Language version: | ActionScript 3.0
|
The BitmapData class lets you work with the data (pixels) of a
Bitmap object
bitmap image. You can use the methods of the BitmapData class
to create arbitrarily sized transparent or opaque bitmap images and manipulate them in various
ways at runtime.
You can also access the BitmapData for a bitmap image
that you load with the flash.display.Loader
class.
This class lets you separate bitmap rendering operations from the
internal display updating routines of Flash Player. By manipulating
a BitmapData object directly, you can create complex images without incurring the
per-frame overhead of constantly redrawing the content from vector data.
The methods of the BitmapData class support
effects that are not available through the filters available to non-bitmap display objects.
A BitmapData object contains an array of pixel data. This data can represent either
a fully opaque bitmap or a transparent bitmap that contains alpha channel data.
Either type of BitmapData object is stored as a buffer of 32-bit integers.
Each 32-bit integer determines the properties of a single pixel in the bitmap.
Each 32-bit integer is a combination of four 8-bit channel values (from 0 to 255) that
describe the alpha transparency and the red, green, and blue (ARGB) values of the pixel.
(For ARGB values, the most significant byte represents the alpha channel value, followed by red,
green, and blue.)
The four channels (alpha, red, green, and blue) are represented as numbers
when you use them with the BitmapData.copyChannel()
method or the
DisplacementMapFilter.componentX
and DisplacementMapFilter.componentY
properties, and these numbers
are represented by the following constants in the BitmapDataChannel class:
BitmapDataChannel.ALPHA
BitmapDataChannel.RED
BitmapDataChannel.GREEN
BitmapDataChannel.BLUE
You can attach BitmapData objects to a Bitmap object by using the
bitmapData
property of the Bitmap object.
You can use a BitmapData object to fill a Graphics object by using the
Graphics.beginBitmapFill()
method.
In the AIR runtime, the DockIcon, Icon, InteractiveIcon, and SystemTrayIcon classes each include
a bitmaps
property that is an array of BitmapData objects that define the bitmap images
for an icon.
In AIR 1.5 and Flash Player 10, the maximum size for a BitmapData object is 8,191 pixels in width or height,
and the total number of pixels cannot exceed 16,777,215 pixels. (So, if a BitmapData object is 8,191 pixels
wide, it can only be 2,048 pixels high.) In Flash Player 9 and earlier and AIR 1.1 and earlier, the limitation is
2,880 pixels in height and 2,880 in width.
Starting with AIR 3 and Flash player 11, the size limits for a BitmapData object have been removed.
The maximum size of a bitmap is now dependent on the operating system.
Calls to any method or property of a BitmapData object throw an ArgumentError error if
the BitmapData object is invalid (for example, if it has height == 0
and
width == 0
) or it has been disposed of via dispose().
View the examples.
height:int
[read-only]
Language version: | ActionScript 3.0
|
The height of the bitmap image in pixels.
Implementation
public function get height():int
rect:Rectangle
[read-only]
Language version: | ActionScript 3.0
|
The rectangle that defines the size and location of the bitmap image. The top and left of the
rectangle are 0; the width and height are equal to the width and height in pixels of the
BitmapData object.
Implementation
public function get rect():Rectangle
transparent:Boolean
[read-only]
Language version: | ActionScript 3.0
|
Defines whether the bitmap image supports per-pixel transparency. You can set this value only when you construct
a BitmapData object by passing in true
for the transparent
parameter of the constructor. Then, after you create
a BitmapData object, you can check whether it supports per-pixel transparency by determining if the value of the
transparent
property is true
.
Implementation
public function get transparent():Boolean
width:int
[read-only]
Language version: | ActionScript 3.0
|
The width of the bitmap image in pixels.
Implementation
public function get width():int
public function BitmapData(width:int, height:int, transparent:Boolean = true, fillColor:uint = 0xFFFFFFFF)
Language version: | ActionScript 3.0
|
Creates a BitmapData object with a specified width and height.
If you specify a value for the fillColor
parameter, every pixel in the bitmap is set
to that color.
By default, the bitmap is created as transparent, unless you pass the value false
for the transparent
parameter. After you create an opaque bitmap, you cannot change it to
a transparent bitmap. Every pixel in an opaque bitmap uses only 24 bits of color channel information.
If you define the bitmap as transparent, every pixel uses 32 bits of color channel information,
including an alpha transparency channel.
In AIR 1.5 and Flash Player 10, the maximum size for a BitmapData object is 8,191 pixels in width or height,
and the total number of pixels cannot exceed 16,777,215 pixels. (So, if a BitmapData object is 8,191 pixels
wide, it can only be 2,048 pixels high.) In Flash Player 9 and earlier and AIR 1.1 and earlier, the limitation is
2,880 pixels in height and 2,880 pixels in width.
If you specify a width or height value that is greater than 2880, a new instance is not created.
Parameters
| width:int — The width of the bitmap image in pixels.
|
|
| height:int — The height of the bitmap image in pixels.
|
|
| transparent:Boolean (default = true ) — Specifies whether the bitmap image supports per-pixel transparency.
The default value is true (transparent). To create a fully transparent bitmap, set the value
of the transparent parameter to true and the value of the fillColor
parameter to 0x00000000 (or to 0). Setting the transparent property to false
can result in minor improvements in rendering performance.
|
|
| fillColor:uint (default = 0xFFFFFFFF ) — A 32-bit ARGB color value that you use to fill the bitmap image area.
The default value is 0xFFFFFFFF (solid white).
|
Throws
| ArgumentError — width and/or height exceed the maximum dimensions.
|
public function applyFilter(sourceBitmapData:BitmapData, sourceRect:Rectangle, destPoint:Point, filter:BitmapFilter):void
Language version: | ActionScript 3.0
|
Takes a source image and a filter object and generates the
filtered image.
This method relies on the behavior of built-in filter
objects, which determine the destination
rectangle that is affected by an input source rectangle.
After a filter is applied, the resulting image can be larger than the input image.
For example, if you use a BlurFilter class
to blur a source rectangle of (50,50,100,100) and a
destination point of (10,10), the area that changes in the
destination image is larger than (10,10,60,60) because of
the blurring. This happens internally during the applyFilter()
call.
