1 files changed, 55 insertions, 0 deletions
diff --git a/source/blender/compositor/operations/COM_AlphaOverMixedOperation.cc b/source/blender/compositor/operations/COM_AlphaOverMixedOperation.cc
new file mode 100644
index 00000000000..b8465ab7ccf
--- /dev/null
+++ b/source/blender/compositor/operations/COM_AlphaOverMixedOperation.cc
@@ -0,0 +1,55 @@
+/*
+ * 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.
+ *
+ * Copyright 2011, Blender Foundation.
+ */
+
+#include "COM_AlphaOverMixedOperation.h"
+
+AlphaOverMixedOperation::AlphaOverMixedOperation()
+{
+  this->m_x = 0.0f;
+}
+
+void AlphaOverMixedOperation::executePixelSampled(float output[4],
+                                                  float x,
+                                                  float y,
+                                                  PixelSampler sampler)
+{
+  float inputColor1[4];
+  float inputOverColor[4];
+  float value[4];
+
+  this->m_inputValueOperation->readSampled(value, x, y, sampler);
+  this->m_inputColor1Operation->readSampled(inputColor1, x, y, sampler);
+  this->m_inputColor2Operation->readSampled(inputOverColor, x, y, sampler);
+
+  if (inputOverColor[3] <= 0.0f) {
+    copy_v4_v4(output, inputColor1);
+  }
+  else if (value[0] == 1.0f && inputOverColor[3] >= 1.0f) {
+    copy_v4_v4(output, inputOverColor);
+  }
+  else {
+    float addfac = 1.0f - this->m_x + inputOverColor[3] * this->m_x;
+    float premul = value[0] * addfac;
+    float mul = 1.0f - value[0] * inputOverColor[3];
+
+    output[0] = (mul * inputColor1[0]) + premul * inputOverColor[0];
+    output[1] = (mul * inputColor1[1]) + premul * inputOverColor[1];
+    output[2] = (mul * inputColor1[2]) + premul * inputOverColor[2];
+    output[3] = (mul * inputColor1[3]) + value[0] * inputOverColor[3];
+  }
+}