Is there a more efficient way to do multi-step animations? - html

Question

Im trying to make transitions very similar to what I have in the code example below. It works pretty well here, but when I use it on the real site it almost never works. Some transition-delays seem to be skipped and its not smooth like in this simplified example. On the site i'm trying to make this as part of a slideshow transition so other transitions are happening at the same time so i'm thinking the GPU can't handle the way I have it set up. Is there another way to accomplish this so that i'm not transitioning each div separately? Can I make one transition not start until the previous one has started? Possibly with keyframes or steps?
function toggleActive(){
var element = document.getElementById('wrap');
element.classList.toggle('active');
}
#wrap{
position:relative;
overflow:hidden;
}
#wrap img{
max-width:100%;
}
.diagonal-transition{
background-color:#edf8fb;
position: absolute;
height: 201%;
width:25%;
transform: rotate(45deg);
top: -200%;
opacity:.7;
transition-duration: .5s;
}
.diag-box-1{
left:67%;
}
.diag-box-2{
left:102.4%;
transition-delay: .5s;
}
.diag-box-3{
left:137.8%;
transition-delay: 1s;
}
.diag-box-4{
left:173.2%;
transition-delay: 1.5s;
}
.diag-box-5{
left:208.7%;
transition-delay: 2s;
}
.active .diag-box-1, .active .diag-box-2, .active .diag-box-3, .active .diag-box-4, .active .diag-box-5{
transform: rotate(45deg) translatey(100%);
}
<div id="wrap">
<img src="https://s8.postimg.cc/3q4ybyfad/parrot.jpg">
<div class="diagonal-transition diag-box-1"></div>
<div class="diagonal-transition diag-box-2"></div>
<div class="diagonal-transition diag-box-3"></div>
<div class="diagonal-transition diag-box-4"></div>
<div class="diagonal-transition diag-box-5"></div>
</div>
<button onclick="toggleActive()">ACTIVE STATE</button>

Answer 1

I would do this differently considering only backgrounds and only one animation. Then you can adjust background-size/background-position to control the behavior of the animation:
function toggleActive() {
var element = document.getElementById('wrap');
element.classList.toggle('active');
}
#wrap {
position: relative;
overflow: hidden;
width: 500px;
height: 300px;
background-image:
linear-gradient(120deg,transparent 0% ,rgba(237, 248, 251, 0.7) 0%,rgba(237, 248, 251, 0.7) 20%,transparent 20.5%),
linear-gradient(120deg,transparent 21%,rgba(237, 248, 251, 0.7) 20%, rgba(237, 248, 251, 0.7) 40%,transparent 40.5%),
linear-gradient(120deg,transparent 41%,rgba(237, 248, 251, 0.7) 40%, rgba(237, 248, 251, 0.7) 60%,transparent 60.5%),
linear-gradient(120deg,transparent 61%,rgba(237, 248, 251, 0.7) 60%, rgba(237, 248, 251, 0.7) 80%,transparent 80.5%),
linear-gradient(120deg,transparent 81%,rgba(237, 248, 251, 0.7) 80%, rgba(237, 248, 251, 0.7) 100%,transparent 100%),
url(https://s8.postimg.cc/3q4ybyfad/parrot.jpg);
background-position:0 0,0 0,0 0,0 0,0 0,center;
background-size: 0 100%,0 100%,0 100%,0 100%,0 100%,cover;
background-repeat: no-repeat;
}
.active {
animation:change 1s linear forwards;
}
#keyframes change {
0% {
background-size: 100% 0,100% 0,100% 0,100% 0,100% 0,cover;
}
20% {
background-size: 100% 100%,100% 0,100% 0,100% 0,100% 0,cover;
}
40% {
background-size: 100% 100%,100% 100%,100% 0,100% 0,100% 0,cover;
}
60% {
background-size: 100% 100%,100% 100%,100% 100%,100% 0,100% 0,cover;
}
80% {
background-size: 100% 100%,100% 100%,100% 100%,100% 100%,100% 0,cover;
}
100% {
background-size: 100% 100%,100% 100%,100% 100%,100% 100%,100% 100%,cover;
}
}
<div id="wrap">
</div>
<button onclick="toggleActive()">ACTIVE STATE</button>