Merge pull request #535 from syoyo/copilot/optimize-json-parser

Add tinygltf_json.h: fast custom JSON parser with optional SIMD acceleration

.gitignore

@@ -70,6 +70,19 @@ tests/tester
 tests/tester_noexcept
 tests/issue-97.gltf
 tests/issue-261.gltf
+tests/issue-495-external.gltf
+# Test-generated output files (written by tester.cc during test run)
+tests/Cube.gltf
+tests/Cube.bin
+tests/Cube.glb
+tests/Cube_BaseColor.png
+tests/Cube_MetallicRoughness.png
+tests/Cube_with_embedded_images.gltf
+tests/Cube_with_image_files.gltf
+tests/tmp.glb
+tests/ issue-236.gltf
+tests/ issue-236.bin
+tests/ 2x2 image  has multiple      spaces.png
 
 # unignore
 !Makefile

CMakeLists.txt

@@ -18,6 +18,7 @@ option(TINYGLTF_BUILD_TESTS "Build unit tests" OFF)
 option(TINYGLTF_HEADER_ONLY "On: header-only mode. Off: create tinygltf library(No TINYGLTF_IMPLEMENTATION required in your project)" OFF)
 option(TINYGLTF_INSTALL "Install tinygltf files during install step. Usually set to OFF if you include tinygltf through add_subdirectory()" ON)
 option(TINYGLTF_INSTALL_VENDOR "Install vendored nlohmann/json and nothings/stb headers" ON)
+option(TINYGLTF_USE_CUSTOM_JSON "Use the built-in fast JSON parser (tinygltf_json.h) instead of nlohmann/json" OFF)
 
 if (TINYGLTF_BUILD_LOADER_EXAMPLE)
   add_executable(loader_example
@@ -46,6 +47,15 @@ if (TINYGLTF_BUILD_TESTS)
     ${CMAKE_CURRENT_SOURCE_DIR}/tests
   )
   add_test(NAME tester COMMAND tester WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/tests)
+
+  # Build and run tests with the custom JSON backend enabled to catch regressions
+  add_executable(tester_customjson tests/tester.cc)
+  target_include_directories(tester_customjson PRIVATE
+    ${CMAKE_CURRENT_SOURCE_DIR}
+    ${CMAKE_CURRENT_SOURCE_DIR}/tests
+  )
+  target_compile_definitions(tester_customjson PRIVATE TINYGLTF_USE_CUSTOM_JSON)
+  add_test(NAME tester_customjson COMMAND tester_customjson WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/tests)
 endif (TINYGLTF_BUILD_TESTS)
 
 #
@@ -71,6 +81,14 @@ else (TINYGLTF_HEADER_ONLY)
           )
 endif (TINYGLTF_HEADER_ONLY)
 
+if (TINYGLTF_USE_CUSTOM_JSON)
+  if (TINYGLTF_HEADER_ONLY)
+    target_compile_definitions(tinygltf INTERFACE TINYGLTF_USE_CUSTOM_JSON)
+  else ()
+    target_compile_definitions(tinygltf PUBLIC TINYGLTF_USE_CUSTOM_JSON)
+  endif ()
+endif ()
+
 if (TINYGLTF_INSTALL)
   install(TARGETS tinygltf EXPORT tinygltfTargets)
   install(EXPORT tinygltfTargets NAMESPACE tinygltf:: FILE TinyGLTFTargets.cmake DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake/tinygltf)
@@ -80,6 +98,7 @@ if (TINYGLTF_INSTALL)
 
   INSTALL ( FILES
     tiny_gltf.h
+    tinygltf_json.h
     ${TINYGLTF_EXTRA_SOUECES}
     DESTINATION
     include

tiny_gltf.h

@@ -1711,7 +1711,11 @@ class TinyGLTF {
 #endif  // __GNUC__
 
 #ifndef TINYGLTF_NO_INCLUDE_JSON
-#ifndef TINYGLTF_USE_RAPIDJSON
+#ifdef TINYGLTF_USE_CUSTOM_JSON
+#ifndef TINYGLTF_NO_INCLUDE_CUSTOM_JSON
+#include "tinygltf_json.h"
+#endif
+#elif !defined(TINYGLTF_USE_RAPIDJSON)
 #include "json.hpp"
 #else
 #ifndef TINYGLTF_NO_INCLUDE_RAPIDJSON
@@ -1799,7 +1803,10 @@ class TinyGLTF {
 
 namespace tinygltf {
 namespace detail {
-#ifdef TINYGLTF_USE_RAPIDJSON
+#ifdef TINYGLTF_USE_CUSTOM_JSON
+// Types and JsonParse are provided by tinygltf_json.h (already included above)
+// via 'namespace tinygltf { namespace detail { ... } }' declarations.
+#elif defined(TINYGLTF_USE_RAPIDJSON)
 
 #ifdef TINYGLTF_USE_RAPIDJSON_CRTALLOCATOR
 // This uses the RapidJSON CRTAllocator.  It is thread safe and multiple
@@ -1871,6 +1878,7 @@ using json_const_array_iterator = json_const_iterator;
 using JsonDocument = json;
 #endif
 
+#ifndef TINYGLTF_USE_CUSTOM_JSON
 void JsonParse(JsonDocument &doc, const char *str, size_t length,
                bool throwExc = false) {
 #ifdef TINYGLTF_USE_RAPIDJSON
@@ -1880,6 +1888,7 @@ void JsonParse(JsonDocument &doc, const char *str, size_t length,
   doc = detail::json::parse(str, str + length, nullptr, throwExc);
 #endif
 }
+#endif  // !TINYGLTF_USE_CUSTOM_JSON
 }  // namespace detail
 }  // namespace tinygltf
 
@@ -3436,6 +3445,7 @@ bool DecodeDataURI(std::vector<unsigned char> *out, std::string &mime_type,
   return true;
 }
 
+#ifndef TINYGLTF_USE_CUSTOM_JSON
 namespace detail {
 bool GetInt(const detail::json &o, int &val) {
 #ifdef TINYGLTF_USE_RAPIDJSON
@@ -3659,6 +3669,7 @@ std::string JsonToString(const detail::json &o, int spacing = -1) {
 }
 
 }  // namespace detail
+#endif  // !TINYGLTF_USE_CUSTOM_JSON
 
 static bool ParseJsonAsValue(Value *ret, const detail::json &o) {
   Value val{};
@@ -6962,6 +6973,7 @@ bool TinyGLTF::LoadBinaryFromFile(Model *model, std::string *err,
 ///////////////////////
 // GLTF Serialization
 ///////////////////////
+#ifndef TINYGLTF_USE_CUSTOM_JSON
 namespace detail {
 detail::json JsonFromString(const char *s) {
 #ifdef TINYGLTF_USE_RAPIDJSON
@@ -7034,6 +7046,7 @@ void JsonReserveArray(detail::json &o, size_t s) {
   (void)(s);
 }
 }  // namespace detail
+#endif  // !TINYGLTF_USE_CUSTOM_JSON
 
 // typedef std::pair<std::string, detail::json> json_object_pair;