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, 30 insertions, 0 deletions

diff --git a/vendor/github.com/Benau/tgsconverter/libtgsconverter/png.go b/vendor/github.com/Benau/tgsconverter/libtgsconverter/png.go
new file mode 100644
index 00000000..cf492ea4
--- /dev/null
+++ b/vendor/github.com/Benau/tgsconverter/libtgsconverter/png.go
@@ -0,0 +1,30 @@
+package libtgsconverter
+
+import "bytes"
+import "image"
+import "image/png"
+
+type topng struct {
+	result []byte
+}
+
+func(to_png *topng) init(w uint, h uint, options ConverterOptions) {
+}
+
+func(to_png *topng) SupportsAnimation() bool {
+	return false
+}
+
+func (to_png *topng) AddFrame(image *image.RGBA, fps uint) error {
+	var data []byte
+	w := bytes.NewBuffer(data)
+	if err := png.Encode(w, image); err != nil {
+		return err
+	}
+	to_png.result = w.Bytes()
+	return nil
+}
+
+func (to_png *topng) Result() []byte {
+	return to_png.result
+}