Compositor: Add Invert option to the movie clip stabilization node

This appears to be really common workflow when you stabilize shot to make compo
easier (roto, some effects and so) and then re-introduce the motion back.

Surely it's doable with some magic nodes and manual network for transforming
but such workflow is too common in VFX to resist adding one small option in
single node for this.

6 files changed, 37 insertions, 8 deletions

diff --git a/source/blender/compositor/nodes/COM_Stabilize2dNode.cpp b/source/blender/compositor/nodes/COM_Stabilize2dNode.cpp
index d1babcc8103..f25c7b3fc2d 100644
--- a/source/blender/compositor/nodes/COM_Stabilize2dNode.cpp
+++ b/source/blender/compositor/nodes/COM_Stabilize2dNode.cpp
@@ -40,11 +40,13 @@ Stabilize2dNode::Stabilize2dNode(bNode *editorNode) : Node(editorNode)
 
 void Stabilize2dNode::convertToOperations(NodeConverter &converter, const CompositorContext &context) const
 {
+	bNode *editorNode = this->getbNode();
 	NodeInput *imageInput = this->getInputSocket(0);
-	MovieClip *clip = (MovieClip *)getbNode()->id;
+	MovieClip *clip = (MovieClip *)editorNode->id;
+	bool invert = (editorNode->custom2 & CMP_NODEFLAG_STABILIZE_INVERSE) != 0;
 	
 	ScaleOperation *scaleOperation = new ScaleOperation();
-	scaleOperation->setSampler((PixelSampler)this->getbNode()->custom1);
+	scaleOperation->setSampler((PixelSampler)editorNode->custom1);
 	RotateOperation *rotateOperation = new RotateOperation();
 	rotateOperation->setDoDegree2RadConversion(false);
 	TranslateOperation *translateOperation = new TranslateOperation();
@@ -53,24 +55,28 @@ void Stabilize2dNode::convertToOperations(NodeConverter &converter, const Compos
 	MovieClipAttributeOperation *xAttribute = new MovieClipAttributeOperation();
 	MovieClipAttributeOperation *yAttribute = new MovieClipAttributeOperation();
 	SetSamplerOperation *psoperation = new SetSamplerOperation();
-	psoperation->setSampler((PixelSampler)this->getbNode()->custom1);
-	
+	psoperation->setSampler((PixelSampler)editorNode->custom1);
+
 	scaleAttribute->setAttribute(MCA_SCALE);
 	scaleAttribute->setFramenumber(context.getFramenumber());
 	scaleAttribute->setMovieClip(clip);
-	
+	scaleAttribute->setInvert(invert);
+
 	angleAttribute->setAttribute(MCA_ANGLE);
 	angleAttribute->setFramenumber(context.getFramenumber());
 	angleAttribute->setMovieClip(clip);
-	
+	angleAttribute->setInvert(invert);
+
 	xAttribute->setAttribute(MCA_X);
 	xAttribute->setFramenumber(context.getFramenumber());
 	xAttribute->setMovieClip(clip);
-	
+	xAttribute->setInvert(invert);
+
 	yAttribute->setAttribute(MCA_Y);
 	yAttribute->setFramenumber(context.getFramenumber());
 	yAttribute->setMovieClip(clip);
-	
+	yAttribute->setInvert(invert);
+
 	converter.addOperation(scaleAttribute);
 	converter.addOperation(angleAttribute);
 	converter.addOperation(xAttribute);
diff --git a/source/blender/compositor/operations/COM_MovieClipAttributeOperation.cpp b/source/blender/compositor/operations/COM_MovieClipAttributeOperation.cpp
index 040a0315d69..5ddf15f7684 100644
--- a/source/blender/compositor/operations/COM_MovieClipAttributeOperation.cpp
+++ b/source/blender/compositor/operations/COM_MovieClipAttributeOperation.cpp
@@ -31,12 +31,14 @@ MovieClipAttributeOperation::MovieClipAttributeOperation() : NodeOperation()
 	this->m_valueSet = false;
 	this->m_framenumber = 0;
 	this->m_attribute = MCA_X;
+	this->m_invert = false;
 }
 
