Add document on schema validation feature.

Now schema validation is getting to work.

LICENSE.rapidjson.txt

@@ -0,0 +1,13 @@
+// Tencent is pleased to support the open source community by making RapidJSON available.
+//
+// Copyright (C) 2015 THL A29 Limited, a Tencent company, and Milo Yip. All rights reserved.
+//
+// Licensed under the MIT License (the "License"); you may not use this file except
+// in compliance with the License. You may obtain a copy of the License at
+//
+// http://opensource.org/licenses/MIT
+//
+// Unless required by applicable law or agreed to in writing, software distributed
+// under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
+// CONDITIONS OF ANY KIND, either express or implied. See the License for the
+// specific language governing permissions and limitations under the License.

README.md

@@ -2,11 +2,11 @@
 
 `TinyGLTF` is a header only C++11 glTF 2.0 https://github.com/KhronosGroup/glTF library.
 
-`TinyGLTF` uses Niels Lohmann's json library(https://github.com/nlohmann/json), so now it requires C++11 compiler.
-If you are looking for old, C++03 version, please use `devel-picojson` branch.
+`TinyGLTF` uses single-header version of RapidJson(https://github.com/Tencent/rapidjson) as a JSON parser.
 
 ## Status
 
+ - v2.3.0 release(Support built-in schema validation)
  - v2.2.0 release(Support loading 16bit PNG. Sparse accessor support)
  - v2.1.0 release(Draco support)
  - v2.0.0 release(22 Aug, 2018)!
@@ -34,6 +34,7 @@ If you are looking for old, C++03 version, please use `devel-picojson` branch.
   * [x] ASCII glTF
   * [x] Binary glTF(GLB)
   * [x] PBR material description
+  * [x] Validate inpit glTF JSON with schema
 * Buffers
   * [x] Parse BASE64 encoded embedded buffer data(DataURI).
   * [x] Load `.bin` file.
@@ -68,6 +69,11 @@ If you are looking for old, C++03 version, please use `devel-picojson` branch.
 * [TinyGltfImporter](http://doc.magnum.graphics/magnum/classMagnum_1_1Trade_1_1TinyGltfImporter.html) plugin for [Magnum](https://github.com/mosra/magnum), a lightweight and modular C++11/C++14 graphics middleware for games and data visualization.
 * Your projects here! (Please send PR)
 
+## For developer
+
+Generate single rapidjson file using this node.js script: https://github.com/Tencent/rapidjson/issues/863
+Add `cursorstreamwrapper.h` and `error/en.h` inclusion in `rapidjson-all.h` before running merge script.
+
 ## TODOs
 
 * [ ] Write C++ code generator which emits C++ code from JSON schema for robust parsing.
@@ -95,7 +101,7 @@ TinyGLTF uses the following third party libraries.
 
 ## Build and example
 
-Copy `stb_image.h`, `stb_image_write.h`, `json.hpp` and `tiny_gltf.h` to your project.
+Copy `stb_image.h`, `stb_image_write.h`, `rapidjson-amalgamation.h` and `tiny_gltf.h` to your project.
 
 ### Loading glTF 2.0 model
 
@@ -104,6 +110,7 @@ Copy `stb_image.h`, `stb_image_write.h`, `json.hpp` and `tiny_gltf.h` to your pr
 #define TINYGLTF_IMPLEMENTATION
 #define STB_IMAGE_IMPLEMENTATION
 #define STB_IMAGE_WRITE_IMPLEMENTATION
+// #define TINYGLTF_ENABLE_SCHEMA_VALIDATOR // optional. enable schema validation API.
 // #define TINYGLTF_NOEXCEPTION // optional. disable exception handling.
 #include "tiny_gltf.h"
 
@@ -116,6 +123,10 @@ std::string warn;
 
 bool ret = loader.LoadASCIIFromFile(&model, &err, &warn, argv[1]);
 //bool ret = loader.LoadBinaryFromFile(&model, &err, &warn, argv[1]); // for binary glTF(.glb)
+// Validate with glTF Schema
+// #if defined(TINYGLTF_ENABLE_SCHEMA_VALIDATOR)
+// bool ret = loader.LoadASCIIFromFileWithValidation(&model, &err, &warn, argv[1]);
+// #endif
 
 if (!warn.empty()) {
   printf("Warn: %s\n", warn.c_str());
@@ -133,6 +144,7 @@ if (!ret) {
 
 ## Compile options
 
+* `TINYGLTF_ENABLE_SCHEMA_VALIDATOR` : Enable API with schema validation. glTF Schema JSON(`gltf.schema.resolved.inc`) are embeded into application binary, thus no need to read glTF Schema file at a runtime.
 * `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.

