GUI to use actual available channels in frame

applications/gui2/src/modules/camera.cpp

@@ -63,7 +63,7 @@ void Camera::_initiate(ftl::data::Frame &frame) {
 		}
 	});
 
-	panel->setAvailableChannels({Channel::Colour, Channel::Right, Channel::Depth});
+	panel->setAvailableChannels(frame.available());
 	setChannel(channel);
 
 	screen->setView(view);
@@ -101,6 +101,7 @@ void Camera::activate(ftl::data::FrameID id) {
 	);
 
 	// For first data, extract useful things and create view
+	// Must be done in GUI thread, hence use of cv.
 	std::unique_lock<std::mutex> lk(m);
 	cv.wait_for(lk, 1s, [this](){ return has_seen_frame_; });
 	_initiate(std::atomic_load(&current_fs_)->frames[frame_idx]);

components/structures/include/ftl/data/new_frame.hpp

@@ -164,7 +164,7 @@ class Frame {
 
 	inline const std::unordered_map<ftl::codecs::Channel, ChangeType> &changed() const { return changed_; }
 
-	std::unordered_set<ftl::codecs::Channel> channels();
+	std::unordered_set<ftl::codecs::Channel> channels() const;
 
 	template <typename T>
 	bool isType(ftl::codecs::Channel c) const;

components/structures/src/new_frame.cpp

@@ -7,6 +7,7 @@ using ftl::data::Session;
 using ftl::data::ChannelConfig;
 using ftl::data::StorageMode;
 using ftl::data::FrameStatus;
+using ftl::codecs::Channel;
 
 #define LOGURU_REPLACE_GLOG 1
 #include <loguru.hpp>
@@ -97,6 +98,19 @@ bool ftl::data::Frame::availableAll(const std::unordered_set<ftl::codecs::Channe
 	return result;
 }
 
+std::unordered_set<ftl::codecs::Channel> ftl::data::Frame::available() const {
+	std::unordered_set<ftl::codecs::Channel> result = channels();
+
+	uint64_t m = 1;
+	// TODO: NAIVE, use ffs or ctz.
+	for (int i=0; i<32; ++i) {
+		if (m & available_) result.emplace(static_cast<Channel>(i));
+		m <<= 1;
+	}
+
+	return result;
+}
+
 void ftl::data::Frame::remove(ftl::codecs::Channel c) {
 	const auto &i = data_.find(c);
 	if (i != data_.end()) {
@@ -377,7 +391,7 @@ Frame Frame::make_standalone() {
 	return f;
 }
 
-std::unordered_set<ftl::codecs::Channel> Frame::channels() {
+std::unordered_set<ftl::codecs::Channel> Frame::channels() const {
 	std::unordered_set<ftl::codecs::Channel> res{};
 	for (const auto& [k, v] : data_) {
 		std::ignore = v;