If the sourceRect
parameter of the sourceBitmapData
parameter is
an interior region, such as (50,50,100,100) in a 200 x 200 image, the filter uses the source
pixels outside the sourceRect
parameter to generate
the destination rectangle.
If the BitmapData object and the object specified as the sourceBitmapData
parameter are the same object, the application uses a temporary copy of the object to
perform the filter. For best performance, avoid this situation.
Parameters
| sourceBitmapData:BitmapData — The input bitmap image to use. The source image can be a different
BitmapData object or it can refer to the current BitmapData instance.
|
|
| sourceRect:Rectangle — A rectangle that defines the area of the source image to use as input.
|
|
| destPoint:Point — The point within the destination image (the current BitmapData
instance) that corresponds to the upper-left corner of the source rectangle.
|
|
| filter:BitmapFilter — The filter object that you use to perform the filtering operation. Each type
of filter has certain requirements, as follows:
- BlurFilter —
This filter can use source and destination images
that are either opaque or transparent. If the formats of the images do
not match, the copy of the source image that is made during the
filtering matches the format of the destination image.
- BevelFilter, DropShadowFilter, GlowFilter —
The destination image of these filters must be a transparent
image. Calling DropShadowFilter or GlowFilter creates an image that
contains the alpha channel data of the drop shadow or glow. It does not
create the drop shadow onto the destination image. If you use any of these
filters with an opaque destination image, an exception
is thrown.
- ConvolutionFilter — This filter can use source and
destination images that are either opaque or transparent.
- ColorMatrixFilter — This filter can use source and
destination images that are either opaque or transparent.
- DisplacementMapFilter — This filter can use source and
destination images that are either opaque or transparent, but the
source and destination image formats must be the same.
|
Throws
| TypeError — The sourceBitmapData, sourceRect, destPoint or filter are null.
|
|
| Error — The transparency of the BitmapData objects are not
compatible with the filter operation.
|
See also
Example
The following example shows how to apply a blur filter to a BitmapData instance:
import flash.display.Bitmap;
import flash.display.BitmapData;
import flash.geom.Point;
import flash.geom.Rectangle;
import flash.filters.BlurFilter;
var bmd:BitmapData = new BitmapData(80, 30, false, 0xFFCC00);
var rect:Rectangle = new Rectangle(10, 10, 40, 10);
bmd.fillRect(rect, 0xFF0000);
var pt:Point = new Point(10, 10);
var filter:BlurFilter = new BlurFilter();
bmd.applyFilter(bmd, rect, pt, filter);
var bm:Bitmap = new Bitmap(bmd);
addChild(bm);
public function clone():BitmapData
Language version: | ActionScript 3.0
|
Returns a new BitmapData object that is a clone of the original instance
with an exact copy of the contained bitmap.
Returns
| BitmapData —
A new BitmapData object that is identical to the original.
|
Example
The following example shows how to clone a BitmapData instance, and it shows that when you modify the
cloned BitmapData instance, the original remains unmodified:
import flash.display.Bitmap;
import flash.display.BitmapData;
var bmd1:BitmapData = new BitmapData(100, 80, false, 0x00000000);
var bmd2:BitmapData = bmd1.clone();
bmd1.setPixel32(1, 1, 0xFFFFFFFF);
trace(bmd1.getPixel32(1, 1).toString(16)); // ffffffff
trace(bmd2.getPixel32(1, 1).toString(16)); // ff000000
var bm1:Bitmap = new Bitmap(bmd1);
this.addChild(bm1);
var bm2:Bitmap = new Bitmap(bmd2);
bm2.x = 110;
this.addChild(bm2);
public function colorTransform(rect:Rectangle, colorTransform:ColorTransform):void
Language version: | ActionScript 3.0
|
Adjusts the color values in a specified area of a bitmap image by using a
ColorTransform
object. If the rectangle
matches the boundaries of the bitmap image, this method transforms the color values of
the entire image.
Parameters
| rect:Rectangle — A Rectangle object that defines the area of the image in which the
ColorTransform object is applied.
|
|
| colorTransform:ColorTransform — A ColorTransform object that describes the color transformation
values to apply.
|
Throws
| TypeError — The rect or colorTransform are null.
|
See also
Example
The following example shows how to apply a color transform to the left half (rectangle) of a
BitmapData object:
import flash.display.Bitmap;
import flash.display.BitmapData;
import flash.geom.Rectangle;
import flash.geom.ColorTransform;
var bmd:BitmapData = new BitmapData(80, 30, false, 0xFF0000);
var cTransform:ColorTransform = new ColorTransform();
cTransform.alphaMultiplier = 0.5
var rect:Rectangle = new Rectangle(0, 0, 40, 30);
bmd.colorTransform(rect, cTransform);
var bm:Bitmap = new Bitmap(bmd);
addChild(bm);
public function compare(otherBitmapData:BitmapData):Object
Language version: | ActionScript 3.0
|
Compares two BitmapData objects. If the two BitmapData objects have the same dimensions
(width and height), the method returns a new BitmapData object, in which each pixel is
the "difference" between the pixels in the two source objects:
- If two pixels are equal, the difference pixel is 0x00000000.
- If two pixels have different RGB values (ignoring the alpha value), the difference
pixel is 0xRRGGBB where RR/GG/BB are the individual difference values between red, green,
and blue channels (the pixel value in the source object minus the pixel value in the
otherBitmapData
object). Alpha channel differences are ignored in this case.
- If only the alpha channel value is different, the pixel value is 0xZZFFFFFF,
where ZZ is the difference in the alpha values (the alpha value in the source object
minus the alpha value in the
otherBitmapData
object).
For example, consider the following two BitmapData objects:
var bmd1:BitmapData = new BitmapData(50, 50, true, 0xFFFF8800);
var bmd2:BitmapData = new BitmapData(50, 50, true, 0xCCCC6600);
var diffBmpData:BitmapData = bmd1.compare(bmd2) as BitmapData;
trace ("0x" + diffBmpData.getPixel(0,0).toString(16); // 0x332200
var bmd1 = new air.BitmapData(50, 50, true, 0xFFFF0000);
var bmd2 = new air.BitmapData(50, 50, true, 0xCCFFAA00);
var diffBmpData = bmd1.compare(bmd2);
Note: The colors used to fill the two BitmapData objects have slightly different RGB values
(0xFF0000 and 0xFFAA00). The result of the compare()
method is a new BitmapData
object with each pixel showing the difference in the RGB values between the two bitmaps.
