1 files changed, 91 insertions, 0 deletions
diff --git a/source/blender/compositor/operations/COM_BrightnessOperation.cc b/source/blender/compositor/operations/COM_BrightnessOperation.cc
new file mode 100644
index 00000000000..3ae1b4aaef4
--- /dev/null
+++ b/source/blender/compositor/operations/COM_BrightnessOperation.cc
@@ -0,0 +1,91 @@
+/*
+ * 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_BrightnessOperation.h"
+
+BrightnessOperation::BrightnessOperation()
+{
+  this->addInputSocket(COM_DT_COLOR);
+  this->addInputSocket(COM_DT_VALUE);
+  this->addInputSocket(COM_DT_VALUE);
+  this->addOutputSocket(COM_DT_COLOR);
+  this->m_inputProgram = nullptr;
+  this->m_use_premultiply = false;
+}
+
+void BrightnessOperation::setUsePremultiply(bool use_premultiply)
+{
+  this->m_use_premultiply = use_premultiply;
+}
+
+void BrightnessOperation::initExecution()
+{
+  this->m_inputProgram = this->getInputSocketReader(0);
+  this->m_inputBrightnessProgram = this->getInputSocketReader(1);
+  this->m_inputContrastProgram = this->getInputSocketReader(2);
+}
+
+void BrightnessOperation::executePixelSampled(float output[4],
+                                              float x,
+                                              float y,
+                                              PixelSampler sampler)
+{
+  float inputValue[4];
+  float a, b;
+  float inputBrightness[4];
+  float inputContrast[4];
+  this->m_inputProgram->readSampled(inputValue, x, y, sampler);
+  this->m_inputBrightnessProgram->readSampled(inputBrightness, x, y, sampler);
+  this->m_inputContrastProgram->readSampled(inputContrast, x, y, sampler);
+  float brightness = inputBrightness[0];
+  float contrast = inputContrast[0];
+  brightness /= 100.0f;
+  float delta = contrast / 200.0f;
+  /*
+   * The algorithm is by Werner D. Streidt
+   * (http://visca.com/ffactory/archives/5-99/msg00021.html)
+   * Extracted of OpenCV demhist.c
+   */
+  if (contrast > 0) {
+    a = 1.0f - delta * 2.0f;
+    a = 1.0f / max_ff(a, FLT_EPSILON);
+    b = a * (brightness - delta);
+  }
+  else {
+    delta *= -1;
+    a = max_ff(1.0f - delta * 2.0f, 0.0f);
+    b = a * brightness + delta;
+  }
+  if (this->m_use_premultiply) {
+    premul_to_straight_v4(inputValue);
+  }
+  output[0] = a * inputValue[0] + b;
+  output[1] = a * inputValue[1] + b;
+  output[2] = a * inputValue[2] + b;
+  output[3] = inputValue[3];
+  if (this->m_use_premultiply) {
+    straight_to_premul_v4(output);
+  }
+}
+
+void BrightnessOperation::deinitExecution()
+{
+  this->m_inputProgram = nullptr;
+  this->m_inputBrightnessProgram = nullptr;
+  this->m_inputContrastProgram = nullptr;
+}