# Visualization Library

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

[Home] [Tutorials] [All Classes] [Grouped Classes]

- Main Page
- Related Pages
- Namespaces
- Classes
- Files

- File List
- File Members

# D:/VL/BuildSystem/VL_DISTRO/Visualization_Library_SDK/src/vlCore/Plane.cpp

Go to the documentation of this file.

    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 <vlCore/Plane.hpp>
    00033 #include <vlCore/AABB.hpp>
    00034
    00035 using namespace vl;
    00036
    00037 //-----------------------------------------------------------------------------
    00038 // Plane
    00039 //-----------------------------------------------------------------------------
    00040 real Plane::distance(const vec3 &v) const
    00041 {
    00042   return dot(v, mNormal) - mOrigin;
    00043 }
    00044 //-----------------------------------------------------------------------------
    00045 bool Plane::isOutside(const AABB& aabb) const
    00046 {
    00047   vec3 pt;
    00048   pt.x() = mNormal.x() >= 0 ? aabb.minCorner().x() : aabb.maxCorner().x();
    00049   pt.y() = mNormal.y() >= 0 ? aabb.minCorner().y() : aabb.maxCorner().y();
    00050   pt.z() = mNormal.z() >= 0 ? aabb.minCorner().z() : aabb.maxCorner().z();
    00051   return distance(pt) >= 0;
    00052 }
    00053 //-----------------------------------------------------------------------------
    00054 int Plane::classify(const AABB& aabb) const
    00055 {
    00056   vec3 corner[] =
    00057   {
    00058     vec3(aabb.minCorner().x(), aabb.minCorner().y(), aabb.minCorner().z()),
    00059     vec3(aabb.minCorner().x(), aabb.minCorner().y(), aabb.maxCorner().z()),
    00060     vec3(aabb.minCorner().x(), aabb.maxCorner().y(), aabb.minCorner().z()),
    00061     vec3(aabb.minCorner().x(), aabb.maxCorner().y(), aabb.maxCorner().z()),
    00062     vec3(aabb.maxCorner().x(), aabb.minCorner().y(), aabb.minCorner().z()),
    00063     vec3(aabb.maxCorner().x(), aabb.minCorner().y(), aabb.maxCorner().z()),
    00064     vec3(aabb.maxCorner().x(), aabb.maxCorner().y(), aabb.minCorner().z()),
    00065     vec3(aabb.maxCorner().x(), aabb.maxCorner().y(), aabb.maxCorner().z())
    00066   };
    00067
    00068   int left  = 0;
    00069   int right = 0;
    00070   real const NEPS = -0.0001f;
    00071   real const PEPS = +0.0001f;
    00072
    00073   for(int i=0;i<8; ++i)
    00074   {
    00075     if ( distance(corner[i]) < NEPS )
    00076       left++;
    00077     else
    00078     if ( distance(corner[i]) > PEPS )
    00079       right++;
    00080     // else -> we don't count the points on the plane
    00081
    00082     if(left && right) // its clearly intersecting the plane
    00083       return 0;
    00084   }
    00085
    00086   if (left)
    00087     return -1;
    00088   else
    00089   if (right)
    00090     return +1;
    00091   else // all the points were on the plane
    00092     return 0;
    00093 }
    00094 //-----------------------------------------------------------------------------

Visualization Library v2011.09.1162 Reference Documentation
Copyright 2005-2011 Michele Bosi. All rights reserved.
Updated on Thu Jan 26 2012 00:43:29.
Permission is granted to use this page to write and publish articles regarding Visualization Library.