Consider the following two BitmapData objects, in which the RGB colors are the same,
but the alpha values are different:
var bmd1:BitmapData = new BitmapData(50, 50, true, 0xFFFFAA00);
var bmd2:BitmapData = new BitmapData(50, 50, true, 0xCCFFAA00);
var diffBmpData:BitmapData = bmd1.compare(bmd2) as BitmapData;
trace ("0x" + diffBmpData.getPixel32(0,0).toString(16); // 0x33ffffff
var bmd1 = new air.BitmapData(50, 50, true, 0xFFFFAA00);
var bmd2 = new air.BitmapData(50, 50, true, 0xCCFFAA00);
var diffBmpData = bmd1.compare(bmd2);
The result of the compare()
method is a new BitmapData
object with each pixel showing the difference in the alpha values between the two bitmaps.
If the BitmapData objects are equivalent (with the same width, height, and identical pixel values),
the method returns the number 0.
If the widths of the BitmapData objects are not equal, the method returns the number -3.
If the heights of the BitmapData objects are not equal, but the widths are the same,
the method returns the number -4.
The following example compares two Bitmap objects with different widths (50 and 60):
var bmd1:BitmapData = new BitmapData(100, 50, false, 0xFFFF0000);
var bmd2:BitmapData = new BitmapData(100, 60, false, 0xFFFFAA00);
trace(bmd1.compare(bmd2)); // -4
var bmd1 = new air.BitmapData(100, 50, false, 0xFFFF0000);
var bmd2 = new air.BitmapData(100, 60, false, 0xFFFFAA00);
trace(bmd1.compare(bmd2)); // -4
Parameters
| otherBitmapData:BitmapData — The BitmapData object to compare with the source BitmapData object.
|
Returns
| Object —
If the two BitmapData objects have the same dimensions (width and height), the
method returns a new BitmapData object that has the difference between the two objects (see the
main discussion). If the BitmapData objects are equivalent, the method returns the number 0.
If the widths of the BitmapData objects are not equal, the method returns the number -3.
If the heights of the BitmapData objects are not equal, the method returns the number -4.
|
Throws
Example
The following example shows the value of a pixel in the BitmapData object that results from
comparing two BitmapData objects of the same dimensions:
import flash.display.Bitmap;
import flash.display.BitmapData;
var bmd1:BitmapData = new BitmapData(50, 50, true, 0xFFFFAA00);
var bmd2:BitmapData = new BitmapData(50, 50, true, 0xCCFFAA00);
var diffBmpData:BitmapData = BitmapData(bmd1.compare(bmd2));
var diffValue:String = diffBmpData.getPixel32(1, 1).toString(16);
trace (diffValue); // 33ffffff
var bm1:Bitmap = new Bitmap(bmd1);
addChild(bm1);
var bm2:Bitmap = new Bitmap(bmd2);
addChild(bm2);
bm2.x = 60;
public function convertColorProfile(source:Screen, destination:Screen):BitmapData
Language version: | ActionScript 3.0
|
Runtime version: | AIR 51.0
|
Create a copy of the image data, converting between color profiles based on the provided
Screen
objects.
To convert a normal/loaded image (in sRGB color profile) so that it is displayed properly on a
display, pass in null
for the source
screen and the application's display
location as the destination
screen. This would be the normal use case for this feature.
Parameters
| source:Screen — A Screen object that will be used to obtain the source color profile. If null,
sRGB will be assumed.
|
|
| destination:Screen — A Screen object that will be used to obtain the destination color profile. If null,
sRGB will be assumed.
|
Returns
| BitmapData —
A new BitmapData object with the appropriate color transformation.
|
public function copyChannel(sourceBitmapData:BitmapData, sourceRect:Rectangle, destPoint:Point, sourceChannel:uint, destChannel:uint):void
Language version: | ActionScript 3.0
|
Transfers data from one channel of another BitmapData object or the current
BitmapData object into a channel of the current BitmapData object.
All of the data in the other channels in the destination BitmapData object are
preserved.
The source channel value and destination channel value can be
one of following values:
BitmapDataChannel.RED
BitmapDataChannel.GREEN
BitmapDataChannel.BLUE
BitmapDataChannel.ALPHA
Parameters
| sourceBitmapData:BitmapData — The input bitmap image to use. The source image can be a different BitmapData object
or it can refer to the current BitmapData object.
|
|
| sourceRect:Rectangle — The source Rectangle object. To copy only channel data from a smaller area
within the bitmap, specify a source rectangle that is smaller than the overall size of the
BitmapData object.
|
|
| destPoint:Point — The destination Point object that represents the upper-left corner of the rectangular area
where the new channel data is placed.
To copy only channel data
from one area to a different area in the destination image, specify a point other than (0,0).
|
|
| sourceChannel:uint — The source channel. Use a value from the BitmapDataChannel class
(BitmapDataChannel.RED , BitmapDataChannel.BLUE ,
BitmapDataChannel.GREEN , BitmapDataChannel.ALPHA ).
|
|
| destChannel:uint — The destination channel. Use a value from the BitmapDataChannel class
(BitmapDataChannel.RED , BitmapDataChannel.BLUE ,
BitmapDataChannel.GREEN , BitmapDataChannel.ALPHA ).
|
Throws
| TypeError — The sourceBitmapData, sourceRect or destPoint are null.
|
See also
Example
The following example shows how to copy the red channel in a BitmapData object to its own
blue channel in a 20 x 20 pixel region:
import flash.display.Bitmap;
import flash.display.BitmapData;
import flash.geom.Rectangle;
import flash.geom.Point;
var bmd:BitmapData = new BitmapData(100, 80, false, 0x00FF0000);
var rect:Rectangle = new Rectangle(0, 0, 20, 20);
var pt:Point = new Point(10, 10);
bmd.copyChannel(bmd, rect, pt, BitmapDataChannel.RED, BitmapDataChannel.BLUE);
var bm:Bitmap = new Bitmap(bmd);
this.addChild(bm);
public function copyPixels(sourceBitmapData:BitmapData, sourceRect:Rectangle, destPoint:Point, alphaBitmapData:BitmapData = null, alphaPoint:Point = null, mergeAlpha:Boolean = false):void
Language version: | ActionScript 3.0
|
Provides a fast routine to perform pixel manipulation
between images with no stretching, rotation, or color effects. This method copies a
rectangular area of a source image to a
rectangular area of the same size at the destination point of the destination
BitmapData object.
