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, 277 insertions, 0 deletions

diff --git a/vendor/github.com/Benau/go_rlottie/lottie_rapidjson_prettywriter.h b/vendor/github.com/Benau/go_rlottie/lottie_rapidjson_prettywriter.h
new file mode 100644
index 00000000..d353faa7
--- /dev/null
+++ b/vendor/github.com/Benau/go_rlottie/lottie_rapidjson_prettywriter.h
@@ -0,0 +1,277 @@
+// 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_PRETTYWRITER_H_
+#define RAPIDJSON_PRETTYWRITER_H_
+
+#include "lottie_rapidjson_writer.h"
+
+#ifdef __GNUC__
+RAPIDJSON_DIAG_PUSH
+RAPIDJSON_DIAG_OFF(effc++)
+#endif
+
+#if defined(__clang__)
+RAPIDJSON_DIAG_PUSH
+RAPIDJSON_DIAG_OFF(c++98-compat)
+#endif
+
+RAPIDJSON_NAMESPACE_BEGIN
+
+//! Combination of PrettyWriter format flags.
+/*! \see PrettyWriter::SetFormatOptions
+ */
+enum PrettyFormatOptions {
+    kFormatDefault = 0,         //!< Default pretty formatting.
+    kFormatSingleLineArray = 1  //!< Format arrays on a single line.
+};
+
+//! Writer with indentation and spacing.
+/*!
+    \tparam OutputStream Type of output os.
+    \tparam SourceEncoding Encoding of source string.
+    \tparam TargetEncoding Encoding of output stream.
+    \tparam StackAllocator Type of allocator for allocating memory of stack.
+*/
+template<typename OutputStream, typename SourceEncoding = UTF8<>, typename TargetEncoding = UTF8<>, typename StackAllocator = CrtAllocator, unsigned writeFlags = kWriteDefaultFlags>
+class PrettyWriter : public Writer<OutputStream, SourceEncoding, TargetEncoding, StackAllocator, writeFlags> {
+public:
+    typedef Writer<OutputStream, SourceEncoding, TargetEncoding, StackAllocator, writeFlags> Base;
+    typedef typename Base::Ch Ch;
+
+    //! Constructor
+    /*! \param os Output stream.
+        \param allocator User supplied allocator. If it is null, it will create a private one.
+        \param levelDepth Initial capacity of stack.
+    */
+    explicit PrettyWriter(OutputStream& os, StackAllocator* allocator = 0, size_t levelDepth = Base::kDefaultLevelDepth) : 
+        Base(os, allocator, levelDepth), indentChar_(' '), indentCharCount_(4), formatOptions_(kFormatDefault) {}
+
+
+    explicit PrettyWriter(StackAllocator* allocator = 0, size_t levelDepth = Base::kDefaultLevelDepth) : 
+        Base(allocator, levelDepth), indentChar_(' '), indentCharCount_(4), formatOptions_(kFormatDefault) {}
+
+#if RAPIDJSON_HAS_CXX11_RVALUE_REFS
+    PrettyWriter(PrettyWriter&& rhs) :
+        Base(std::forward<PrettyWriter>(rhs)), indentChar_(rhs.indentChar_), indentCharCount_(rhs.indentCharCount_), formatOptions_(rhs.formatOptions_) {}
+#endif
+
+    //! Set custom indentation.
+    /*! \param indentChar       Character for indentation. Must be whitespace character (' ', '\\t', '\\n', '\\r').
+        \param indentCharCount  Number of indent characters for each indentation level.
+        \note The default indentation is 4 spaces.
+    */
+    PrettyWriter& SetIndent(Ch indentChar, unsigned indentCharCount) {
+        RAPIDJSON_ASSERT(indentChar == ' ' || indentChar == '\t' || indentChar == '\n' || indentChar == '\r');
+        indentChar_ = indentChar;
+        indentCharCount_ = indentCharCount;
+        return *this;
+    }
+
+    //! Set pretty writer formatting options.
