Implement iterator for SAJSON backend(W.I.P).

README.md

@@ -153,6 +153,7 @@ if (!ret) {
 
 ## Compile options
 
+* `TINYGLTF_ENABLE_SERIALIZER` : Enable glTF serialization feature.
 * `TINYGLTF_NOEXCEPTION` : Disable C++ exception in JSON parsing. You can use `-fno-exceptions` or by defining the symbol `JSON_NOEXCEPTION` and `TINYGLTF_NOEXCEPTION`  to fully remove C++ exception codes when compiling TinyGLTF.
 * `TINYGLTF_NO_STB_IMAGE` : Do not load images with stb_image. Instead use `TinyGLTF::SetImageLoader(LoadimageDataFunction LoadImageData, void *user_data)` to set a callback for loading images.
 * `TINYGLTF_NO_STB_IMAGE_WRITE` : Do not write images with stb_image_write. Instead use `TinyGLTF::SetImageWriter(WriteimageDataFunction WriteImageData, void *user_data)` to set a callback for writing images.

tiny_gltf.h

@@ -26,6 +26,8 @@
 // THE SOFTWARE.
 
 // Version:
+//  - v2.4.3 Experimental sajson(lightweight JSON parser) backend support.
+//           Introduce TINYGLTF_ENABLE_SERIALIZER.
 //  - v2.4.2 Decode percent-encoded URI.
 //  - v2.4.1 Fix some glTF object class does not have `extensions` and/or
 //  `extras` property.
@@ -43,6 +45,7 @@
 //
 // Tiny glTF loader is using following third party libraries:
 //
+//  - sajso: Lightweight C++ JSON library.
 //  - jsonhpp: C++ JSON library.
 //  - base64: base64 decode/encode library.
 //  - stb_image: Image loading library.
@@ -1249,7 +1252,13 @@ struct FsCallbacks {
 
 bool FileExists(const std::string &abs_filename, void *);
 
-std::string ExpandFilePath(const std::string &filepath, void *);
+///
+/// Expand file path(e.g. `~` to home directory on posix, `%APPDATA%` to `C:\Users\tinygltf\AppData`)
+///
+/// @param[in] filepath File path string. Assume UTF-8
+/// @param[in] userdata User data. Set to `nullptr` if you don't need it.
+///
+std::string ExpandFilePath(const std::string &filepath, void *userdata);
 
 bool ReadWholeFile(std::vector<unsigned char> *out, std::string *err,
                    const std::string &filepath, void *);
@@ -1317,6 +1326,8 @@ class TinyGLTF {
                             const std::string &base_dir = "",
                             unsigned int check_sections = REQUIRE_VERSION);
 
+#if defined(TINYGLTF_ENABLE_SERIALIZER)
+
   ///
   /// Write glTF to stream, buffers and images will be embeded
   ///
@@ -1330,16 +1341,22 @@ class TinyGLTF {
                             bool embedImages, bool embedBuffers,
                             bool prettyPrint, bool writeBinary);
 
+#endif
+
   ///
   /// Set callback to use for loading image data
   ///
   void SetImageLoader(LoadImageDataFunction LoadImageData, void *user_data);
 
+#if defined(TINYGLTF_ENABLE_SERIALIZER)
+
   ///
   /// Set callback to use for writing image data
   ///
   void SetImageWriter(WriteImageDataFunction WriteImageData, void *user_data);
 
+#endif
+
   ///
   /// Set callbacks to use for filesystem (fs) access and their user data
   ///
@@ -1501,14 +1518,38 @@ class TinyGLTF {
 #endif  // __GNUC__
 
