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cssmaskcss-shapesclip-path

Mask image with a triangle at the bottom

I'm trying to figure out how to best mask a div with an angular shape like so--if the top div in this case will be a background image, and both divs would be 100% width:

Mask image with a triangle at the bottom

I've seen lots of tutorials out there on how to mask an image with a circle shape, but none on how you would mask the border of a div like the red area. I know there must be a better way than doing this with bitmaps, but am at a loss.

Would it be best to do this with clip-path or SVG? I'm not all that concerned about older browsers, if the result is that they see the red/blue divs separated with a flat line. The entire red area will be a background image, so if old(er) browsers miss out on that angular border, so be it.

Solution

  • You can use transform (skew and rotate) to achieve this effect without the use of clip-path which has low support

    .container {
  width: 500px;
  height: 300px;
  background: linear-gradient(lightblue, dodgerblue);
  position: relative;
  overflow:hidden;
}

.container:after{
  position:absolute;
  content:"";
  width:100%;
  height:100%;
  left:-50%;
  top:-50%;
  background:#D0021B;
  transform-origin: 0 100%; 
  transform:skewY(15deg);
}

.container:before{
  position:absolute;
  content:"";
  width:100%;
  height:100%;
  left:50%;
  top:-50%;
  background:#D0021B;
  transform-origin: 100% 0; 
  transform:skewY(-15deg);
}
    <div class="container"></div>

    For background images, you should apply top:50% on both the pseudo-elements

    .container {
  width: 500px;
  height: 300px;
  background: url("http://i.imgur.com/5NK0H1e.jpg");
  position: relative;
  overflow: hidden;
}
.container:after {
  position: absolute;
  content: "";
  width: 100%;
  height: 100%;
  left: -50%;
  top: 50%;
  background: linear-gradient(lightblue,dodgerblue);
  transform: skew(10deg) rotate(10deg);
}
.container:before {
  position: absolute;
  content: "";
  width: 100%;
  height: 100%;
  left: 50%;
  top: 50%;
  background:linear-gradient(lightblue,dodgerblue);
  transform: skew(-10deg) rotate(-10deg);
}
    <div class="container"></div>