envutil_dispatch.h

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/*   utility to convert and extract images from 360 degree environments */
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/*            Copyright 2024 by Kay F. Jahnke                           */
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// this header defines class dispatch_base, which is used to dispatch to
// SIMD-ISA-specific code. dispatch_base has a pure virtual member function
// 'payload', ISA-specific derived 'dispatch' classes will define this
// function. When dispatch is called via a dispatch_base pointer, the
// ISA-specific code in the derived class is invoked.

#include "envutil_basic.h" // we use projection_t

#ifndef DISPATCH_BASE
#define DISPATCH_BASE

struct dispatch_base
{
  // 'hwy_isa' will hold highway's HWY_TARGET value for
  // the given nested namespace.

  std::size_t hwy_target ;
  std::string hwy_target_name ;
  std::string hwy_target_str ;

  // next we have pure virtual member function definitions for
  // payload code. In this program, we only have one payload
  // function.

  virtual int payload ( int nchannels ,
                        int ninputs ,
                        projection_t projection ) const = 0 ;
} ;

// get_dispatch will yield a dispatch_base pointer to the ISA-specific
// payload code best suited for the CPU currently running the code.

namespace project
{
  extern const dispatch_base * const get_dispatch() ;
} ;

#endif