1 files changed, 84 insertions, 0 deletions
diff --git a/source/blender/compositor/operations/COM_DifferenceMatteOperation.cpp b/source/blender/compositor/operations/COM_DifferenceMatteOperation.cpp
new file mode 100644
index 00000000000..92d9e29dcec
--- /dev/null
+++ b/source/blender/compositor/operations/COM_DifferenceMatteOperation.cpp
@@ -0,0 +1,84 @@
+/*
+ * Copyright 2011, Blender Foundation.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * Contributor: 
+ *		Jeroen Bakker 
+ *		Monique Dewanchand
+ */
+
+#include "COM_DifferenceMatteOperation.h"
+#include "BLI_math.h"
+
+DifferenceMatteOperation::DifferenceMatteOperation(): NodeOperation() {
+	addInputSocket(COM_DT_COLOR);
+	addInputSocket(COM_DT_COLOR);
+	addOutputSocket(COM_DT_VALUE);
+
+	inputImage1Program = NULL;
+	inputImage2Program = NULL;
+}
+
+void DifferenceMatteOperation::initExecution() {
+	this->inputImage1Program = this->getInputSocketReader(0);
+	this->inputImage2Program = this->getInputSocketReader(1);
+}
+void DifferenceMatteOperation::deinitExecution() {
+	this->inputImage1Program= NULL;
+	this->inputImage2Program= NULL;
+}
+
+void DifferenceMatteOperation::executePixel(float* outputValue, float x, float y, PixelSampler sampler, MemoryBuffer *inputBuffers[]) {
+	float inColor1[4];
+	float inColor2[4];
+
+	const float tolerence=this->settings->t1;
+	const float falloff=this->settings->t2;
+	float difference;
+	float alpha;
+
+	this->inputImage1Program->read(inColor1, x, y, sampler, inputBuffers);
+	this->inputImage2Program->read(inColor2, x, y, sampler, inputBuffers);
+
+	difference= fabs(inColor2[0]-inColor1[0])+
+			   fabs(inColor2[1]-inColor1[1])+
+			   fabs(inColor2[2]-inColor1[2]);
+
+	/*average together the distances*/
+	difference=difference/3.0;
+
+	/*make 100% transparent*/
+	if(difference < tolerence) {
+		outputValue[0]=0.0;
+	}
+	/*in the falloff region, make partially transparent */
+	else if(difference < falloff+tolerence) {
+		difference=difference-tolerence;
+		alpha=difference/falloff;
+		/*only change if more transparent than before */
+		if(alpha < inColor1[3]) {
+			outputValue[0]=alpha;
+		}
+		else { /* leave as before */
+			outputValue[0]=inColor1[3];
+		}
+	}
+	else {
+		/*foreground object*/
+		outputValue[0]= inColor1[3];
+	}
+}
+