BUG: ReadStlFile-Fix error logic when reading an ASCI STL File.

Add an experimental function to convert from ASCI file to a binary STL file. This could be used in the actual filter to add support for reading ASCII STL files. Signed-off-by: Michael Jackson <[email protected]>
BlueQuartzSoftware · Jan 31, 2024 · ce87e64 · ce87e64
1 parent 0ff43b9
commit ce87e64
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Showing 3 changed files with 133 additions and 35 deletions.
diff --git a/src/Plugins/SimplnxCore/src/SimplnxCore/Filters/ReadStlFileFilter.cpp b/src/Plugins/SimplnxCore/src/SimplnxCore/Filters/ReadStlFileFilter.cpp
@@ -112,37 +112,28 @@ IFilter::PreflightResult ReadStlFileFilter::preflightImpl(const DataStructure& d
 
   std::vector<PreflightValue> preflightUpdatedValues;
 
-  // If the filter needs to pass back some updated values via a key:value string:string set of values
-  // you can declare and update that string here.
-
-  // Collect all the errors
-  std::vector<Error> errors;
-
   // Validate that the STL File is binary and readable.
-  int32_t stlFileType = StlUtilities::DetermineStlFileType(pStlFilePathValue);
-  if(stlFileType < 0)
+  StlConstants::StlFileType stlFileType = StlUtilities::DetermineStlFileType(pStlFilePathValue);
+  if(stlFileType == StlConstants::StlFileType::ASCI)
+  {
+    return {MakeErrorResult<OutputActions>(
+        StlConstants::k_UnsupportedFileType,
+        fmt::format("The Input STL File is ASCII which is not currently supported. Please convert it to a binary STL file using another program.", pStlFilePathValue.string()))};
+  }
+  if(stlFileType == StlConstants::StlFileType::FileOpenError)
   {
-    Error result = {StlConstants::k_UnsupportedFileType,
-                    fmt::format("The Input STL File is ASCII which is not currently supported. Please convert it to a binary STL file using another program.", pStlFilePathValue.string())};
-    errors.push_back(result);
+    return {MakeErrorResult<OutputActions>(StlConstants::k_ErrorOpeningFile, fmt::format("Error opening the STL file.", pStlFilePathValue.string()))};
   }
-  if(stlFileType > 0)
+  if(stlFileType == StlConstants::StlFileType::HeaderParseError)
   {
-    Error result = {StlConstants::k_ErrorOpeningFile, fmt::format("Error reading the STL file.", pStlFilePathValue.string())};
-    errors.push_back(result);
+    return {MakeErrorResult<OutputActions>(StlConstants::k_ErrorOpeningFile, fmt::format("Error reading the header from STL file.", pStlFilePathValue.string()))};
   }
 
   // Now get the number of Triangles according to the STL Header
   int32_t numTriangles = StlUtilities::NumFacesFromHeader(pStlFilePathValue);
   if(numTriangles < 0)
   {
-    Error result = {StlConstants::k_ErrorOpeningFile, fmt::format("Error reading the STL file.", pStlFilePathValue.string())};
-    errors.push_back(result);
-  }
-
-  if(!errors.empty())
-  {
-    return {nonstd::make_unexpected(std::move(errors))};
+    return {MakeErrorResult<OutputActions>(numTriangles, fmt::format("Error extracting the number of triangles from the STL file.", pStlFilePathValue.string()))};
   }
 
   // This can happen in a LOT of STL files. Just means the writer didn't go back and update the header.

diff --git a/src/Plugins/SimplnxCore/src/SimplnxCore/utils/StlUtilities.cpp b/src/Plugins/SimplnxCore/src/SimplnxCore/utils/StlUtilities.cpp
@@ -1,14 +1,21 @@
 #include "StlUtilities.hpp"
 
+#include <filesystem>
+#include <fstream>
+#include <iostream>
+#include <sstream>
+#include <string>
+#include <vector>
+
 using namespace nx::core;
 
-int32_t StlUtilities::DetermineStlFileType(const fs::path& path)
+StlConstants::StlFileType StlUtilities::DetermineStlFileType(const fs::path& path)
 {
   // Open File
   FILE* f = std::fopen(path.string().c_str(), "rb");
   if(nullptr == f)
   {
-    return StlConstants::k_ErrorOpeningFile;
+    return StlConstants::StlFileType::FileOpenError;
   }
 
   // Read the first 256 bytes of data, that should be enough but I'm sure someone will write
@@ -17,29 +24,29 @@ int32_t StlUtilities::DetermineStlFileType(const fs::path& path)
   if(std::fread(header.data(), 1, StlConstants::k_STL_HEADER_LENGTH, f) != StlConstants::k_STL_HEADER_LENGTH)
   {
     std::ignore = std::fclose(f);
-    return StlConstants::k_StlHeaderParseError;
+    return StlConstants::StlFileType::HeaderParseError;
   }
   // close the file
   std::ignore = std::fclose(f);
 
