Warning, /webapps/qmlonline/qml/examples/shadereffect.qml is written in an unsupported language. File is not indexed.

 import QtQuick 2.7
 import QtQuick.Controls 2.3
 
 Rectangle {
     color: "red"
     anchors.fill: parent
 
     ShaderEffect {
         Image {
             id: profilePic
             source: "https://farm8.staticflickr.com/7861/46451042134_cb4cefce18_b.jpg"
             visible: false
         }
 
         property variant src: profilePic
         width: 400
         height: width
         anchors.centerIn: parent
 
         vertexShader: "
             uniform highp mat4 qt_Matrix;
             attribute highp vec4 qt_Vertex;
             attribute highp vec2 qt_MultiTexCoord0;
             varying highp vec2 coord;
             void main() {
                 coord = qt_MultiTexCoord0;
                 gl_Position = qt_Matrix * qt_Vertex;
             }
         "
         fragmentShader: "
             #ifdef GL_ES
                 precision mediump float;
             #endif
 
             varying highp vec2 coord;
             uniform sampler2D src;
             uniform lowp float qt_Opacity;
             void main() {
                 float d = distance(coord, vec2(0.5, 0.5));
                 if(d > 0.5) {
                     gl_FragColor = vec4(0, 0, 0, 0) * qt_Opacity;
                     return;
                 }
                 lowp vec4 tex = texture2D(src, coord);
                 gl_FragColor = vec4(tex.rgb, tex.a) * qt_Opacity;
             }
         "
     }
 }