// Filename: shader.h
// Created by:  mike (09Jan97)
//
////////////////////////////////////////////////////////////////////
//
// PANDA 3D SOFTWARE
// Copyright (c) 2001, Disney Enterprises, Inc.  All rights reserved
//
// All use of this software is subject to the terms of the Panda 3d
// Software license.  You should have received a copy of this license
// along with this source code; you will also find a current copy of
// the license at http://www.panda3d.org/license.txt .
//
// To contact the maintainers of this program write to
// panda3d@yahoogroups.com .
//
////////////////////////////////////////////////////////////////////
#ifndef SHADER_H
#define SHADER_H
//
////////////////////////////////////////////////////////////////////
// Includes
////////////////////////////////////////////////////////////////////
#include <pandabase.h>

#include <configurable.h>
#include <namedNode.h>
#include <projectionNode.h>
#include <typedReferenceCount.h>
#include <graphicsStateGuardian.h>
#include <allAttributesWrapper.h>
#include <allTransitionsWrapper.h>
#include <pointerTo.h>

////////////////////////////////////////////////////////////////////
// Defines
////////////////////////////////////////////////////////////////////

////////////////////////////////////////////////////////////////////
//       Class : Shader
// Description : Renders an effect on a list of receiving objects
////////////////////////////////////////////////////////////////////
class EXPCL_SHADER Shader : public ReferenceCount, public Configurable
{
protected:

  Shader();

  int _priority;
  bool _multipass_on;

public:

  virtual ~Shader(void) { }

  virtual void pre_apply(Node *, const AllAttributesWrapper &,
                         const AllTransitionsWrapper &,
                         GraphicsStateGuardian *);


  virtual void apply(Node *, const AllAttributesWrapper &,
                     const AllTransitionsWrapper &,
                     GraphicsStateGuardian *);

  virtual void set_priority(int priority);
  virtual int get_priority(void) const;
  virtual void set_multipass(bool on);

public:

  // This is used to visualize partial results, for debugging (and demos)
  class EXPCL_SHADER Visualize {
  public:
    Visualize(void);
    virtual ~Visualize(void);
    virtual void DisplayTexture(PT(Texture)&, Shader*) = 0;
    virtual void DisplayPixelBuffer(PT(PixelBuffer)&, Shader*) = 0;
    virtual void Flush(void) = 0;
  };

  static INLINE Visualize* get_viz(void);
  static INLINE void set_viz(Visualize*);

  static TypeHandle get_class_type() {
    return _type_handle;
  }
  static void init_type() {
    ReferenceCount::init_type();
    Configurable::init_type();
    register_type(_type_handle, "Shader",
                  ReferenceCount::get_class_type(),
                  Configurable::get_class_type());
  }
  virtual TypeHandle get_type() const {
    return get_class_type();
  }
  virtual TypeHandle force_init_type() {init_type(); return get_class_type();}

  static Visualize* _viz;

private:

  static TypeHandle _type_handle;
};

////////////////////////////////////////////////////////////////////
//       Class : FrustumShader
// Description : Shader that computes effect based on a frustum
//               (most often a light or a camera) for a list of
//               receiving objects
////////////////////////////////////////////////////////////////////
class EXPCL_SHADER FrustumShader : public Shader
{
protected:

  FrustumShader(void) : Shader() { }

public:

  virtual ~FrustumShader(void) { }

  INLINE int get_num_frusta(void) const { return _frusta.size(); }
  INLINE int add_frustum(ProjectionNode* frust);
  INLINE int remove_frustum(ProjectionNode* frust);

  typedef pvector<ProjectionNode *> ProjectionVector;

protected:

  ProjectionVector                      _frusta;

public:

  static TypeHandle get_class_type() {
    return _type_handle;
  }
  static void init_type() {
    Shader::init_type();
    register_type(_type_handle, "FrustumShader",
                  Shader::get_class_type());
  }
  virtual TypeHandle get_type() const {
    return get_class_type();
  }

private:

  static TypeHandle _type_handle;
};

#include "shader.I"

#endif
