ACTIONSCRIPT 3 Developer’s Guide en

ACTIONSCRIPT 3.0 DEVELOPER’S GUIDE
Working with Pixel Bender shaders
var shaderData:ShaderData = myShader.data;
var inputs:Vector. = new Vector.();
var parameters:Vector. = new Vector.();
var metadata:Vector. = new Vector.();
for (var prop:String in shaderData)
{
if (shaderData[prop] is ShaderInput)
{
inputs[inputs.length] = shaderData[prop];
}
else if (shaderData[prop] is ShaderParameter)
{
parameters[parameters.length] = shaderData[prop];
}
else
{
metadata[metadata.length] = shaderData[prop];
}
}
// do something with the inputs or properties
Specifying shader input values
Flash Player 10 and later, Adobe AIR 1.5 and later
Many shaders expect one or more input images that are used in the shader processing. However, in many cases an
input is specified automatically when the Shader object is used. For example, suppose a shader requires one input, and
that shader is used as a filter. When the filter is applied to a display object or BitmapData object, that object is
automatically set as the input. In that case you do not explicitly set an input value.
However, in some cases, especially if a shader defines multiple inputs, you do explicitly set a value for an input. Each
input that is defined in a shader is represented in ActionScript by a ShaderInput object. The ShaderInput object is a
property of the ShaderData instance in the Shader object’s data property, as described in “Identifying shader inputs
and parameters” on page 305. For example, suppose a shader defines an input named src, and that shader is linked to
a Shader object named myShader. In that case you access the ShaderInput object corresponding to the src input using
the following identifier:
myShader.data.src
Each ShaderInput object has an input property that is used to set the value for the input. You set the input property
to a BitmapData instance to specify image data. You can also set the input property to a BitmapData or
Vector. instance to specify binary or number data. For details and restrictions on using a BitmapData or
Vector. instance as an input, see the ShaderInput.input listing in the ActionScript 3.0 Reference for the
Adobe Flash Platform.
In addition to the input property, a ShaderInput object has properties that can be used to determine what type of
image the input expects. These properties include the width, height, and channels properties. Each ShaderInput
object also has an index property that is useful for determining whether an explicit value must be provided for the
input. If a shader expects more inputs than the number that are automatically set, then you set values for those inputs.
For details on the different ways to use a shader, and whether input values are automatically set, see “Using a shader”
on page 310.
Last updated 6/6/2012
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