FasTC/BPTCEncoder/include/BC7Compressor.h

/* FasTC
 * Copyright (c) 2012 University of North Carolina at Chapel Hill.
 * All rights reserved.
 *
 * Permission to use, copy, modify, and distribute this software and its
 * documentation for educational, research, and non-profit purposes, without
 * fee, and without a written agreement is hereby granted, provided that the
 * above copyright notice, this paragraph, and the following four paragraphs
 * appear in all copies.
 *
 * Permission to incorporate this software into commercial products may be
 * obtained by contacting the authors or the Office of Technology Development
 * at the University of North Carolina at Chapel Hill <otd@unc.edu>.
 *
 * This software program and documentation are copyrighted by the University of
 * North Carolina at Chapel Hill. The software program and documentation are
 * supplied "as is," without any accompanying services from the University of
 * North Carolina at Chapel Hill or the authors. The University of North
 * Carolina at Chapel Hill and the authors do not warrant that the operation of
 * the program will be uninterrupted or error-free. The end-user understands
 * that the program was developed for research purposes and is advised not to
 * rely exclusively on the program for any reason.
 *
 * IN NO EVENT SHALL THE UNIVERSITY OF NORTH CAROLINA AT CHAPEL HILL OR THE
 * AUTHORS BE LIABLE TO ANY PARTY FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL,
 * OR CONSEQUENTIAL DAMAGES, INCLUDING LOST PROFITS, ARISING OUT OF THE USE OF
 * THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF THE UNIVERSITY OF NORTH CAROLINA
 * AT CHAPEL HILL OR THE AUTHORS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH
 * DAMAGE.
 *
 * THE UNIVERSITY OF NORTH CAROLINA AT CHAPEL HILL AND THE AUTHORS SPECIFICALLY
 * DISCLAIM ANY WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE AND ANY 
 * STATUTORY WARRANTY OF NON-INFRINGEMENT. THE SOFTWARE PROVIDED HEREUNDER IS ON
 * AN "AS IS" BASIS, AND THE UNIVERSITY  OF NORTH CAROLINA AT CHAPEL HILL AND
 * THE AUTHORS HAVE NO OBLIGATIONS TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, 
 * ENHANCEMENTS, OR MODIFICATIONS.
 *
 * Please send all BUG REPORTS to <pavel@cs.unc.edu>.
 *
 * The authors may be contacted via:
 *
 * Pavel Krajcevski
 * Dept of Computer Science
 * 201 S Columbia St
 * Frederick P. Brooks, Jr. Computer Science Bldg
 * Chapel Hill, NC 27599-3175
 * USA
 * 
 * <http://gamma.cs.unc.edu/FasTC/>
 */

// The original lisence from the code available at the following location:
// http://software.intel.com/en-us/vcsource/samples/fast-texture-compression
//
// This code has been modified significantly from the original.

//------------------------------------------------------------------------------
// Copyright 2011 Intel Corporation
// All Rights Reserved
//
// Permission is granted to use, copy, distribute and prepare derivative works
// of this software for any purpose and without fee, provided, that the above
// copyright notice and this statement appear in all copies.  Intel makes no
// representations about the suitability of this software for any purpose.  THIS
// SOFTWARE IS PROVIDED "AS IS." INTEL SPECIFICALLY DISCLAIMS ALL WARRANTIES,
// EXPRESS OR IMPLIED, AND ALL LIABILITY, INCLUDING CONSEQUENTIAL AND OTHER
// INDIRECT DAMAGES, FOR THE USE OF THIS SOFTWARE, INCLUDING LIABILITY FOR
// INFRINGEMENT OF ANY PROPRIETARY RIGHTS, AND INCLUDING THE WARRANTIES OF
// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.  Intel does not assume
// any responsibility for any errors which may appear in this software nor any
// responsibility to update it.
//
//------------------------------------------------------------------------------

#ifndef BPTCENCODER_INCLUDE_BC7COMPRESSOR_H_
#define BPTCENCODER_INCLUDE_BC7COMPRESSOR_H_

#include "BC7Config.h"
#include "CompressionJob.h"

#include <iosfwd>

namespace BC7C {
  // This is the error metric that is applied to our error measurement algorithm
  // in order to bias calculation towards results that are more in-line with
  // how the Human Visual System works. Uniform error means that each color
  // channel is treated equally. For a while, the widely accepted non-uniform
  // metric has been to give red 30%, green 59% and blue 11% weight when
  // computing the error between two pixels.
  enum ErrorMetric {
    eErrorMetric_Uniform,     // Treats r, g, and b channels equally
    eErrorMetric_Nonuniform,  // { 0.3, 0.59, 0.11 }

    kNumErrorMetrics
  };

  // Sets the error metric to be the one specified.
  void SetErrorMetric(ErrorMetric e);

  // Retreives a float4 pointer for the r, g, b, a weights for each color
  // channel, in that order, based on the current error metric.
  const float *GetErrorMetric();

  // Returns the enumeration for the current error metric.
  ErrorMetric GetErrorMetricEnum();

  // Sets the number of steps that we use to perform simulated annealing. In
  // general, a larger number produces better results. The default is set to 50.
  // This metric works on a logarithmic scale -- twice the value will double the
  // compute time, but only decrease the error by two times a factor.
  void SetQualityLevel(int q);
  int GetQualityLevel();

  // Compress the image given as RGBA data to BC7 format. Width and Height are
  // the dimensions of the image in pixels.
  void Compress(const FasTC::CompressionJob &);

  // Perform a compression while recording all of the choices the compressor
  // made into a list of statistics. We can use this to see whether or not
  // certain heuristics are working, such as whether or not certain modes are
  // being chosen more often than others, etc.
  void CompressWithStats(const FasTC::CompressionJob &, std::ostream *logStream);

#ifdef HAS_SSE_41
  // Compress the image given as RGBA data to BC7 format using an algorithm
  // optimized for SIMD enabled platforms. Width and Height are the dimensions
  // of the image in pixels.
  void CompressImageBC7SIMD(const unsigned char* inBuf, unsigned char* outBuf,
                            unsigned int width, unsigned int height);
#endif

#ifdef HAS_ATOMICS
  // This is a threadsafe version of the compression function that is designed
  // to compress a list of textures. If this function is called with the same
  // argument from multiple threads, they will work together to compress all of
  // the images in the list.
  void CompressAtomic(FasTC::CompressionJobList &);
#endif

#ifdef FOUND_NVTT_BC7_EXPORT
  // These functions take the same arguments as Compress and CompressWithStats,
  // but they use the NVTT compressor if it was supplied to CMake.
  void CompressNVTT(const FasTC::CompressionJob &);
  void CompressNVTTWithStats(const FasTC::CompressionJob &,
                             std::ostream *logStream);
#endif

  // Decompress the image given as BC7 data to R8G8B8A8 format. Width and Height
  // are the dimensions of the image in pixels.
  void Decompress(const FasTC::DecompressionJob &);
}  // namespace BC7C

#endif  // BPTCENCODER_INCLUDE_BC7COMPRESSOR_H_