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, 70 insertions, 0 deletions

diff --git a/vendor/github.com/Benau/go_rlottie/lottie_rapidjson_memorybuffer.h b/vendor/github.com/Benau/go_rlottie/lottie_rapidjson_memorybuffer.h
new file mode 100644
index 00000000..100a46fd
--- /dev/null
+++ b/vendor/github.com/Benau/go_rlottie/lottie_rapidjson_memorybuffer.h
@@ -0,0 +1,70 @@
+// 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_MEMORYBUFFER_H_
+#define RAPIDJSON_MEMORYBUFFER_H_
+
+#include "lottie_rapidjson_stream.h"
+#include "lottie_rapidjson_internal_stack.h"
+
+RAPIDJSON_NAMESPACE_BEGIN
+
+//! Represents an in-memory output byte stream.
+/*!
+    This class is mainly for being wrapped by EncodedOutputStream or AutoUTFOutputStream.
+
+    It is similar to FileWriteBuffer but the destination is an in-memory buffer instead of a file.
+
+    Differences between MemoryBuffer and StringBuffer:
+    1. StringBuffer has Encoding but MemoryBuffer is only a byte buffer. 
+    2. StringBuffer::GetString() returns a null-terminated string. MemoryBuffer::GetBuffer() returns a buffer without terminator.
+
+    \tparam Allocator type for allocating memory buffer.
+    \note implements Stream concept
+*/
+template <typename Allocator = CrtAllocator>
+struct GenericMemoryBuffer {
+    typedef char Ch; // byte
+
+    GenericMemoryBuffer(Allocator* allocator = 0, size_t capacity = kDefaultCapacity) : stack_(allocator, capacity) {}
+
+    void Put(Ch c) { *stack_.template Push<Ch>() = c; }
+    void Flush() {}
+
+    void Clear() { stack_.Clear(); }
+    void ShrinkToFit() { stack_.ShrinkToFit(); }
+    Ch* Push(size_t count) { return stack_.template Push<Ch>(count); }
+    void Pop(size_t count) { stack_.template Pop<Ch>(count); }
+
+    const Ch* GetBuffer() const {
+        return stack_.template Bottom<Ch>();
+    }
+
+    size_t GetSize() const { return stack_.GetSize(); }
+
+    static const size_t kDefaultCapacity = 256;
+    mutable internal::Stack<Allocator> stack_;
+};
+
+typedef GenericMemoryBuffer<> MemoryBuffer;
+
+//! Implement specialized version of PutN() with memset() for better performance.
+template<>
+inline void PutN(MemoryBuffer& memoryBuffer, char c, size_t n) {
+    std::memset(memoryBuffer.stack_.Push<char>(n), c, n * sizeof(c));
+}
+
+RAPIDJSON_NAMESPACE_END
+
+#endif // RAPIDJSON_MEMORYBUFFER_H_