CuGLES

class CuGLES : public CuEGL  
{

public:
    void Ortho(double left, double right, double bottom, double top, double Near, double Far);
    void Frustum( double fovy, double aspect, double zNear, double zFar );
    void Viewport(int x, int y, int width, int height);
#if 0
    void DrawArrays(const void *pvlist, const void *pnvlist, const void *ptclist,int stride, int numvertices);
    void DrawElements(const void *pvlist, const void *pnvlist, const void *ptclist,int stride, int numvertices,
        const void *pfaceindex, int numfaceindex);
#endif
    
    CuGLES();
    virtual ~CuGLES();

};

CuGLES::CuGLES()
{

}

CuGLES::~CuGLES()
{

}

#if 0
void CuGLES::DrawArrays(const void *pvlist, const void *pnvlist, const void *ptclist, int stride, int numvertices)
{

    glTexCoordPointer(2, GL_FIXED, stride, ptclist);
    // setup client states
    glEnableClientState(GL_TEXTURE_COORD_ARRAY);    // setup arrays
    // first the vertices
    glVertexPointer(3, GL_FIXED , stride, pvlist);
    glEnableClientState(GL_VERTEX_ARRAY);


    // next the normals
//  glNormalPointer(GL_SHORT, stride, pnvlist);
    glNormalPointer(GL_FIXED , stride, pnvlist);
    glEnableClientState(GL_NORMAL_ARRAY);

    glDrawArrays(GL_TRIANGLES , 0, numvertices);


    glDisableClientState(GL_VERTEX_ARRAY);
    glDisableClientState(GL_NORMAL_ARRAY);
    glDisableClientState(GL_TEXTURE_COORD_ARRAY);

}


void CuGLES::DrawElements(const void *pvlist, const void *pnvlist, const void *ptclist,int stride, int numvertices,
    const void *pfaceindex, int numfaceindex)
{

    glTexCoordPointer(2, GL_FIXED, stride, ptclist);
    // setup client states
    glEnableClientState(GL_TEXTURE_COORD_ARRAY);


    // setup arrays
    // first the vertices
    glVertexPointer(3, GL_FIXED , stride, pvlist);
    glEnableClientState(GL_VERTEX_ARRAY);


    // next the normals
    glNormalPointer(GL_FIXED , stride, pnvlist);
    glEnableClientState(GL_NORMAL_ARRAY);

    glDrawElements(GL_TRIANGLES , numfaceindex, GL_UNSIGNED_BYTE , pfaceindex);


    glDisableClientState(GL_VERTEX_ARRAY);
    glDisableClientState(GL_NORMAL_ARRAY);
    glDisableClientState(GL_TEXTURE_COORD_ARRAY);

}
#endif

void CuGLES::Viewport(int x, int y, int width, int height)
{
    glViewport(x,y,width,height);
}

#define PI_     3.14159265358979323846
void CuGLES::Frustum(double fovy, double aspect, double zNear, double zFar)
{
    // 設定投影
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();

    float right, left, top, bottom;
    top = zNear * tan(fovy * PI_ / 180.0 / 2 );
    bottom = -top;
    right = top * aspect;
    left = -right;

    glFrustumx(EGL_FixedFromFloat(left), EGL_FixedFromFloat(right),
        EGL_FixedFromFloat(bottom), EGL_FixedFromFloat(top),
        EGL_FixedFromFloat(zNear), EGL_FixedFromFloat(zFar) );

}

void CuGLES::Ortho(double left, double right, double bottom, double top, double Near, double Far)
{

    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    glOrthox(
        EGL_FixedFromFloat(left),
        EGL_FixedFromFloat(right),
        EGL_FixedFromFloat(bottom), 
        EGL_FixedFromFloat(top), 
        EGL_FixedFromFloat(Near), 
        EGL_FixedFromFloat(Far));

}

完全不了解為什麼要繼承, 想不起來.