From: Mikko Rasa <tdb@tdb.fi>
Date: Tue, 23 Sep 2014 20:23:14 +0000 (+0300)
Subject: Add an asynchronous update interface to Bufferable
X-Git-Url: http://git.tdb.fi/?p=libs%2Fgl.git;a=commitdiff_plain;h=6c525eff3eaaa617648a869449ed3bddf9c1936d

Add an asynchronous update interface to Bufferable
---

diff --git a/source/bufferable.cpp b/source/bufferable.cpp
index 04793fb7..569ffb2f 100644
--- a/source/bufferable.cpp
+++ b/source/bufferable.cpp
@@ -43,6 +43,11 @@ void Bufferable::use_buffer(Buffer *buf, Bufferable *prev)
 	update_offset();
 }
 
+Bufferable::AsyncUpdater *Bufferable::refresh_async() const
+{
+	return dirty ? new AsyncUpdater(*this) : 0;
+}
+
 void Bufferable::unlink_from_buffer()
 {
 	if(prev_in_buffer)
@@ -108,19 +113,56 @@ void Bufferable::update_buffer() const
 		be in use, so reupload it. */
 		for(const Bufferable *b=prev_in_buffer; b; b=b->prev_in_buffer)
 			if(!b->dirty)
-				b->upload_data();
+				b->upload_data(0);
 		for(const Bufferable *b=next_in_buffer; b; b=b->next_in_buffer)
 			if(!b->dirty)
-				b->upload_data();
+				b->upload_data(0);
 	}
 
-	upload_data();
+	upload_data(0);
 	dirty = false;
 }
 
-void Bufferable::upload_data() const
+void Bufferable::upload_data(char *target) const
+{
+	if(target)
+	{
+		const char *source = reinterpret_cast<const char *>(get_data_pointer());
+		copy(source, source+get_data_size(), target);
+	}
+	else
+		buffer->sub_data(offset, get_data_size(), get_data_pointer());
+}
+
+
+Bufferable::AsyncUpdater::AsyncUpdater(const Bufferable &b):
+	bufferable(b)
 {
-	buffer->sub_data(offset, get_data_size(), get_data_pointer());
+	buffer_resized = bufferable.resize_buffer();
+	mapped_address = reinterpret_cast<char *>(bufferable.buffer->map(WRITE_ONLY));
+}
+
+Bufferable::AsyncUpdater::~AsyncUpdater()
+{
+	bufferable.buffer->unmap();
+}
+
+void Bufferable::AsyncUpdater::upload_data()
+{
+	bufferable.upload_data(mapped_address+bufferable.offset);
+	// Update all bufferables in the same buffer at once
+	for(const Bufferable *b=bufferable.prev_in_buffer; b; b=b->prev_in_buffer)
+		if(b->dirty || buffer_resized)
+		{
+			b->upload_data(mapped_address+b->offset);
+			b->dirty = false;
+		}
+	for(const Bufferable *b=bufferable.next_in_buffer; b; b=b->next_in_buffer)
+		if(b->dirty || buffer_resized)
+		{
+			b->upload_data(mapped_address+b->offset);
+			b->dirty = false;
+		}
 }
 
 } // namespace GL
diff --git a/source/bufferable.h b/source/bufferable.h
index d7d7e45f..f157c628 100644
--- a/source/bufferable.h
+++ b/source/bufferable.h
@@ -14,6 +14,21 @@ uploading fresh data to the buffer.
 */
 class Bufferable
 {
+public:
+	class AsyncUpdater
+	{
+	private:
+		const Bufferable &bufferable;
+		char *mapped_address;
+		bool buffer_resized;
+
+	public:
+		AsyncUpdater(const Bufferable &);
+		~AsyncUpdater();
+
+		void upload_data();
+	};
+
 private:
 	Buffer *buffer;
 	unsigned offset;
@@ -34,6 +49,8 @@ public:
 	/** Uploads new data into the buffer if necessary. */
 	void refresh() const { if(dirty) update_buffer(); }
 
+	AsyncUpdater *refresh_async() const;
+
 private:
 	void unlink_from_buffer();
 
@@ -69,8 +86,9 @@ protected:
 	/** Resizes the buffer if necessary and calls upload_data(). */
 	void update_buffer() const;
 
-	/** Uploads data to the buffer. */
-	virtual void upload_data() const;
+	/** Uploads data to the buffer.  Receives pointer to mapped buffer memory as
+	parameter.  If null, buffer interface should be used instead. */
+	virtual void upload_data(char *) const;
 };
 
 } // namespace GL
diff --git a/source/uniformblock.cpp b/source/uniformblock.cpp
index 498973f9..09060eb7 100644
--- a/source/uniformblock.cpp
+++ b/source/uniformblock.cpp
@@ -44,11 +44,15 @@ void UniformBlock::offset_changed()
 	buf_range = 0;
 }
 
-void UniformBlock::upload_data() const
+void UniformBlock::upload_data(char *target) const
 {
 	if(!buf_range)
 		buf_range = new BufferRange(*get_buffer(), get_offset(), size);
-	buf_range->data(&data[0]);
+
+	if(target)
+		copy(data.begin(), data.end(), target);
+	else
+		buf_range->data(&data[0]);
 }
 
 void UniformBlock::attach(int index, const Uniform &uni)
diff --git a/source/uniformblock.h b/source/uniformblock.h
index 877a255f..02e9086e 100644
--- a/source/uniformblock.h
+++ b/source/uniformblock.h
@@ -39,7 +39,7 @@ private:
 	virtual const void *get_data_pointer() const { return &data[0]; }
 	virtual unsigned get_alignment() const;
 	virtual void offset_changed();
-	virtual void upload_data() const;
+	virtual void upload_data(char *) const;
 
 public:
 	void attach(int, const Uniform &);