texture.cpp

这是在s60第五版上用Open GL开发的软件

    glEnableClientState( GL_TEXTURE_COORD_ARRAY );
    glEnableClientState( GL_NORMAL_ARRAY        );

    /* Set array pointers. */
    glVertexPointer(   3, GL_BYTE, 0, vertices     );
    glTexCoordPointer( 2, GL_BYTE, 0, nokTexCoords );
    glNormalPointer(   GL_BYTE, 0, normals         );

    /* Set up global ambient light. */
    glLightModelxv( GL_LIGHT_MODEL_AMBIENT, globalAmbient );

    /* Set up lamp. */
    glEnable(   GL_LIGHT0 );
    glLightxv( GL_LIGHT0, GL_DIFFUSE,  lightDiffuseLamp  );
    glLightxv( GL_LIGHT0, GL_AMBIENT,  lightAmbientLamp  );
    glLightxv( GL_LIGHT0, GL_SPECULAR, lightSpecularLamp );
    glLightxv( GL_LIGHT0, GL_POSITION, lightPositionLamp );

    /* Set shading mode*/
    glShadeModel( GL_FLAT );

    /* Set the blending function for translucency. */
    glBlendFunc( GL_ONE, GL_ONE );

    /* Do not use perspective correction, can be enabled from the menu */
    glHint( GL_PERSPECTIVE_CORRECTION_HINT, GL_FASTEST );

    /* Symbian menu item initialization. See CTextureAppUi.cpp for more. */
    iPerspectiveCorrEnabled = EFalse; // no texture perspective correction
    iTextureWrapEnabled     = EFalse; // no texture wrapping
    iLightingEnabled        = EFalse; // no lighting
    iBlendingEnabled        = EFalse; // no blending

    // Pushing the textures into the loading queue.
    _LIT(KIcons1, "icons1.jpg");
    _LIT(KIcons2, "icons2.jpg");
    _LIT(KIcons3, "icons3.jpg");
    _LIT(KIcons4, "icons4.jpg");
    iTextureManager->RequestToLoad(KIcons1, &iIcons1 );
    iTextureManager->RequestToLoad(KIcons2, &iIcons2 );
    iTextureManager->RequestToLoad(KIcons3, &iIcons3 );
    iTextureManager->RequestToLoad(KIcons4, &iIcons4 );

    //Start to load the textures.
    TRAPD( err, iTextureManager->DoLoadL() );
    if ( err != KErrNone )
    {
      _LIT(KImagesMissing, "Images missing");
      User::Panic( KImagesMissing, 0 );
    }
}


// -----------------------------------------------------------------------------
// CTexture::AppExit
// Relase any allocations made in AppInit
// -----------------------------------------------------------------------------
//
void CTexture::AppExit( void )
{
    delete iTextureManager;
}


// -----------------------------------------------------------------------------
// CTexture::AppCycle
// OpenGL ES main rendering loop.
// -----------------------------------------------------------------------------
//
void CTexture::AppCycle( TInt aFrame, TRotationDirection aDirection )
{
  glClear( GL_COLOR_BUFFER_BIT );

  /* Animate and draw the cube. */
  glLoadIdentity();
  gluLookAt( 0.f, 0.f, 120.f,     // Camera position
             0.f, 0.f,   0.f,     // Look at point
             0.f, 1.f,   0.f );   // Up direction

  switch (aDirection)
  {
    case ERotationRight: glRotatex( aFrame << 16,    0    , 1 << 16,    0   ); break; 
    case ERotationLeft:  glRotatex( aFrame << 16,    0    , 1 << 16,    0   ); break; 
  };

  /* Scale the cube coordinates to fit the screen. */
  glScalex( 16 << 16, 16 << 16, 16 << 16 );
  glTranslatex(0, 1<<16,0);
 
