Okay this is what I've got so far. I've got a shader based on the horizontal gaussian blur shader that can be found at http://www.adobe.com/devnet/flex/articles/pixel_bender_basics_flex_air.html
Its been altered to have two inputs (one for background and one per foreground as per http://help.adobe.com/en_US/ActionScript/3.0_ProgrammingAS3/WSB19E965E-CCD2-4174-8077-8E5D0141A4A8.html the shader is as follows: <languageVersion: 1.0;> kernel HorizontalGaussianBlur < namespace : "com.adobe.example"; vendor : "Adobe Systems Inc."; version : 1; description : "The horizontal convolution of a Gaussian blur"; > { input image4 background; input image4 foreground; output pixel4 dst; void evaluatePixel() { pixel4 center, band1, band2, band3, band4, band5, band6; float2 pos = outCoord(); int radius = 6; //Sample image in bands if( radius > 5 ) { band4 = sampleNearest(background, float2(pos.x - 6.0, pos.y)) + sampleNearest(background, float2(pos.x + 6.0, pos.y)); } if( radius > 4 ) { band4 = sampleNearest(background, float2(pos.x - 5.0, pos.y)) + sampleNearest(background, float2(pos.x + 5.0, pos.y)); } if( radius > 3 ) { band4 = sampleNearest(background, float2(pos.x - 4.0, pos.y)) + sampleNearest(background, float2(pos.x + 4.0, pos.y)); } if( radius > 2 ) { band3 = sampleNearest(background, float2(pos.x - 3.0, pos.y)) + sampleNearest(background, float2(pos.x + 3.0, pos.y)); } if( radius > 1 ) { band2 = sampleNearest(background, float2(pos.x - 2.0, pos.y)) + sampleNearest(background, float2(pos.x + 2.0, pos.y)); } band1 = sampleNearest(background, float2(pos.x - 1.0, pos.y)) + sampleNearest(background, float2(pos.x + 1.0, pos.y)); center = sampleNearest(background, pos); //Apply weights and compute resulting pixel if( radius == 6 ) { dst = (band6 + (band5 * 12.0) + (band4 * 66.0) + (band3 * 220.0) + (band2 * 495.0) + (band1 * 792.0) + (center * 924.0))/4096.0; } if( radius == 5 ) { dst = (band5 + (band4 * 10.0) + (band3 * 45.0) + (band2 * 120.0) + (band1 * 210.0) + (center * 252.0))/1024.0; } if( radius == 4 ) { dst = (band4 + (band3 * 8.0) + (band2 * 28.0) + (band1 * 56.0) + (center * 70.0))/256.0; } if( radius == 3 ) { dst = (band3 + (band2 * 6.0) + (band1 * 15.0) + (center * 20.0))/64.0; } if( radius == 2 ) { dst = (band2 + (band1 * 4.0) + (center * 6.0))/16.0; } if( radius == 1 ) { dst = (band1 + (center * 2.0))/4.0; } } } I've then tried applying to a component. which gives the following error. ArgumentError: Error #2167: The Shader does not have the required number of inputs for this operation. at flash.display::DisplayObject/set blendShader() at mx.binding::Binding/defaultDestFunc()[E:\dev\4.y\frameworks\projects\framework\src\mx\binding\Binding.as:282] at Function/http://adobe.com/AS3/2006/builtin::call() at mx.binding::Binding/innerExecute()[E:\dev\4.y\frameworks\projects\framework\src\mx\binding\Binding.as:485] at Function/http://adobe.com/AS3/2006/builtin::apply() at mx.binding::Binding/wrapFunctionCall()[E:\dev\4.y\frameworks\projects\framework\src\mx\binding\Binding.as:395] at mx.binding::Binding/execute()[E:\dev\4.y\frameworks\projects\framework\src\mx\binding\Binding.as:333] at mx.binding::BindingManager$/executeBindings()[E:\dev\4.y\frameworks\projects\framework\src\mx\binding\BindingManager.as:153] but as far as I can see there are two inputs and according to the page listed above when using a shader as a blender it needs two inputs. (I'm only using one input the foreground one is being ignored) any ideas? --- In flexcoders@yahoogroups.com, Wes <wesley.acheson@...> wrote: > > Hi. > > I'm wondering if there is any way to blur the contents behind a component. > Similiar to how an alert box works but not the entire display. I think that > it should be possible based on a couple of facts. > > 1 blendmode means that a component must be able to know the visuals behind it. > 2 even changing an alpha must mean the player is aware of underlying visuals > as there are pixel maths involved. > 3 blend modes which are not native to the flash player are implemented as > shaders. > 4 gaussian blur could be implemented as a custom shader if necessary. > > I have seen AS2 implementations but they rely on getting a bitmap of an > entire background. This obviously doesn't work with overlapping components. > > Ideally for simplicity I'd do this as a custom background on a spark > titlewindow component. Initially as this can be dragged arround. > > If this can't be implemented as a shader is there any way to link the size > and position of two unrelated components. This would be useful for > underlays/overlaying > > Wes > > Sent from my Kindle Fire >
