From e33e19d0587146859d48a134ec9fd94e7b7ba5cd Mon Sep 17 00:00:00 2001 From: "FWoltermann@gmail.com" Date: Thu, 8 Dec 2011 14:53:40 +0000 Subject: Initial upload --- Opcode/OPC_MeshInterface.cpp | 299 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 299 insertions(+) create mode 100644 Opcode/OPC_MeshInterface.cpp (limited to 'Opcode/OPC_MeshInterface.cpp') diff --git a/Opcode/OPC_MeshInterface.cpp b/Opcode/OPC_MeshInterface.cpp new file mode 100644 index 0000000..3a1d653 --- /dev/null +++ b/Opcode/OPC_MeshInterface.cpp @@ -0,0 +1,299 @@ +/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////// +/* + * OPCODE - Optimized Collision Detection + * Copyright (C) 2001 Pierre Terdiman + * Homepage: http://www.codercorner.com/Opcode.htm + */ +/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////// + +/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////// +/** + * Contains a mesh interface. + * \file OPC_MeshInterface.cpp + * \author Pierre Terdiman + * \date November, 27, 2002 + */ +/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////// + +/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////// +/** + * This structure holds 3 vertex-pointers. It's mainly used by collision callbacks so that the app doesn't have + * to return 3 vertices to OPCODE (36 bytes) but only 3 pointers (12 bytes). It seems better but I never profiled + * the alternative. + * + * \class VertexPointers + * \author Pierre Terdiman + * \version 1.3 + * \date March, 20, 2001 +*/ +/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////// + +/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////// +/** + * 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: + * - callbacks, if OPC_USE_CALLBACKS is defined in OPC_Settings.h. + * - else pointers. + * + * 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: + * + * \code + * 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)); + * \endcode + * + * 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: + * - a vertex made of three 32-bits floating point values + * - a triangle made of three 32-bits integer vertex references + * ...then you may want to use pointers instead of callbacks. This is the same, except OPCODE will directly + * use provided pointers to access the topology and geometry, without using a callback. It might be faster, + * but probably not as safe. Pointers have been introduced in OPCODE 1.2. + * + * Ex: + * + * \code + * // Setup pointers + * MeshInterface0->SetPointers(Mesh0->GetFaces(), Mesh0->GetVerts()); + * MeshInterface1->SetPointers(Mesh1->GetFaces(), Mesh1->GetVerts()); + * \endcode + * + * + * 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. + * + * \class MeshInterface + * \author Pierre Terdiman + * \version 1.3 + * \date November, 27, 2002 +*/ +/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////// + +/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////// +// Precompiled Header +#include "Stdafx.h" + +using namespace Opcode; + +/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////// +/** + * Constructor. + */ +/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////// +MeshInterface::MeshInterface() : +#ifdef OPC_USE_CALLBACKS + mUserData (null), + mObjCallback (null), +#else + mTris (null), + mVerts (null), + #ifdef OPC_USE_STRIDE + mTriStride (sizeof(IndexedTriangle)), + mVertexStride (sizeof(Point)), + #endif +#endif + mNbTris (0), + mNbVerts (0) +{ +} + +/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////// +/** + * Destructor. + */ +/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////// +MeshInterface::~MeshInterface() +{ +} + +/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////// +/** + * Checks the mesh interface is valid, i.e. things have been setup correctly. + * \return true if valid + */ +/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////// +bool MeshInterface::IsValid() const +{ + if(!mNbTris || !mNbVerts) return false; +#ifdef OPC_USE_CALLBACKS + if(!mObjCallback) return false; +#else + if(!mTris || !mVerts) return false; +#endif + return true; +} + +/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////// +/** + * Checks the mesh itself is valid. + * Currently we only look for degenerate faces. + * \return number of degenerate faces + */ +/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////// +udword MeshInterface::CheckTopology() const +{ + // Check topology. If the model contains degenerate faces, collision report can be wrong in some cases. + // e.g. it happens with the standard MAX teapot. So clean your meshes first... If you don't have a mesh cleaner + // you can try this: www.codercorner.com/Consolidation.zip + + udword NbDegenerate = 0; + + VertexPointers VP; + + // Using callbacks, we don't have access to vertex indices. Nevertheless we still can check for + // redundant vertex pointers, which cover all possibilities (callbacks/pointers/strides). + for(udword i=0;i