Migrate shadereffects example to be cross-backend

...while demonstrating best practices like file selectors.

Task-number: QTBUG-52914
Change-Id: Ibf7bca77b7b142f5ccb956e05efc5be974d53c79
Reviewed-by: Andy Nichols <andy.nichols@qt.io>

1 files changed, 13 insertions, 0 deletions

diff --git a/examples/quick/shadereffects/content/shaders/wobble.frag b/examples/quick/shadereffects/content/shaders/wobble.frag
new file mode 100644
index 0000000000..fedbb68254
--- /dev/null
+++ b/examples/quick/shadereffects/content/shaders/wobble.frag
@@ -0,0 +1,13 @@
+uniform lowp float qt_Opacity;
+uniform highp float amplitude;
+uniform highp float frequency;
+uniform highp float time;
+uniform sampler2D source;
+
+varying highp vec2 qt_TexCoord0;
+
+void main()
+{
+    highp vec2 p = sin(time + frequency * qt_TexCoord0);
+    gl_FragColor = texture2D(source, qt_TexCoord0 + amplitude * vec2(p.y, -p.x)) * qt_Opacity;
+}