From 9d041d8497e5f6fc64d977480d65358bd2af5065 Mon Sep 17 00:00:00 2001
From: wmayer <wmayer@users.sourceforge.net>
Date: Fri, 26 Aug 2022 12:39:04 +0200
Subject: [PATCH] Base: implement loading of OpenInventor files (currently only
 SoIndexedFaceSet is supported)

---
 src/Base/Builder3D.cpp | 167 +++++++++++++++++++++++++++++++++++++++++
 src/Base/Builder3D.h   |  54 +++++++++++++
 src/Base/PreCompiled.h |   3 +
 3 files changed, 224 insertions(+)

diff --git a/src/Base/Builder3D.cpp b/src/Base/Builder3D.cpp
index 63fff62420..8d219ad42f 100644
--- a/src/Base/Builder3D.cpp
+++ b/src/Base/Builder3D.cpp
@@ -24,9 +24,13 @@
 #include "PreCompiled.h"
 
 #ifndef _PreComp_
+# include <algorithm>
 # include <cassert>
 # include <string>
 # include <fstream>
+# include <boost/algorithm/string.hpp>
+# include <boost/lexical_cast.hpp>
+# include <boost/tokenizer.hpp>
 #endif
 
 #include "Builder3D.h"
@@ -920,3 +924,166 @@ void InventorBuilder::addTransformation(const Vector3f& translation, const Vecto
          << " " << fAngle << std::endl;
     result << Base::blanks(indent) <<  "}" << std::endl;
 }
+
+// -----------------------------------------------------------------------------
+
+template<typename T>
+std::vector<T> InventorLoader::readData(const char* fieldName) const
+{
+    std::vector<T> fieldValues;
+    std::string str;
+
+    // search for 'fieldName' and '['
+    bool found = false;
+    while (std::getline(inp, str)) {
+        std::string::size_type point = str.find(fieldName);
+        std::string::size_type open = str.find("[");
+        if (point != std::string::npos && open > point) {
+            str = str.substr(open);
+            found = true;
+            break;
+        }
+    }
+
+    if (!found)
+        return {};
+
+    do {
+        boost::char_separator<char> sep(" ,");
+        boost::tokenizer<boost::char_separator<char> > tokens(str, sep);
+        std::vector<std::string> token_results;
+        token_results.assign(tokens.begin(),tokens.end());
+
+        for (const auto& it : token_results) {
+            try {
+                T value = boost::lexical_cast<T>(it);
+                fieldValues.emplace_back(value);
+            }
+            catch (const boost::bad_lexical_cast&) {
+            }
+        }
+
+        // search for ']' to finish the reading
+        if (str.find("]") != std::string::npos)
+            break;
+    }
+    while (std::getline(inp, str));
+
+    return fieldValues;
+}
+
+std::vector<Vector3f> InventorLoader::convert(const std::vector<float>& data) const
+{
+    if (data.size() % 3 != 0)
+        throw std::string("Reading failed");
+
+    std::size_t len = data.size() / 3;
+    std::vector<Vector3f> points;
+    points.reserve(len);
+
+    for (std::size_t i = 0; i < len; i++) {
+        float x = data[3 * i];
+        float y = data[3 * i + 1];
+        float z = data[3 * i + 2];
+        points.emplace_back(x, y, z);
+    }
+
+    return points;
+}
+
+std::vector<std::vector<int32_t>> InventorLoader::split(const std::vector<int32_t>& data)
+{
+    std::vector<std::vector<int32_t>> splitdata;
+    std::vector<int32_t>::const_iterator begin = data.cbegin();
+    std::vector<int32_t>::const_iterator it = begin;
+
+    while ((it = std::find(begin, data.cend(), -1)) != data.cend()) {
+        splitdata.emplace_back(begin, it);
+        begin = it;
+        std::advance(begin, 1);
+    }
+    return splitdata;
+}
+
+std::vector<InventorLoader::Face> InventorLoader::convert(const std::vector<int32_t>& data) const
+{
+    std::vector<std::vector<int32_t>> coordIndex = split(data);
+    std::vector<Face> faces;
+    faces.reserve(coordIndex.size());
+    for (const auto it : coordIndex) {
+        if (it.size() == 3) {
+            faces.emplace_back(it[0], it[1], it[2]);
+        }
+        else if (it.size() == 4) {
+            faces.emplace_back(it[0], it[1], it[2]);
+            faces.emplace_back(it[0], it[2], it[3]);
+        }
+    }
+    return faces;
+}
+
+void InventorLoader::readNormals()
+{
+    auto data = readData<float>("vector");
+    vector = convert(data);
+}
+
+void InventorLoader::readCoords()
+{
+    auto data = readData<float>("point");
+    points = convert(data);
+}
+
+void InventorLoader::readFaceSet()
+{
+    auto data = readData<int32_t>("coordIndex");
+    faces = convert(data);
+}
+
+bool InventorLoader::read()
+{
+    if (!inp || inp.bad())
+        return false;
+
+    std::string line;
+
+    // Verify it's an Inventor 2.1 file
+    std::getline(inp, line);
+    if (line.find("#Inventor V2.1 ascii") == std::string::npos)
+        return false;
+
+    while (std::getline(inp, line)) {
+        // read the normals if they are defined
+        if (line.find("Normal {") != std::string::npos) {
+            readNormals();
+        }
+        else if (line.find("Coordinate3 {") != std::string::npos) {
+            readCoords();
+        }
+        else if (line.find("IndexedFaceSet {") != std::string::npos) {
+            readFaceSet();
+            break;
+        }
+    }
+    return true;
+}
+
+bool InventorLoader::isValid() const
+{
+    int32_t value{static_cast<int32_t>(points.size())};
+    auto inRange = [value](const Face& f) {
+        if (f.p1 < 0 || f.p1 >= value)
+            return false;
+        if (f.p2 < 0 || f.p2 >= value)
+            return false;
+        if (f.p3 < 0 || f.p3 >= value)
+            return false;
+        return true;
+    };
+    for (auto it : faces) {
+        if (!inRange(it))
+            return false;
+    }
+
+    return true;
+}
diff --git a/src/Base/Builder3D.h b/src/Base/Builder3D.h
index 59161ecc00..c94b70dcf5 100644
--- a/src/Base/Builder3D.h
+++ b/src/Base/Builder3D.h
@@ -340,6 +340,60 @@ private:
     int indent;
 };
 
