices > 3);
for( unsigned int b = 0; b < face.mNumIndices - 2; b++)
{
newFaces.push_back( aiFace());
aiFace& nface = newFaces.back();
nface.mNumIndices = 3;
nface.mIndices = new unsigned int[3];
nface.mIndices[0] = face.mIndices[0];
nface.mIndices[1] = face.mIndices[b+1];
nface.mIndices[2] = face.mIndices[b+2];
}
}
}
// kill the old faces
delete [] pMesh->mFaces;
// and insert our newly generated faces
pMesh->mNumFaces = newFaces.size();
pMesh->mFaces = new aiFace[pMesh->mNumFaces];
for( unsigned int a = 0; a < newFaces.size(); a++)
pMesh->mFaces[a] = newFaces[a];
}