1 files changed, 120 insertions, 0 deletions
diff --git a/source/blender/compositor/operations/COM_ChannelMatteOperation.cc b/source/blender/compositor/operations/COM_ChannelMatteOperation.cc
new file mode 100644
index 00000000000..15375589888
--- /dev/null
+++ b/source/blender/compositor/operations/COM_ChannelMatteOperation.cc
@@ -0,0 +1,120 @@
+/*
+ * 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 2012, Blender Foundation.
+ */
+
+#include "COM_ChannelMatteOperation.h"
+#include "BLI_math.h"
+
+ChannelMatteOperation::ChannelMatteOperation()
+{
+  addInputSocket(COM_DT_COLOR);
+  addOutputSocket(COM_DT_VALUE);
+
+  this->m_inputImageProgram = nullptr;
+}
+
+void ChannelMatteOperation::initExecution()
+{
+  this->m_inputImageProgram = this->getInputSocketReader(0);
+
+  this->m_limit_range = this->m_limit_max - this->m_limit_min;
+
+  switch (this->m_limit_method) {
+    /* SINGLE */
+    case 0: {
+      /* 123 / RGB / HSV / YUV / YCC */
+      const int matte_channel = this->m_matte_channel - 1;
+      const int limit_channel = this->m_limit_channel - 1;
+      this->m_ids[0] = matte_channel;
+      this->m_ids[1] = limit_channel;
+      this->m_ids[2] = limit_channel;
+      break;
+    }
+    /* MAX */
+    case 1: {
+      switch (this->m_matte_channel) {
+        case 1: {
+          this->m_ids[0] = 0;
+          this->m_ids[1] = 1;
+          this->m_ids[2] = 2;
+          break;
+        }
+        case 2: {
+          this->m_ids[0] = 1;
+          this->m_ids[1] = 0;
+          this->m_ids[2] = 2;
+          break;
+        }
+        case 3: {
+          this->m_ids[0] = 2;
+          this->m_ids[1] = 0;
+          this->m_ids[2] = 1;
+          break;
+        }
+        default:
+          break;
+      }
+      break;
+    }
+    default:
+      break;
+  }
+}
+
+void ChannelMatteOperation::deinitExecution()
+{
+  this->m_inputImageProgram = nullptr;
+}
+
+void ChannelMatteOperation::executePixelSampled(float output[4],
+                                                float x,
+                                                float y,
+                                                PixelSampler sampler)
+{
+  float inColor[4];
+  float alpha;
+
+  const float limit_max = this->m_limit_max;
+  const float limit_min = this->m_limit_min;
+  const float limit_range = this->m_limit_range;
+
+  this->m_inputImageProgram->readSampled(inColor, x, y, sampler);
+
+  /* matte operation */
+  alpha = inColor[this->m_ids[0]] - MAX2(inColor[this->m_ids[1]], inColor[this->m_ids[2]]);
+
+  /* flip because 0.0 is transparent, not 1.0 */
+  alpha = 1.0f - alpha;
+
+  /* test range */
+  if (alpha > limit_max) {
+    alpha = inColor[3]; /*whatever it was prior */
+  }
+  else if (alpha < limit_min) {
+    alpha = 0.0f;
+  }
+  else { /*blend */
+    alpha = (alpha - limit_min) / limit_range;
+  }
+
+  /* Store matte(alpha) value in [0] to go with
+   * COM_SetAlphaMultiplyOperation and the Value output.
+   */
+
+  /* Don't make something that was more transparent less transparent. */
+  output[0] = MIN2(alpha, inColor[3]);
+}