D627: Memory usage optimization for the compositor.

The compostor used a fixed size of 4 floats to hold pixel data. this
patch will select size of a pixel based on its type.
It uses 1 float for Value, 3 float for vector and 4 floats for color
data types.

When benchmarking on shots (opening shot of caminandes) we get a
reduction of memory of 30% and a tiny speedup as less data
transformations needs to take place (but these are negligable.

More information of the patch can be found on
https://developer.blender.org/D627 and
http://wiki.blender.org/index.php/Dev:Ref/Proposals/Compositor2014_p1.1_TD

Developers: jbakker & mdewanchand
Thanks for Sergey for his indept review.

1 files changed, 1 insertions, 1 deletions

diff --git a/source/blender/compositor/operations/COM_WriteBufferOperation.h b/source/blender/compositor/operations/COM_WriteBufferOperation.h
index 96466df979c..9220cb179c6 100644
--- a/source/blender/compositor/operations/COM_WriteBufferOperation.h
+++ b/source/blender/compositor/operations/COM_WriteBufferOperation.h
@@ -35,7 +35,7 @@ class WriteBufferOperation : public NodeOperation {
 	bool m_single_value; /* single value stored in buffer */
 	NodeOperation *m_input;
 public:
-	WriteBufferOperation();
+	WriteBufferOperation(DataType datatype);
 	~WriteBufferOperation();
 	MemoryProxy *getMemoryProxy() { return this->m_memoryProxy; }
 	void executePixelSampled(float output[4], float x, float y, PixelSampler sampler);