If you include the alphaBitmap
and alphaPoint
parameters, you can use a secondary
image as an alpha source for the source image. If the source
image has alpha data, both sets of alpha data are used to
composite pixels from the source image to the destination image. The
alphaPoint
parameter is the point in the alpha image that
corresponds to the upper-left corner of the source
rectangle. Any pixels outside the intersection of the source
image and alpha image are not copied to the destination image.
The mergeAlpha
property controls whether or not the alpha
channel is used when a transparent image is copied onto
another transparent image. To copy
pixels with the alpha channel data, set the mergeAlpha
property to true
. By default, the mergeAlpha
property is
false
.
Parameters
| sourceBitmapData:BitmapData — The input bitmap image from which to copy pixels. The source image can be a
different BitmapData instance, or it can refer to the current BitmapData
instance.
|
|
| sourceRect:Rectangle — A rectangle that defines the area of the source image to use as input.
|
|
| destPoint:Point — The destination point that represents the upper-left corner of the rectangular
area where the new pixels are placed.
|
|
| alphaBitmapData:BitmapData (default = null ) — A secondary, alpha BitmapData object source.
|
|
| alphaPoint:Point (default = null ) — The point in the alpha BitmapData object source that corresponds to
the upper-left corner of the sourceRect parameter.
|
|
| mergeAlpha:Boolean (default = false ) — To use the alpha channel, set the value to
true . To copy pixels with no alpha channel, set the value to
false .
|
Throws
| TypeError — The sourceBitmapData, sourceRect, destPoint are null.
|
Example
The following example shows how to copy pixels from a 20 x 20 pixel region in one BitmapData object
to another BitmapData object:
import flash.display.Bitmap;
import flash.display.BitmapData;
import flash.geom.Rectangle;
import flash.geom.Point;
var bmd1:BitmapData = new BitmapData(40, 40, false, 0x000000FF);
var bmd2:BitmapData = new BitmapData(80, 40, false, 0x0000CC44);
var rect:Rectangle = new Rectangle(0, 0, 20, 20);
var pt:Point = new Point(10, 10);
bmd2.copyPixels(bmd1, rect, pt);
var bm1:Bitmap = new Bitmap(bmd1);
this.addChild(bm1);
var bm2:Bitmap = new Bitmap(bmd2);
this.addChild(bm2);
bm2.x = 50;
public function copyPixelsToByteArray(rect:Rectangle, data:ByteArray):void
Language version: | ActionScript 3.0
|
Fills a byte array from a rectangular region of pixel data.
Starting at the position
index of the ByteArray, this method
writes an unsigned integer (a 32-bit unmultiplied pixel value)
for each pixel into the byte array. If necessary, the byte array's size is
increased to the necessary number of bytes to hold all the pixel data.
Parameters
| rect:Rectangle — A rectangular area in the current BitmapData object
|
|
| data:ByteArray — the destination ByteArray object
|
Throws
| TypeError — if the rect argument is null
or the data argument is null
|
See also
public static function decode(data:ByteArray):BitmapData
Language version: | ActionScript 3.0
|
Runtime version: | AIR 50.0
|
Decompresses encoded image data (PNG/GIF89a/JPEG) into a new BitmapData object using data
provided in a ByteArray. The image format is determined by the runtime and supports the
same formats as can be provided within a SWF file's DefineBitsJPEG2
tag.
Parameters
| data:ByteArray — The ByteArray object containing the compressed image data
|
Returns
| BitmapData —
A BitmapData containing the decoded image.
|
public function dispose():void
Language version: | ActionScript 3.0
|
Frees memory that is used to store the BitmapData object.
When the dispose()
method is called on an image, the width and height of the image are set to 0.
All subsequent calls to methods or properties of this BitmapData instance fail, and an
exception is thrown.
BitmapData.dispose()
releases the memory occupied by the actual bitmap data, immediately (a bitmap can consume up to 64 MB of memory).
After using BitmapData.dispose()
, the BitmapData object is no longer usable and the Flash runtime throws an exception if you call
functions on the BitmapData object.
However, BitmapData.dispose()
does not garbage collect the BitmapData object (approximately 128 bytes); the memory occupied by the actual
BitmapData object is released at the time the BitmapData object is collected by the garbage collector.
See also
Example
The following example shows the effect of calling a method of a BitmapData object after a call to the
dispose()
method (an exception is thrown):
import flash.display.BitmapData;
var myBitmapData:BitmapData = new BitmapData(100, 80, false, 0x000000FF);
trace(myBitmapData.getPixel(1, 1)); // 255 == 0xFF
myBitmapData.dispose();
try {
trace(myBitmapData.getPixel(1, 1));
} catch (error:Error) {
trace(error); // ArgumentError
}
public function draw(source:IBitmapDrawable, matrix:Matrix = null, colorTransform:ColorTransform = null, blendMode:String = null, clipRect:Rectangle = null, smoothing:Boolean = false):void
Language version: | ActionScript 3.0
|
Draws the source
display object onto the bitmap image, using the
Flash runtime vector renderer.
You can specify matrix
, colorTransform
,
blendMode
, and a destination clipRect
parameter to control
how the rendering performs. Optionally, you can specify whether the bitmap
should be smoothed when scaled (this works only if the source object
is a BitmapData object).
Note: The drawWithQuality()
method works exactly
like the draw()
method, but instead of using the Stage.quality
property
to determine the quality of vector rendering, you specify the quality
parameter
to the drawWithQuality()
method.
This method directly corresponds to how objects are drawn
with the standard vector renderer for objects in the authoring tool
interface.
