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, 54 insertions, 37 deletions

diff --git a/source/blender/compositor/intern/COM_MemoryBuffer.cpp b/source/blender/compositor/intern/COM_MemoryBuffer.cpp
index c59ecced93c..58767960cc8 100644
--- a/source/blender/compositor/intern/COM_MemoryBuffer.cpp
+++ b/source/blender/compositor/intern/COM_MemoryBuffer.cpp
@@ -27,6 +27,18 @@
 using std::min;
 using std::max;
 
+static unsigned int determine_num_channels(DataType datatype) {
+	switch (datatype) {
+	case COM_DT_VALUE:
+		return COM_NUM_CHANNELS_VALUE;
+	case COM_DT_VECTOR:
+		return COM_NUM_CHANNELS_VECTOR;
+	case COM_DT_COLOR:
+	default:
+		return COM_NUM_CHANNELS_COLOR;
+	}
+}
+
 unsigned int MemoryBuffer::determineBufferSize()
 {
 	return getWidth() * getHeight();
@@ -34,61 +46,62 @@ unsigned int MemoryBuffer::determineBufferSize()
 
 int MemoryBuffer::getWidth() const
 {
-	return this->m_rect.xmax - this->m_rect.xmin;
+	return this->m_width;
 }
 int MemoryBuffer::getHeight() const
 {
-	return this->m_rect.ymax - this->m_rect.ymin;
+	return this->m_height;
 }
 
 MemoryBuffer::MemoryBuffer(MemoryProxy *memoryProxy, unsigned int chunkNumber, rcti *rect)
 {
 	BLI_rcti_init(&this->m_rect, rect->xmin, rect->xmax, rect->ymin, rect->ymax);
+	this->m_width = BLI_rcti_size_x(&this->m_rect);
+	this->m_height = BLI_rcti_size_y(&this->m_rect);
 	this->m_memoryProxy = memoryProxy;
 	this->m_chunkNumber = chunkNumber;
-	this->m_buffer = (float *)MEM_mallocN_aligned(sizeof(float) * determineBufferSize() * COM_NUMBER_OF_CHANNELS, 16, "COM_MemoryBuffer");
+	this->m_num_channels = determine_num_channels(memoryProxy->getDataType());
+	this->m_buffer = (float *)MEM_mallocN_aligned(sizeof(float) * determineBufferSize() * this->m_num_channels, 16, "COM_MemoryBuffer");
 	this->m_state = COM_MB_ALLOCATED;
-	this->m_datatype = COM_DT_COLOR;
-	this->m_chunkWidth = this->m_rect.xmax - this->m_rect.xmin;
+	this->m_datatype = memoryProxy->getDataType();;
 }
 
 MemoryBuffer::MemoryBuffer(MemoryProxy *memoryProxy, rcti *rect)
 {
 	BLI_rcti_init(&this->m_rect, rect->xmin, rect->xmax, rect->ymin, rect->ymax);
+	this->m_width = BLI_rcti_size_x(&this->m_rect);
+	this->m_height = BLI_rcti_size_y(&this->m_rect);
 	this->m_memoryProxy = memoryProxy;
 	this->m_chunkNumber = -1;
-	this->m_buffer = (float *)MEM_mallocN_aligned(sizeof(float) * determineBufferSize() * COM_NUMBER_OF_CHANNELS, 16, "COM_MemoryBuffer");
+	this->m_num_channels = determine_num_channels(memoryProxy->getDataType());
+	this->m_buffer = (float *)MEM_mallocN_aligned(sizeof(float) * determineBufferSize() * this->m_num_channels, 16, "COM_MemoryBuffer");
+	this->m_state = COM_MB_TEMPORARILY;
+	this->m_datatype = memoryProxy->getDataType();
+}
+MemoryBuffer::MemoryBuffer(DataType dataType, rcti *rect)
+{
+	BLI_rcti_init(&this->m_rect, rect->xmin, rect->xmax, rect->ymin, rect->ymax);
+	this->m_width = BLI_rcti_size_x(&this->m_rect);
+	this->m_height = BLI_rcti_size_y(&this->m_rect);
+	this->m_height = this->m_rect.ymax - this->m_rect.ymin;
+	this->m_memoryProxy = NULL;
+	this->m_chunkNumber = -1;
+	this->m_num_channels = determine_num_channels(dataType);
+	this->m_buffer = (float *)MEM_mallocN_aligned(sizeof(float) * determineBufferSize() * this->m_num_channels, 16, "COM_MemoryBuffer");
 	this->m_state = COM_MB_TEMPORARILY;
-	this->m_datatype = COM_DT_COLOR;
-	this->m_chunkWidth = this->m_rect.xmax - this->m_rect.xmin;
+	this->m_datatype = dataType;
 }
 MemoryBuffer *MemoryBuffer::duplicate()
 {
 	MemoryBuffer *result = new MemoryBuffer(this->m_memoryProxy, &this->m_rect);
-	memcpy(result->m_buffer, this->m_buffer, this->determineBufferSize() * COM_NUMBER_OF_CHANNELS * sizeof(float));
+	memcpy(result->m_buffer, this->m_buffer, this->determineBufferSize() * this->m_num_channels * sizeof(float));
 	return result;
 }
 void MemoryBuffer::clear()
 {
-	memset(this->m_buffer, 0, this->determineBufferSize() * COM_NUMBER_OF_CHANNELS * sizeof(float));
+	memset(this->m_buffer, 0, this->determineBufferSize() * this->m_num_channels * sizeof(float));
 }
 