  /* Draw the remaining side of the cube with the ogles.jpg texture. */
  glBindTexture(  GL_TEXTURE_2D, iIcons2.iID );
  glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST );
  glDrawElements( GL_TRIANGLES, 2 * 3, GL_UNSIGNED_BYTE, triangles2 );
  
  glBindTexture(  GL_TEXTURE_2D, iIcons3.iID );
  glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST );
  glDrawElements( GL_TRIANGLES, 2 * 3, GL_UNSIGNED_BYTE, triangles3 );
  
  glBindTexture(  GL_TEXTURE_2D, iIcons2.iID );
  glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST );
  glDrawElements( GL_TRIANGLES, 2 * 3, GL_UNSIGNED_BYTE, triangles4 );
  
  glBindTexture(  GL_TEXTURE_2D, iIcons3.iID );
  glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST );
  glDrawElements( GL_TRIANGLES, 2 * 3, GL_UNSIGNED_BYTE, triangles5 ); 
  
     
  glTranslatex(0, -2<<16,0);

  /* Draw the remaining side of the cube with the ogles.jpg texture. */
  glBindTexture(  GL_TEXTURE_2D, iIcons1.iID );
  glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST );
  glDrawElements( GL_TRIANGLES, 2 * 3, GL_UNSIGNED_BYTE, triangles2 );
  
  glBindTexture(  GL_TEXTURE_2D, iIcons4.iID );
  glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST );
  glDrawElements( GL_TRIANGLES, 2 * 3, GL_UNSIGNED_BYTE, triangles3 );
  
  glBindTexture(  GL_TEXTURE_2D, iIcons1.iID );
  glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST );
  glDrawElements( GL_TRIANGLES, 2 * 3, GL_UNSIGNED_BYTE, triangles4 );
  
  glBindTexture(  GL_TEXTURE_2D, iIcons4.iID );
  glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST );
  glDrawElements( GL_TRIANGLES, 2 * 3, GL_UNSIGNED_BYTE, triangles5 );        
}

// -------------------------------------------------------------------------------------------------------
// CBillboard::OnStartLoadingTextures()
// Called for a MTextureLoadingListener by the texture manager when texture loading operation starts
// -------------------------------------------------------------------------------------------------------

void CTexture::OnStartLoadingTexturesL()
{
  SetStateL( ELoadingTextures );
}

// ------------------------------------------------------------------------------------------------------------
// CBillboard::OnEndLoadingTextures()
// Called for a MTextureLoadingListener by the texture manager when texture loading operation is completed
// ------------------------------------------------------------------------------------------------------------
void CTexture::OnEndLoadingTexturesL()
{
  if ( GetState() == ELoadingTextures )
  {
    SetStateL( ERunning );
    AppCycle( 0, ERotationRight );
  }
}

// ---------------------------------------------------------
// CBillboard::OnEnterState( TInt aState )
// Called by TFiniteStateMachine when the f.s.m enters a new state
// ---------------------------------------------------------

void CTexture::OnEnterStateL( TInt /*aState*/ )
	{
	    // Nothing to do here...
	}

//----------------------------------------------------------
// The following methods are called by the CTextureAppUi
// class when handling the incoming menu events.
//----------------------------------------------------------


// -----------------------------------------------------------------------------
// CTexture::TogglePerspective
// User defines whether or not to use perspective correction when rendering
// -----------------------------------------------------------------------------
//
void CTexture::TogglePerspective( void )
{
    if( iPerspectiveCorrEnabled)
    {
    	iPerspectiveCorrEnabled = EFalse;
    	glHint( GL_PERSPECTIVE_CORRECTION_HINT, GL_FASTEST );
    }
    else
    {
    	iPerspectiveCorrEnabled = ETrue;
    	glHint( GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST );
    }
}