-  size_t solid_pos = header.find("solid", 0);
+  size_t solidPos = header.find("solid", 0);
   // The word 'solid' was not found ANYWHERE in the first 80 bytes.
-  if(solid_pos == std::string::npos)
+  if(solidPos == std::string::npos)
   {
-    return 0;
+    return StlConstants::StlFileType::Binary;
   }
   // 'solid' was found as the first 5 bytes of the header. This is am ambiguous case so let's try to find 'facet'
-  if(solid_pos == 0)
+  if(solidPos == 0)
   {
-    size_t facet_pos = header.find("facet", solid_pos + 6);
-    if(facet_pos == std::string::npos)
+    size_t facetPos = header.find("facet", solidPos + 6);
+    if(facetPos == std::string::npos)
     {
       // 'facet' was NOT found so this is a binary file.
-      return 0;
+      return StlConstants::StlFileType::Binary;
     }
-    return 1;
+    return StlConstants::StlFileType::ASCI;
   }
-  return 0;
+  return StlConstants::StlFileType::Binary;
 }
 
 int32_t StlUtilities::NumFacesFromHeader(const fs::path& path)
@@ -71,3 +78,80 @@ int32_t StlUtilities::NumFacesFromHeader(const fs::path& path)
   std::ignore = std::fclose(f);
   return triCount;
 }
+
+struct Triangle
+{
+  float normal[3];
+  float vertex1[3];
+  float vertex2[3];
+  float vertex3[3];
+};
+
+void StlUtilities::ConvertAsciiToBinaryStl(const std::filesystem::path& inputPath, const std::filesystem::path& outputPath)
+{
+  std::ifstream asciiFile(inputPath);
+  std::ofstream binaryFile(outputPath, std::ios::binary);
+
+  if(!asciiFile.is_open() || !binaryFile.is_open())
+  {
+    throw std::runtime_error("Could not open files");
+  }
+
+  // Write the header
+  std::string header = "Converted by ChatGPT generated Algorithm";
+  header.resize(80, ' ');
+  binaryFile.write(header.c_str(), 80);
+
+  // Read ASCII STL and store triangles
+  std::vector<Triangle> triangles;
+  std::string line;
+  Triangle tri;
+
+  while(std::getline(asciiFile, line))
+  {
+    std::istringstream iss(line);
+    std::string token;
+    iss >> token;
+
+    if(token == "facet")
+    {
+      iss >> token; // Skip "normal" word
+      for(int i = 0; i < 3; ++i)
+      {
+        iss >> tri.normal[i];
+      }
+    }
+    else if(token == "vertex")
+    {
+      if(iss >> tri.vertex1[0] >> tri.vertex1[1] >> tri.vertex1[2])
+      {
+        std::getline(asciiFile, line); // Read next vertex line
+        std::istringstream iss2(line);
+        iss2 >> token; // Skip "vertex" word
+        iss2 >> tri.vertex2[0] >> tri.vertex2[1] >> tri.vertex2[2];
+
+        std::getline(asciiFile, line); // Read next vertex line
+        std::istringstream iss3(line);
+        iss3 >> token; // Skip "vertex" word
+        iss3 >> tri.vertex3[0] >> tri.vertex3[1] >> tri.vertex3[2];
+
+        triangles.push_back(tri);
+      }
+    }
+  }
+
+  // Write the number of triangles
+  uint32_t numTriangles = static_cast<uint32_t>(triangles.size());
+  binaryFile.write(reinterpret_cast<const char*>(&numTriangles), sizeof(numTriangles));
+
+  // Write triangles
+  for(const auto& t : triangles)
+  {
+    binaryFile.write(reinterpret_cast<const char*>(&t), sizeof(Triangle));
+    uint16_t attributeByteCount = 0;
+    binaryFile.write(reinterpret_cast<const char*>(&attributeByteCount), sizeof(attributeByteCount));
+  }
+}
+
+// Example usage:
+// convertAsciiToBinarySTL("input_ascii.stl", "output_binary.stl");
diff --git a/src/Plugins/SimplnxCore/src/SimplnxCore/utils/StlUtilities.hpp b/src/Plugins/SimplnxCore/src/SimplnxCore/utils/StlUtilities.hpp
@@ -19,13 +19,28 @@ inline constexpr int32_t k_StlHeaderParseError = -1104;
 inline constexpr int32_t k_TriangleCountParseError = -1105;
 inline constexpr int32_t k_TriangleParseError = -1106;
 inline constexpr int32_t k_AttributeParseError = -1107;
+
+enum class StlFileType : int
+{
+  Binary = 0,
+  ASCI = 1,
+  FileOpenError = 2,
+  HeaderParseError = 3
+};
 } // namespace StlConstants
 
 namespace StlUtilities
 {
 // -----------------------------------------------------------------------------
-// Returns 0 for Binary, 1 for ASCII, anything else is an error.
-int32_t DetermineStlFileType(const fs::path& path);
+/**
+ * @brief This function will determine if the given STL file is ASCII or BINARY.
+ *
+ * This could give a false positive for BINARY for _any_ file that doesn't have
+ * the first few lines of a valid ASCII STL file.
+ * @param path The path to the file to check
+ * @return Enumeration that represents either the type of file or a possible parsing error
+ */
+StlConstants::StlFileType DetermineStlFileType(const fs::path& path);
 
 /**
  * @brief Returns the number of triangles in the file according to the header. This
@@ -34,5 +49,13 @@ int32_t DetermineStlFileType(const fs::path& path);
  * @return Number of triangle faces
  */
 int32_t NumFacesFromHeader(const fs::path& path);
+
+/**
+ * @brief A very basic function to convert a well behaved ASCII STL File into a binary STL file
+ * @param inputPath The input ASCII STL File
+ * @param outputPath The output Binary STL file
+ */
+void ConvertAsciiToBinaryStl(const std::filesystem::path& inputPath, const std::filesystem::path& outputPath);
+
 } // namespace StlUtilities
 } // namespace nx::core