S60 3rd Edition SDK for Symbian OS Example Applications Guide

Billboard.h

/*
* ==============================================================================
*  Name        : Billboard.h
*  Part of     : OpenGLEx / Billboard
*  Interface   : 
*  Description : 
*  Version     : 
*
*  Copyright (c) 2004-2006 Nokia Corporation.
*  This material, including documentation and any related 
*  computer programs, is protected by copyright controlled by 
*  Nokia Corporation.
* ==============================================================================
*/

#ifndef __BILLBOARH__
#define __BILLBOARH__

// INCLUDES
#include <e32base.h> // for CBase definition
#include <GLES\gl.h> // OpenGL ES header file
#include "utils.h"

// MACROS
#define FRUSTUM_LEFT   -1.f     //left vertical clipping plane
#define FRUSTUM_RIGHT   1.f     //right vertical clipping plane
#define FRUSTUM_BOTTOM -1.f     //bottom horizontal clipping plane
#define FRUSTUM_TOP     1.f     //top horizontal clipping plane
#define FRUSTUM_NEAR    3.f     //near depth clipping plane
#define FRUSTUM_FAR  1000.f     //far depth clipping plane

// CLASS DECLARATION

/**
 * Class that does the actual OpenGL ES rendering.
 * Subclass of CFiniteStateMachine because the application
 * needs to handle loading textures and running states.
 */
class CBillboard : public CFiniteStateMachine, public MTextureLoadingListener
        {
        public:   // Constructors and destructor
  
        /**
         * Factory method for creating a new CBillboard object.
         */
                static CBillboard* NewL( TUint aWidth, TUint aHeight);

        /**
         * Destructor. Does nothing.
         */
                virtual ~CBillboard();

        public: // New functions

        /**
         * Initializes OpenGL ES, sets the vertex and color
         * arrays and pointers. Also selects the shading mode and
         * creates the CTextureManager instance and starts loading
         * of required textures.
         */
                void AppInitL( void );

        /**
         * Called upon application exit. Destroys the CTextureManager
         * instance that was created in AppInitL() method.
         */
                void AppExit( void );

        /**
         * Renders one frame.
         * @param aFrame Number of the frame to be rendered.
         */
                void AppCycle( TInt aFrame);

                /**
                 * Draws the ground plane.
                 * @param aFrame Current frame number.
                 */
                void DrawPlane( TInt aFrame  );

                /**
                 * Draws a tree.
                 * @param aFrame Current frame number.
                 * @param aI Counter.
                 * @param aJ Counter.
                 */
                void DrawTree( TInt aFrame, TInt aI, TInt aJ );

                /**
                 * Draws clouds.
                 * @param aFrame Current frame number
                 */
                void DrawCloud( TInt aFrame);

        /**
         * Called when the finite state machine enters a new state.
         * Does nothing in this implementation.
         * @param aState State that is about to be entered.
         */
                void OnEnterStateL( TInt aState );

        /**
         * Called when texture manager starts loading the textures.
         * Sets the current state to "loading textures".
         */
                void OnStartLoadingTexturesL();

        /**
         * Called when texture manager has completed texture loading.
         * Changes the current state to "running".
         */
                void OnEndLoadingTexturesL();

                /**
                 * Returns the system time using TTime.
                 * @return Current system time.
                 */
                TTime GetTimeTick(); 

                /**
                 * Returns the elapsed time between the current and the previous frame.
                 * @return Elapsed time between the current and the previous frame in seconds.
                 */
                GLfixed GetElapsedTime();

                /**
                 * Returns the current frame rate in frames per second.
                 * @return Current f.p.s.
                 */
                GLfixed GetFPSCount();
    
                /**
                 * Move the camera from/to the origin.
                 * @param aDirection Direction to move the camera.
                 * @param aTime Time interval that is used as the basis for calculating the movement.
                 */
                void MoveCamera(GLint aDirection, GLfixed aTime = 0);

                /**
                 * Turn the camera in azimuth.
                 * @param aDirection Direction to turn the camera.
                 * @param aTime Time interval that is used as the basis for calculating the movement.
                 */
                void TurnCamera(GLint aDirection, GLfixed aTime = 0);
                
                /**
                 * Notifies that the screen size has dynamically changed during execution of
                 * this program. Resets the viewport to this new size and sets this size
                 * to the CTextureManager.
         * @param aWidth New width of the screen.
         * @param aHeight New height of the screen.
                 */
                void SetScreenSize( TUint aWidth, TUint aHeight );


        protected:
        
        /**
         * Standard constructor that must never Leave.
         * Stores the given screen width and height.
         * @param aWidth Width of the screen.
         * @param aHeight Height of the screen.
         */
                CBillboard( TUint aWidth, TUint aHeight);
        
        /**
         * Second phase contructor. Does nothing.
         */
                void ConstructL( void );
    
        public:  // Data

        /**
         * Application states:
         * ELoadingTextures - indicates that the app. is loading textures.
         * ERunning - indicates that the app. is running.
         */
                enum 
                        {
                        ELoadingTextures, 
                        ERunning
                        };
                
        /** Animation direction and speed for moving the camera. */
                GLbyte iDirection;

        private:  // Data
        
        /** Width of the screen */
        TUint iScreenWidth;
        /** Height of the screen */
        TUint iScreenHeight;

        /** Texture manager that is used to load the used textures. */
                CTextureManager * iTextureManager;

                /** Tree texture. */
                TTexture iTreeTexture;
                /** Grass texture. */
                TTexture iGrassTexture;
                /** Cloud texture. */
                TTexture iCloudTexture;
                /** Cloud texture coordinates. */
                GLshort iCloudTextureCoords[8];
                /** Cloud texture offset. Used to animate the clouds in the sky. */
                GLshort iTextureOffset;

                /** Camera. */
                TCamerax iCamera;
                /** Camera azimuth. */
                GLfixed iAzimuth;
                /** Camera distance. */
                GLfixed iDistance;

                /** Time begin. */
                TTime iT0;
                /** Time end. */
                TTime iT1;
                /** Time delta = elapsed time */
                GLfixed iElapsedTime;
                /** Counter for frames per second. */
                GLfixed iFPSCount;

        /** Vertice coordinates drawing the clouds. */
        GLfloat iCloudVertices[12];

                /** Lookup-table for sin, cos, tan. */
                CLookUpTable * iLookUpTable;
};


#endif      // __BILLBOARH_

// End of File

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© Nokia 2006