/**
 * Enable/Disable texture wrapping.
 */
// -----------------------------------------------------------------------------
// CTexture::ToggleWrapping
// Implement texture wrapping by changing the texture matrix scale
// -----------------------------------------------------------------------------
//
void CTexture::ToggleWrapping( void )
{
    if( iTextureWrapEnabled )
    {
    	iTextureWrapEnabled = EFalse;
    	glMatrixMode( GL_TEXTURE );
    	glLoadIdentity();
    	glScalef( 1.0f/255.0f, 1.0f/255.0f, 1.0f );
    	glTranslatef( 128.0f, 128.0f, 1.0f );
    	glMatrixMode( GL_MODELVIEW );
    }
    /* Texture wrapping is implemented here simply by changing the scale of
       texture matrix. Now the coordinate values are between [0,2], which
       causes the texture to wrap one time. */
    else
    {
    	iTextureWrapEnabled = ETrue;
    	glMatrixMode( GL_TEXTURE );
    	glLoadIdentity();
    	glScalef( 1.0f/128.0f, 1.0f/128.0f, 1.0f );
    	glTranslatef( 128.0f, 128.0f, 1.0f );
    	glMatrixMode( GL_MODELVIEW );
    }
}

/**
 * Enable/Disable lighting.
 */
// -----------------------------------------------------------------------------
// CTexture::ToggleLighting
// When using textures with lights the texenv must be set to GL_MODULATE,
// and shade model must be GL_SMOOTH.
// -----------------------------------------------------------------------------
//
void CTexture::ToggleLighting( void )
{
    // If texture loading is still going on, return from this method without doing anything.
	if ( GetState() == ELoadingTextures )
    {
        return;
    }

    if( iLightingEnabled )
    {
    	iLightingEnabled = EFalse;
    	glShadeModel( GL_FLAT );  // Don't need smooth shading when no lights
    	glDisable( GL_LIGHTING ); // Disable lighting

    	/* Set both textures environments to GL_REPLACE. */
    	glBindTexture( GL_TEXTURE_2D, iIcons1.iID );
    	glTexEnvx(  GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE );
	    glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST );

    	glBindTexture( GL_TEXTURE_2D, iIcons2.iID );
    	glTexEnvx(  GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE );
	    glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST );
    }
    else
    {
    	iLightingEnabled = ETrue;
    	glShadeModel( GL_SMOOTH ); // For the lighting to work properly
    	glEnable( GL_LIGHTING );   // Enable lighting

    	/* Set both textures environments to GL_MODULATE. */
    	glBindTexture( GL_TEXTURE_2D, iIcons1.iID );
    	glTexEnvx(  GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE );
	    glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST );

    	glBindTexture( GL_TEXTURE_2D, iIcons2.iID );
    	glTexEnvx(  GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE );
	    glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST );
    }
}


// -----------------------------------------------------------------------------
// CTexture::ToggleBlending
// User defines whether or not blending is enabled from the menu.
// -----------------------------------------------------------------------------
//
void CTexture::ToggleBlending( void )
{
    if( iBlendingEnabled )
    {
        // Blending was enabled, disable blending
        iBlendingEnabled = EFalse;
        glDisable( GL_BLEND );
        glEnable( GL_CULL_FACE  );
    }
    else
    {
        // Blending was disabled, enable blending
        iBlendingEnabled = ETrue;
        glEnable( GL_BLEND );
        glDisable( GL_CULL_FACE  );
    }
}

// -----------------------------------------------------------------------------
// CTexture::SetScreenSize
// Reacts to the dynamic screen size change during execution of this program.
// -----------------------------------------------------------------------------
//
void CTexture::SetScreenSize( TUint aWidth, TUint aHeight )
    {
    iScreenWidth  = aWidth;
    iScreenHeight = aHeight;

    // Notify the texture manager of screen size change
    iTextureManager->SetScreenSize( aWidth, aHeight );

    // Reinitialize viewport and projection.
    glViewport( 0, 0, iScreenWidth, iScreenHeight );

    // Recalculate the view frustrum
    glMatrixMode( GL_PROJECTION );
    glLoadIdentity();
    GLfloat aspectRatio = (GLfloat)(iScreenWidth) / (GLfloat)(iScreenHeight);
    glFrustumf( FRUSTUM_LEFT * aspectRatio, FRUSTUM_RIGHT * aspectRatio,
                FRUSTUM_BOTTOM, FRUSTUM_TOP,
                FRUSTUM_NEAR, FRUSTUM_FAR );
    glMatrixMode( GL_MODELVIEW );
    }