-float *MemoryBuffer::convertToValueBuffer()
-{
-	const unsigned int size = this->determineBufferSize();
-	unsigned int i;
-
-	float *result = (float *)MEM_mallocN(sizeof(float) * size, __func__);
-
-	const float *fp_src = this->m_buffer;
-	float       *fp_dst = result;
-
-	for (i = 0; i < size; i++, fp_dst++, fp_src += COM_NUMBER_OF_CHANNELS) {
-		*fp_dst = *fp_src;
-	}
-
-	return result;
-}
 
 float MemoryBuffer::getMaximumValue()
 {
@@ -98,7 +111,7 @@ float MemoryBuffer::getMaximumValue()
 
 	const float *fp_src = this->m_buffer;
 
-	for (i = 0; i < size; i++, fp_src += COM_NUMBER_OF_CHANNELS) {
+	for (i = 0; i < size; i++, fp_src += this->m_num_channels) {
 		float value = *fp_src;
 		if (value > result) {
 			result = value;
@@ -116,7 +129,7 @@ float MemoryBuffer::getMaximumValue(rcti *rect)
 	BLI_rcti_isect(rect, &this->m_rect, &rect_clamp);
 
 	if (!BLI_rcti_is_empty(&rect_clamp)) {
-		MemoryBuffer *temp = new MemoryBuffer(NULL, &rect_clamp);
+		MemoryBuffer *temp = new MemoryBuffer(this->m_datatype, &rect_clamp);
 		temp->copyContentFrom(this);
 		float result = temp->getMaximumValue();
 		delete temp;
@@ -152,9 +165,9 @@ void MemoryBuffer::copyContentFrom(MemoryBuffer *otherBuffer)
 
 
 	for (otherY = minY; otherY < maxY; otherY++) {
-		otherOffset = ((otherY - otherBuffer->m_rect.ymin) * otherBuffer->m_chunkWidth + minX - otherBuffer->m_rect.xmin) * COM_NUMBER_OF_CHANNELS;
-		offset = ((otherY - this->m_rect.ymin) * this->m_chunkWidth + minX - this->m_rect.xmin) * COM_NUMBER_OF_CHANNELS;
-		memcpy(&this->m_buffer[offset], &otherBuffer->m_buffer[otherOffset], (maxX - minX) * COM_NUMBER_OF_CHANNELS * sizeof(float));
+		otherOffset = ((otherY - otherBuffer->m_rect.ymin) * otherBuffer->m_width + minX - otherBuffer->m_rect.xmin) * this->m_num_channels;
+		offset = ((otherY - this->m_rect.ymin) * this->m_width + minX - this->m_rect.xmin) * this->m_num_channels;
+		memcpy(&this->m_buffer[offset], &otherBuffer->m_buffer[otherOffset], (maxX - minX) * this->m_num_channels * sizeof(float));
 	}
 }
 
@@ -163,9 +176,8 @@ void MemoryBuffer::writePixel(int x, int y, const float color[4])
 	if (x >= this->m_rect.xmin && x < this->m_rect.xmax &&
 	    y >= this->m_rect.ymin && y < this->m_rect.ymax)
 	{
-		const int offset = (this->m_chunkWidth * (y - this->m_rect.ymin) + x - this->m_rect.xmin) * COM_NUMBER_OF_CHANNELS;
-		copy_v4_v4(&this->m_buffer[offset], color);
-	}
+		const int offset = (this->m_width * (y - this->m_rect.ymin) + x - this->m_rect.xmin) * this->m_num_channels;
+		memcpy(&this->m_buffer[offset], color, sizeof(float)*this->m_num_channels);	}
 }
 
 void MemoryBuffer::addPixel(int x, int y, const float color[4])
@@ -173,8 +185,12 @@ void MemoryBuffer::addPixel(int x, int y, const float color[4])
 	if (x >= this->m_rect.xmin && x < this->m_rect.xmax &&
 	    y >= this->m_rect.ymin && y < this->m_rect.ymax)
 	{
-		const int offset = (this->m_chunkWidth * (y - this->m_rect.ymin) + x - this->m_rect.xmin) * COM_NUMBER_OF_CHANNELS;
-		add_v4_v4(&this->m_buffer[offset], color);
+		const int offset = (this->m_width * (y - this->m_rect.ymin) + x - this->m_rect.xmin) * this->m_num_channels;
+		 float *dst = &this->m_buffer[offset];
+		 const float *src = color;
+		 for (int i = 0; i < this->m_num_channels ; i++, dst++, src++) {
+			 *dst += *src;
+		 }
 	}
 }
 
@@ -208,8 +224,9 @@ static void read_ewa_pixel_sampled(void *userdata, int x, int y, float result[4]
 	}
 }
 
-void MemoryBuffer::readEWA(float result[4], const float uv[2], const float derivatives[2][2], PixelSampler sampler)
+void MemoryBuffer::readEWA(float *result, const float uv[2], const float derivatives[2][2], PixelSampler sampler)
 {
+	BLI_assert(this->m_datatype==COM_DT_COLOR);
 	ReadEWAData data;
 	data.buffer = this;
 	data.sampler = sampler;