new test GUI code

_G.
{
    tex_background = TEXTURE("ui/bg1.png"),
    tex_button_core_n = TEXTURE("ui/button_core.png"),
    tex_button_core_h = TEXTURE("ui/button_core_h.png"),
    tex_button_core_c = TEXTURE("ui/button_core_c.png"),
    tex_button_core_f = TEXTURE("ui/button_core_f.png"),
};

function ButtonShader( ctrl )
{
    tex = if( ctrl.clickedL, tex_button_core_c,
        if( ctrl.hover, tex_button_core_h, tex_button_core_n ) );
    ctrl.DTex( tex );
    ctrl.DButton( 0, 0, ctrl.width, ctrl.height, 4, 4/128 );
    ctrl.DFont( "core", ctrl.height / 2 );
    ctrl.DText( ctrl.text, ctrl.width / 2,
        ctrl.height / 2 + ctrl.InvIS( ctrl.clickedL ),
        HALIGN_CENTER, VALIGN_CENTER );
    if( ctrl.focused )
    {
        ctrl.DTex( tex_button_core_f );
        ctrl.DButton( 0, 0, ctrl.width, ctrl.height, 4, 4/128 );
    }
}

function CreateButton( x, y, w, h, text )
{
    ctrl = this.CreateControl( x, y, w, h );
    ocb = ctrl.eventCallback;
    function button_callback( ev ) use( ocb )
    {
        if( ev.type == GUI_Event_BtnUp )
        {
            if( this.Hit( ev.x, ev.y ) && ev.button == GUI_MB_Left )
                this.InvokeCallbacks( "onclick" );
            return 1;
        }
        return this!ocb( ev );
    }
    ctrl.eventCallback = button_callback;
    ctrl.shaders.push( ButtonShader );
    ctrl.text = text;
    ctrl.focusable = true;
    return ctrl;
}

function YesNoQuestion( text )
{
    answer = null;
    factor = 0.0;

    scr_overlay = ROOT.CreateScreen( GUI_ScrMode_Crop, 100, 100 ).{ z = 1000 };
    scr_overlay.shaders.push(function( ctrl )
    {
        ctrl.DCol( 0, 0.5 );
        ctrl.DQuad( 0, 0, ctrl.width, ctrl.height );
    });
    scr_bgr = ROOT.CreateScreen( GUI_ScrMode_Fit, 200, 100 ).{
        z = 1001, xscale = 0.4, yscale = 0.4, text = text };
    scr_bgr.shaders.push(function( ctrl ) use( factor )
    {
        // background
        ctrl.DCol( 0.1, 0.3, 0.7, 0.5 );
        ctrl.DQuad( 0, 0, 200, 100 );
        // top border
        ctrl.DCol( 0.7, 1 );
        ctrl.DQuad( 0, 0, 200 * factor, 20 );
        ctrl.DCol( 0.8, 1 );
        ctrl.DQuad( 0, 20, 200 * factor, 21 );
        ctrl.DCol( 0.0, 0.2 );
        ctrl.DQuad( 0, 21, 200 * factor, 24 );
        // question text
        ctrl.DCol( 0.02, 1 * factor );
        ctrl.DFont( "core", 10 );
        ctrl.DText( ctrl.text, 5, 10, HALIGN_LEFT, VALIGN_CENTER );
    });

    btn_yes = scr_bgr!CreateButton( 10, 70, 60, 20, "Yes" );
    btn_yes.AddCallback( "onclick", function() use(answer){ answer = true; } );
    btn_no = scr_bgr!CreateButton( 200-70, 70, 60, 20, "No" );
    btn_no.AddCallback( "onclick", function() use(answer){ answer = false; } );

    SetFocusRoot( scr_bgr );

    function min(a,b){ return if(a<b,a,b); }
    while( factor < 1 )
    {
        factor = min( factor + 0.05, 1 );
        yield 0.01;
    }

    while( answer === null )
    {
        yield;
    }

    return answer;
}

global scr_background = ROOT.CreateScreen( GUI_ScrMode_Crop, 512, 512 ).{ z = -1 };
t = 0;
scr_background.shaders.push(function( ctrl, dt ) use( t )
{
    t += dt;
    ctrl.DTex( tex_background );
    ctrl.DQuadExt( 0, 0, 512, 512, t * -0.02 );
    process_threads();
});

global scr_mainmenu = ROOT.CreateScreen( GUI_ScrMode_Fit, 100, 100 );
scr_mainmenu.shaders.push(function( ctrl )
{
    ctrl.DCol( 0, 0.5 );
    ctrl.DQuad( 5, 5, ctrl.width - 5, ctrl.height - 5 );
});

global scr_button1 = scr_mainmenu!CreateButton( 10, 10, 40, 5, "Click me" );
scr_button1.AddCallback( "onclick", function()
{
    println( "clicked!" );
    thread YesNoQuestion( "Do you want to do something?" );
});

global scr_button2 = scr_mainmenu!CreateButton( 10, 20, 40, 5, "Click me 2" );
scr_button2.AddCallback( "onclick", function()
{
    println( "clicked 2!" );
    thread YesNoQuestion( "Do you want to do something?" );
});