From: Mikko Rasa <tdb@tdb.fi>
Date: Sun, 26 Aug 2012 12:06:15 +0000 (+0300)
Subject: Align uniform blocks properly
X-Git-Url: http://git.tdb.fi/?p=libs%2Fgl.git;a=commitdiff_plain;h=c21d4de686e7abd51b0a779af00f06ce459e18d6

Align uniform blocks properly
---

diff --git a/source/buffer.cpp b/source/buffer.cpp
index f0926874..f3b40da6 100644
--- a/source/buffer.cpp
+++ b/source/buffer.cpp
@@ -176,5 +176,11 @@ unsigned BufferRange::get_n_uniform_buffer_bindings()
 	return count;
 }
 
+unsigned BufferRange::get_uniform_buffer_alignment()
+{
+	static unsigned align = get_i(GL_UNIFORM_BUFFER_OFFSET_ALIGNMENT);
+	return align;
+}
+
 } // namespace GL
 } // namespace Msp
diff --git a/source/buffer.h b/source/buffer.h
index 6f0a9708..206cec8d 100644
--- a/source/buffer.h
+++ b/source/buffer.h
@@ -135,6 +135,7 @@ private:
 
 public:
 	static unsigned get_n_uniform_buffer_bindings();
+	static unsigned get_uniform_buffer_alignment();
 };
 
 } // namespace GL
diff --git a/source/bufferable.cpp b/source/bufferable.cpp
index 12e0aef7..abd10b3a 100644
--- a/source/bufferable.cpp
+++ b/source/bufferable.cpp
@@ -58,6 +58,9 @@ void Bufferable::update_buffer_offset()
 	if(prev_in_buffer)
 		offset = prev_in_buffer->buffer_offset+prev_in_buffer->get_data_size();
 
+	unsigned align = get_alignment();
+	offset += align-1;
+	offset -= offset%align;
 	if(offset!=buffer_offset)
 	{
 		buffer_offset = offset;
diff --git a/source/bufferable.h b/source/bufferable.h
index fa81554d..f5ae043c 100644
--- a/source/bufferable.h
+++ b/source/bufferable.h
@@ -25,6 +25,7 @@ private:
 
 protected:
 	virtual unsigned get_data_size() const = 0;
+	virtual unsigned get_alignment() const { return 1; }
 
 	void update_buffer_offset();
 	virtual void offset_changed() { }
diff --git a/source/uniformblock.cpp b/source/uniformblock.cpp
index 6ea0d320..a87a6a42 100644
--- a/source/uniformblock.cpp
+++ b/source/uniformblock.cpp
@@ -27,6 +27,11 @@ UniformBlock::~UniformBlock()
 	delete buf_range;
 }
 
+unsigned UniformBlock::get_alignment() const
+{
+	return BufferRange::get_uniform_buffer_alignment();
+}
+
 void UniformBlock::offset_changed()
 {
 	delete buf_range;
diff --git a/source/uniformblock.h b/source/uniformblock.h
index 66b3c7e0..12b24de3 100644
--- a/source/uniformblock.h
+++ b/source/uniformblock.h
@@ -33,6 +33,7 @@ public:
 
 private:
 	virtual unsigned get_data_size() const { return size; }
+	virtual unsigned get_alignment() const;
 	virtual void offset_changed();
 	virtual void upload_data() const;