+/**
+ * Loads an OpenInventor file.
+ * @author Werner Mayer
+ */
+class BaseExport InventorLoader {
+public:
+    struct Face {
+        Face(int32_t p1, int32_t p2, int32_t p3)
+            : p1(p1), p2(p2), p3(p3) {}
+        int32_t p1, p2, p3;
+    };
+
+    explicit InventorLoader(std::istream &inp) : inp(inp) {
+    }
+
+    /// Start the read process. Returns true if successful and false otherwise.
+    /// The obtained data can be accessed with the appropriate getter functions.
+    bool read();
+
+    /// Checks if the loaded data are valid
+    bool isValid() const;
+
+    /// Return the vectors of an SoNormal node
+    const std::vector<Vector3f>& getVector() {
+        return vector;
+    }
+
+    /// Return the points of an SoCoordinate3 node
+    const std::vector<Vector3f>& getPoints() {
+        return points;
+    }
+
+    /// Return the faces of an SoIndexedFaceSet node
+    const std::vector<Face>& getFaces() {
+        return faces;
+    }
+
+private:
+    void readNormals();
+    void readCoords();
+    void readFaceSet();
+    template<typename T>
+    std::vector<T> readData(const char*) const;
+    std::vector<Vector3f> convert(const std::vector<float>&) const;
+    std::vector<Face> convert(const std::vector<int32_t>&) const;
+    static std::vector<std::vector<int32_t>> split(const std::vector<int32_t>&);
+
+private:
+    std::vector<Vector3f> vector;
+    std::vector<Vector3f> points;
+    std::vector<Face> faces;
+    std::istream &inp;
+};
+
 } //namespace Base
 
 #endif // BASE_BUILDER3D_H
diff --git a/src/Base/PreCompiled.h b/src/Base/PreCompiled.h
index 79566cc4d0..1e4bc9ef17 100644
--- a/src/Base/PreCompiled.h
+++ b/src/Base/PreCompiled.h
@@ -114,7 +114,10 @@
 #include <boost/filesystem/path.hpp>
 #include <boost/filesystem/operations.hpp>
 #include <boost/filesystem/exception.hpp>
+#include <boost/algorithm/string.hpp>
+#include <boost/lexical_cast.hpp>
 #include <boost/regex.hpp>
+#include <boost/tokenizer.hpp>
 
 // QtCore
 #include <QBuffer>