From 98cc25ffe956bc162c053c96df659ba40dfe2d6e Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Tue, 23 Sep 2014 20:11:16 +0300
Subject: [PATCH] Refactor the internal interface of Bufferable a bit

---
 source/batch.cpp       |  5 -----
 source/batch.h         |  2 +-
 source/bufferable.cpp  | 32 +++++++++++++++++++++++++-------
 source/bufferable.h    |  9 ++++++++-
 source/uniformblock.h  |  1 +
 source/vertexarray.cpp |  5 -----
 source/vertexarray.h   |  2 +-
 7 files changed, 36 insertions(+), 20 deletions(-)

diff --git a/source/batch.cpp b/source/batch.cpp
index 7100653e..1b0c47bf 100644
--- a/source/batch.cpp
+++ b/source/batch.cpp
@@ -196,11 +196,6 @@ void Batch::append_index(unsigned i)
 		data.push_back(i);
 }
 
-void Batch::upload_data() const
-{
-	get_buffer()->sub_data(get_offset(), data.size(), &data[0]);
-}
-
 unsigned Batch::get_index_size() const
 {
 	if(data_type==UNSIGNED_SHORT)
diff --git a/source/batch.h b/source/batch.h
index 907a0b7f..0ce4ecf1 100644
--- a/source/batch.h
+++ b/source/batch.h
@@ -56,7 +56,7 @@ public:
 private:
 	void append_index(unsigned);
 	virtual unsigned get_data_size() const { return data.size(); }
-	virtual void upload_data() const;
+	virtual const void *get_data_pointer() const { return &data[0]; }
 	unsigned get_index_size() const;
 public:
 	unsigned size() const { return data.size()/get_index_size(); }
diff --git a/source/bufferable.cpp b/source/bufferable.cpp
index eb3f1c00..04793fb7 100644
--- a/source/bufferable.cpp
+++ b/source/bufferable.cpp
@@ -80,9 +80,8 @@ void Bufferable::update_offset()
 	the buffer is actually used. */
 }
 
-void Bufferable::update_buffer() const
+bool Bufferable::resize_buffer() const
 {
-	BindRestore bind(buffer, buffer->get_type());
 	if(offset+get_data_size()>=buffer->get_size())
 	{
 		const Bufferable *last = this;
@@ -93,17 +92,36 @@ void Bufferable::update_buffer() const
 		if(total_size>buffer->get_size())
 		{
 			buffer->data(total_size, 0);
-			/* Resizing the buffer invalidates its contents.  Non-dirty data may
-			be in use, so reupload it. */
-			for(const Bufferable *b=last; b; b=b->prev_in_buffer)
-				if(!b->dirty)
-					b->upload_data();
+			return true;
 		}
 	}
 
+	return false;
+}
+
+void Bufferable::update_buffer() const
+{
+	BindRestore bind(buffer, buffer->get_type());
+	if(resize_buffer())
+	{
+		/* Resizing the buffer invalidates its contents.  Non-dirty data may
+		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();
+		for(const Bufferable *b=next_in_buffer; b; b=b->next_in_buffer)
+			if(!b->dirty)
+				b->upload_data();
+	}
+
 	upload_data();
 	dirty = false;
 }
 
+void Bufferable::upload_data() const
+{
+	buffer->sub_data(offset, get_data_size(), get_data_pointer());
+}
+
 } // namespace GL
 } // namespace Msp
diff --git a/source/bufferable.h b/source/bufferable.h
index c8c9393c..d7d7e45f 100644
--- a/source/bufferable.h
+++ b/source/bufferable.h
@@ -44,6 +44,9 @@ protected:
 	/** Returns the amount of data to be stored in the buffer, in bytes. */
 	virtual unsigned get_data_size() const = 0;
 
+	/** Returns a pointer to the start of data in client memory. */
+	virtual const void *get_data_pointer() const = 0;
+
 	/** Returns the alignment required for the data, in bytes.  The offset is
 	guaranteed to be a multiple of this. */
 	virtual unsigned get_alignment() const { return 1; }
@@ -59,11 +62,15 @@ protected:
 	/** Called when the offset for the data has changed. */
 	virtual void offset_changed() { }
 
+private:
+	bool resize_buffer() const;
+
+protected:
 	/** Resizes the buffer if necessary and calls upload_data(). */
 	void update_buffer() const;
 
 	/** Uploads data to the buffer. */
-	virtual void upload_data() const = 0;
+	virtual void upload_data() const;
 };
 
 } // namespace GL
diff --git a/source/uniformblock.h b/source/uniformblock.h
index 192e7c2e..877a255f 100644
--- a/source/uniformblock.h
+++ b/source/uniformblock.h
@@ -36,6 +36,7 @@ public:
 
 private:
 	virtual unsigned get_data_size() const { return size; }
+	virtual const void *get_data_pointer() const { return &data[0]; }
 	virtual unsigned get_alignment() const;
 	virtual void offset_changed();
 	virtual void upload_data() const;
diff --git a/source/vertexarray.cpp b/source/vertexarray.cpp
index 72fd8a48..38481099 100644
--- a/source/vertexarray.cpp
+++ b/source/vertexarray.cpp
@@ -103,11 +103,6 @@ unsigned VertexArray::get_data_size() const
 	return data.size()*sizeof(float);
 }
 
-void VertexArray::upload_data() const
-{
-	get_buffer()->sub_data(get_offset(), get_data_size(), &data[0]);
-}
-
 void VertexArray::apply() const
 {
 	if(format.empty())
diff --git a/source/vertexarray.h b/source/vertexarray.h
index e38f0aff..0223a1f4 100644
--- a/source/vertexarray.h
+++ b/source/vertexarray.h
@@ -61,7 +61,7 @@ public:
 	float *modify(unsigned);
 private:
 	virtual unsigned get_data_size() const;
-	virtual void upload_data() const;
+	virtual const void *get_data_pointer() const { return &data[0]; }
 
 public:
 	unsigned size() const { return data.size()/stride; }
-- 
2.45.2