Compositor: New Exposure Node

This new node increases the radiance of an image by a scalar value.
Previously, the only way to adjust the the exposure of an image was with
math node or using the scene's color management.

Reviewed By: jbakker

Differential Revision: https://developer.blender.org/D9677

2 files changed, 106 insertions, 0 deletions

diff --git a/source/blender/compositor/operations/COM_ColorExposureOperation.cpp b/source/blender/compositor/operations/COM_ColorExposureOperation.cpp
new file mode 100644
index 00000000000..8a475432cc8
--- /dev/null
+++ b/source/blender/compositor/operations/COM_ColorExposureOperation.cpp
@@ -0,0 +1,57 @@
+/*
+ * 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 2020, Blender Foundation.
+ */
+
+#include "COM_ColorExposureOperation.h"
+
+ExposureOperation::ExposureOperation() : NodeOperation()
+{
+  this->addInputSocket(COM_DT_COLOR);
+  this->addInputSocket(COM_DT_VALUE);
+  this->addOutputSocket(COM_DT_COLOR);
+  this->m_inputProgram = NULL;
+}
+
+void ExposureOperation::initExecution()
+{
+  this->m_inputProgram = this->getInputSocketReader(0);
+  this->m_inputExposureProgram = this->getInputSocketReader(1);
+}
+
+void ExposureOperation::executePixelSampled(float output[4],
+                                            float x,
+                                            float y,
+                                            PixelSampler sampler)
+{
+  float inputValue[4];
+  float inputExposure[4];
+  this->m_inputProgram->readSampled(inputValue, x, y, sampler);
+  this->m_inputExposureProgram->readSampled(inputExposure, x, y, sampler);
+  const float exposure = pow(2, inputExposure[0]);
+
+  output[0] = inputValue[0] * exposure;
+  output[1] = inputValue[1] * exposure;
+  output[2] = inputValue[2] * exposure;
+
+  output[3] = inputValue[3];
+}
+
+void ExposureOperation::deinitExecution()
+{
+  this->m_inputProgram = NULL;
+  this->m_inputExposureProgram = NULL;
+}
diff --git a/source/blender/compositor/operations/COM_ColorExposureOperation.h b/source/blender/compositor/operations/COM_ColorExposureOperation.h
new file mode 100644
index 00000000000..a65d5acbe6c
--- /dev/null
+++ b/source/blender/compositor/operations/COM_ColorExposureOperation.h
@@ -0,0 +1,49 @@
+/*
+ * 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 2020, Blender Foundation.
+ */
+
+#ifndef __COM_COLOREXPOSUREOPERATION_H__
+#define __COM_COLOREXPOSUREOPERATION_H__
+#include "COM_NodeOperation.h"
+
+class ExposureOperation : public NodeOperation {
+ private:
+  /**
+   * Cached reference to the inputProgram
+   */
+  SocketReader *m_inputProgram;
+  SocketReader *m_inputExposureProgram;
+
+ public:
+  ExposureOperation();
+
+  /**
+   * the inner loop of this program
+   */
+  void executePixelSampled(float output[4], float x, float y, PixelSampler sampler);
+
+  /**
+   * Initialize the execution
+   */
+  void initExecution();
+
+  /**
+   * Deinitialize the execution
+   */
+  void deinitExecution();
+};
+#endif