stlinit.cpp File Reference

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <assert.h>
#include <boost/log/trivial.hpp>
#include <boost/nowide/cstdio.hpp>
#include <boost/predef/other/endian.h>
#include "stl.h"
#include "libslic3r/LocalesUtils.hpp"

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Functions
static FILE *	stl_open_count_facets (stl_file *stl, const char *file)
static bool	stl_read (stl_file *stl, FILE *fp, int first_facet, bool first)
bool	stl_open (stl_file *stl, const char *file)
void	stl_allocate (stl_file *stl)
void	stl_reallocate (stl_file *stl)
void	stl_facet_stats (stl_file *stl, stl_facet facet, bool &first)

Function Documentation

stl_allocate()

void stl_allocate

(

stl_file *

stl

)

{
    //  Allocate memory for the entire .STL file.
    stl->facet_start.assign(stl->stats.number_of_facets, stl_facet());
    // Allocate memory for the neighbors list.
    stl->neighbors_start.assign(stl->stats.number_of_facets, stl_neighbors());
}

References stl_file::facet_start, stl_file::neighbors_start, stl_stats::number_of_facets, and stl_file::stats.

Referenced by stl_open().

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stl_facet_stats()

void stl_facet_stats	(	stl_file *	stl,
		stl_facet	facet,
		bool &	first
	)

{
  // While we are going through all of the facets, let's find the
  // maximum and minimum values for x, y, and z
 
  if (first) {
    // Initialize the max and min values the first time through
    stl->stats.min = facet.vertex[0];
    stl->stats.max = facet.vertex[0];
    stl_vertex diff = (facet.vertex[1] - facet.vertex[0]).cwiseAbs();
    stl->stats.shortest_edge = std::max(diff(0), std::max(diff(1), diff(2)));
    first = false;
  }
 
  // Now find the max and min values.
  for (size_t i = 0; i < 3; ++ i) {
    stl->stats.min = stl->stats.min.cwiseMin(facet.vertex[i]);
    stl->stats.max = stl->stats.max.cwiseMax(facet.vertex[i]);
  }
}

References cwiseAbs(), stl_stats::max, stl_stats::min, stl_stats::shortest_edge, stl_file::stats, and stl_facet::vertex.

Referenced by stl_read().

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stl_open()

bool stl_open	(	stl_file *	stl,
		const char *	file
	)

{
    Slic3r::CNumericLocalesSetter locales_setter;
  stl->clear();
  FILE *fp = stl_open_count_facets(stl, file);
  if (fp == nullptr)
    return false;
  stl_allocate(stl);
  bool result = stl_read(stl, fp, 0, true);
    fclose(fp);
    return result;
}

References stl_file::clear(), stl_allocate(), stl_open_count_facets(), and stl_read().

Referenced by Slic3r::TriangleMesh::ReadSTLFile().

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stl_open_count_facets()

static FILE * stl_open_count_facets ( stl_file *  stl, const char *  file  )

static

{
    // Open the file in binary mode first.
    FILE *fp = boost::nowide::fopen(file, "rb");
    if (fp == nullptr) {
    BOOST_LOG_TRIVIAL(error) << "stl_open_count_facets: Couldn't open " << file << " for reading";
      return nullptr;
    }
    // Find size of file.
    fseek(fp, 0, SEEK_END);
    long file_size = ftell(fp);
 
    // Check for binary or ASCII file.
    fseek(fp, HEADER_SIZE, SEEK_SET);
  unsigned char chtest[128];
    if (! fread(chtest, sizeof(chtest), 1, fp)) {
    BOOST_LOG_TRIVIAL(error) << "stl_open_count_facets: The input is an empty file: " << file;
      fclose(fp);
      return nullptr;
    }
    stl->stats.type = ascii;
    for (size_t s = 0; s < sizeof(chtest); s++) {
      if (chtest[s] > 127) {
          stl->stats.type = binary;
          break;
      }
    }
    rewind(fp);
 
    uint32_t num_facets = 0;
 
    // Get the header and the number of facets in the .STL file.
    // If the .STL file is binary, then do the following:
    if (stl->stats.type == binary) {
      // Test if the STL file has the right size.
      if (((file_size - HEADER_SIZE) % SIZEOF_STL_FACET != 0) || (file_size < STL_MIN_FILE_SIZE)) {
      BOOST_LOG_TRIVIAL(error) << "stl_open_count_facets: The file " << file << " has the wrong size.";
          fclose(fp);
          return nullptr;
      }
      num_facets = (file_size - HEADER_SIZE) / SIZEOF_STL_FACET;
 
