irrlicht/source/Irrlicht/COctTreeTriangleSelector.cpp

193 lines
4.7 KiB
C++

// Copyright (C) 2002-2007 Nikolaus Gebhardt
// This file is part of the "Irrlicht Engine".
// For conditions of distribution and use, see copyright notice in irrlicht.h
#include "COctTreeTriangleSelector.h"
#include "ISceneNode.h"
#include "os.h"
namespace irr
{
namespace scene
{
//! constructor
COctTreeTriangleSelector::COctTreeTriangleSelector(const IMesh* mesh,
const ISceneNode* node, s32 minimalPolysPerNode)
: CTriangleSelector(mesh, node), Root(0), NodeCount(0),
MinimalPolysPerNode(minimalPolysPerNode)
{
#ifdef _DEBUG
setDebugName("COctTreeTriangleSelector");
#endif
if (!Triangles.empty())
{
u32 start = os::Timer::getRealTime();
// create the triangle octtree
Root = new SOctTreeNode();
Root->Triangles = Triangles;
constructOctTree(Root);
u32 end = os::Timer::getRealTime();
c8 tmp[255];
sprintf(tmp, "Needed %ums to create OctTreeTriangleSelector.(%d nodes, %u polys)",
end - start, NodeCount, Triangles.size());
os::Printer::log(tmp, ELL_INFORMATION);
}
}
//! destructor
COctTreeTriangleSelector::~COctTreeTriangleSelector()
{
delete Root;
}
void COctTreeTriangleSelector::constructOctTree(SOctTreeNode* node)
{
++NodeCount;
node->Box.reset(node->Triangles[0].pointA);
// get bounding box
const u32 cnt = node->Triangles.size();
for (u32 i=0; i<cnt; ++i)
{
node->Box.addInternalPoint(node->Triangles[i].pointA);
node->Box.addInternalPoint(node->Triangles[i].pointB);
node->Box.addInternalPoint(node->Triangles[i].pointC);
}
const core::vector3df& middle = node->Box.getCenter();
core::vector3df edges[8];
node->Box.getEdges(edges);
core::aabbox3d<f32> box;
core::array<core::triangle3df> keepTriangles;
// calculate children
if (!node->Box.isEmpty() && (s32)node->Triangles.size() > MinimalPolysPerNode)
for (s32 ch=0; ch<8; ++ch)
{
box.reset(middle);
box.addInternalPoint(edges[ch]);
node->Child[ch] = new SOctTreeNode();
for (s32 i=0; i<(s32)node->Triangles.size(); ++i)
{
if (node->Triangles[i].isTotalInsideBox(box))
{
node->Child[ch]->Triangles.push_back(node->Triangles[i]);
//node->Triangles.erase(i);
//--i;
}
else
{
keepTriangles.push_back(node->Triangles[i]);
}
}
memcpy(node->Triangles.pointer(), keepTriangles.pointer(),
sizeof(core::triangle3df)*keepTriangles.size());
node->Triangles.set_used(keepTriangles.size());
keepTriangles.set_used(0);
if (node->Child[ch]->Triangles.empty())
{
delete node->Child[ch];
node->Child[ch] = 0;
}
else
constructOctTree(node->Child[ch]);
}
}
//! Gets all triangles which lie within a specific bounding box.
void COctTreeTriangleSelector::getTriangles(core::triangle3df* triangles,
s32 arraySize, s32& outTriangleCount,
const core::aabbox3d<f32>& box,
const core::matrix4* transform) const
{
core::matrix4 mat;
core::aabbox3d<f32> invbox = box;
if (SceneNode)
{
mat = SceneNode->getAbsoluteTransformation();
mat.makeInverse();
mat.transformBox(invbox);
}
mat.makeIdentity();
if (transform)
mat = *transform;
if (SceneNode)
mat *= SceneNode->getAbsoluteTransformation();
s32 trianglesWritten = 0;
if (Root)
getTrianglesFromOctTree(Root, trianglesWritten,
arraySize, invbox, &mat, triangles);
outTriangleCount = trianglesWritten;
}
void COctTreeTriangleSelector::getTrianglesFromOctTree(
SOctTreeNode* node, s32& trianglesWritten,
s32 maximumSize, const core::aabbox3d<f32>& box,
const core::matrix4* mat, core::triangle3df* triangles) const
{
if (!box.intersectsWithBox(node->Box))
return;
s32 cnt = node->Triangles.size();
if (cnt + trianglesWritten > maximumSize)
cnt -= cnt + trianglesWritten - maximumSize;
s32 i;
for (i=0; i<cnt; ++i)
{
triangles[trianglesWritten] = node->Triangles[i];
mat->transformVect(triangles[trianglesWritten].pointA);
mat->transformVect(triangles[trianglesWritten].pointB);
mat->transformVect(triangles[trianglesWritten].pointC);
++trianglesWritten;
}
for (i=0; i<8; ++i)
if (node->Child[i])
getTrianglesFromOctTree(node->Child[i], trianglesWritten,
maximumSize, box, mat, triangles);
}
//! Gets all triangles which have or may have contact with a 3d line.
void COctTreeTriangleSelector::getTriangles(core::triangle3df* triangles, s32 arraySize,
s32& outTriangleCount, const core::line3d<f32>& line,
const core::matrix4* transform) const
{
core::aabbox3d<f32> box(line.start);
box.addInternalPoint(line.end);
// TODO: Could be optimized for line a little bit more.
COctTreeTriangleSelector::getTriangles(triangles, arraySize, outTriangleCount,
box, transform);
}
} // end namespace scene
} // end namespace irr