# Visualization Library

A lightweight C++ OpenGL middleware for 2D/3D graphics

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# D:/VL/BuildSystem/VL_DISTRO/Visualization_Library_SDK/src/vlGraphics/RayIntersector.cpp

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    00001 /**************************************************************************************/
    00002 /*                                                                                    */
    00003 /*  Visualization Library                                                             */
    00004 /*  http://www.visualizationlibrary.org                                               */
    00005 /*                                                                                    */
    00006 /*  Copyright (c) 2005-2010, Michele Bosi                                             */
    00007 /*  All rights reserved.                                                              */
    00008 /*                                                                                    */
    00009 /*  Redistribution and use in source and binary forms, with or without modification,  */
    00010 /*  are permitted provided that the following conditions are met:                     */
    00011 /*                                                                                    */
    00012 /*  - Redistributions of source code must retain the above copyright notice, this     */
    00013 /*  list of conditions and the following disclaimer.                                  */
    00014 /*                                                                                    */
    00015 /*  - Redistributions in binary form must reproduce the above copyright notice, this  */
    00016 /*  list of conditions and the following disclaimer in the documentation and/or       */
    00017 /*  other materials provided with the distribution.                                   */
    00018 /*                                                                                    */
    00019 /*  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND   */
    00020 /*  ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED     */
    00021 /*  WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE            */
    00022 /*  DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR  */
    00023 /*  ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES    */
    00024 /*  (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;      */
    00025 /*  LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON    */
    00026 /*  ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT           */
    00027 /*  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS     */
    00028 /*  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.                      */
    00029 /*                                                                                    */
    00030 /**************************************************************************************/
    00031
    00032 #include <vlGraphics/RayIntersector.hpp>
    00033 #include <vlGraphics/SceneManager.hpp>
    00034
    00035 using namespace vl;
    00036
    00037 //-----------------------------------------------------------------------------
    00038 void RayIntersector::intersect(const Ray& ray, SceneManager* scene_manager)
    00039 {
    00040   actors()->clear();
    00041   scene_manager->extractActors( *actors() );
    00042   setRay(ray);
    00043   intersect();
    00044 }
    00045 //-----------------------------------------------------------------------------
    00046 void RayIntersector::intersect()
    00047 {
    00048   mIntersections.clear();
    00049   for(int i=0; i<actors()->size(); ++i)
    00050   {
    00051     if (!frustum().cull(actors()->at(i)->boundingBox()))
    00052     {
    00053       intersect(actors()->at(i));
    00054     }
    00055   }
    00056
    00057   std::sort( mIntersections.begin(), mIntersections.end(), sorter );
    00058 }
    00059 //-----------------------------------------------------------------------------
    00060 void RayIntersector::intersect(Actor* act)
    00061 {
    00062   Geometry* geom = cast<Geometry>(act->lod(0));
    00063   if (geom)
    00064     intersectGeometry(act, geom);
    00065 }
    00066 //-----------------------------------------------------------------------------
    00067 void RayIntersector::intersectGeometry(Actor* act, Geometry* geom)
    00068 {
    00069   ArrayAbstract* posarr = geom->vertexArray() ? geom->vertexArray() : geom->vertexAttribArray(vl::VA_Position) ? geom->vertexAttribArray(vl::VA_Position)->data() : NULL;
    00070   if (posarr)
    00071   {
    00072     mat4 matrix = act->transform() ? act->transform()->worldMatrix() : mat4();
    00073     for(int i=0; i<geom->drawCalls()->size(); ++i)
    00074     {
    00075       DrawCall* prim = geom->drawCalls()->at(i);
    00076       int itri = 0;
    00077       for(TriangleIterator trit = prim->triangleIterator(); trit.hasNext(); trit.next(), ++itri)
    00078       {
    00079         int ia = trit.a();
    00080         int ib = trit.b();
    00081         int ic = trit.c();
    00082         vec3 a = posarr->getAsVec3(ia);
    00083         vec3 b = posarr->getAsVec3(ib);
    00084         vec3 c = posarr->getAsVec3(ic);
    00085         if (act->transform())
    00086         {
    00087           a = matrix * a;
    00088           b = matrix * b;
    00089           c = matrix * c;
    00090         }
    00091         intersectTriangle(a, b, c, ia, ib, ic, act, geom, prim, itri);
    00092       }
    00093     }
    00094   }
    00095 }
    00096 //-----------------------------------------------------------------------------
    00097 template<class T>
    00098 void RayIntersector::intersectTriangle(const T& a, const T& b, const T& c, int ia, int ib, int ic, Actor* act, Geometry* geom, DrawCall* prim, int tri_idx)
    00099 {
    00100   T v1 = b-a;
    00101   T v2 = c-a;
    00102   T n = cross(v1,v2).normalize();
    00103   real det = (real)dot(n,(T)ray().direction());
    00104   if(det == 0)
    00105     return;
    00106   real t = (real)dot(n, a-(T)ray().origin()) / det;
    00107   if (t<0)
    00108     return;
    00109   vec3  rp = ray().origin() + ray().direction() * t;
    00110   T fp = (T)rp;
    00111   T pts[] = { a, b, c, a };
    00112   for(int i=0; i<3; ++i)
    00113   {
    00114     T bi_norm = -cross(pts[i+1]-pts[i],n).normalize();
    00115     if (dot(fp-pts[i],bi_norm) < 0)
    00116       return;
    00117   }
    00118   ref<RayIntersectionGeometry> record = new vl::RayIntersectionGeometry;
    00119   record->setIntersectionPoint( rp );
    00120   record->setTriangleIndex(tri_idx);
    00121   record->setTriangle(ia, ib, ic);
    00122   record->setActor(act);
    00123   record->setGeometry(geom);
    00124   record->setPrimitives(prim);
    00125   record->setDistance( t );
    00126   mIntersections.push_back(record);
    00127 }
    00128 //-----------------------------------------------------------------------------

Visualization Library v2011.09.1162 Reference Documentation
Copyright 2005-2011 Michele Bosi. All rights reserved.
Updated on Thu Jan 26 2012 00:43:42.
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