I think it is:
SunDirection(-0.3714, -0.7428, 0.5571)
Just extracted some default values from the source code
SetWindowTitle( "AppGameKit Player" );
SetSyncRate( 60, 0 );
SetErrorMode( 1 );
SetVirtualResolution( 100, 100 );
SetShadowSmoothing( 1 );
SetShadowMapSize( 1024, 1024 );
SetShadowRange( -1 );
SetShadowBias( 0.001f );
SetShadowLightStepSize( 0 );
SetVirtualResolution( 100, 100 );
SetDisplayAspect( 2.0f/3.0f );
SetOrientationAllowed( 1,1,1,1 );
EnableClearColor( 1 );
EnableClearDepth( 1 );
SetDefaultMagFilter( 1 );
SetDefaultMinFilter( 1 );
m_fAlphaTestThreashold = 0.5f;
m_iDeviceVolume = 100;
// add main camera back
mainCamera->SetPosition( 0, 10, -20 );
m_AmbientColor.Set( 0.3f, 0.3f, 0.3f );
SetFogColor( 161, 186, 209 );
SetFogRange( 50, 700 );
//SkyBox
SetSkyColor( 0.63f, 0.72f, 0.82f );
SetHorizonColor( 1.0f, 1.0f, 1.0f );
SetSunColor( 1.0f, 0.9f, 0.7f );
SetSunSize( 5.0f, 50.0f );
SetHorizonSize( 4.0f, 0.0f );
SetSunVisible( 1 );
//Directional light
m_color.Set( 1,1,1 );
m_direction.Set( -0.3714f, -0.7428f, 0.5571f );
// 2D Gravity
gravity.Set(0.0f, 10.0f);
// misc vars
SetPrintColor(255,255,255);
m_iRandSeed = 1;
m_fViewZoom = 1.0f;
m_fSyncTime = 1/60.0f;
m_sCurrentDir.SetStr("media/");
// AGK joystick
m_fJoystickDeadZone = 0.15f;
// Physics variables
SetPhysicsWallBottom( 1 );
SetPhysicsWallTop( 1 );
SetPhysicsWallLeft( 1 );
SetPhysicsWallRight( 1 );
m_phyScale = 0.2f;
m_iMaxPolygonPoints = 8;
