#include <OPC_MeshInterface.h>
Public Member Functions | |
udword | CheckTopology () const |
inline_ udword | GetNbTriangles () const |
inline_ udword | GetNbVertices () const |
inline_ void | GetTriangle (VertexPointers &vp, udword index) const |
inline_ const IndexedTriangle * | GetTris () const |
inline_ const Point * | GetVerts () const |
bool | IsValid () const |
MeshInterface () | |
bool | RemapClient (udword nb_indices, const udword *permutation) const |
inline_ void | SetNbTriangles (udword nb) |
inline_ void | SetNbVertices (udword nb) |
bool | SetPointers (const IndexedTriangle *tris, const Point *verts) |
~MeshInterface () | |
Public Attributes | |
bool | Single |
Use single or double precision vertices. | |
Private Attributes | |
udword | mNbTris |
Number of triangles in the input model. | |
udword | mNbVerts |
Number of vertices in the input model. | |
const IndexedTriangle * | mTris |
Array of indexed triangles. | |
const Point * | mVerts |
Array of vertices. | |
Static Private Attributes | |
static Point | VertexCache [3] |
This class is an interface between us and user-defined meshes. Meshes can be defined in a lot of ways, and here we try to support most of them.
Basically you have two options:
If using pointers, you can also use strides or not. Strides are used when OPC_USE_STRIDE is defined.
CALLBACKS:
Using callbacks is the most generic way to feed OPCODE with your meshes. Indeed, you just have to give access to three vertices at the end of the day. It's up to you to fetch them from your database, using whatever method you want. Hence your meshes can lie in system memory or AGP, be indexed or not, use 16 or 32-bits indices, you can decompress them on-the-fly if needed, etc. On the other hand, a callback is called each time OPCODE needs access to a particular triangle, so there might be a slight overhead.
To make things clear: geometry & topology are NOT stored in the collision system, in order to save some ram. So, when the system needs them to perform accurate intersection tests, you're requested to provide the triangle-vertices corresponding to a given face index.
Ex:
static void ColCallback(udword triangle_index, VertexPointers& triangle, udword user_data) { // Get back Mesh0 or Mesh1 (you also can use 2 different callbacks) Mesh* MyMesh = (Mesh*)user_data; // Get correct triangle in the app-controlled database const Triangle* Tri = MyMesh->GetTriangle(triangle_index); // Setup pointers to vertices for the collision system triangle.Vertex[0] = MyMesh->GetVertex(Tri->mVRef[0]); triangle.Vertex[1] = MyMesh->GetVertex(Tri->mVRef[1]); triangle.Vertex[2] = MyMesh->GetVertex(Tri->mVRef[2]); } // Setup callbacks MeshInterface0->SetCallback(ColCallback, udword(Mesh0)); MeshInterface1->SetCallback(ColCallback, udword(Mesh1));
Of course, you should make this callback as fast as possible. And you're also not supposed to modify the geometry *after* the collision trees have been built. The alternative was to store the geometry & topology in the collision system as well (as in RAPID) but we have found this approach to waste a lot of ram in many cases.
POINTERS:
If you're internally using the following canonical structures:
Ex:
// Setup pointers
MeshInterface0->SetPointers(Mesh0->GetFaces(), Mesh0->GetVerts());
MeshInterface1->SetPointers(Mesh1->GetFaces(), Mesh1->GetVerts());
STRIDES:
If your vertices are D3D-like entities interleaving a position, a normal and/or texture coordinates (i.e. if your vertices are FVFs), you might want to use a vertex stride to skip extra data OPCODE doesn't need. Using a stride shouldn't be notably slower than not using it, but it might increase cache misses. Please also note that you *shouldn't* read from AGP or video-memory buffers !
In any case, compilation flags are here to select callbacks/pointers/strides at compile time, so choose what's best for your application. All of this has been wrapped into this MeshInterface.
Definition at line 53 of file OPC_MeshInterface.h.
udword MeshInterface::CheckTopology | ( | ) | const |
Checks the mesh itself is valid. Currently we only look for degenerate faces.
inline_ udword MeshInterface::GetNbTriangles | ( | ) | const [inline] |
Definition at line 60 of file OPC_MeshInterface.h.
inline_ udword MeshInterface::GetNbVertices | ( | ) | const [inline] |
Definition at line 61 of file OPC_MeshInterface.h.
inline_ void MeshInterface::GetTriangle | ( | VertexPointers & | vp, |
udword | index | ||
) | const [inline] |
Fetches a triangle given a triangle index.
vp | [out] required triangle's vertex pointers |
index | [in] triangle index |
Definition at line 118 of file OPC_MeshInterface.h.
inline_ const IndexedTriangle* MeshInterface::GetTris | ( | ) | const [inline] |
Definition at line 91 of file OPC_MeshInterface.h.
inline_ const Point* MeshInterface::GetVerts | ( | ) | const [inline] |
Definition at line 92 of file OPC_MeshInterface.h.
bool MeshInterface::IsValid | ( | ) | const |
Checks the mesh interface is valid, i.e. things have been setup correctly.
bool MeshInterface::RemapClient | ( | udword | nb_indices, |
const udword * | permutation | ||
) | const |
Remaps client's mesh according to a permutation.
nb_indices | [in] number of indices in the permutation (will be checked against number of triangles) |
permutation | [in] list of triangle indices |
inline_ void MeshInterface::SetNbTriangles | ( | udword | nb | ) | [inline] |
Definition at line 62 of file OPC_MeshInterface.h.
inline_ void MeshInterface::SetNbVertices | ( | udword | nb | ) | [inline] |
Definition at line 63 of file OPC_MeshInterface.h.
bool MeshInterface::SetPointers | ( | const IndexedTriangle * | tris, |
const Point * | verts | ||
) |
Pointers control: setups object pointers. Must provide access to faces and vertices for a given object.
tris | [in] pointer to triangles |
verts | [in] pointer to vertices |
udword MeshInterface::mNbTris [private] |
Number of triangles in the input model.
Definition at line 178 of file OPC_MeshInterface.h.
udword MeshInterface::mNbVerts [private] |
Number of vertices in the input model.
Definition at line 179 of file OPC_MeshInterface.h.
const IndexedTriangle* MeshInterface::mTris [private] |
Array of indexed triangles.
Definition at line 186 of file OPC_MeshInterface.h.
const Point* MeshInterface::mVerts [private] |
Array of vertices.
Definition at line 187 of file OPC_MeshInterface.h.
Use single or double precision vertices.
Definition at line 193 of file OPC_MeshInterface.h.
Point MeshInterface::VertexCache[3] [static, private] |
Definition at line 195 of file OPC_MeshInterface.h.