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, 10 insertions, 8 deletions

diff --git a/source/blender/compositor/operations/COM_TextureOperation.cpp b/source/blender/compositor/operations/COM_TextureOperation.cpp
index ede767cbff7..da01aa3b7ca 100644
--- a/source/blender/compositor/operations/COM_TextureOperation.cpp
+++ b/source/blender/compositor/operations/COM_TextureOperation.cpp
@@ -77,12 +77,9 @@ void TextureBaseOperation::determineResolution(unsigned int resolution[2], unsig
 
 void TextureAlphaOperation::executePixelSampled(float output[4], float x, float y, PixelSampler sampler)
 {
-	TextureBaseOperation::executePixelSampled(output, x, y, sampler);
-	output[0] = output[3];
-	output[1] = 0.0f;
-	output[2] = 0.0f;
-	output[3] = 0.0f;
-}
+	float color[4];
+	TextureBaseOperation::executePixelSampled(color, x, y, sampler);
+	output[0] = color[3];}
 
 void TextureBaseOperation::executePixelSampled(float output[4], float x, float y, PixelSampler sampler)
 {
@@ -124,18 +121,23 @@ MemoryBuffer *TextureBaseOperation::createMemoryBuffer(rcti *rect2)
 {
 	int height = getHeight();
 	int width = getWidth();
+	DataType datatype = this->getOutputSocket()->getDataType();
+	int add = 4;
+	if (datatype == COM_DT_VALUE) {
+		add = 1;
+	}
 
 	rcti rect;
 	rect.xmin = 0;
 	rect.ymin = 0;
 	rect.xmax = width;
 	rect.ymax = height;
-	MemoryBuffer *result = new MemoryBuffer(NULL, &rect);
+	MemoryBuffer *result = new MemoryBuffer(datatype, &rect);
 
 	float *data = result->getBuffer();
 
 	for (int y = 0; y < height; y++) {
-		for (int x = 0; x < width; x++, data += 4) {
+		for (int x = 0; x < width; x++, data += add) {
 			this->executePixelSampled(data, x, y, COM_PS_NEAREST);
 		}
 	}