The source display object does not use any of its applied transformations
for this call. It is treated as it exists in the library or
file, with no matrix transform, no color transform, and no blend
mode. To draw a display object (such as a movie clip) by using its own transform properties,
you can copy its transform
property object to the transform
property
of the Bitmap object that uses the BitmapData object.
This method is supported over RTMP in Flash Player 9.0.115.0
and later and in Adobe AIR. You can control access to streams on
Flash Media Server in a server-side script. For more information, see the Client.audioSampleAccess
and Client.videoSampleAccess
properties in
Server-Side ActionScript Language Reference for Adobe Flash Media Server.
If the source object and (in the case of a Sprite or MovieClip object) all
of its child objects do not come from the same domain as the caller, or are not in a content that is
accessible to the caller by having called the Security.allowDomain()
method, a call to
the draw()
throws a SecurityError exception. This restriction does not apply
to AIR content in the application security sandbox.
There are also restrictions on using a loaded bitmap image as the source
.
A call to the draw()
method is successful if the loaded image comes from the same domain as the caller.
Also, a cross-domain policy file on the image's server can grant permission to the domain of the SWF content
calling the draw()
method. In this case, you must set the checkPolicyFile
property
of a LoaderContext object, and use this object as the context
parameter when calling the load()
method of the Loader object used to load the image. These restrictions do not apply to AIR content in the
application security sandbox.
On Windows, the draw()
method cannot capture SWF content embedded in an HTML
page in an HTMLLoader object in Adobe AIR.
The draw()
method cannot capture PDF content in Adobe AIR.
Nor can it capture or SWF content embedded in HTML in which the wmode
attribute is set
to "window"
in Adobe AIR.
Parameters
| source:IBitmapDrawable — The display object or BitmapData object to draw to the BitmapData object.
(The DisplayObject and BitmapData classes implement the IBitmapDrawable interface.)
|
|
| matrix:Matrix (default = null ) — A Matrix object used to scale, rotate, or translate the coordinates
of the bitmap. If you do not want to apply a matrix transformation to the image,
set this parameter to an identity matrix, created with the default
new Matrix() constructor, or pass a null value.
|
|
| colorTransform:ColorTransform (default = null ) — A ColorTransform object that you use to adjust the color values of
the bitmap. If no object is supplied, the bitmap image's colors are not transformed.
If you must pass this parameter but you do not want to transform the image, set this
parameter to a ColorTransform object created with the default new ColorTransform()
constructor.
|
|
| blendMode:String (default = null ) — A string value, from the flash.display.BlendMode class, specifying the
blend mode to be applied to the resulting bitmap.
|
|
| clipRect:Rectangle (default = null ) — A Rectangle object that defines the area of the source object to draw.
If you do not supply this value, no clipping occurs and the entire source object is drawn.
|
|
| smoothing:Boolean (default = false ) — A Boolean value that determines whether a BitmapData object is
smoothed when scaled or rotated, due to a scaling or rotation in the matrix
parameter. The smoothing parameter only applies if the source
parameter is a BitmapData object. With smoothing set to false ,
the rotated or scaled BitmapData image can appear pixelated or jagged. For example, the following
two images use the same BitmapData object for the source parameter, but the
smoothing parameter is set to true on the left and false
on the right:
Drawing a bitmap with smoothing set to true takes longer
than doing so with smoothing set to false .
|
Throws
| ArgumentError — The source parameter is not a BitmapData
or DisplayObject object.
|
|
| SecurityError — The source object and (in the case of
a Sprite or MovieClip object) all of its child objects do not come from the same domain as
the caller, or are not in a content that is accessible to the caller by having called the
Security.allowDomain() method. This restriction does not apply
to AIR content in the application security sandbox.
|
|
| ArgumentError — The source is null or not a valid IBitmapDrawable object.
|
See also
Example
The following example shows how to draw a TextField object to a BitmapData object:
import flash.display.Bitmap;
import flash.display.BitmapData;
import flash.text.TextField;
var tf:TextField = new TextField();
tf.text = "bitmap text";
var myBitmapData:BitmapData = new BitmapData(80, 20);
myBitmapData.draw(tf);
var bmp:Bitmap = new Bitmap(myBitmapData);
this.addChild(bmp);
public function drawWithQuality(source:IBitmapDrawable, matrix:Matrix = null, colorTransform:ColorTransform = null, blendMode:String = null, clipRect:Rectangle = null, smoothing:Boolean = false, quality:String = null):void
Language version: | ActionScript 3.0
|
Draws the source
display object onto the bitmap image, using the
Flash runtime vector renderer.
You can specify matrix
, colorTransform
,
blendMode
, and a destination clipRect
parameter to control
how the rendering performs. Optionally, you can specify whether the bitmap
should be smoothed when scaled (this works only if the source object
is a BitmapData object).
Note: The drawWithQuality()
method works exactly
like the draw()
method, but instead of using the Stage.quality
property
to determine the quality of vector rendering, you specify the quality
parameter
to the drawWithQuality()
method.
This method directly corresponds to how objects are drawn
with the standard vector renderer for objects in the authoring tool
interface.
The source display object does not use any of its applied transformations
for this call. It is treated as it exists in the library or
file, with no matrix transform, no color transform, and no blend
mode. To draw a display object (such as a movie clip) by using its own transform properties,
you can copy its transform
property object to the transform
property
of the Bitmap object that uses the BitmapData object.
This method is supported over RTMP in Flash Player 9.0.115.0
and later and in Adobe AIR. You can control access to streams on
Flash Media Server in a server-side script. For more information, see the Client.audioSampleAccess
and Client.videoSampleAccess
properties in
Server-Side ActionScript Language Reference for Adobe Flash Media Server.
If the source object and (in the case of a Sprite or MovieClip object) all
of its child objects do not come from the same domain as the caller, or are not in a content that is
accessible to the caller by having called the Security.allowDomain()
method, a call to
the drawWithQuality()
throws a SecurityError exception. This restriction does not apply
to AIR content in the application security sandbox.
There are also restrictions on using a loaded bitmap image as the source
.
A call to the drawWithQuality()
method is successful if the loaded image comes from the same domain as the caller.
Also, a cross-domain policy file on the image's server can grant permission to the domain of the SWF content
calling the drawWithQuality()
method. In this case, you must set the checkPolicyFile
property
of a LoaderContext object, and use this object as the context
parameter when calling the load()
method of the Loader object used to load the image. These restrictions do not apply to AIR content in the
application security sandbox.
