/*!
 * @file graphics_engine.h

  *  defines a Interface between orxonox and graphical input

    handles graphical SDL-initialisation, textures, resolutions, and so on
 */

#ifndef _GRAPHICS_ENGINE_H
#define _GRAPHICS_ENGINE_H

#include "event_listener.h"

#include "sdlincl.h"
#include "glincl.h"
#include <list>

#include "substring.h"

// Forward Declaration
class Text;
class WorldEntity;
class GraphicsEffect;
class TiXmlElement;

//! class to handle graphics
/**
   handles graphical SDL-initialisation, textures, resolutions, and so on
 */
class GraphicsEngine : public EventListener
{
  public:
    virtual ~GraphicsEngine();
    /** @returns a Pointer to the only object of this Class */
    inline static GraphicsEngine* getInstance() { if (!GraphicsEngine::singletonRef) GraphicsEngine::singletonRef = new GraphicsEngine();  return GraphicsEngine::singletonRef; };

    virtual void loadParams(const TiXmlElement* root);

    int init();
    int initFromPreferences();

    void setWindowName(const std::string& windowName, const std::string& icon);

    int setResolution(int width, int height, int bpp);
    void setFullscreen(bool fullscreen = false);
    void toggleFullscreen();
    static void setBackgroundColor(GLclampf red, GLclampf green, GLclampf blue, GLclampf alpha = 1.0);

    inline void setAntialiasing(bool flag) { this->bAntialiasing = flag; }
    inline bool getAntialiasing() { return this->bAntialiasing; }

    /** @returns the x resolution */
    inline int getResolutionX() const { return this->resolutionX; };
    /** @returns the y resolution */
    inline int getResolutionY() const { return this->resolutionY; };
    /** @returns the Bits Per Pixel */
    inline int getbbp() const { return this->bitsPerPixel; };

    void resolutionChanged(const SDL_ResizeEvent& resizeInfo);

    static void enter2DMode();
    static void leave2DMode();

    void wireframe();

    static void storeMatrices();
    static GLdouble modMat[16];
    static GLdouble projMat[16];
    static GLint viewPort[4];

    void update(float dt);
    void tick(float dt);

    void drawBackgroundElements() const;
    void draw() const;
    void toggleFPSdisplay();
    void displayFPS(bool display);

    void listModes();
    bool hwSupportsEXT(const std::string& extension);

    /** @brief swaps the GL_BUFFERS */
    inline static void swapBuffers() { SDL_GL_SwapBuffers(); };

    void process(const Event  &event);

    void loadGraphicsEffects(const TiXmlElement* root);



  private:
    GraphicsEngine();
    int initVideo(unsigned int resX, unsigned int resY, unsigned int bbp);
    void setGLattribs();
    void grabHardwareSettings();

  public:

  private:
    static GraphicsEngine*     singletonRef;       //!< Pointer to the only instance of this Class
    bool                       isInit;             //!< if the GraphicsEngine is initialized.

    // state.
    SDL_Surface*               screen;             //!< the screen we draw to
    int                        resolutionX;        //!< the X-resoultion of the screen
    int                        resolutionY;        //!< the Y-resolution of the screen
    int                        bitsPerPixel;       //!< the bits per pixels of the screen
    Uint32                     fullscreenFlag;     //!< if we are in fullscreen mode
    Uint32                     videoFlags;         //!< flags for video
    SDL_Rect**                 videoModes;         //!< list of resolutions

    bool                       fogEnabled;         //!< If Fog should be enabled.
    bool                       shadowsEnabled;     //!< If Shadows should be enabled.
    bool                       particlesEnabled;   //!< If particles should be enabled.
    bool                       bAntialiasing;      //!< true if antialiasing enabled

    int                        particlesValue;     //!< How many particles
    int                        textureQuality;     //!< the quality of Textures
    int                        filteringMethod;    //!< The filtering Method of textures.
    int                        modelQuality;       //!< The quality of the Models loaded.
    int                        antialiasingDepth;  //!< the Depth of the AntiAlias-Filter.

    // HARDWARE-Settings:
    std::string                hwRenderer;         //!< HW-renderer-string
    std::string                hwVendor;           //!< HW-vendor-string
    std::string                hwVersion;          //!< HW-version-string
    SubString                  hwExtensions;       //!< All suported Extensions.

    // FPS-related
    bool                       bDisplayFPS;        //!< is true if the fps should be displayed
    float                      currentFPS;         //!< the current frame rate: frames per seconds
    float                      maxFPS;             //!< maximal frame rate we ever got since start of the game
    float                      minFPS;             //!< minimal frame rate we ever got since start.

    const std::list<BaseObject*>* graphicsEffects; //!< list of graphics effects


#ifndef NO_TEXT
  Text*          geTextCFPS;                    //!< Text for the current FPS
  Text*          geTextMaxFPS;                  //!< Text for the max FPS
  Text*          geTextMinFPS;                  //!< Text for the min FPS
#endif /* NO_TEXT */
};

#endif /* _GRAPHICS_ENGINE_H */