      // Read the header.
      if (fread(stl->stats.header, LABEL_SIZE, 1, fp) > 79)
          stl->stats.header[80] = '\0';
 
      // Read the int following the header.  This should contain # of facets.
      uint32_t header_num_facets;
      bool header_num_faces_read = fread(&header_num_facets, sizeof(uint32_t), 1, fp) != 0;
#if BOOST_ENDIAN_BIG_BYTE
      // Convert from little endian to big endian.
      stl_internal_reverse_quads((char*)&header_num_facets, 4);
#endif /* BOOST_ENDIAN_BIG_BYTE */
      if (! header_num_faces_read || num_facets != header_num_facets)
      BOOST_LOG_TRIVIAL(info) << "stl_open_count_facets: Warning: File size doesn't match number of facets in the header: " << file;
    }
    // Otherwise, if the .STL file is ASCII, then do the following:
    else
    {
      // Reopen the file in text mode (for getting correct newlines on Windows)
      // fix to silence a warning about unused return value.
      // obviously if it fails we have problems....
      fp = boost::nowide::freopen(file, "r", fp);
 
    // do another null check to be safe
      if (fp == nullptr) {
      BOOST_LOG_TRIVIAL(error) << "stl_open_count_facets: Couldn't open " << file << " for reading";
          fclose(fp);
          return nullptr;
      }
    
      // Find the number of facets.
    char linebuf[100];
    int num_lines = 1;
    while (fgets(linebuf, 100, fp) != nullptr) {
        // Don't count short lines.
        if (strlen(linebuf) <= 4)
          continue;
        // Skip solid/endsolid lines as broken STL file generators may put several of them.
        if (strncmp(linebuf, "solid", 5) == 0 || strncmp(linebuf, "endsolid", 8) == 0)
          continue;
        ++ num_lines;
    }
 
      rewind(fp);
    
      // Get the header.
    int i = 0;
      for (; i < 80 && (stl->stats.header[i] = getc(fp)) != '\n'; ++ i) ;
      stl->stats.header[i] = '\0'; // Lose the '\n'
      stl->stats.header[80] = '\0';
 
      num_facets = num_lines / ASCII_LINES_PER_FACET;
    }
 
    stl->stats.number_of_facets += num_facets;
    stl->stats.original_num_facets = stl->stats.number_of_facets;
    return fp;
}

References ascii, ASCII_LINES_PER_FACET, binary, error, stl_stats::header, HEADER_SIZE, LABEL_SIZE, stl_stats::number_of_facets, stl_stats::original_num_facets, SEEK_SET, SIZEOF_STL_FACET, stl_file::stats, STL_MIN_FILE_SIZE, and stl_stats::type.

Referenced by stl_open().

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stl_read()

static bool stl_read ( stl_file *  stl, FILE *  fp, int  first_facet, bool  first  )

static

{
  if (stl->stats.type == binary)
      fseek(fp, HEADER_SIZE, SEEK_SET);
    else
      rewind(fp);
 
    char normal_buf[3][32];
    for (uint32_t i = first_facet; i < stl->stats.number_of_facets; ++ i) {
        stl_facet facet;
 
