ShSwizzle.hpp

// Sh: A GPU metaprogramming language.
//
// Copyright 2003-2005 Serious Hack Inc.
// 
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
//
// This library 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
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, 
// MA  02110-1301, USA
#ifndef SHSWIZZLE_HPP
#define SHSWIZZLE_HPP

#include <iosfwd>
//#include <vector>
#include "ShDllExport.hpp"
#include "ShException.hpp"

namespace SH {

class
SH_DLLEXPORT
ShSwizzle {
public:

  // Null swizzle
  ShSwizzle();

  ShSwizzle(int srcSize);
  ShSwizzle(int srcSize, int i0);
  ShSwizzle(int srcSize, int i0, int i1);
  ShSwizzle(int srcSize, int i0, int i1, int i2);
  ShSwizzle(int srcSize, int i0, int i1, int i2, int i3);
  ShSwizzle(int srcSize, int size, int* indices);

  ShSwizzle(const ShSwizzle& other);

  /* Construct swizzle from repeating other n times */ 
  ShSwizzle(const ShSwizzle& other, int n);
  ~ShSwizzle();

  ShSwizzle& operator=(const ShSwizzle& other);
  
  ShSwizzle& operator*=(const ShSwizzle& other);

  ShSwizzle operator*(const ShSwizzle& other) const;

  int size() const { return m_size; }

  int operator[](int i) const;

  bool identity() const;

  bool operator==(const ShSwizzle& other) const;
  
private:
  // copies the other swizzle's elements 
  void copy(const ShSwizzle &other, bool islocal);

  // throws an exception if index < 0 or index >= m_srcSize
  void checkSrcSize(int index); 

  // allocates the m_indices array to current m_size
  // returns true 
  bool alloc(); 

  // deallocates the m_indices array 
  void dealloc();

  // returns whether we're using local 
  bool local() const;

  // returns the identity swiz value on this machine
  int idswiz() const;

  // Declare these two first so alignment problems don't make the ShSwizzle struct larger
  int m_srcSize;
  int m_size;

  // when srcSize <= 255 and size <= 4, use local.
  // local is always initialized to 0x03020101, so identity comparison is
  // just an integer comparison using intval
  union {
    unsigned char local[4];
    int intval;
    int* ptr;
  } m_index;

  friend SH_DLLEXPORT std::ostream& operator<<(std::ostream& out, const ShSwizzle& swizzle);
};

class
SH_DLLEXPORT ShSwizzleException : public ShException 
{
public:
  ShSwizzleException(const ShSwizzle& s, int idx, int size);
};
  
}

#include "ShSwizzleImpl.hpp"
  
#endif

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