+    /*! \param options Formatting options.
+    */
+    PrettyWriter& SetFormatOptions(PrettyFormatOptions options) {
+        formatOptions_ = options;
+        return *this;
+    }
+
+    /*! @name Implementation of Handler
+        \see Handler
+    */
+    //@{
+
+    bool Null()                 { PrettyPrefix(kNullType);   return Base::EndValue(Base::WriteNull()); }
+    bool Bool(bool b)           { PrettyPrefix(b ? kTrueType : kFalseType); return Base::EndValue(Base::WriteBool(b)); }
+    bool Int(int i)             { PrettyPrefix(kNumberType); return Base::EndValue(Base::WriteInt(i)); }
+    bool Uint(unsigned u)       { PrettyPrefix(kNumberType); return Base::EndValue(Base::WriteUint(u)); }
+    bool Int64(int64_t i64)     { PrettyPrefix(kNumberType); return Base::EndValue(Base::WriteInt64(i64)); }
+    bool Uint64(uint64_t u64)   { PrettyPrefix(kNumberType); return Base::EndValue(Base::WriteUint64(u64));  }
+    bool Double(double d)       { PrettyPrefix(kNumberType); return Base::EndValue(Base::WriteDouble(d)); }
+
+    bool RawNumber(const Ch* str, SizeType length, bool copy = false) {
+        RAPIDJSON_ASSERT(str != 0);
+        (void)copy;
+        PrettyPrefix(kNumberType);
+        return Base::EndValue(Base::WriteString(str, length));
+    }
+
+    bool String(const Ch* str, SizeType length, bool copy = false) {
+        RAPIDJSON_ASSERT(str != 0);
+        (void)copy;
+        PrettyPrefix(kStringType);
+        return Base::EndValue(Base::WriteString(str, length));
+    }
+
+#if RAPIDJSON_HAS_STDSTRING
+    bool String(const std::basic_string<Ch>& str) {
+        return String(str.data(), SizeType(str.size()));
+    }
+#endif
+
+    bool StartObject() {
+        PrettyPrefix(kObjectType);
+        new (Base::level_stack_.template Push<typename Base::Level>()) typename Base::Level(false);
+        return Base::WriteStartObject();
+    }
+
+    bool Key(const Ch* str, SizeType length, bool copy = false) { return String(str, length, copy); }
+
+#if RAPIDJSON_HAS_STDSTRING
+    bool Key(const std::basic_string<Ch>& str) {
+        return Key(str.data(), SizeType(str.size()));
+    }
+#endif
+	
+    bool EndObject(SizeType memberCount = 0) {
+        (void)memberCount;
+        RAPIDJSON_ASSERT(Base::level_stack_.GetSize() >= sizeof(typename Base::Level)); // not inside an Object
+        RAPIDJSON_ASSERT(!Base::level_stack_.template Top<typename Base::Level>()->inArray); // currently inside an Array, not Object
+        RAPIDJSON_ASSERT(0 == Base::level_stack_.template Top<typename Base::Level>()->valueCount % 2); // Object has a Key without a Value
+       
+        bool empty = Base::level_stack_.template Pop<typename Base::Level>(1)->valueCount == 0;
+
+        if (!empty) {
+            Base::os_->Put('\n');
+            WriteIndent();
+        }
+        bool ret = Base::EndValue(Base::WriteEndObject());
+        (void)ret;
+        RAPIDJSON_ASSERT(ret == true);
+        if (Base::level_stack_.Empty()) // end of json text
+            Base::Flush();
+        return true;
+    }
+
+    bool StartArray() {
+        PrettyPrefix(kArrayType);
+        new (Base::level_stack_.template Push<typename Base::Level>()) typename Base::Level(true);
+        return Base::WriteStartArray();
+    }
+
+    bool EndArray(SizeType memberCount = 0) {
+        (void)memberCount;
+        RAPIDJSON_ASSERT(Base::level_stack_.GetSize() >= sizeof(typename Base::Level));
+        RAPIDJSON_ASSERT(Base::level_stack_.template Top<typename Base::Level>()->inArray);
+        bool empty = Base::level_stack_.template Pop<typename Base::Level>(1)->valueCount == 0;
+
+        if (!empty && !(formatOptions_ & kFormatSingleLineArray)) {
+            Base::os_->Put('\n');
+            WriteIndent();
+        }
+        bool ret = Base::EndValue(Base::WriteEndArray());
+        (void)ret;
+        RAPIDJSON_ASSERT(ret == true);
+        if (Base::level_stack_.Empty()) // end of json text
+            Base::Flush();
+        return true;
+    }
+
+    //@}
+
+    /*! @name Convenience extensions */
+    //@{
+
+    //! Simpler but slower overload.