On Windows, the drawWithQuality()
method cannot capture SWF content embedded in an HTML
page in an HTMLLoader object in Adobe AIR.
The drawWithQuality()
method cannot capture PDF content in Adobe AIR.
Nor can it capture or SWF content embedded in HTML in which the wmode
attribute is set
to "window"
in Adobe AIR.
Parameters
| source:IBitmapDrawable — The display object or BitmapData object to draw to the BitmapData object.
(The DisplayObject and BitmapData classes implement the IBitmapDrawable interface.)
|
|
| matrix:Matrix (default = null ) — A Matrix object used to scale, rotate, or translate the coordinates
of the bitmap. If you do not want to apply a matrix transformation to the image,
set this parameter to an identity matrix, created with the default
new Matrix() constructor, or pass a null value.
|
|
| colorTransform:ColorTransform (default = null ) — A ColorTransform object that you use to adjust the color values of
the bitmap. If no object is supplied, the bitmap image's colors are not transformed.
If you must pass this parameter but you do not want to transform the image, set this
parameter to a ColorTransform object created with the default new ColorTransform()
constructor.
|
|
| blendMode:String (default = null ) — A string value, from the flash.display.BlendMode class, specifying the
blend mode to be applied to the resulting bitmap.
|
|
| clipRect:Rectangle (default = null ) — A Rectangle object that defines the area of the source object to draw.
If you do not supply this value, no clipping occurs and the entire source object is drawn.
|
|
| smoothing:Boolean (default = false ) — A Boolean value that determines whether a BitmapData object is
smoothed when scaled or rotated, due to a scaling or rotation in the matrix
parameter. The smoothing parameter only applies if the source
parameter is a BitmapData object. With smoothing set to false ,
the rotated or scaled BitmapData image can appear pixelated or jagged. For example, the following
two images use the same BitmapData object for the source parameter, but the
smoothing parameter is set to true on the left and false
on the right:
Drawing a bitmap with smoothing set to true takes longer
than doing so with smoothing set to false .
|
|
| quality:String (default = null ) — Any of one of the StageQuality values. Selects the antialiasing quality to be used
when drawing vectors graphics.
|
Throws
| ArgumentError — The source parameter is not a BitmapData
or DisplayObject object.
|
|
| SecurityError — The source object and (in the case of
a Sprite or MovieClip object) all of its child objects do not come from the same domain as
the caller, or are not in a content that is accessible to the caller by having called the
Security.allowDomain() method. This restriction does not apply
to AIR content in the application security sandbox.
|
|
| ArgumentError — The source is null or not a valid IBitmapDrawable object.
|
See also
Example
The following example shows how to draw a TextField object to a BitmapData object:
import flash.display.Bitmap;
import flash.display.BitmapData;
import flash.text.TextField;
var tf:TextField = new TextField();
tf.text = "bitmap text";
var myBitmapData:BitmapData = new BitmapData(80, 20);
myBitmapData.drawWithQuality(tf, , , , , , StageQuality.LOW);
var bmp:Bitmap = new Bitmap(myBitmapData);
this.addChild(bmp);
public function encode(rect:Rectangle, compressor:Object, byteArray:ByteArray = null):ByteArray
Language version: | ActionScript 3.0
|
Compresses this BitmapData object using the selected compressor algorithm
and returns a new ByteArray object.
Optionally, writes the resulting data to the specified ByteArray.
The compressor
argument specifies the encoding algorithm, and can be
PNGEncoderOptions, JPEGEncoderOptions, or JPEGXREncoderOptions.
The following example compresses a BitmapData object using the JPEGEncoderOptions:
// Compress a BitmapData object as a JPEG file.
var bitmapData:BitmapData = new BitmapData(640,480,false,0x00FF00);
var byteArray:ByteArray = new ByteArray();
bitmapData.encode(new Rectangle(0,0,640,480), new flash.display.JPEGEncoderOptions(), byteArray);
Parameters
| rect:Rectangle — The area of the BitmapData object to compress.
|
|
| compressor:Object — The compressor type to use.
Valid values are: flash.display.PNGEncoderOptions ,
flash.display.JPEGEncoderOptions , and flash.display.JPEGXREncoderOptions .
|
|
| byteArray:ByteArray (default = null ) — The output ByteArray to hold the encoded image.
|
Returns
| ByteArray —
A ByteArray containing the encoded image.
|
See also
public function fillRect(rect:Rectangle, color:uint):void
Language version: | ActionScript 3.0
|
Fills a rectangular area of pixels with a specified ARGB color.
Parameters
| rect:Rectangle — The rectangular area to fill.
|
|
| color:uint — The ARGB color value that fills the area. ARGB colors are often
specified in hexadecimal format; for example, 0xFF336699.
|
Throws
See also
Example
The following example shows how to fill a rectangular region of a BitmapData object with blue:
import flash.display.Bitmap;
import flash.display.BitmapData;
import flash.geom.Rectangle;
var myBitmapData:BitmapData = new BitmapData(40, 40, false, 0x0000FF00);
var rect:Rectangle = new Rectangle(0, 0, 20, 20);
myBitmapData.fillRect(rect, 0x0000FF);
var bm:Bitmap = new Bitmap(myBitmapData);
addChild(bm);
public function floodFill(x:int, y:int, color:uint):void
Language version: | ActionScript 3.0
|
Performs a flood fill operation on an image starting
at an (x, y) coordinate and filling with a certain color. The
floodFill()
method is similar to the paint bucket tool in various paint
programs. The color is an ARGB color that contains alpha information and
color information.
