1 files changed, 59 insertions, 0 deletions
diff --git a/source/blender/compositor/operations/COM_AlphaOverPremultiplyOperation.cpp b/source/blender/compositor/operations/COM_AlphaOverPremultiplyOperation.cpp
new file mode 100644
index 00000000000..635a6308601
--- /dev/null
+++ b/source/blender/compositor/operations/COM_AlphaOverPremultiplyOperation.cpp
@@ -0,0 +1,59 @@
+/*
+ * 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_AlphaOverPremultiplyOperation.h"
+
+AlphaOverPremultiplyOperation::AlphaOverPremultiplyOperation(): MixBaseOperation() {
+}
+
+void AlphaOverPremultiplyOperation::executePixel(float* outputValue, float x, float y, PixelSampler sampler, MemoryBuffer *inputBuffers[]) {
+	float inputColor1[4];
+	float inputOverColor[4];
+	float value[4];
+	
+	inputValueOperation->read(value, x, y, sampler, inputBuffers);
+	inputColor1Operation->read(inputColor1, x, y, sampler, inputBuffers);
+	inputColor2Operation->read(inputOverColor, x, y, sampler, inputBuffers);
+	
+	/* Zero alpha values should still permit an add of RGB data */
+	if(inputOverColor[3]<0.0f) {
+		outputValue[0] = inputColor1[0];
+		outputValue[1] = inputColor1[1];
+		outputValue[2] = inputColor1[2];
+		outputValue[3] = inputColor1[3];
+	}
+	else if(value[0]==1.0f && inputOverColor[3]>=1.0f) {
+		outputValue[0] = inputOverColor[0];
+		outputValue[1] = inputOverColor[1];
+		outputValue[2] = inputOverColor[2];
+		outputValue[3] = inputOverColor[3];
+	}
+	else {
+		float mul= 1.0f - value[0]*inputOverColor[3];
+	
+		outputValue[0]= (mul*inputColor1[0]) + value[0]*inputOverColor[0];
+		outputValue[1]= (mul*inputColor1[1]) + value[0]*inputOverColor[1];
+		outputValue[2]= (mul*inputColor1[2]) + value[0]*inputOverColor[2];
+		outputValue[3]= (mul*inputColor1[3]) + value[0]*inputOverColor[3];
+	}
+}
+