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, 3 insertions, 4 deletions

diff --git a/source/blender/compositor/operations/COM_GaussianAlphaXBlurOperation.cpp b/source/blender/compositor/operations/COM_GaussianAlphaXBlurOperation.cpp
index c78347e7b1c..dde57ab640f 100644
--- a/source/blender/compositor/operations/COM_GaussianAlphaXBlurOperation.cpp
+++ b/source/blender/compositor/operations/COM_GaussianAlphaXBlurOperation.cpp
@@ -102,15 +102,14 @@ void GaussianAlphaXBlurOperation::executePixel(float output[4], int x, int y, vo
 
 	/* *** this is the main part which is different to 'GaussianXBlurOperation'  *** */
 	int step = getStep();
-	int offsetadd = getOffsetAdd();
-	int bufferindex = ((xmin - bufferstartx) * 4) + ((ymin - bufferstarty) * 4 * bufferwidth);
+	int bufferindex = ((xmin - bufferstartx)) + ((ymin - bufferstarty) * bufferwidth);
 
 	/* gauss */
 	float alpha_accum = 0.0f;
 	float multiplier_accum = 0.0f;
 
 	/* dilate */
-	float value_max = finv_test(buffer[(x * 4) + (y * 4 * bufferwidth)], do_invert); /* init with the current color to avoid unneeded lookups */
+	float value_max = finv_test(buffer[(x) + (y * bufferwidth)], do_invert); /* init with the current color to avoid unneeded lookups */
 	float distfacinv_max = 1.0f; /* 0 to 1 */
 
 	for (int nx = xmin; nx < xmax; nx += step) {
@@ -134,7 +133,7 @@ void GaussianAlphaXBlurOperation::executePixel(float output[4], int x, int y, vo
 				distfacinv_max = multiplier;
 			}
 		}
-		bufferindex += offsetadd;
+		bufferindex += step;
 	}
 
 	/* blend between the max value and gauss blue - gives nice feather */