The Distance Node in 2.49/2.5/2.6 pre-tiles has a different calculation for RGB and YCC. While RGB

calculate the distance in 3d between R,G and B, the YCC only takes Cb and Cr
into consideration.

This commit makes COM_DistanceMatteOperation inheritable and expose the calculate distance function
to be re-implemented for the YCC node operation.

Thanks Troy Sobotka for the report over email.
Patch incorporates review suggestions by Jeroen Bakker.

1 files changed, 94 insertions, 0 deletions

diff --git a/source/blender/compositor/operations/COM_DistanceRGBMatteOperation.cpp b/source/blender/compositor/operations/COM_DistanceRGBMatteOperation.cpp
new file mode 100644
index 00000000000..df3809ba129
--- /dev/null
+++ b/source/blender/compositor/operations/COM_DistanceRGBMatteOperation.cpp
@@ -0,0 +1,94 @@
+/*
+ * 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:
+ *		Dalai Felinto
+ */
+
+#include "COM_DistanceRGBMatteOperation.h"
+#include "BLI_math.h"
+
+DistanceRGBMatteOperation::DistanceRGBMatteOperation() : NodeOperation()
+{
+	this->addInputSocket(COM_DT_COLOR);
+	this->addInputSocket(COM_DT_COLOR);
+	this->addOutputSocket(COM_DT_VALUE);
+
+	this->m_inputImageProgram = NULL;
+	this->m_inputKeyProgram = NULL;
+}
+
+void DistanceRGBMatteOperation::initExecution()
+{
+	this->m_inputImageProgram = this->getInputSocketReader(0);
+	this->m_inputKeyProgram = this->getInputSocketReader(1);
+}
+
+void DistanceRGBMatteOperation::deinitExecution()
+{
+	this->m_inputImageProgram = NULL;
+	this->m_inputKeyProgram = NULL;
+}
+
+float DistanceRGBMatteOperation::calculateDistance(float key[4], float image[4])
+{
+	return sqrt(pow((key[0] - image[0]), 2) +
+	            pow((key[1] - image[1]), 2) +
+	            pow((key[2] - image[2]), 2));
+}
+
+void DistanceRGBMatteOperation::executePixel(float output[4], float x, float y, PixelSampler sampler)
+{
+	float inKey[4];
+	float inImage[4];
+
+	const float tolerance = this->m_settings->t1;
+	const float falloff = this->m_settings->t2;
+
+	float distance;
+	float alpha;
+
+	this->m_inputKeyProgram->read(inKey, x, y, sampler);
+	this->m_inputImageProgram->read(inImage, x, y, sampler);
+	
+	distance = this->calculateDistance(inKey, inImage);
+
+	/* store matte(alpha) value in [0] to go with
+	 * COM_SetAlphaOperation and the Value output
+	 */
+ 
+	/*make 100% transparent */
+	if (distance < tolerance) {
+		output[0] = 0.f;
+	}
+	/*in the falloff region, make partially transparent */
+	else if (distance < falloff + tolerance) {
+		distance = distance - tolerance;
+		alpha = distance / falloff;
+		/*only change if more transparent than before */
+		if (alpha < inImage[3]) {
+			output[0] = alpha;
+		}
+		else { /* leave as before */
+			output[0] = inImage[3];
+		}
+	}
+	else {
+		/* leave as before */
+		output[0] = inImage[3];
+	}
+}