 void MovieClipAttributeOperation::executePixelSampled(float output[4],
                                                       float /*x*/, float /*y*/,
                                                       PixelSampler /*sampler*/)
 {
+	/* TODO(sergey): This code isn't really thread-safe. */
 	if (!this->m_valueSet) {
 		float loc[2], scale, angle;
 		loc[0] = 0.0f;
@@ -61,6 +63,14 @@ void MovieClipAttributeOperation::executePixelSampled(float output[4],
 				this->m_value = loc[1];
 				break;
 		}
+		if (this->m_invert) {
+			if (this->m_attribute != MCA_SCALE) {
+				this->m_value = -this->m_value;
+			}
+			else {
+				this->m_value = 1.0f / this->m_value;
+			}
+		}
 		this->m_valueSet = true;
 	}
 	output[0] = this->m_value;
diff --git a/source/blender/compositor/operations/COM_MovieClipAttributeOperation.h b/source/blender/compositor/operations/COM_MovieClipAttributeOperation.h
index 49c86c7fafc..731b9debaf0 100644
--- a/source/blender/compositor/operations/COM_MovieClipAttributeOperation.h
+++ b/source/blender/compositor/operations/COM_MovieClipAttributeOperation.h
@@ -41,6 +41,7 @@ private:
 	float m_value;
 	bool m_valueSet;
 	int m_framenumber;
+	bool m_invert;
 	MovieClipAttribute m_attribute;
 public:
 	/**
@@ -57,5 +58,6 @@ public:
 	void setMovieClip(MovieClip *clip) { this->m_clip = clip; }
 	void setFramenumber(int framenumber) { this->m_framenumber = framenumber; }
 	void setAttribute(MovieClipAttribute attribute) { this->m_attribute = attribute; }
+	void setInvert(bool invert) { this->m_invert = invert; }
 };
 #endif
diff --git a/source/blender/editors/space_node/drawnode.c b/source/blender/editors/space_node/drawnode.c
index 64b0653c8dd..c830b94588c 100644
--- a/source/blender/editors/space_node/drawnode.c
+++ b/source/blender/editors/space_node/drawnode.c
@@ -2035,6 +2035,7 @@ static void node_composit_buts_stabilize2d(uiLayout *layout, bContext *C, Pointe
 		return;
 
 	uiItemR(layout, ptr, "filter_type", 0, "", ICON_NONE);
+	uiItemR(layout, ptr, "invert", 0, NULL, ICON_NONE);
 }
 
 static void node_composit_buts_translate(uiLayout *layout, bContext *UNUSED(C), PointerRNA *ptr)
diff --git a/source/blender/makesdna/DNA_node_types.h b/source/blender/makesdna/DNA_node_types.h
index 1176ce1c9e6..fd3391f970e 100644
--- a/source/blender/makesdna/DNA_node_types.h
+++ b/source/blender/makesdna/DNA_node_types.h
@@ -1110,6 +1110,11 @@ enum {
 	CMP_NODEFLAG_PLANETRACKDEFORM_MOTION_BLUR = 1,
 };
 
+/* Stabilization node */
+enum {
+	CMP_NODEFLAG_STABILIZE_INVERSE = 1,
+};
+
 #define CMP_NODE_PLANETRACKDEFORM_MBLUR_SAMPLES_MAX 64
 
 /* Point Density shader node */
diff --git a/source/blender/makesrna/intern/rna_nodetree.c b/source/blender/makesrna/intern/rna_nodetree.c
index da86701128a..2b1113746be 100644
--- a/source/blender/makesrna/intern/rna_nodetree.c
+++ b/source/blender/makesrna/intern/rna_nodetree.c
@@ -5826,6 +5826,11 @@ static void def_cmp_stabilize2d(StructRNA *srna)
 	RNA_def_property_enum_items(prop, node_sampler_type_items);
 	RNA_def_property_ui_text(prop, "Filter", "Method to use to filter stabilization");
 	RNA_def_property_update(prop, NC_NODE | NA_EDITED, "rna_Node_update");
+
+	prop = RNA_def_property(srna, "invert", PROP_BOOLEAN, PROP_NONE);
+	RNA_def_property_boolean_sdna(prop, NULL, "custom2", CMP_NODEFLAG_STABILIZE_INVERSE);
+	RNA_def_property_ui_text(prop, "Invert", "Invert stabilization to re-introduce motion to the frame");
+	RNA_def_property_update(prop, NC_NODE | NA_EDITED, "rna_Node_update");
 }
 
 static void def_cmp_moviedistortion(StructRNA *srna)