doc-svg/exercices/vision/reponse1.md

layout, title

layout	title
layouts/page.njk	SVG - Exercice - Filtre

SVG couvrant toute la page

<svg height="100%" width="100%">
</svg>

Photo et rectangle noir par dessus

<image href="street1.jpg" height="100%" width="100%" />
<rect width="100%" height="100%" />

Dégrédé radial

<radialGradient id="Gradient" r="0.4">
  <stop offset="0%" stop-color="white"/>
  <stop offset="20%" stop-color="white"/>
  <stop offset="100%" stop-color="black"/>
</radialGradient>

<mask id="masque">
  <circle id="centre" r="2%" fill="url(#Gradient)" />
</mask>

Ajouter le masque sur le rectangle noir

<rect width="100%" height="100%" mask="url(#masque)" />

Code javascript pour suivre la souris

document.body.onmousemove = event => 
{
  document.getElementById("centre").setAttribute("cx", event.clientX );
  document.getElementById("centre").setAttribute("cy", event.clientY );
}

Code complet

<svg height="100%" width="100%">
  <defs>
    <radialGradient id="Gradient" r="0.4">
      <stop offset="0%" stop-color="white"/>
      <stop offset="20%" stop-color="white"/>
      <stop offset="100%" stop-color="black"/>
    </radialGradient>
    <mask id="masque">
      <circle id="centre" cx="512" cy="342" r="20%" fill="url(#Gradient)" />
    </mask>
  </defs>
  <image href="street1.jpg" x="0" y="0" height="100%" width="100%" />
  <rect width="100%" height="100%" mask="url(#masque)" />
</svg>
<script>
document.body.onmousemove = event => 
{
  document.getElementById("centre").setAttribute("cx", event.clientX );
  document.getElementById("centre").setAttribute("cy", event.clientY );
}
</script>

Voir la solution