 #ifndef TINYGLTF_NO_INCLUDE_JSON
-#ifndef TINYGLTF_USE_RAPIDJSON
-#include "json.hpp"
-#else
+#if defined(TINYGLTF_USE_RAPIDJSON)
 #include "document.h"
 #include "prettywriter.h"
 #include "rapidjson.h"
 #include "stringbuffer.h"
 #include "writer.h"
+#elif defined(TINYGLTF_USE_SAJSON)
+
+#ifdef __clang__
+
+#if __has_warning("-Wc99-extensions")
+#pragma clang diagnostic ignored "-Wc99-extensions"
+#endif
+
+#if __has_warning("-Wshadow-field-in-constructor")
+#pragma clang diagnostic ignored "-Wshadow-field-in-constructor"
+#endif
+
+#endif
+
+#include "sajson.h"
+
+// Serialization is not available for sajson backend.
+#ifdef TINYGLTF_ENABLE_SERIALIZER
+#undef TINYGLTF_ENABLE_SERIALIZER
+#endif
+
+#else
+
+// Default = nlohmann json
+#include "json.hpp"
+
 #endif
 #endif
 
@@ -1644,7 +1685,62 @@ struct JsonDocument : public rapidjson::Document {
 
 #endif  // TINYGLTF_USE_RAPIDJSON_CRTALLOCATOR
 
-#else
+#elif defined(TINYGLTF_USE_SAJSON)
+
+using json = sajson::value;
+using JsonDocument = json;
+
+// TODO(syoyo): Implement
+// muda
+
+class sajson_const_iterator
+{
+ public:
+  sajson_const_iterator() = default;
+  sajson_const_iterator(const sajson::value &v) : _v(v) {
+  }
+
+  sajson_const_iterator(const sajson_const_iterator &rhs) = default;
+  sajson_const_iterator &operator=(const sajson_const_iterator &rhs) = default;
+
+  std::string key() const {
+  }
+
+  sajson::value &value() {
+    return _v;
+  }
+
+  sajson::value *begin() {
+    return &_v;
+  }
+
+  bool operator!=(sajson_const_iterator &rhs) {
+    // TODO
+    assert(0);
+    return false;
+  }
+
+  sajson_const_iterator &operator++() {
+    // TODO
+    assert(0);
+    return (*this);
+  }
+
+  sajson::value &operator*() {
+    return _v;
+  }
+
+ private:
+  // `sajson::value` itself is a small struct, so having a copy of it
+  // does not affect performance and memory consumption.
+  sajson::value _v;
+
+};
+
+using json_const_iterator = sajson_const_iterator;
+using json_const_array_iterator = json_const_iterator;
+
+#else // nlohmann JSON
 using nlohmann::json;
 using json_const_iterator = json::const_iterator;
 using json_const_array_iterator = json_const_iterator;
@@ -1656,6 +1752,14 @@ void JsonParse(JsonDocument &doc, const char *str, size_t length,
 #ifdef TINYGLTF_USE_RAPIDJSON
   (void)throwExc;
   doc.Parse(str, length);
+#elif defined(TINYGLTF_USE_SAJSON)
+  // This code path is not available.
+  (void)doc;
+  (void)str;
+  (void)length;
+  (void)throwExc;
+  //doc = sajson::parse(sajson::dynamic_allocation(), sajson::mutable_string_view(length, const_cast<char *>(str)));
+  //doc.parse(sajson::dynamic_allocation(), sajson::mutable_string_view(length, const_cast<char *>(str)));
 #else
   doc = json::parse(str, str + length, nullptr, throwExc);
 #endif
@@ -2387,11 +2491,15 @@ bool LoadImageData(Image *image, const int image_idx, std::string *err,
 }
 #endif
 
+#if defined(TINYGLTF_ENABLE_SERIALIZER)
+
 void TinyGLTF::SetImageWriter(WriteImageDataFunction func, void *user_data) {
   WriteImageData = func;
   write_image_user_data_ = user_data;
 }
 
+#endif
+
 #ifndef TINYGLTF_NO_STB_IMAGE_WRITE
 static void WriteToMemory_stbi(void *context, void *data, int size) {
   std::vector<unsigned char> *buffer =
@@ -2882,6 +2990,15 @@ bool GetInt(const json &o, int &val) {
     }
   }
 
