Add get_buffered_amount() to WebRTCDataChannel (GDNative)

[dsnopek]

This is a companion to these PRs:

• Godot 4.x: Add get_buffered_amount() to WebRTCDataChannel godot#50658
• Godot 3.x: Add get_buffered_amount() to WebRTCDataChannel (Godot 3.x) godot#50659

This requires a minor change to godot-headers in order to compile:

diff --git a/net/godot_webrtc.h b/net/godot_webrtc.h
index 15e2df8..d5260cc 100644
--- a/net/godot_webrtc.h
+++ b/net/godot_webrtc.h
@@ -108,6 +108,13 @@ typedef struct {
        void *next; /* For extension? */
 } godot_net_webrtc_data_channel;
 
+/* Extensions to WebRTCDataChannel */
+typedef struct {
+       int (*get_buffered_amount)(const void *);
+
+       void *next; /* For extension? */
+} godot_net_webrtc_data_channel_ext;
+
 /* Set the default GDNative library */
 godot_error GDAPI godot_net_set_webrtc_library(const godot_net_webrtc_library *);
 /* Binds a WebRTCPeerConnectionGDNative to the provided interface */

As explained on the Godot 4.x PR, this has some backwards compatibility challenges. The godot_net_webrtc_data_channel struct changes, which will cause old version of the GDNative plugin to not work until updated, and also updated versions of the GDNative plugin won't work with older versions of Godot. So, I'm not sure how to handle that...

UPDATE: Backcompat is now handled per suggestion from @Faless!

[dsnopek]

Here's a PR to godot-headers that should allow this to actually build:

godotengine/godot-headers#94

[Faless]

I think for now you can add that struct in this repository (without updating godot-cpp).
In src/net/WebRTCDataChannelNative.hpp:

#if GODOT_NET_WEBRTC_API_MAJOR == 3 && GODOT_NET_WEBRTC_API_MINOR < 4
extern "C" {
/* Extensions to WebRTCDataChannel */
typedef struct {
	int (*get_buffered_amount)(const void *);

	void *next; /* For extension? */
} godot_net_webrtc_data_channel_ext;
}
#endif

See my comment godotengine/godot#50659 (comment)

[dsnopek]

Alright, I added the conditional definition of the struct.

[Faless]

Woah, sorry, I forgot to merge this it seems 😞 .

[Faless]

Thanks!

[dsnopek]

Thanks!!