src/BufferReadBinary.cc

   1 /*
   2         Buffer for reading binary STL file
   3 */
   4 #include "BufferReadBinary.hh"
   5
   6 BufferReadBinary::BufferReadBinary(std::string& fileTarget)
   7     : remain(0), readIn(0), numTrianglesInBlock(0)
   8 {
   9     prebuffer          = new char[PREBUFFER_SIZE + BUFFER_SIZE];
  10     buffer             = prebuffer + PREBUFFER_SIZE;
  11     fn                 = open(fileTarget.c_str(), O_RDONLY);
  12     readIn             = read(fn, buffer, BUFFER_SIZE);
  13     phead              = buffer + 80;
  14     numTrianglesInFile = *(uint32_t*)phead;
  15     phead += sizeof(uint32_t);
  16     readIn -= 84;
  17     numTrianglesInBlock = readIn / 50;
  18     remain              = readIn % 50;
  19 }
  20 BufferReadBinary::~BufferReadBinary()
  21 {
  22     delete[] prebuffer;
  23     close(fn);
  24 }
  25 uint32_t BufferReadBinary::getNumTrianglesInFile()
  26 {
  27     return numTrianglesInFile;
  28 }
  29 uint32_t BufferReadBinary::getNumTrianglesInBlock()
  30 {
  31     return numTrianglesInBlock;
  32 }
  33 void BufferReadBinary::step2Bytes() { phead += 2; }
  34 void BufferReadBinary::stepFloat() { phead += sizeof(float); }
  35 float BufferReadBinary::getFloat() { return *(float*)phead; }
  36 void BufferReadBinary::readBuffer()
  37 {
  38     char* pd = buffer - remain;
  39     char* pf = buffer + BUFFER_SIZE - remain;
  40     for (int i = remain; i > 0; i--, pd++, pf++) *pd = *pf;
  41     readIn              = read(fn, buffer, BUFFER_SIZE);
  42     phead               = buffer - remain;
  43     numTrianglesInBlock = (readIn + remain) / 50;
  44     remain              = (readIn + remain) % 50;
  45 }