ShBackend.hpp

// Sh: A GPU metaprogramming language.
//
// Copyright 2003-2006 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 SHBACKEND_HPP
#define SHBACKEND_HPP

#include <vector>
#include <iosfwd>
#include <string>
#include "ShDllExport.hpp"
#include "ShRefCount.hpp"
#include "ShProgram.hpp"
#include "ShProgramSet.hpp"
#include "ShVariableNode.hpp"

#if defined(_WIN32)
#elif defined(__APPLE__) && !defined(AUTOTOOLS)
#include <CoreFoundation/CoreFoundation.h>
#else
  struct lt_dlhandle_struct;
#endif

namespace SH  {

class ShStream;

class
SH_DLLEXPORT ShBackendCode : public ShRefCountable {
public:
  virtual ~ShBackendCode();

  virtual bool allocateRegister(const ShVariableNodePtr& var) = 0;

  virtual void freeRegister(const ShVariableNodePtr& var) = 0;
  
  virtual void upload() = 0;

  virtual void bind() = 0;

  virtual void unbind() = 0;

  virtual void update() = 0;

  virtual void updateUniform(const ShVariableNodePtr& uniform) = 0;

  virtual std::ostream& print(std::ostream& out) = 0;

  // (Useful for how to format long tuple input on targets 
  // that only support limited tuple lengths) 
  virtual std::ostream& describe_interface(std::ostream& out) = 0;

  virtual std::ostream& describe_bindings(std::ostream& out) = 0;
};

typedef ShPointer<ShBackendCode> ShBackendCodePtr;
typedef ShPointer<const ShBackendCode> ShBackendCodeCPtr;

// A backend-specific set of programs, to be linked together/bound at once
class
SH_DLLEXPORT ShBackendSet : public ShRefCountable {
public:
  virtual ~ShBackendSet();

  virtual void link() = 0;

  virtual void bind() = 0;
  virtual void unbind() = 0;
};

typedef ShPointer<ShBackendSet> ShBackendSetPtr;
typedef ShPointer<const ShBackendSet> ShBackendSetCPtr;

class ShTransformer;
class
SH_DLLEXPORT ShBackend : public ShRefCountable {
public:
  virtual ~ShBackend();

  std::string name() const { return m_name;}

  std::string version() const { return m_version; }

  virtual ShBackendCodePtr generate_code(const std::string& target,
                                         const ShProgramNodeCPtr& shader) = 0;

  virtual ShBackendSetPtr generate_set(const ShProgramSet& s);
  
  virtual void execute(const ShProgramNodeCPtr& program, ShStream& dest) = 0;
  
  virtual void unbind_all_programs();

  static void unbind_all_backends();

  static bool use_backend(const std::string& backend_name);

  static bool have_backend(const std::string& backend_name);

  static void clear_backends();

  static std::string target_handler(const std::string& target, bool restrict_to_selected);

  static ShPointer<ShBackend> get_backend(const std::string& target);

  static std::list<std::string> derived_targets(const std::string& target);

  typedef ShBackend* InstantiateEntryPoint();
  typedef int TargetCostEntryPoint(const std::string &);

  static void register_backend(const std::string& backend_name, InstantiateEntryPoint *instantiate, TargetCostEntryPoint *target_cost);
  
#if defined(_WIN32)
  typedef void* LibraryHandle;
#elif defined(__APPLE__) && !defined(AUTOTOOLS)
  typedef CFBundleRef LibraryHandle;
#else
  typedef lt_dlhandle_struct* LibraryHandle;
#endif
  
  class LibraryInformation : public ShRefCountable {
  public:
    LibraryInformation(LibraryHandle handle, InstantiateEntryPoint* instantiate_function, TargetCostEntryPoint* target_cost_function) :
      m_handle(handle), m_instantiate_function(instantiate_function), m_target_cost_function(target_cost_function)
    {}
    
    LibraryHandle handle() { return m_handle; }
    InstantiateEntryPoint* instantiate_function() { return m_instantiate_function; }
    TargetCostEntryPoint* target_cost_function() { return m_target_cost_function; }
  private: 
    LibraryHandle m_handle;
    InstantiateEntryPoint* m_instantiate_function;
    TargetCostEntryPoint* m_target_cost_function;
  };

  typedef std::map<std::string, ShPointer<LibraryInformation> > LibraryMap;
  typedef std::map<std::string, ShPointer<ShBackend> > BackendMap;
  typedef std::set<std::string> BackendSet;
  
protected:
  ShBackend(const std::string& name, const std::string& version);
  
private:
  static BackendMap* m_instantiated_backends;
  static BackendSet* m_selected_backends;
  static LibraryMap* m_loaded_libraries;
  static bool m_done_init;
  static bool m_all_backends_loaded;

  std::string m_name;
  std::string m_version;

  static void init();

  static std::string lookup_filename(const std::string& backend_name);

  static bool is_valid_name(const std::string& backend_name);

  static void load_all_backends();

  static bool load_library(const std::string& filename);

  static void load_libraries(const std::string& directory);

  static int target_cost(const std::string& backend_name, const std::string& target);
  
  static void check_target(const std::string& target, const std::string& generic_target, 
                           std::list<std::string>& derived_targets);

  static ShPointer<ShBackend> instantiate_backend(const std::string& backend_name);
};

typedef ShPointer<ShBackend> ShBackendPtr;
typedef ShPointer<const ShBackend> ShBackendCPtr;

}

#endif

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