Compositor: Add option to extend image bounds when blurring

It is handy when doing some roto work and it's required to blur some
mask or overaly before alpha-overing it on top of the footage.

Quite straightforward option with the only limitation that variable
size blur is not supported.

Reviewers: campbellbarton

Subscribers: hype, sebastian_k

Differential Revision: https://developer.blender.org/D1663

1 files changed, 12 insertions, 0 deletions

diff --git a/source/blender/compositor/operations/COM_BlurBaseOperation.cpp b/source/blender/compositor/operations/COM_BlurBaseOperation.cpp
index dc5f80e55f3..2003d6e7b69 100644
--- a/source/blender/compositor/operations/COM_BlurBaseOperation.cpp
+++ b/source/blender/compositor/operations/COM_BlurBaseOperation.cpp
@@ -39,6 +39,7 @@ BlurBaseOperation::BlurBaseOperation(DataType data_type) : NodeOperation()
 	memset(&m_data, 0, sizeof(NodeBlurData));
 	this->m_size = 1.0f;
 	this->m_sizeavailable = false;
+	this->m_extend_bounds = false;
 }
 void BlurBaseOperation::initExecution()
 {
@@ -174,3 +175,14 @@ void BlurBaseOperation::updateSize()
 		this->m_sizeavailable = true;
 	}
 }
+
+void BlurBaseOperation::determineResolution(unsigned int resolution[2],
+                                            unsigned int preferredResolution[2])
+{
+	NodeOperation::determineResolution(resolution,
+	                                   preferredResolution);
+	if (this->m_extend_bounds) {
+		resolution[0] += 2 * this->m_size * m_data.sizex;
+		resolution[1] += 2 * this->m_size * m_data.sizey;
+	}
+}