Push the dropping of non-visible lines into the serialization logic

Makes things way less gross and trivially faster.

src/include/aegisub/subtitles_provider.h

@@ -44,7 +44,7 @@ struct VideoFrame;
 class SubtitlesProvider {
 public:
 	virtual ~SubtitlesProvider() = default;
-	virtual void LoadSubtitles(AssFile *subs)=0;
+	virtual void LoadSubtitles(AssFile *subs, int time = -1)=0;
 	virtual void DrawSubtitles(VideoFrame &dst, double time)=0;
 };
 

src/subtitle_format_ass.cpp

@@ -135,9 +135,14 @@ void AssSubtitleFormat::WriteFile(const AssFile *src, agi::fs::path const& filen
 	writer.WriteExtradata(src->Extradata);
 }
 
-void AssSubtitleFormat::WriteToStream(const AssFile *src, std::ostream &ostr) {
+void AssSubtitleFormat::WriteToStream(const AssFile *src, std::ostream &ostr, int time) {
 	Writer writer(ostr);
 	writer.Write(src->Info);
 	writer.Write(src->Styles);
-	writer.Write(src->Events);
+
+	writer.file.WriteLineToFile("[Events]");
+	for (auto const& line : src->Events) {
+		if (!line.Comment && time < 0 || !(line.Start > time || line.End <= time))
+			writer.file.WriteLineToFile(line.GetEntryData());
+	}
 }

src/subtitle_format_ass.h

@@ -28,5 +28,5 @@ public:
 
 	void ReadFile(AssFile *target, agi::fs::path const& filename, agi::vfr::Framerate const& fps, std::string const& forceEncoding) const override;
 	void WriteFile(const AssFile *src, agi::fs::path const& filename, agi::vfr::Framerate const& fps, std::string const& encoding) const override;
-	static void WriteToStream(const AssFile *src, std::ostream &ostr);
+	static void WriteToStream(const AssFile *src, std::ostream &ostr, int time);
 };

src/subtitles_provider_csri.cpp

@@ -73,7 +73,7 @@ class CSRISubtitlesProvider final : public SubtitlesProvider {
 public:
 	CSRISubtitlesProvider(std::string subType);
 
-	void LoadSubtitles(AssFile *subs);
+	void LoadSubtitles(AssFile *subs, int time);
 	void DrawSubtitles(VideoFrame &dst, double time);
 };
 
@@ -92,9 +92,9 @@ CSRISubtitlesProvider::CSRISubtitlesProvider(std::string type) {
 		throw agi::InternalError("CSRI renderer vanished between initial list and creation?", 0);
 }
 
-void CSRISubtitlesProvider::LoadSubtitles(AssFile *subs) {
+void CSRISubtitlesProvider::LoadSubtitles(AssFile *subs, int time) {
 	ostr.rdbuf()->clear();
-	AssSubtitleFormat::WriteToStream(subs, ostr);
+	AssSubtitleFormat::WriteToStream(subs, ostr, time);
 
 	if (tempfile.empty())
 		tempfile = unique_path(config::path->Decode("?temp/csri-%%%%-%%%%-%%%%-%%%%.ass"));

src/subtitles_provider_libass.cpp

@@ -131,7 +131,7 @@ public:
 	LibassSubtitlesProvider(agi::BackgroundRunner *br);
 	~LibassSubtitlesProvider();
 
-	void LoadSubtitles(AssFile *subs) override;
+	void LoadSubtitles(AssFile *subs, int time) override;
 	void DrawSubtitles(VideoFrame &dst, double time) override;
 };
 
@@ -155,10 +155,10 @@ LibassSubtitlesProvider::~LibassSubtitlesProvider() {
 	if (ass_track) ass_free_track(ass_track);
 }
 
-void LibassSubtitlesProvider::LoadSubtitles(AssFile *subs) {
+void LibassSubtitlesProvider::LoadSubtitles(AssFile *subs, int time) {
 	boost::interprocess::basic_ovectorstream<std::vector<char>> ostr;
 	ostr.reserve(0x4000);
-	AssSubtitleFormat::WriteToStream(subs, ostr);
+	AssSubtitleFormat::WriteToStream(subs, ostr, time);
 
 	if (ass_track) ass_free_track(ass_track);
 	ass_track = ass_read_memory(library, const_cast<char *>(ostr.vector().data()), ostr.vector().size(), nullptr);

src/threaded_frame_source.cpp

@@ -29,11 +29,8 @@
 #include "video_frame.h"
 #include "video_provider_manager.h"
 
-#include <libaegisub/address_of_adaptor.h>
 #include <libaegisub/dispatch.h>
 
-#include <boost/range/adaptor/indirected.hpp>
-#include <boost/range/algorithm_ext.hpp>
 #include <condition_variable>
 #include <functional>
 #include <mutex>
@@ -67,28 +64,8 @@ std::shared_ptr<VideoFrame> ThreadedFrameSource::ProcFrame(int frame_number, dou
 			}
 			else {
 				AssFixStylesFilter().ProcessSubs(subs.get(), nullptr);
-
 				single_frame = frame_number;
-				// Copying a nontrivially sized AssFile is fairly slow, so
-				// instead muck around with its innards to just temporarily
-				// remove the non-visible lines without deleting them
-				std::deque<AssDialogue*> full;
-				boost::push_back(full, subs->Events | agi::address_of);
-				subs->Events.remove_if([=](AssDialogue const& diag) {
-					return diag.Start > time || diag.End <= time;
-				});
-
-				try {
-					subs_provider->LoadSubtitles(subs.get());
-
-					subs->Events.clear();
-					boost::push_back(subs->Events, full | boost::adaptors::indirected);
-				}
-				catch (...) {
-					subs->Events.clear();
-					boost::push_back(subs->Events, full | boost::adaptors::indirected);
-					throw;
-				}
+				subs_provider->LoadSubtitles(subs.get(), time);
 			}
 		}
 	}