// Desired framerate:
var fps=30;
// Fade in / Fade out time in seconds:
var fade_time=0.5;

var fade=0;
var dfade=1/(fps*fade_time);
var current_image=0;
var time_to_change=false;

function changeImage() {
	time_to_change=true;
}

function fader() {
	if (time_to_change) {
		fade = fade + dfade;
		if ((fade<0) || (fade>1)) {
			dfade = -dfade;
		}
		if (fade>1) {
			next_image = "";
			current_image++;
			if (current_image>7) {
				current_image = 0;
			}
			switch (current_image) {
				case 0:		next_image = "index_files/slideshow/slide01.jpg"; break;
				case 1: 	next_image = "index_files/slideshow/slide02.jpg"; break;
				case 2:		next_image = "index_files/slideshow/slide03.jpg"; break;
				case 3: 	next_image = "index_files/slideshow/slide04.jpg"; break;
				case 4:		next_image = "index_files/slideshow/slide05.jpg"; break;
				case 5: 	next_image = "index_files/slideshow/slide06.jpg"; break;
				case 6:		next_image = "index_files/slideshow/slide07.jpg"; break;
				case 7: 	next_image = "index_files/slideshow/slide08.jpg"; break;
				default:	next_image = "index_files/slideshow/slide01.jpg";
						current_image = 0;
						break;
			}
			next_image = "url('" + next_image + "')";
			//alert(next_image);
			document.getElementById("slideshow_image").style.backgroundImage=next_image;
		}
		if (fade<0) {
			time_to_change=false;
		}

		temp = String(Math.round(fade*100));
		temp = "alpha(opacity=" + temp + ")";
		//document.getElementById("output_box").value=temp;
		document.getElementById("slideshow_filter").style.opacity=fade;
		document.getElementById("slideshow_filter").style.filter=temp;
	}
}

function fadeImage() {
	fade = fade + dfade;
	if ((fade<0) || (fade>1)) {
		dfade = -dfade;
	}

	temp = String(Math.round(fade*100));
	temp = "alpha(opacity=" + temp + ")";
	document.getElementById("output_box").value=temp;
	document.getElementById("fade_filter").style.opacity=fade;
	document.getElementById("fade_filter").style.filter=temp;
}

window.setInterval("fader()", 1000/fps);
window.setInterval("changeImage()", 5000);