+  return false;
+#elif defined(TINYGLTF_USE_SAJSON)
+  auto type = o.get_type();
+
+  if (type == sajson::TYPE_INTEGER) {
+    val = static_cast<int>(o.get_number_value());
+    return true;
+  }
+
   return false;
 #else
   auto type = o.type();
@@ -2914,6 +3031,16 @@ bool GetNumber(const json &o, double &val) {
     return true;
   }
 
+  return false;
+#elif defined(TINYGLTF_USE_SAJSON)
+  auto type = o.get_type();
+
+  if ((type == sajson::TYPE_DOUBLE) ||
+      (type == sajson::TYPE_INTEGER)) {
+    val = static_cast<double>(o.get_number_value());
+    return true;
+  }
+
   return false;
 #else
   if (o.is_number()) {
@@ -2932,6 +3059,15 @@ bool GetString(const json &o, std::string &val) {
     return true;
   }
 
+  return false;
+#elif defined(TINYGLTF_USE_SAJSON)
+  auto type = o.get_type();
+
+  if (type == sajson::TYPE_STRING) {
+    val = o.as_string();
+    return true;
+  }
+
   return false;
 #else
   if (o.type() == json::value_t::string) {
@@ -2946,6 +3082,8 @@ bool GetString(const json &o, std::string &val) {
 bool IsArray(const json &o) {
 #ifdef TINYGLTF_USE_RAPIDJSON
   return o.IsArray();
+#elif defined(TINYGLTF_USE_SAJSON)
+  return o.get_type() == sajson::TYPE_ARRAY;
 #else
   return o.is_array();
 #endif
@@ -2954,6 +3092,10 @@ bool IsArray(const json &o) {
 json_const_array_iterator ArrayBegin(const json &o) {
 #ifdef TINYGLTF_USE_RAPIDJSON
   return o.Begin();
+#elif TINYGLTF_USE_SAJSON
+  // TODO(syoyo): Implement
+  assert(0);
+  return json_const_array_iterator(o);
 #else
   return o.begin();
 #endif
@@ -2962,6 +3104,10 @@ json_const_array_iterator ArrayBegin(const json &o) {
 json_const_array_iterator ArrayEnd(const json &o) {
 #ifdef TINYGLTF_USE_RAPIDJSON
   return o.End();
+#elif TINYGLTF_USE_SAJSON
+  // TODO(syoyo): Implement
+  assert(0);
+  return json_const_array_iterator(o);
 #else
   return o.end();
 #endif
@@ -2970,6 +3116,8 @@ json_const_array_iterator ArrayEnd(const json &o) {
 bool IsObject(const json &o) {
 #ifdef TINYGLTF_USE_RAPIDJSON
   return o.IsObject();
+#elif defined(TINYGLTF_USE_SAJSON)
+  return o.get_type() == sajson::TYPE_OBJECT;
 #else
   return o.is_object();
 #endif
@@ -2978,6 +3126,11 @@ bool IsObject(const json &o) {
 json_const_iterator ObjectBegin(const json &o) {
 #ifdef TINYGLTF_USE_RAPIDJSON
   return o.MemberBegin();
+#elif defined(TINYGLTF_USE_SAJSON)
+  assert(o.get_type() == sajson::TYPE_OBJECT);
+  // TODO(syoyo): Implement
+  assert(0);
+  return json_const_iterator(o);
 #else
   return o.begin();
 #endif
@@ -2986,6 +3139,11 @@ json_const_iterator ObjectBegin(const json &o) {
 json_const_iterator ObjectEnd(const json &o) {
 #ifdef TINYGLTF_USE_RAPIDJSON
   return o.MemberEnd();
+#elif defined(TINYGLTF_USE_SAJSON)
+  assert(o.get_type() == sajson::TYPE_OBJECT);
+  // TODO(syoyo): Implement
+  assert(0);
+  return json_const_iterator(o);
 #else
   return o.end();
 #endif
@@ -2994,6 +3152,10 @@ json_const_iterator ObjectEnd(const json &o) {
 const char *GetKey(json_const_iterator &it) {
 #ifdef TINYGLTF_USE_RAPIDJSON
   return it->name.GetString();
