Convert .tgs with go libraries (and cgo) (telegram) (#1569)

This commit adds support for go/cgo tgs conversion when building with the -tags `cgo`
The default binaries are still "pure" go and uses the old way of converting.

* Move lottie_convert.py conversion code to its own file

* Add optional libtgsconverter

* Update vendor

* Apply suggestions from code review

* Update bridge/helper/libtgsconverter.go

Co-authored-by: Wim <wim@42.be>

1 files changed, 71 insertions, 0 deletions

diff --git a/vendor/github.com/Benau/go_rlottie/lottie_rapidjson_memorystream.h b/vendor/github.com/Benau/go_rlottie/lottie_rapidjson_memorystream.h
new file mode 100644
index 00000000..933319e8
--- /dev/null
+++ b/vendor/github.com/Benau/go_rlottie/lottie_rapidjson_memorystream.h
@@ -0,0 +1,71 @@
+// 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.
+
+#ifndef RAPIDJSON_MEMORYSTREAM_H_
+#define RAPIDJSON_MEMORYSTREAM_H_
+
+#include "lottie_rapidjson_stream.h"
+
+#ifdef __clang__
+RAPIDJSON_DIAG_PUSH
+RAPIDJSON_DIAG_OFF(unreachable-code)
+RAPIDJSON_DIAG_OFF(missing-noreturn)
+#endif
+
+RAPIDJSON_NAMESPACE_BEGIN
+
+//! Represents an in-memory input byte stream.
+/*!
+    This class is mainly for being wrapped by EncodedInputStream or AutoUTFInputStream.
+
+    It is similar to FileReadBuffer but the source is an in-memory buffer instead of a file.
+
+    Differences between MemoryStream and StringStream:
+    1. StringStream has encoding but MemoryStream is a byte stream.
+    2. MemoryStream needs size of the source buffer and the buffer don't need to be null terminated. StringStream assume null-terminated string as source.
+    3. MemoryStream supports Peek4() for encoding detection. StringStream is specified with an encoding so it should not have Peek4().
+    \note implements Stream concept
+*/
+struct MemoryStream {
+    typedef char Ch; // byte
+
+    MemoryStream(const Ch *src, size_t size) : src_(src), begin_(src), end_(src + size), size_(size) {}
+
+    Ch Peek() const { return RAPIDJSON_UNLIKELY(src_ == end_) ? '\0' : *src_; }
+    Ch Take() { return RAPIDJSON_UNLIKELY(src_ == end_) ? '\0' : *src_++; }
+    size_t Tell() const { return static_cast<size_t>(src_ - begin_); }
+
+    Ch* PutBegin() { RAPIDJSON_ASSERT(false); return 0; }
+    void Put(Ch) { RAPIDJSON_ASSERT(false); }
+    void Flush() { RAPIDJSON_ASSERT(false); }
+    size_t PutEnd(Ch*) { RAPIDJSON_ASSERT(false); return 0; }
+
+    // For encoding detection only.
+    const Ch* Peek4() const {
+        return Tell() + 4 <= size_ ? src_ : 0;
+    }
+
+    const Ch* src_;     //!< Current read position.
+    const Ch* begin_;   //!< Original head of the string.
+    const Ch* end_;     //!< End of stream.
+    size_t size_;       //!< Size of the stream.
+};
+
+RAPIDJSON_NAMESPACE_END
+
+#ifdef __clang__
+RAPIDJSON_DIAG_POP
+#endif
+
+#endif // RAPIDJSON_MEMORYBUFFER_H_