loader_example.cc

@@ -2,6 +2,7 @@
 // TODO(syoyo): Print extensions and extras for each glTF object.
 //
 #define TINYGLTF_IMPLEMENTATION
+#define TINYGLTF_ENABLE_SCHEMA_VALIDATOR
 #define STB_IMAGE_IMPLEMENTATION
 #define STB_IMAGE_WRITE_IMPLEMENTATION
 #include "tiny_gltf.h"
@@ -640,8 +641,13 @@ int main(int argc, char **argv) {
   } else {
     std::cout << "Reading ASCII glTF" << std::endl;
     // assume ascii glTF.
+#if defined(TINYGLTF_ENABLE_SCHEMA_VALIDATOR)
+    ret =
+        gltf_ctx.LoadASCIIFromFileWithValidation(&model, &err, &warn, input_filename.c_str());
+#else
     ret =
         gltf_ctx.LoadASCIIFromFile(&model, &err, &warn, input_filename.c_str());
+#endif
   }
 
   if (!warn.empty()) {

tools/schema_ref_resolver/README.md

@@ -0,0 +1,20 @@
+Create single schema string by deferencing $ref in glTF schema JSON for embedding JSON scheme string in C++.
+
+## Setup
+
+Use python2
+
+```
+$ pip2 install jsonpath-rw
+$ pip2 install simplejson
+```
+
+Put `ref_resolver.py` and `generate_single_schema_doc.py` to glTF schema direcotry(i.e. `$glTF/specification/2.0/schema`)
+
+## Generate
+
+Run `generate_single_schema_doc.py`
+
+## TODO
+
+* [ ] Print date and git commit id?

tools/schema_ref_resolver/generate_single_schema_doc.py

@@ -0,0 +1,37 @@
+# for print with `end` parameter
+from __future__ import print_function
+
+import json
+from ref_resolver import RefResolver
+import base64
+
+f = open("glTF.schema.json")
+j = json.loads(f.read())
+
+# call to API resolve method
+RefResolver("glTF.schema.json").resolve(j)
+
+j_str = json.dumps(j, indent=2)
+
+
+# Run json.dumps twice to get escaped string
+escaped_str = json.dumps(j_str)
+
+# MSVC does not accept string larger than 16K.
+# https://docs.microsoft.com/en-us/cpp/error-messages/compiler-errors-1/compiler-error-c2026?view=vs-2019
+# Also, it has a hard limit of 65,535 bytes even splitting a string with double quotation.
+# So, we write string as an array of string(then application must concatenate it)
+
+# https://stackoverflow.com/questions/9475241/split-string-every-nth-character
+n = 8000 # Conservative number
+
+splitted_string = [escaped_str[i:i+n] for i in range(0, len(escaped_str), n)]
+#print(len(splitted_string))
+
+print("const char *kglTFSchemaStrings[] = {", end='')
+for (i, s) in enumerate(splitted_string):
+    print(s, end='')
+    if i != (len(splitted_string) - 1):
+        print('",\n"', end='')
+
+print("};")

tools/schema_ref_resolver/ref_resolver.py

@@ -0,0 +1,82 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+from urlparse import urlparse, urljoin
+import simplejson as json
+from os.path import isfile
+import jsonpath_rw
+import requests
+
+
+cache = {}
+
+class RefResolver:
+
+    def __init__(self):
+        self.url_fragments = None
+
+    def __init__(self, id):
+        self.id = id
+        if id is not None:
+            self.url_fragments = urlparse(id)
+        else:
+            self.url_fragments = None
+
+
+
+    def resolve(self, json_obj):
+        if isinstance(json_obj, dict):
+            for key, value in json_obj.items():
+                if key == "$ref":
+                    ref_frag = urlparse(value)
+                    ref_file = ref_frag.netloc + ref_frag.path
+                    json_dump = {}
+                    if ref_file in cache:
+                        json_dump = cache[ref_file]
+                    else:
+                        if self.url_fragments.scheme in ['http', 'https']:
+                            ref_url = urljoin(self.id, ref_file)
+                            if callable(requests.Response.json):
+                                json_dump = requests.get(ref_url).json()
+                            else:
+                                json_dump = requests.get(ref_url).json
+                            ref_id = None
+                            if 'tilte' in json_dump:
+                                ref_id = json_dump['title']
+                            cache[ref_file] = json_dump
+                            RefResolver(ref_id).resolve(json_dump)
+                            cache[ref_file] = json_dump
+                        #elif self.url_fragments.scheme == 'file':
+                        else:
+                            if isfile(ref_file):
+                                # if the ref is another file -> go there and get it
+                                json_dump = json.load(open(ref_file))
+                                ref_id = None
+                                if 'title' in json_dump:
+                                    ref_id = json_dump['title']
+                                cache[ref_file] = json_dump
+                                RefResolver(ref_id).resolve(json_dump)
+                                cache[ref_file] = json_dump
+                            else:
+                                # if the ref is in the same file grab it from the same file
+                                json_dump = json.load(open(self.url_fragments.netloc+self.url_fragments.path))
+                                cache[ref_file] = json_dump
+
+                    ref_path_expr = "$" + ".".join(ref_frag.fragment.split("/"))
+                    path_expression = jsonpath_rw.parse(ref_path_expr)
+                    list_of_values = [match.value for match in path_expression.find(json_dump)]
+
+                    if len(list_of_values) > 0:
+                        resolution = list_of_values[0]
+                        return resolution
+
+                resolved = self.resolve(value)
+                if resolved is not None:
+                    json_obj[key] = resolved
+        elif isinstance(json_obj, list):
+            for (key, value) in enumerate(json_obj):
+                resolved = self.resolve(value)
+                if resolved is not None:
+                    json_obj[key] = resolved
+        return None