Parameters
| x:int — The x coordinate of the image.
|
|
| y:int — The y coordinate of the image.
|
|
| color:uint — The ARGB color to use as a fill.
|
Example
The following example shows how to fill a region of a BitmapData object that is, the region
surrounding the pixel defined by the point
(10, 10)
in which all colors match the color at that
point with red
import flash.display.Bitmap;
import flash.display.BitmapData;
import flash.geom.Rectangle;
var myBitmapData:BitmapData = new BitmapData(40, 40, false, 0x0000FF00);
var rect:Rectangle = new Rectangle(0, 0, 20, 20);
myBitmapData.fillRect(rect, 0x000000FF);
rect = new Rectangle(15, 15, 25, 25);
myBitmapData.fillRect(rect, 0x000000FF);
myBitmapData.floodFill(10, 10, 0x00FF0000);
var bm:Bitmap = new Bitmap(myBitmapData);
addChild(bm);
public function generateFilterRect(sourceRect:Rectangle, filter:BitmapFilter):Rectangle
Language version: | ActionScript 3.0
|
Determines the destination rectangle that the applyFilter()
method call affects, given a
BitmapData object, a source rectangle, and a filter object.
For example, a blur filter normally affects an area larger than the size of the original
image. A 100 x 200 pixel image that is being filtered by a default BlurFilter
instance, where blurX = blurY = 4
generates a destination rectangle of
(-2,-2,104,204)
.
The generateFilterRect()
method lets you find out the size of this destination
rectangle in advance so that you can size the destination image appropriately before you perform a filter
operation.
Some filters clip their destination rectangle based on the source image size.
For example, an inner DropShadow
does not generate a larger result than its source
image. In this API, the BitmapData object is used as the source bounds and not the
source rect
parameter.
Parameters
| sourceRect:Rectangle — A rectangle defining the area of the source image to use as input.
|
|
| filter:BitmapFilter — A filter object that you use to calculate the destination rectangle.
|
Returns
| Rectangle —
A destination rectangle computed by using an image, the sourceRect parameter,
and a filter.
|
Throws
| TypeError — The sourceRect or filter are null.
|
Example
The following example shows how you can use the
generateFilterRect()
method to
determine the rectangular area that the result of a blur filter will occupy. The results of the
generateFilterRect()
method are output by the
trace()
function:
import flash.display.Bitmap;
import flash.display.BitmapData;
import flash.geom.Point;
import flash.geom.Rectangle;
import flash.filters.BlurFilter;
var bmd:BitmapData = new BitmapData(80, 30, false, 0xFFCC00);
var rect:Rectangle = new Rectangle(10, 10, 40, 10);
bmd.fillRect(rect, 0xFF0000);
var pt:Point = new Point(10, 10);
var filter:BlurFilter = new BlurFilter();
trace(bmd.generateFilterRect(rect, filter));
// (x=8, y=8, w=44, h=14)
bmd.applyFilter(bmd, rect, pt, filter);
var bm:Bitmap = new Bitmap(bmd);
addChild(bm);
Note that the
generateFilterRect()
method does not apply the filter. Call the
applyFilter()
method
to apply the filter.
public function getColorBoundsRect(mask:uint, color:uint, findColor:Boolean = true):Rectangle
Language version: | ActionScript 3.0
|
Determines a rectangular region that either fully encloses all pixels of a specified color within the
bitmap image (if the findColor
parameter is set to true
) or fully encloses
all pixels that do not include the specified color (if the findColor
parameter is set
to false
).
For example, if you have a source image and you want to determine the rectangle of
the image that contains a nonzero alpha channel, pass
{mask: 0xFF000000, color: 0x00000000}
as parameters. If the findColor
parameter is set to true
, the entire image is searched for the bounds of pixels
for which (value & mask) == color
(where value
is the color value
of the pixel). If the findColor
parameter is set to false
, the entire
image is searched for the bounds of pixels for which (value & mask) != color
(where value
is the color value of the pixel). To determine white space around an
image, pass {mask: 0xFFFFFFFF, color: 0xFFFFFFFF}
to find the bounds of nonwhite pixels.
Parameters
| mask:uint — A hexadecimal value, specifying the bits of the ARGB color to consider. The color
value is combined with this hexadecimal value, by using the & (bitwise AND) operator.
|
|
| color:uint — A hexadecimal value, specifying the ARGB color to match (if findColor
is set to true ) or not to match (if findColor
is set to false ).
|
|
| findColor:Boolean (default = true ) — If the value is set to true , returns the bounds of a color value in an image.
If the value is set to false , returns the bounds of where this color doesn't exist in an image.
|
Returns
| Rectangle —
The region of the image that is the specified color.
|
Example
The following example creates a BitmapData object with red in the top half of its pixels. It then calls
the
getColorBoundsRect()
method to determine the rectangle in which pixels are red (0xFF0000), and
then it calls the same method to determine the rectangle in which pixels are not red (by setting the
findColor
parameter to
false
:
import flash.display.Bitmap;
import flash.display.BitmapData;
import flash.geom.Rectangle;
var bmd:BitmapData = new BitmapData(80, 40, false, 0xFFFFFF);
var rect:Rectangle = new Rectangle(0, 0, 80, 20);
bmd.fillRect(rect, 0xFF0000);
var maskColor:uint = 0xFFFFFF;
var color:uint = 0xFF0000;
var redBounds:Rectangle = bmd.getColorBoundsRect(maskColor, color, true);
trace(redBounds); // (x=0, y=0, w=80, h=20)
var notRedBounds:Rectangle = bmd.getColorBoundsRect(maskColor, color, false);
trace(notRedBounds); // (x=0, y=20, w=80, h=20)
var bm:Bitmap = new Bitmap(bmd);
addChild(bm);
public function getPixel(x:int, y:int):uint
Language version: | ActionScript 3.0
|
Returns an integer that represents an RGB pixel value from a BitmapData object at
a specific point (x, y). The getPixel()
method returns an
unmultiplied pixel value. No alpha information is returned.
All pixels in a BitmapData object are stored as premultiplied color values.
A premultiplied image pixel has the red, green, and blue
color channel values already multiplied by the alpha data. For example, if the
alpha value is 0, the values for the RGB channels are also 0, independent of their unmultiplied
values. This loss of data can cause some problems when you perform operations. All BitmapData
methods take and return unmultiplied values. The internal pixel representation is converted
from premultiplied to unmultiplied before it is returned as a value. During a set operation,
the pixel value is premultiplied before the raw image pixel is set.