+#elif defined(TINYGLTF_USE_SAJSON)
+  // TODO(syoyo): Implement
+  assert(0);
+  return nullptr;
 #else
   return it.key().c_str();
 #endif
@@ -3006,6 +3168,10 @@ bool FindMember(const json &o, const char *member, json_const_iterator &it) {
   }
   it = o.FindMember(member);
   return it != o.MemberEnd();
+#elif defined(TINYGLTF_USE_SAJSON)
+  // TODO(syoyo): Implement
+  assert(0);
+  return false;
 #else
   it = o.find(member);
   return it != o.end();
@@ -3015,6 +3181,10 @@ bool FindMember(const json &o, const char *member, json_const_iterator &it) {
 const json &GetValue(json_const_iterator &it) {
 #ifdef TINYGLTF_USE_RAPIDJSON
   return it->value;
+#elif defined(TINYGLTF_USE_SAJSON)
+  // TODO(syoyo): Implement
+  assert(0);
+  return it.value();
 #else
   return it.value();
 #endif
@@ -3033,6 +3203,11 @@ std::string JsonToString(const json &o, int spacing = -1) {
     o.Accept(writer);
   }
   return buffer.GetString();
+#elif defined(TINYGLTF_USE_SAJSON)
+  // Serialize is not available for Sajson
+  (void)o;
+  (void)spacing;
+  return std::string();
 #else
   return o.dump(spacing);
 #endif
@@ -3088,7 +3263,10 @@ static bool ParseJsonAsValue(Value *ret, const json &o) {
       break;
       // all types are covered, so no `case default`
   }
-#else
+#elif defined(TINYGLTF_USE_SAJSON)
+  // TODO
+  assert(0);
+#else // json.hpp
   switch (o.type()) {
     case json::value_t::object: {
       Value::Object value_object;
@@ -3171,6 +3349,11 @@ static bool ParseBooleanProperty(bool *ret, std::string *err, const json &o,
   if (isBoolean) {
     boolValue = value.GetBool();
   }
+#elif defined(TINYGLTF_USE_SAJSON)
+  isBoolean = value.is_boolean();
+  if (isBoolean) {
+    boolValue = value.get_boolean_value();
+  }
 #else
   isBoolean = value.is_boolean();
   if (isBoolean) {
@@ -3260,6 +3443,11 @@ static bool ParseUnsignedProperty(size_t *ret, std::string *err, const json &o,
     uValue = value.GetUint64();
     isUValue = true;
   }
+#elif defined(TINYGLTF_USE_SAJSON)
+  isUValue = value.get_type() == sajson::TYPE_INTEGER;
+  if (isUValue) {
+    uValue = value.get_integer_value();
+  }
 #else
   isUValue = value.is_number_unsigned();
   if (isUValue) {
@@ -6038,10 +6226,13 @@ bool TinyGLTF::LoadFromString(Model *model, std::string *err, std::string *warn,
   // 19. Parse Extras
   ParseExtrasProperty(&model->extras, v);
 
+#if !defined(TINYGLTF_USE_SAJSON)
+  // TODO(syoyo): Support SAJSON backend
   if (store_original_json_for_extras_and_extensions_) {
     model->extras_json_string = JsonToString(v["extras"]);
     model->extensions_json_string = JsonToString(v["extensions"]);
   }
+#endif
 
   return true;
 }
@@ -6208,6 +6399,8 @@ bool TinyGLTF::LoadBinaryFromFile(Model *model, std::string *err,
   return ret;
 }
 
+#if defined(TINYGLTF_ENABLE_SERIALIZER)
+
 ///////////////////////
 // GLTF Serialization
 ///////////////////////
@@ -7613,6 +7806,8 @@ bool TinyGLTF::WriteGltfSceneToFile(Model *model, const std::string &filename,
   return true;
 }
 
+#endif // TINYGLTF_ENABLE_SERIALIZER
+
 }  // namespace tinygltf
 
 #ifdef __clang__