Revision of Twine: Sugarcane custom CSS passage transitions from Tue, 02/26/2013 - 00:02

I've modified my previous Sugarcane passage transition code to allow you to define your own transitions with CSS.

The code
First, include this code in a script passage:

History.prototype.display=function(d,b,a){var c=tale.get(d);this.history.unshift({passage:c,variables:clone(this.history[0].variables)});
this.history[0].hash=this.save();var e=c.render();e.style.visibility="visible";if(a!="offscreen"){var p=$("passages");
for(var i=0;i<p.childNodes.length;i+=1){var q=p.childNodes[i];q.classList.add("transition-out");
setTimeout(function(){p.removeChild(q);},1000);}e.classList.add("transition-in");
setTimeout(function(){e.classList.remove("transition-in");},1);p.appendChild(e);}if((a=="quietly")||(a=="offscreen")){e.style.visibility="visible";
}if(a!="offscreen"){document.title=tale.title;this.hash=this.save();document.title+=": "+c.title;
window.location.hash=this.hash;window.scroll(0,0);}return e;};

What this does is remove the default JavaScript transition from Sugarcane, and cause the outgoing passage to gain a "transition-out" class, and the incoming passage to instantly gain and lose a "transition-in" class. This enables you to define new passage transitions by styling these 3 classes using CSS.

CSS Examples

In order for there to be a transition, you must specify the transition property for your passage elements. A very basic example is as follows:

.passage {
	transition: 0.25s linear;
	-webkit-transition: 0.25s linear;
}
The transition property causes elements to transition between styles when they gain and lose them, in a specific way. In this case, it's a quarter-second, purely linear transition. (Other options than "linear" are listed here.) The maximum duration time before the departing passage is removed is 1 second.

The current versions of Opera, Firefox and IE support the plain transition property, but you need to also include the -webkit variant in order to work in Chrome and Safari (you can also include -khtml-transition for Konqueror users, few though they may be).

Now that you've defined the transition itself, you can define the styles that the passages can transition from and to.

A very basic example:

.transition-in {
	position:absolute;
	opacity:0;
}
When a new passage arrives, its style will transition from the "transition-in" style to the normal passage style. In this case, it starts invisible ("opacity:0") and fades in to visibility. Note the "position:absolute" - both "transition-in" and "transition-out" should have either position:absolute or position:fixed if you want them to neatly appear above or below each other.
.transition-out {
	position:absolute;
	opacity:0;
}

Putting identical styles for "transition-out" means that departing passages will fade out of visibility as well. With all 3 of these CSS snippets, you've replicated the "dissolve" transition linked above.

A broad number of CSS attributes can be used with this technique. Experiment!

Combining with tag-based CSS

If you use my tag-based passage CSS code, you can tie transitions to passages tagged with a particular tag. For instance, to bind the "dissolve" transition to passages tagged with "t8n-dissolve":

body[data-tags~=t8n-dissolve] .transition-in {
	position:absolute;
	opacity:0;
}
body[data-tags~=t8n-dissolve] .passage {
	transition:1s;
	-webkit-transition: 1s;
}
body[data-tags~=t8n-dissolve] .transition-out {
	position:absolute;
	opacity:0;
}
I recommend prefixing all transition-based tags with something identical, like "t8n" (a numeronym of "transition"). This way, you can then define a default transition to be used only when no "t8n" tags are present:
body:not([data-tags*=t8n]) .transition-in {
	opacity:0;
	transform: translate(0,3rem);
	-webkit-transform: translate(0,3rem);
	position:absolute;
}
body:not([data-tags*=t8n]) .passage {
	transition: 2s;
	-webkit-transition: 2s;
}
body:not([data-tags*=t8n]) .transition-out {
	opacity:0;
	transform: translate(0,-3rem);
	-webkit-transform: translate(0,-3rem);
	position:absolute;
}

(Remember that [data-tags*=t8n] selects elements whose tags contain "t8n", and :not() selects elements that do not fulfill the requirement in the brackets.)

It's important that if you use multiple transitions, the default transition should be guarded using body:not([data-tags*=t8n]), so that its code doesn't interfere with the other transitions' code.

To see an example where the first four passages are tagged "t8n-dissolve" and the rest are not, see here.

Live examples
All examples are "The Sky in the Room" by Porpentine.

