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void GLAPIENTRY
gluPerspective(GLdouble fovy, GLdouble aspect, GLdouble zNear, GLdouble zFar)
{
    GLdouble m[4][4];
    double sine, cotangent, deltaZ;
    double radians = fovy / 2 * __glPi / 180;

    deltaZ = zFar - zNear;
    sine = sin(radians);
    if ((deltaZ == 0) || (sine == 0) || (aspect == 0)) {
        return;
    }
    cotangent = COS(radians) / sine;

    __gluMakeIdentityd(&m[0][0]);
    m[0][0] = cotangent / aspect;
    m[1][1] = cotangent;
    m[2][2] = -(zFar + zNear) / deltaZ;
    m[2][3] = -1;
    m[3][2] = -2 * zNear * zFar / deltaZ;
    m[3][3] = 0;
    glMultMatrixd(&m[0][0]);
}