+    bool String(const Ch* str) { return String(str, internal::StrLen(str)); }
+    bool Key(const Ch* str) { return Key(str, internal::StrLen(str)); }
+
+    //@}
+
+    //! Write a raw JSON value.
+    /*!
+        For user to write a stringified JSON as a value.
+
+        \param json A well-formed JSON value. It should not contain null character within [0, length - 1] range.
+        \param length Length of the json.
+        \param type Type of the root of json.
+        \note When using PrettyWriter::RawValue(), the result json may not be indented correctly.
+    */
+    bool RawValue(const Ch* json, size_t length, Type type) {
+        RAPIDJSON_ASSERT(json != 0);
+        PrettyPrefix(type);
+        return Base::EndValue(Base::WriteRawValue(json, length));
+    }
+
+protected:
+    void PrettyPrefix(Type type) {
+        (void)type;
+        if (Base::level_stack_.GetSize() != 0) { // this value is not at root
+            typename Base::Level* level = Base::level_stack_.template Top<typename Base::Level>();
+
+            if (level->inArray) {
+                if (level->valueCount > 0) {
+                    Base::os_->Put(','); // add comma if it is not the first element in array
+                    if (formatOptions_ & kFormatSingleLineArray)
+                        Base::os_->Put(' ');
+                }
+
+                if (!(formatOptions_ & kFormatSingleLineArray)) {
+                    Base::os_->Put('\n');
+                    WriteIndent();
+                }
+            }
+            else {  // in object
+                if (level->valueCount > 0) {
+                    if (level->valueCount % 2 == 0) {
+                        Base::os_->Put(',');
+                        Base::os_->Put('\n');
+                    }
+                    else {
+                        Base::os_->Put(':');
+                        Base::os_->Put(' ');
+                    }
+                }
+                else
+                    Base::os_->Put('\n');
+
+                if (level->valueCount % 2 == 0)
+                    WriteIndent();
+            }
+            if (!level->inArray && level->valueCount % 2 == 0)
+                RAPIDJSON_ASSERT(type == kStringType);  // if it's in object, then even number should be a name
+            level->valueCount++;
+        }
+        else {
+            RAPIDJSON_ASSERT(!Base::hasRoot_);  // Should only has one and only one root.
+            Base::hasRoot_ = true;
+        }
+    }
+
+    void WriteIndent()  {
+        size_t count = (Base::level_stack_.GetSize() / sizeof(typename Base::Level)) * indentCharCount_;
+        PutN(*Base::os_, static_cast<typename OutputStream::Ch>(indentChar_), count);
+    }
+
+    Ch indentChar_;
+    unsigned indentCharCount_;
+    PrettyFormatOptions formatOptions_;
+
+private:
+    // Prohibit copy constructor & assignment operator.
+    PrettyWriter(const PrettyWriter&);
+    PrettyWriter& operator=(const PrettyWriter&);
+};
+
+RAPIDJSON_NAMESPACE_END
+
+#if defined(__clang__)
+RAPIDJSON_DIAG_POP
+#endif
+
+#ifdef __GNUC__
+RAPIDJSON_DIAG_POP
+#endif
+
+#endif // RAPIDJSON_RAPIDJSON_H_