vlookup.h
Go to the documentation of this file.00001 #ifndef VLOOKUP_H 00002 00003 #define VLOOKUP_H 00004 00060 // CodeSnippet provided by John W. Ratcliff 00061 // on March 23, 2006. 00062 // 00063 // mailto: jratcliff@infiniplex.net 00064 // 00065 // Personal website: http://jratcliffscarab.blogspot.com 00066 // Coding Website: http://codesuppository.blogspot.com 00067 // FundRaising Blog: http://amillionpixels.blogspot.com 00068 // Fundraising site: http://www.amillionpixels.us 00069 // New Temple Site: http://newtemple.blogspot.com 00070 // 00071 // This snippet shows how to 'hide' the complexity of 00072 // the STL by wrapping some useful piece of functionality 00073 // around a handful of discrete API calls. 00074 // 00075 // This API allows you to create an indexed triangle list 00076 // from a collection of raw input triangles. Internally 00077 // it uses an STL set to build the lookup table very rapidly. 00078 // 00079 // Here is how you would use it to build an indexed triangle 00080 // list from a raw list of triangles. 00081 // 00082 // (1) create a 'VertexLookup' interface by calling 00083 // 00084 // VertexLook vl = Vl_createVertexLookup(); 00085 // 00086 // (2) For each vertice in each triangle call: 00087 // 00088 // unsigned int i1 = Vl_getIndex(vl,p1); 00089 // unsigned int i2 = Vl_getIndex(vl,p2); 00090 // unsigned int i3 = Vl_getIndex(vl,p3); 00091 // 00092 // save the 3 indices into your triangle list array. 00093 // 00094 // (3) Get the vertex array by calling: 00095 // 00096 // const double *vertices = Vl_getVertices(vl); 00097 // 00098 // (4) Get the number of vertices so you can copy them into 00099 // your own buffer. 00100 // unsigned int vcount = Vl_getVcount(vl); 00101 // 00102 // (5) Release the VertexLookup interface when you are done with it. 00103 // Vl_releaseVertexLookup(vl); 00104 // 00105 // Teaches the following lessons: 00106 // 00107 // How to wrap the complexity of STL and C++ classes around a 00108 // simple API interface. 00109 // 00110 // How to use an STL set and custom comparator operator for 00111 // a complex data type. 00112 // 00113 // How to create a template class. 00114 // 00115 // How to achieve significant performance improvements by 00116 // taking advantage of built in STL containers in just 00117 // a few lines of code. 00118 // 00119 // You could easily modify this code to support other vertex 00120 // formats with any number of interpolants. 00121 // 00122 // Hide C++ classes from the rest of your application by 00123 // keeping them in the CPP and wrapping them in a namespace 00124 // Uses an STL set to create an index table for a bunch of vertex positions 00125 // used typically to re-index a collection of raw triangle data. 00126 00127 namespace ConvexDecomposition 00128 { 00129 00130 typedef void * VertexLookup; 00131 00132 VertexLookup Vl_createVertexLookup(void); 00133 void Vl_releaseVertexLookup(VertexLookup vlook); 00134 00135 unsigned int Vl_getIndex(VertexLookup vlook,const double *pos); // get index. 00136 const double * Vl_getVertices(VertexLookup vlook); 00137 00138 unsigned int Vl_getVcount(VertexLookup vlook); 00139 00140 }; 00141 00142 00143 #endif