[Bf-blender-cvs] SVN commit: /data/svn/bf-blender [59188] trunk/blender/source/blender/ compositor/operations: Fix for #36468, "Buffer Groups" option changes compositing output.

[Lukas Toenne]

Revision: 59188
          http://projects.blender.org/scm/viewvc.php?view=rev&root=bf-blender&revision=59188
Author:   lukastoenne
Date:     2013-08-16 13:11:15 +0000 (Fri, 16 Aug 2013)
Log Message:
-----------
Fix for #36468, "Buffer Groups" option changes compositing output.

Problem is that the read/write buffer operations only work with actual
image inputs. If a singular value is used as group input no actual
buffer will be created, the write operation does not schedule any chunks
and the ReadBufferOperation subsequently returns zero
(MemoryBuffer::read).

The fix uses the (0,0) resolution to detect single value input of the
WriteBufferOperation. The actual resolution is then clamped to (1,1) to
ensure we have a single pixel to store the value in. A m_single_value
flag is also set, so we can reliably distinguish this from genuine image
resolutions without having to check m_width/m_height later on.

The ReadBufferOperation copies this flag from the associated
WriteBufferOperation and if set will always return the single value from
pixel (0,0).

Modified Paths:
--------------
    trunk/blender/source/blender/compositor/operations/COM_ReadBufferOperation.cpp
    trunk/blender/source/blender/compositor/operations/COM_ReadBufferOperation.h
    trunk/blender/source/blender/compositor/operations/COM_WriteBufferOperation.cpp
    trunk/blender/source/blender/compositor/operations/COM_WriteBufferOperation.h

Modified: trunk/blender/source/blender/compositor/operations/COM_ReadBufferOperation.cpp
===================================================================
--- trunk/blender/source/blender/compositor/operations/COM_ReadBufferOperation.cpp	2013-08-16 13:06:40 UTC (rev 59187)
+++ trunk/blender/source/blender/compositor/operations/COM_ReadBufferOperation.cpp	2013-08-16 13:11:15 UTC (rev 59188)
@@ -27,6 +27,7 @@
 ReadBufferOperation::ReadBufferOperation() : NodeOperation()
 {
 	this->addOutputSocket(COM_DT_COLOR);
+	this->m_single_value = false;
 	this->m_offset = 0;
 	this->m_buffer = NULL;
 }
@@ -47,11 +48,17 @@
 		if (this->m_memoryProxy->getExecutor()) {
 			this->m_memoryProxy->getExecutor()->setResolution(resolution);
 		}
+
+		m_single_value = operation->isSingleValue();
 	}
 }
 void ReadBufferOperation::executePixel(float output[4], float x, float y, PixelSampler sampler)
 {
-	if (sampler == COM_PS_NEAREST) {
+	if (m_single_value) {
+		/* write buffer has a single value stored at (0,0) */
+		m_buffer->read(output, 0, 0);
+	}
+	else if (sampler == COM_PS_NEAREST) {
 		m_buffer->read(output, x, y);
 	}
 	else {
@@ -61,7 +68,13 @@
 
 void ReadBufferOperation::executePixel(float output[4], float x, float y, float dx, float dy, PixelSampler sampler)
 {
-	m_buffer->readEWA(output, x, y, dx, dy, sampler);
+	if (m_single_value) {
+		/* write buffer has a single value stored at (0,0) */
+		m_buffer->read(output, 0, 0);
+	}
+	else {
+		m_buffer->readEWA(output, x, y, dx, dy, sampler);
+	}
 }
 
 bool ReadBufferOperation::determineDependingAreaOfInterest(rcti *input, ReadBufferOperation *readOperation, rcti *output)

Modified: trunk/blender/source/blender/compositor/operations/COM_ReadBufferOperation.h
===================================================================
--- trunk/blender/source/blender/compositor/operations/COM_ReadBufferOperation.h	2013-08-16 13:06:40 UTC (rev 59187)
+++ trunk/blender/source/blender/compositor/operations/COM_ReadBufferOperation.h	2013-08-16 13:11:15 UTC (rev 59188)
@@ -29,6 +29,7 @@
 class ReadBufferOperation : public NodeOperation {
 private:
 	MemoryProxy *m_memoryProxy;
+	bool m_single_value; /* single value stored in buffer, copied from associated write operation */
 	unsigned int m_offset;
 	MemoryBuffer *m_buffer;
 public:

Modified: trunk/blender/source/blender/compositor/operations/COM_WriteBufferOperation.cpp
===================================================================
--- trunk/blender/source/blender/compositor/operations/COM_WriteBufferOperation.cpp	2013-08-16 13:06:40 UTC (rev 59187)
+++ trunk/blender/source/blender/compositor/operations/COM_WriteBufferOperation.cpp	2013-08-16 13:11:15 UTC (rev 59188)
@@ -174,6 +174,21 @@
 	delete clKernelsToCleanUp;
 }
 
+void WriteBufferOperation::determineResolution(unsigned int resolution[2], unsigned int preferredResolution[2])
+{
+	NodeOperation::determineResolution(resolution, preferredResolution);
+	/* make sure there is at least one pixel stored in case the input is a single value */
+	m_single_value = false;
+	if (resolution[0] == 0) {
+		resolution[0] = 1;
+		m_single_value = true;
+	}
+	if (resolution[1] == 0) {
+		resolution[1] = 1;
+		m_single_value = true;
+	}
+}
+
 void WriteBufferOperation::readResolutionFromInputSocket()
 {
 	NodeOperation *inputOperation = this->getInputOperation(0);

Modified: trunk/blender/source/blender/compositor/operations/COM_WriteBufferOperation.h
===================================================================
--- trunk/blender/source/blender/compositor/operations/COM_WriteBufferOperation.h	2013-08-16 13:06:40 UTC (rev 59187)
+++ trunk/blender/source/blender/compositor/operations/COM_WriteBufferOperation.h	2013-08-16 13:11:15 UTC (rev 59188)
@@ -32,6 +32,7 @@
  */
 class WriteBufferOperation : public NodeOperation {
 	MemoryProxy *m_memoryProxy;
+	bool m_single_value; /* single value stored in buffer */
 	NodeOperation *m_input;
 public:
 	WriteBufferOperation();
@@ -40,11 +41,13 @@
 	MemoryProxy *getMemoryProxy() { return this->m_memoryProxy; }
 	void executePixel(float output[4], float x, float y, PixelSampler sampler);
 	const bool isWriteBufferOperation() const { return true; }
+	bool isSingleValue() const { return m_single_value; }
 	
 	void executeRegion(rcti *rect, unsigned int tileNumber);
 	void initExecution();
 	void deinitExecution();
 	void executeOpenCLRegion(OpenCLDevice *device, rcti *rect, unsigned int chunkNumber, MemoryBuffer **memoryBuffers, MemoryBuffer *outputBuffer);
+	void determineResolution(unsigned int resolution[2], unsigned int preferredResolution[2]);
 	void readResolutionFromInputSocket();
 	inline NodeOperation *getInput() {
 		return m_input;