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, 88 insertions, 0 deletions

diff --git a/vendor/github.com/Benau/go_rlottie/vector_vinterpolator.h b/vendor/github.com/Benau/go_rlottie/vector_vinterpolator.h
new file mode 100644
index 00000000..fb7fa937
--- /dev/null
+++ b/vendor/github.com/Benau/go_rlottie/vector_vinterpolator.h
@@ -0,0 +1,88 @@
+/*
+ * Copyright (c) 2020 Samsung Electronics Co., Ltd. All rights reserved.
+
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#ifndef VINTERPOLATOR_H
+#define VINTERPOLATOR_H
+
+#include "vector_vpoint.h"
+
+V_BEGIN_NAMESPACE
+
+class VInterpolator {
+public:
+    VInterpolator()
+    { /* caller must call Init later */
+    }
+
+    VInterpolator(float aX1, float aY1, float aX2, float aY2)
+    {
+        init(aX1, aY1, aX2, aY2);
+    }
+
+    VInterpolator(VPointF pt1, VPointF pt2)
+    {
+        init(pt1.x(), pt1.y(), pt2.x(), pt2.y());
+    }
+
+    void init(float aX1, float aY1, float aX2, float aY2);
+
+    float value(float aX) const;
+
+    void GetSplineDerivativeValues(float aX, float& aDX, float& aDY) const;
+
+private:
+    void CalcSampleValues();
+
+    /**
+     * Returns x(t) given t, x1, and x2, or y(t) given t, y1, and y2.
+     */
+    static float CalcBezier(float aT, float aA1, float aA2);
+
+    /**
+     * Returns dx/dt given t, x1, and x2, or dy/dt given t, y1, and y2.
+     */
+    static float GetSlope(float aT, float aA1, float aA2);
+
+    float GetTForX(float aX) const;
+
+    float NewtonRaphsonIterate(float aX, float aGuessT) const;
+
+    float BinarySubdivide(float aX, float aA, float aB) const;
+
+    static float A(float aA1, float aA2) { return 1.0f - 3.0f * aA2 + 3.0f * aA1; }
+
+    static float B(float aA1, float aA2) { return 3.0f * aA2 - 6.0f * aA1; }
+
+    static float C(float aA1) { return 3.0f * aA1; }
+
+    float mX1;
+    float mY1;
+    float mX2;
+    float mY2;
+    enum { kSplineTableSize = 11 };
+    float              mSampleValues[kSplineTableSize];
+    static const float kSampleStepSize;
+};
+
+V_END_NAMESPACE
+
+#endif  // VINTERPOLATOR_H