+static void NinePatchMaskEffectSizeConstraint( Vector2& current, const PropertyInputContainer& inputs )
+{
+ const Vector3& actorSize = inputs[0]->GetVector3();
+ current.x = actorSize.x;
+ current.y = actorSize.y;
+}
+
+inline void DoApply( ImageActor actor, const std::string& maskImage, const Vector2& maskSize, Vector4 maskBorder )
+{
+ const char* ALPHA_MASK_VERTEX_SHADER_SOURCE =
+ "precision mediump float;\n"
+ "uniform vec2 uImageSize; \n"
+ "uniform vec2 uMaskSize; \n"
+ "varying vec2 vMaskTexCoord; \n"
+ " \n"
+ "void main() \n"
+ "{ \n"
+ " gl_Position = uMvpMatrix * vec4(aPosition, 1.0); \n"
+ " \n"
+ " // Ignore mask UVs for image \n"
+ " \n"
+ " highp vec2 halfImageSize = uImageSize * 0.5; \n"
+ " vTexCoord = (aPosition.xy + halfImageSize) / uImageSize; \n"
+ " \n"
+ " // UVs were calculated for image size, so convert for mask size \n"
+ " \n"
+ " highp vec2 halfMaskSize = uMaskSize * 0.5; \n"
+ " highp vec2 halfSizeDelta = halfImageSize - halfMaskSize; \n"
+ " \n"
+ " highp vec2 maskPosition = aPosition.xy; \n"
+ " maskPosition.x -= halfSizeDelta.x * sign(aPosition.x); \n"
+ " maskPosition.y -= halfSizeDelta.y * sign(aPosition.y); \n"
+ " \n"
+ " vMaskTexCoord = (maskPosition + halfMaskSize) / uMaskSize; \n"
+ "} \n";
+
+ const char* ALPHA_MASK_FRAGMENT_SHADER_SOURCE =
+ "varying mediump vec2 vMaskTexCoord; \n"
+ " \n"
+ "void main() \n"
+ "{ \n"
+ " highp vec4 mask = texture2D(sEffect, vMaskTexCoord); \n"
+ " gl_FragColor = texture2D(sTexture, vTexCoord) * uColor * vec4(1,1,1,mask.a); \n"
+ "} \n";
+
+ ShaderEffect maskEffect = ShaderEffect::New(
+ ALPHA_MASK_VERTEX_SHADER_SOURCE,
+ ALPHA_MASK_FRAGMENT_SHADER_SOURCE,
+ ShaderEffect::GeometryHints( ShaderEffect::HINT_BLENDING ) );
+
+ maskEffect.SetEffectImage( ResourceImage::New( maskImage ) );
+
+ maskEffect.SetUniform( "uImageSize", Vector2(0,0) /*Constrained to actor size*/ );
+
+ Constraint constraint = Constraint::New<Vector2>( maskEffect, maskEffect.GetPropertyIndex("uImageSize"), NinePatchMaskEffectSizeConstraint );
+ constraint.AddSource( Source(actor, Actor::Property::SIZE) );
+ constraint.Apply();
+
+ maskEffect.SetUniform( "uMaskSize", maskSize );
+
+ // Actor must provide nine-patch style geometry for this effect to work
+ actor.SetStyle( ImageActor::STYLE_NINE_PATCH );
+ actor.SetNinePatchBorder( maskBorder );
+
+ actor.SetShaderEffect( maskEffect );
+}
+