Compositor: Add Anti-Aliasing node

This is an implementation of Enhanced Subpixel Morphological Antialiasing (SMAA)

The algorithm was proposed by:
  Jorge Jimenez, Jose I. Echevarria, Tiago Sousa, Diego Gutierrez

This node provides only SMAA 1x mode, so the operation will be done with no spatial
multisampling nor temporal supersampling. See Patch for comparisons.

The existing AA operation seems to be used only for binary images by some other nodes.
Using SMAA for binary images needs no important parameter such as "threshold", so we
perhaps can switch the operation to SMAA, though that changes existing behavior.

Notes:
1. The program code assumes the screen coordinates are DirectX style that the
   vertical direction is upside-down, so "top" and "bottom" actually represent bottom
   and top, respectively.

Thanks for Habib Gahbiche (zazizizou) to polish and finalize this patch.

Reviewed By: jbakker

Differential Revision: https://developer.blender.org/D2411

1 files changed, 147 insertions, 0 deletions

diff --git a/source/blender/compositor/operations/COM_SMAAOperation.h b/source/blender/compositor/operations/COM_SMAAOperation.h
new file mode 100644
index 00000000000..8ac6fea6818
--- /dev/null
+++ b/source/blender/compositor/operations/COM_SMAAOperation.h
@@ -0,0 +1,147 @@
+/*
+ * Copyright 2017, 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: IRIE Shinsuke
+ */
+
+#ifndef _COM_SMAAOperation_h
+#define _COM_SMAAOperation_h
+#include "COM_NodeOperation.h"
+
+/*-----------------------------------------------------------------------------*/
+/* Edge Detection (First Pass) */
+
+class SMAAEdgeDetectionOperation : public NodeOperation {
+ protected:
+  SocketReader *m_imageReader;
+  SocketReader *m_valueReader;
+
+  float m_threshold;
+  float m_contrast_limit;
+
+ public:
+  SMAAEdgeDetectionOperation();
+
+  /**
+   * the inner loop of this program
+   */
+  virtual void executePixel(float output[4], int x, int y, void *data) override;
+
+  /**
+   * Initialize the execution
+   */
+  void initExecution() override;
+
+  /**
+   * Deinitialize the execution
+   */
+  void deinitExecution() override;
+
+  void setThreshold(float threshold);
+
+  void setLocalContrastAdaptationFactor(float factor);
+
+  bool determineDependingAreaOfInterest(rcti *input,
+                                        ReadBufferOperation *readOperation,
+                                        rcti *output) override;
+};
+
+/*-----------------------------------------------------------------------------*/
+/*  Blending Weight Calculation (Second Pass) */
+
+class SMAABlendingWeightCalculationOperation : public NodeOperation {
+ private:
+  SocketReader *m_imageReader;
+
+  int m_corner_rounding;
+
+ public:
+  SMAABlendingWeightCalculationOperation();
+
+  /**
+   * the inner loop of this program
+   */
+  void executePixel(float output[4], int x, int y, void *data);
+
+  /**
+   * Initialize the execution
+   */
+  void initExecution();
+  void *initializeTileData(rcti *rect);
+
+  /**
+   * Deinitialize the execution
+   */
+  void deinitExecution();
+
+  void setCornerRounding(float rounding);
+
+  bool determineDependingAreaOfInterest(rcti *input,
+                                        ReadBufferOperation *readOperation,
+                                        rcti *output);
+
+ private:
+  /* Diagonal Search Functions */
+  int searchDiag1(int x, int y, int dir, bool *found);
+  int searchDiag2(int x, int y, int dir, bool *found);
+  void calculateDiagWeights(int x, int y, const float edges[2], float weights[2]);
+  bool isVerticalSearchUnneeded(int x, int y);
+
+  /* Horizontal/Vertical Search Functions */
+  int searchXLeft(int x, int y);
+  int searchXRight(int x, int y);
+  int searchYUp(int x, int y);
+  int searchYDown(int x, int y);
+
+  /*  Corner Detection Functions */
+  void detectHorizontalCornerPattern(float weights[2], int left, int right, int y, int d1, int d2);
+  void detectVerticalCornerPattern(float weights[2], int x, int top, int bottom, int d1, int d2);
+};
+
+/*-----------------------------------------------------------------------------*/
+/* Neighborhood Blending (Third Pass) */
+
+class SMAANeighborhoodBlendingOperation : public NodeOperation {
+ private:
+  SocketReader *m_image1Reader;
+  SocketReader *m_image2Reader;
+
+ public:
+  SMAANeighborhoodBlendingOperation();
+
+  /**
+   * the inner loop of this program
+   */
+  void executePixel(float output[4], int x, int y, void *data);
+
+  /**
+   * Initialize the execution
+   */
+  void initExecution();
+  void *initializeTileData(rcti *rect);
+
+  /**
+   * Deinitialize the execution
+   */
+  void deinitExecution();
+
+  bool determineDependingAreaOfInterest(rcti *input,
+                                        ReadBufferOperation *readOperation,
+                                        rcti *output);
+};
+
+#endif