      if (stl->stats.type == binary) {
          // Read a single facet from a binary .STL file. We assume little-endian architecture!
          if (fread(&facet, 1, SIZEOF_STL_FACET, fp) != SIZEOF_STL_FACET)
            return false;
#if BOOST_ENDIAN_BIG_BYTE
          // Convert the loaded little endian data to big endian.
          stl_internal_reverse_quads((char*)&facet, 48);
#endif /* BOOST_ENDIAN_BIG_BYTE */
      } else {
      // Read a single facet from an ASCII .STL file
      // skip solid/endsolid
      // (in this order, otherwise it won't work when they are paired in the middle of a file)
      fscanf(fp, " endsolid%*[^\n]\n");
      fscanf(fp, " solid%*[^\n]\n");  // name might contain spaces so %*s doesn't work and it also can be empty (just "solid")
      // Leading space in the fscanf format skips all leading white spaces including numerous new lines and tabs.
      int res_normal     = fscanf(fp, " facet normal %31s %31s %31s", normal_buf[0], normal_buf[1], normal_buf[2]);
      assert(res_normal == 3);
      int res_outer_loop = fscanf(fp, " outer loop");
      assert(res_outer_loop == 0);
      int res_vertex1    = fscanf(fp, " vertex %f %f %f", &facet.vertex[0](0), &facet.vertex[0](1), &facet.vertex[0](2));
      assert(res_vertex1 == 3);
      int res_vertex2    = fscanf(fp, " vertex %f %f %f", &facet.vertex[1](0), &facet.vertex[1](1), &facet.vertex[1](2));
      assert(res_vertex2 == 3);
      // Trailing whitespace is there to eat all whitespaces and empty lines up to the next non-whitespace.
      int res_vertex3    = fscanf(fp, " vertex %f %f %f ", &facet.vertex[2](0), &facet.vertex[2](1), &facet.vertex[2](2));
      assert(res_vertex3 == 3);
      // Some G-code generators tend to produce text after "endloop" and "endfacet". Just ignore it.
      char buf[2048];
      fgets(buf, 2047, fp);
      bool endloop_ok = strncmp(buf, "endloop", 7) == 0 && (buf[7] == '\r' || buf[7] == '\n' || buf[7] == ' ' || buf[7] == '\t');
      assert(endloop_ok);
      // Skip the trailing whitespaces and empty lines.
      fscanf(fp, " ");
      fgets(buf, 2047, fp);
      bool endfacet_ok = strncmp(buf, "endfacet", 8) == 0 && (buf[8] == '\r' || buf[8] == '\n' || buf[8] == ' ' || buf[8] == '\t');
      assert(endfacet_ok);
      if (res_normal != 3 || res_outer_loop != 0 || res_vertex1 != 3 || res_vertex2 != 3 || res_vertex3 != 3 || ! endloop_ok || ! endfacet_ok) {
        BOOST_LOG_TRIVIAL(error) << "Something is syntactically very wrong with this ASCII STL! ";
        return false;
      }
 
      // The facet normal has been parsed as a single string as to workaround for not a numbers in the normal definition.
      if (sscanf(normal_buf[0], "%f", &facet.normal(0)) != 1 ||
          sscanf(normal_buf[1], "%f", &facet.normal(1)) != 1 ||
          sscanf(normal_buf[2], "%f", &facet.normal(2)) != 1) {
          // Normal was mangled. Maybe denormals or "not a number" were stored?
          // Just reset the normal and silently ignore it.
          memset(&facet.normal, 0, sizeof(facet.normal));
      }
    }
 
#if 0
    // Report close to zero vertex coordinates. Due to the nature of the floating point numbers,
    // close to zero values may be represented with singificantly higher precision than the rest of the vertices.
    // It may be worth to round these numbers to zero during loading to reduce the number of errors reported
    // during the STL import.
    for (size_t j = 0; j < 3; ++ j) {
    if (facet.vertex[j](0) > -1e-12f && facet.vertex[j](0) < 1e-12f)
        printf("stl_read: facet %d(0) = %e\r\n", j, facet.vertex[j](0));
    if (facet.vertex[j](1) > -1e-12f && facet.vertex[j](1) < 1e-12f)
        printf("stl_read: facet %d(1) = %e\r\n", j, facet.vertex[j](1));
    if (facet.vertex[j](2) > -1e-12f && facet.vertex[j](2) < 1e-12f)
        printf("stl_read: facet %d(2) = %e\r\n", j, facet.vertex[j](2));
    }
#endif
 
    // Write the facet into memory.
    stl->facet_start[i] = facet;
    stl_facet_stats(stl, facet, first);
    }
  
    stl->stats.size = stl->stats.max - stl->stats.min;
    stl->stats.bounding_diameter = stl->stats.size.norm();
    return true;
}

References binary, stl_stats::bounding_diameter, error, stl_file::facet_start, HEADER_SIZE, stl_stats::max, stl_stats::min, stl_facet::normal, stl_stats::number_of_facets, SEEK_SET, stl_stats::size, SIZEOF_STL_FACET, stl_file::stats, stl_facet_stats(), stl_stats::type, and stl_facet::vertex.

Referenced by stl_open().

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stl_reallocate()

void stl_reallocate

(

stl_file *

stl

)

{
  stl->facet_start.resize(stl->stats.number_of_facets);
  stl->neighbors_start.resize(stl->stats.number_of_facets);
}

References stl_file::facet_start, stl_file::neighbors_start, stl_stats::number_of_facets, and stl_file::stats.