Package | flash.display |
Class | public class Shader |
Inheritance | Shader Object |
Subclasses | ColorBurnShader, ColorDodgeShader, ColorShader, ExclusionShader, HueShader, LuminosityMaskShader, LuminosityShader, SaturationShader, SoftLightShader |
Language Version: | ActionScript 3.0 |
Runtime Versions: | Flash Player 10, AIR 1.5 |
shader
property of a
ShaderFilter object.
A shader defines a function that executes on all the pixels in an image, one pixel at a time. The result of each call to the function is the output color at that pixel coordinate in the image. A shader can specify one or more input images, which are images whose content can be used in determining the output of the function. A shader can also specify one or more parameters, which are input values that can be used in calculating the function output. In a single shader execution, the input and parameter values are constant. The only thing that varies is the coordinate of the pixel whose color is the function result. Shader function calls for multiple output pixel coordinates execute in parallel to improve shader execution performance.
The shader bytecode can be loaded at run time using a URLLoader instance. The following example demonstrates loading a shader bytecode file at run time and linking it to a Shader instance.
var loader:URLLoader = new URLLoader(); loader.dataFormat = URLLoaderDataFormat.BINARY; loader.addEventListener(Event.COMPLETE, onLoadComplete); loader.load(new URLRequest("myShader.pbj")); var shader:Shader; function onLoadComplete(event:Event):void { // Create a new shader and set the loaded data as its bytecode shader = new Shader(); shader.byteCode = loader.data; // You can also pass the bytecode to the Shader() constructor like this: // shader = new Shader(loader.data); // do something with the shader }
You can also embed the shader into the SWF at compile time using the
[Embed]
metadata tag. The [Embed]
metadata tag
is only available if you use the Flex SDK to compile the SWF. The
[Embed]
tag's source
parameter points to
the shader file, and its mimeType
parameter is
"application/octet-stream"
, as in this example:
[Embed(source="myShader.pbj", mimeType="application/octet-stream)] var MyShaderClass:Class; // ... // create a new shader and set the embedded shader as its bytecode var shaderShader = new Shader(); shader.byteCode = new MyShaderClass(); // You can also pass the bytecode to the Shader() constructor like this: // var shader:Shader = new Shader(new MyShaderClass()); // do something with the shader
In either case, you link the raw shader (the URLLoader.data
property
or an instance of the [Embed]
data class) to the Shader instance. As
the previous examples demonstrate, you can do this in two ways. You can
pass the shader bytecode as an argument
to the Shader()
constructor. Alternatively, you can set it as the Shader
instance's byteCode
property.
Once a Shader instance is created, it can be used in one of several ways:
- A shader fill: The output of the shader is used as a fill for
content drawn with the drawing API. Pass the Shader instance as
an argument to the
Graphics.beginShaderFill()
method. - A shader filter: The output of the shader is used as a graphic filter
applied to a display object. Assign the Shader instance to the
shader
property of a ShaderFilter instance. - A blend mode: The output of the shader is rendered as the blending
between two overlapping display objects. Assign the Shader instance
to the
blendShader
property of the upper of the two display objects. - Background shader processing: The shader executes in the background,
avoiding the possibility of freezing the display, and dispatches an
event when processing is complete. Assign the Shader instance to
the
shader
property of a ShaderJob instance.
See also
flash.display.Graphics.beginShaderFill()
flash.display.ShaderJob
flash.filters.ShaderFilter
flash.net.URLLoader
Property | Defined By | ||
---|---|---|---|
byteCode : ByteArray [write-only]
The raw shader bytecode for this Shader instance. | Shader | ||
constructor : Object
A reference to the class object or constructor function for a given object instance. | Object | ||
data : ShaderData
Provides access to parameters, input images, and metadata for the Shader instance. | Shader | ||
precisionHint : String
The precision of math operations performed by the shader. | Shader | ||
prototype : Object [static]
A reference to the prototype object of a class or function object. | Object |
Method | Defined By | ||
---|---|---|---|
Creates a new Shader instance. | Shader | ||
Indicates whether an object has a specified property defined. | Object | ||
Indicates whether an instance of the Object class is in the prototype chain of the object specified
as the parameter. | Object | ||
Indicates whether the specified property exists and is enumerable. | Object | ||
Sets the availability of a dynamic property for loop operations. | Object | ||
Returns the string representation of this object, formatted according to locale-specific conventions. | Object | ||
Returns the string representation of the specified object. | Object | ||
Returns the primitive value of the specified object. | Object |
byteCode | property |
byteCode:ByteArray
[write-only] Language Version: | ActionScript 3.0 |
Runtime Versions: | Flash Player 10, AIR 1.5 |
The raw shader bytecode for this Shader instance.
