background image's fadeInOut transitions produces weird effect in white all the texts

Question

Well this problem is kind of weird,

I have a website where the background image changes with a fadeIn/Out transition

Video: http://www.screenr.com/ZCvs

Web in action: http://toniweb.us/gm

The markup:

        <div class="fondo" onclick="descargar(2,500);descargar(1,500);"></div>
        <div id="headerimgs">
            <div id="headerimg1" class="headerimg"></div>
            <div id="headerimg2" class="headerimg"></div>
        </div>
        <!-- Inicio Cabecera -->

CSS:

.headerimg { 
    background-position: center top; background-repeat: no-repeat; width:100%;position:absolute;height:100%;cursor:pointer; 
     -webkit-background-size: cover;
        -moz-background-size: cover;
        -o-background-size: cover;
        background-size: cover;

}
.headerimg img{ 
    min-width:100%; width:100%; height:100%;
}

    .fondo{
    position:absolute;
    z-index:1;
    width:100%;
    height:100%;
    cursor:pointer;
}

Javascript:

/*Gestion de pase de imágenes de fondo*/
$(document).ready(function() {
    /*controla la velocidad de la animación*/
    var slideshowSpeed = 3000;
    var transitionSpeed = 2000;
    var timeoutSpeed = 500;

    /*No tocar*/
    var interval;
    var activeContainer = 1;    
    var currentImg = 0;
    var animating = false;
    var navigate = function(direction) {
        // Si ya estamos navegando, entonces no hacemos nada!
        if(animating) {
            return;
        }
        currentImg++;
        if(currentImg == photos.length + 1) {
            currentImg = 1;
        }
        // Tenemos dos, uno en el que tenemos la imagen que se ve y otro d?nde tenemos la imagen siguiente
        var currentContainer = activeContainer;
        // Esto puedo optimizarlo con la funci?n modulo, y cambiar 1 y 2 por 0 y 1-> active = mod2(active + 1)
        if(activeContainer == 1) {
            activeContainer = 2;
        } else {
            activeContainer = 1;
        }
        // hay que decrementar el ?ndice porque empieza por cero
        cargarImagen(photos[currentImg - 1], currentContainer, activeContainer);
    };
    var currentZindex = -1;
    var cargarImagen = function(photoObject, currentContainer, activeContainer) {
        animating = true;
        // Nos aseguramos que el nuevo contenedor está siempre dentro del cajon
        currentZindex--;
        //if(currentZindex < 0) currentZindex=1;
        // Actualizar la imagen
        $("#headerimg" + activeContainer).css({
            "background-image" : "url(" + photoObject + ")",
            "display" : "block",
            "z-index" : currentZindex
        });
        // FadeOut antigua
        // Cuando la transición se ha completado, mostramos el header 
        $("#headerimg" + currentContainer).fadeOut(transitionSpeed,function() {
            setTimeout(function() {
                $("#headertxt").css({"display" : "block"});
                animating = false;
            }, timeoutSpeed);
        });
    };
    //ver la primera
     navigate("next");
    //iniciar temporizador que mostrará las siguientes



    interval = setInterval(function() {
        navigate("next");
    }, slideshowSpeed);

});

there is also an overlay div (class fondo) (height and width 100%) so i can dectect when the background has been clicked (i can not use directly the background div because the transition makes it have negative z-index)

the problem is that this transition produces a weird effect in all white texts

any idea what am i missing?

Answer 1

I don't know what caused the glitches on your computer, I can't reproduce it: I test using IE7,8,9, latest Chrome and Firefox on Windows 7. Please provide us with more information about your setup. Did you visit a 3d-enabled website before testing your own site? It seems like a graphics-card bug. Did you use the latest browser and graphics card drivers?

On a side note, something you might want to consider is making your fade animation easier: it stutters a bit in Chrome after initial load.

The easiest animation that can do this thing is a window.setInterval with the following code executing:

function(){
    var container = $('#headerimgs');
    var current = container.children('div:visible:first');
    var next = (current.next().length > 1) ? current.next() : container.children('div:visible');

    current.fadeOut(300);
    next.fadeIn(300);
}

Fiddle a bit with the durations to get the exact effect you want. Note, you'll need to position the .headerimg divs absolutely, so they overlap completely.

Answer 2

Trace your fade in / out start and ending...

Chances are it might be an asyncronous error, in which more then one fade in / out is occurring or is left occurring at the same time, that may have been set incorrectly...

This is more of a conjuncture then an answer, however these flickering issues with fadeIn / out, tend to boil down to this (from experience, 90+% of the time).

Also check if you have any mouseover / mouseenter CSS properties / events.

Apologies that i cant trace it myself: as i cant seem to repro the error either.

Random : Chrome sometimes do not show these asyncronous errors, due to it being too fast. The error can end up being a frame (or none), that is effectively invisible to the eye. Likewise for really fast computers.