| <!DOCTYPE html> |
| <title>CSS Backdrop Filters Animation: Opacity</title> |
| <link rel="author" title="Mason Freed" href="mailto:masonfreed@chromium.org"> |
| <link rel="help" href="https://drafts.fxtf.org/filter-effects-2/#BackdropFilterProperty"> |
| <link rel="match" href="backdrop-filters-opacity-ref.html"> |
| <style> |
| /* Note that per the spec, the backdrop image is read back, filters |
| are applied, any additional content is drawn, and then the resulting |
| image is composited back into the parent (over the top of the |
| existing backdrop image) using source-over compositing. In this case, |
| the only backdrop filter is opacity, so the backdrop image will be |
| filtered by opacity 50%, the green box (100% opacity) is drawn over |
| that at 100% opacity, and then the entire thing is composited into |
| the backdrop, which already contains the 100% opacity blue square. |
| So the blue square stays 100% blue. */ |
| .square { |
| position: absolute; |
| width: 100px; |
| height: 100px; |
| top: 100px; |
| left: 100px; |
| background: blue; |
| } |
| .filt { |
| backdrop-filter: opacity(50%); |
| position: absolute; |
| width: 200px; |
| height: 200px; |
| top: 50px; |
| left: 50px; |
| } |
| .greenbox { |
| position: absolute; |
| width: 50px; |
| height: 50px; |
| top: 75px; |
| left: 75px; |
| background: green; |
| } |
| </style> |
| <p>You should see a blue square with a green box inside.</p> |
| <div class="square"></div> |
| <div class="filt"> |
| <div class="greenbox"></div> |
| </div> |
