DropShadowEffect.qml Example File

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 import QtQuick 1.0
 import Qt.labs.shaders 1.0

 Item {
     id: main
     property real blur: 0.0
     property alias color: shadowEffectWithHBlur.color
     property alias sourceItem: source.sourceItem

     ShaderEffectSource {
         id: source
         smooth: true
         hideSource: false
     }

     ShaderEffectItem {
         id: shadowEffectWithHBlur
         anchors.fill: parent

         property color color: "grey"
         property variant sourceTexture: source;
         property real xStep: main.blur / main.width

         vertexShader:"
             uniform highp mat4 qt_ModelViewProjectionMatrix;
             attribute highp vec4 qt_Vertex;
             attribute highp vec2 qt_MultiTexCoord0;
             uniform highp float xStep;
             varying highp vec2 qt_TexCoord0;
             varying highp vec2 qt_TexCoord1;
             varying highp vec2 qt_TexCoord2;
             varying highp vec2 qt_TexCoord4;
             varying highp vec2 qt_TexCoord5;
             varying highp vec2 qt_TexCoord6;

             void main(void)
             {
                 highp vec2 shift = vec2(xStep, 0.);
                 qt_TexCoord0 = qt_MultiTexCoord0 - 2.5 * shift;
                 qt_TexCoord1 = qt_MultiTexCoord0 - 1.5 * shift;
                 qt_TexCoord2 = qt_MultiTexCoord0 - 0.5 * shift;
                 qt_TexCoord4 = qt_MultiTexCoord0 + 0.5 * shift;
                 qt_TexCoord5 = qt_MultiTexCoord0 + 1.5 * shift;
                 qt_TexCoord6 = qt_MultiTexCoord0 + 2.5 * shift;
                 gl_Position =  qt_ModelViewProjectionMatrix * qt_Vertex;
             }
         "

         fragmentShader:"
             uniform highp vec4 color;
             uniform lowp sampler2D sourceTexture;
             varying highp vec2 qt_TexCoord0;
             varying highp vec2 qt_TexCoord1;
             varying highp vec2 qt_TexCoord2;
             varying highp vec2 qt_TexCoord4;
             varying highp vec2 qt_TexCoord5;
             varying highp vec2 qt_TexCoord6;

             void main() {
                 highp vec4 sourceColor = (texture2D(sourceTexture, qt_TexCoord0) * 0.1
                 + texture2D(sourceTexture, qt_TexCoord1) * 0.15
                 + texture2D(sourceTexture, qt_TexCoord2) * 0.25
                 + texture2D(sourceTexture, qt_TexCoord4) * 0.25
                 + texture2D(sourceTexture, qt_TexCoord5) * 0.15
                 + texture2D(sourceTexture, qt_TexCoord6) * 0.1);
                 gl_FragColor = mix(vec4(0), color, sourceColor.a);
             }
         "
     }

     ShaderEffectSource {
         id: hBlurredShadow
         smooth: true
         sourceItem: shadowEffectWithHBlur
         hideSource: true
     }

     ShaderEffectItem {
         id: finalEffect
         anchors.fill: parent

         property color color: "grey"
         property variant sourceTexture: hBlurredShadow;
         property real yStep: main.blur / main.height

         vertexShader:"
             uniform highp mat4 qt_ModelViewProjectionMatrix;
             attribute highp vec4 qt_Vertex;
             attribute highp vec2 qt_MultiTexCoord0;
             uniform highp float yStep;
             varying highp vec2 qt_TexCoord0;
             varying highp vec2 qt_TexCoord1;
             varying highp vec2 qt_TexCoord2;
             varying highp vec2 qt_TexCoord4;
             varying highp vec2 qt_TexCoord5;
             varying highp vec2 qt_TexCoord6;

             void main(void)
             {
                 highp vec2 shift = vec2(0., yStep);
                 qt_TexCoord0 = qt_MultiTexCoord0 - 2.5 * shift;
                 qt_TexCoord1 = qt_MultiTexCoord0 - 1.5 * shift;
                 qt_TexCoord2 = qt_MultiTexCoord0 - 0.5 * shift;
                 qt_TexCoord4 = qt_MultiTexCoord0 + 0.5 * shift;
                 qt_TexCoord5 = qt_MultiTexCoord0 + 1.5 * shift;
                 qt_TexCoord6 = qt_MultiTexCoord0 + 2.5 * shift;
                 gl_Position =  qt_ModelViewProjectionMatrix * qt_Vertex;
             }
         "

         fragmentShader:"
             uniform highp vec4 color;
             uniform lowp sampler2D sourceTexture;
             uniform highp float qt_Opacity;
             varying highp vec2 qt_TexCoord0;
             varying highp vec2 qt_TexCoord1;
             varying highp vec2 qt_TexCoord2;
             varying highp vec2 qt_TexCoord4;
             varying highp vec2 qt_TexCoord5;
             varying highp vec2 qt_TexCoord6;

             void main() {
                 highp vec4 sourceColor = (texture2D(sourceTexture, qt_TexCoord0) * 0.1
                 + texture2D(sourceTexture, qt_TexCoord1) * 0.15
                 + texture2D(sourceTexture, qt_TexCoord2) * 0.25
                 + texture2D(sourceTexture, qt_TexCoord4) * 0.25
                 + texture2D(sourceTexture, qt_TexCoord5) * 0.15
                 + texture2D(sourceTexture, qt_TexCoord6) * 0.1);
                 gl_FragColor = sourceColor * qt_Opacity;
             }
         "
     }
 }