Implementation
public function set byteCode(value:ByteArray):void
data | property |
data:ShaderData
Language Version: | ActionScript 3.0 |
Runtime Versions: | Flash Player 10, AIR 1.5 |
Provides access to parameters, input images, and metadata for the Shader instance.
ShaderParameter objects representing parameters for the shader, ShaderInput objects
representing the input images for the shader, and other values representing the
shader's metadata are dynamically added as properties of the data
property object when the Shader instance is created. Those properties can be
used to introspect the shader and to set parameter and input values.
For information about accessing and manipulating the dynamic properties of
the data
object, see the ShaderData class description.
Implementation
public function get data():ShaderData
public function set data(value:ShaderData):void
See also
precisionHint | property |
precisionHint:String
Language Version: | ActionScript 3.0 |
Runtime Versions: | Flash Player 10, AIR 1.5 |
The precision of math operations performed by the shader.
The set of possible values for the precisionHint
property is defined
by the constants in the ShaderPrecision class.
The default value is ShaderPrecision.FULL
. Setting the precision
to ShaderPrecision.FAST
can speed up math operations at the expense
of precision.
Full precision mode (ShaderPrecision.FULL
) computes all math
operations to the full width of the IEEE 32-bit floating standard and provides
consistent behavior on all platforms. In this mode, some math operations such
as trigonometric and exponential functions can be slow.
Fast precision mode (ShaderPrecision.FAST
) is designed for
maximum performance but does not work consistently on different platforms
and individual CPU configurations. In many cases, this level of precision
is sufficient to create graphic effects without visible artifacts.
The precision mode selection affects the following shader operations. These operations are faster on an Intel processor with the SSE instruction set:
sin(x)
cos(x)
tan(x)
asin(x)
acos(x)
atan(x)
atan(x, y)
exp(x)
exp2(x)
log(x)
log2(x)
pow(x, y)
reciprocal(x)
sqrt(x)
Implementation
public function get precisionHint():String
public function set precisionHint(value:String):void
See also
Shader | () | Constructor |
public function Shader(code:ByteArray = null)
Language Version: | ActionScript 3.0 |
Runtime Versions: | Flash Player 10, AIR 1.5 |
Creates a new Shader instance.
Parameterscode:ByteArray (default = null ) — The raw shader bytecode to link to the Shader.
|
Note that this example assumes there's a shader bytecode file named "donothing.pbj" in the same directory as the output directory for the application. The Pixel Bender source code for the DoNothing shader is available in the ShaderData class example.
package { import flash.display.Shader; import flash.display.Sprite; import flash.events.Event; import flash.net.URLLoader; import flash.net.URLLoaderDataFormat; import flash.net.URLRequest; public class LoadedShaderExample extends Sprite { private var loader:URLLoader; public function LoadedShaderExample() { loader = new URLLoader(); loader.dataFormat = URLLoaderDataFormat.BINARY; loader.addEventListener(Event.COMPLETE, loadCompleteHandler); loader.load(new URLRequest("donothing.pbj")); } private function loadCompleteHandler(event:Event):void { var shader:Shader = new Shader(); shader.byteCode = loader.data; // do something with the Shader instance } } }
Note that this example assumes there's a shader bytecode file named "donothing.pbj" in the same directory as the source code for the application, and that the Flex SDK is used to compile the SWF. The Pixel Bender source code for the DoNothing shader is available in the ShaderData class example.
package { import flash.display.Shader; import flash.display.Sprite; public class EmbeddedShaderExample extends Sprite { [Embed(source="donothing.pbj", mimeType="application/octet-stream")] private static var DoNothingShader:Class; public function EmbeddedShaderExample() { var shader:Shader = new Shader(); shader.byteCode = new DoNothingShader(); // do something with the Shader instance } } }
Fri Mar 19 2010, 02:45 AM -07:00