Fade in (the default transition)

.transition-in {
	opacity:0;
	position:absolute;
}
.passage:not(.transition-out) {
	transition: 1s;
	-webkit-transition: 1s;
}
.transition-out {
	opacity:0;
	position:absolute;
}

Specifying :not(.transition-out) means that the transition is applied only for the incoming passage - the departing one instantly gets opacity:0. Note that specifying passage.transition-in would not do anything, since it is by removing the transition-in class that the transition is initiated.

Dissolve

.transition-in {
	position:absolute;
	opacity:0;
}
.passage {
	transition: 1s;
	-webkit-transition: 1s;
}
.transition-out {
	position:absolute;
	opacity:0;
}

Retro 8-bit four-step fade in

.transition-in {
	opacity:0;
	position:absolute;
}
.passage:not(.transition-out) {
	transition: 0.8s steps(3);
	-webkit-transition: 0.8s steps(3);
}
.transition-out {
	opacity:0;
	position:absolute;
}

Fade out

.transition-in {
	opacity:0;
	position:absolute;
}
.passage:not(.transition-out) {
	transition: 0s 1s;
	-webkit-transition: 0s 1s;
}
.transition-out {
	transition: 1s;
	-webkit-transition: 1s;
	opacity:0;
	position:absolute;
}

Vertical wipe
Sadly, this currently only works if you give the passage div a fixed width and height.
If you use this, replace all instances of "1200px" and "800px" with dimensions appropriate for your story.

.transition-in {
	clip: rect(0px, 1200px, 0px, 0px) !important;
}
.passage {
	clip: rect(0px, 1200px, 800px, 0px);
	width: 1200px;
	height: 800px;
	position: absolute;
	transition: 1s linear;
	-webkit-transition: 1s linear;
}
.transition-out {
	clip: rect(800px, 1200px, 800px, 0px);
}

Zoom In

.transition-in {
	opacity:0;
	transform: scale(0.8,0.8);
	-webkit-transform: scale(0.8,0.8);
	position:absolute;
}
.passage {
	width: calc(100% - 12em); // Necessary to keep the zoom origin point consistent.
	width: -webkit-calc(100% - 12em);
	transition: 0.5s ease-out;
	-webkit-transition: 0.5s ease-out;
}
.transition-out {
	opacity:0;
	transform: scale(2,2);
	-webkit-transform: scale(2,2);
	position:absolute;
}

Fast scroll up
Ideally you would use "vh" (viewport height) units instead of "rem" (root em) units, but not enough browsers support it yet. ;_;
You can also make it a slow fading scroll if you change the lengths to something short (like 3rem).

.transition-in {
	opacity:0;
	transform: translate(0,-100rem);
	-webkit-transform: translate(0,-100rem);
	position:absolute;
}
.passage {
	transition: 1s;
	-webkit-transition: 1s;
}
.transition-out {
	opacity:0;
	transform: translate(0,100rem);
	-webkit-transform: translate(0,100rem);
	position:absolute;
}

Garage door
This would work well with a story whose passage divs have a fixed width and height, but unlike the vertical wipe it isn't strictly necessary.

.transition-in {
	opacity:0;
	position:absolute;
}
.passage {
	background-color: #000;
	transition: 1s ease-in;
	-webkit-transition: 1s ease-in;
}
.transition-out {
	position:absolute;
	z-index:3;
	transform: translate(0,-200%);
	-webkit-transform: translate(0,-200%);
}

Focus

.transition-in {
	color:transparent;
	text-shadow: #fff 0 0 1em;
	position:absolute;
}
.passage:not(.transition-out) {
	transition: 1s;
	-webkit-transition: 1s;
}
.transition-out {
	opacity:0;
	position:absolute;
}

"Blur Merge"

.transition-in {
	color:transparent;
	text-shadow: #fff -4em 0 1em, #fff 4em 0 1em;
	position:absolute;
}
.passage:not(.transition-out) {
	transition: 1s;
	-webkit-transition: 1s;
}
.transition-out {
	opacity:0;
	position:absolute;
}

AttachmentSize
tsitr_fadein.html92.69 KB
tsitr_fadeout.html92.74 KB
tsitr_scrollup.html92.82 KB
tsitr_focus.html92.76 KB
tsitr_sillyrotate.html92.92 KB
tsitr_retrofadein.html92.71 KB
tsitr_spin5seconds.html92.98 KB
tsitr_blur_merge.html92.74 KB
tsitr_garagedoor.html92.78 KB
tsitr_zoomin2.html92.92 KB
tsitr_verticalwipe.html92.87 KB
tsitr_t8ntest.html93.84 KB
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