Parameters
| x:int — The x position of the pixel.
|
|
| y:int — The y position of the pixel.
|
Returns
| uint —
A number that represents an RGB pixel value. If the (x, y) coordinates are
outside the bounds of the image, the method returns 0.
|
See also
Example
The following example creates a BitmapData object filled with red, then uses the
getPixel()
method to determine the color value in the upper-left pixel:
import flash.display.BitmapData;
var bmd:BitmapData = new BitmapData(80, 40, false, 0xFF0000);
var pixelValue:uint = bmd.getPixel(0, 0);
trace(pixelValue.toString(16)); // ff0000;
public function getPixel32(x:int, y:int):uint
Language version: | ActionScript 3.0
|
Returns an ARGB color value that contains alpha channel data and RGB
data. This method is similar to the getPixel()
method, which returns an
RGB color without alpha channel data.
All pixels in a BitmapData object are stored as premultiplied color values.
A premultiplied image pixel has the red, green, and blue
color channel values already multiplied by the alpha data. For example, if the
alpha value is 0, the values for the RGB channels are also 0, independent of their unmultiplied
values. This loss of data can cause some problems when you perform operations. All BitmapData
methods take and return unmultiplied values. The internal pixel representation is converted
from premultiplied to unmultiplied before it is returned as a value. During a set operation,
the pixel value is premultiplied before the raw image pixel is set.
Parameters
| x:int — The x position of the pixel.
|
|
| y:int — The y position of the pixel.
|
Returns
| uint —
A number representing an ARGB pixel value. If the (x, y) coordinates are
outside the bounds of the image, 0 is returned.
|
See also
Example
The following example creates a BitmapData object filled with a color, then uses the
getPixel32()
method to determine the color value in the upper-left pixel, and then
determines the hexidecimal values for each color component (alpha, red, green, and blue):
import flash.display.BitmapData;
var bmd:BitmapData = new BitmapData(80, 40, true, 0xFF44AACC);
var pixelValue:uint = bmd.getPixel32(0, 0);
var alphaValue:uint = pixelValue >> 24 & 0xFF;
var red:uint = pixelValue >> 16 & 0xFF;
var green:uint = pixelValue >> 8 & 0xFF;
var blue:uint = pixelValue & 0xFF;
trace(alphaValue.toString(16)); // ff
trace(red.toString(16)); // 44
trace(green.toString(16)); // aa
trace(blue.toString(16)); // cc
public function getPixels(rect:Rectangle):ByteArray
Language version: | ActionScript 3.0
|
Generates a byte array from a rectangular region of pixel data.
Writes an unsigned integer (a 32-bit unmultiplied pixel value)
for each pixel into the byte array.
Parameters
| rect:Rectangle — A rectangular area in the current BitmapData object.
|
Returns
| ByteArray —
A ByteArray representing the pixels in the given Rectangle.
|
Throws
See also
Example
The following example creates a BitmapData object filled with random noise pixels, then uses the
getPixels()
method to fill a ByteArray object with the pixel values of the BitmapData object
import flash.display.BitmapData;
import flash.geom.Rectangle;
import flash.utils.ByteArray;
var bmd:BitmapData = new BitmapData(80, 40, true);
var seed:int = int(Math.random() * int.MAX_VALUE);
bmd.noise(seed);
var bounds:Rectangle = new Rectangle(0, 0, bmd.width, bmd.height);
var pixels:ByteArray = bmd.getPixels(bounds);
public function getVector(rect:Rectangle):Vector.<uint>
Language version: | ActionScript 3.0
|
Generates a vector array from a rectangular region of pixel data.
Returns a Vector object of unsigned integers (a 32-bit unmultiplied pixel value)
for the specified rectangle.
Parameters
| rect:Rectangle — A rectangular area in the current BitmapData object.
|
Returns
| Vector.<uint> — A Vector representing the given Rectangle.
|
Throws
public function histogram(hRect:Rectangle = null):Vector.<Vector.<Number>>
Language version: | ActionScript 3.0
|
Computes a 256-value binary number histogram of a BitmapData object. This method returns a Vector object
containing four Vector.<Number> instances (four Vector objects that contain Number objects).
The four Vector instances represent the red, green, blue and alpha components
in order. Each Vector instance contains 256 values that represent the population
count of an individual component value, from 0 to 255.
Parameters
| hRect:Rectangle (default = null ) — The area of the BitmapData object to use.
|
Returns
public function hitTest(firstPoint:Point, firstAlphaThreshold:uint, secondObject:Object, secondBitmapDataPoint:Point = null, secondAlphaThreshold:uint = 1):Boolean
Language version: | ActionScript 3.0
|
Performs pixel-level hit detection between one bitmap image
and a point, rectangle, or other bitmap image. A hit is defined as
an overlap of a point or rectangle over an opaque pixel, or two
overlapping opaque pixels. No stretching,
rotation, or other transformation of either object is considered when
the hit test is performed.
If an image is an opaque image, it is considered a fully opaque rectangle for this
method. Both images must be transparent images to perform pixel-level hit testing that
considers transparency. When you are testing two transparent images, the alpha threshold
parameters control what alpha channel values, from 0 to 255, are considered opaque.
Parameters
| firstPoint:Point — A position of the upper-left corner of the BitmapData image in an arbitrary coordinate space.
The same coordinate space is used in defining the secondBitmapPoint parameter.
|
|
| firstAlphaThreshold:uint — The smallest alpha channel value that is considered opaque for this hit test.
|
|
| secondObject:Object — A Rectangle, Point, Bitmap, or BitmapData object.
|
|
| secondBitmapDataPoint:Point (default = null ) — A point that defines a pixel location in the second BitmapData object.
Use this parameter only when the value of secondObject is a
BitmapData object.
|
|
| secondAlphaThreshold:uint (default = 1 ) — The smallest alpha channel value that is considered opaque in the second BitmapData object.
Use this parameter only when the value of secondObject is a
BitmapData object and both BitmapData objects are transparent.
|
Returns
| Boolean —
A value of true if a hit occurs; otherwise, false .
|
Throws
| ArgumentError — The secondObject parameter is not a Point, Rectangle,
Bitmap, or BitmapData object.
|
|
| TypeError — The firstPoint is null.
|
Example
The following example creates a BitmapData object that is only opaque in a rectangular region
(20, 20, 40, 40) and calls the
hitTest()
method with a Point object as the
secondObject
.
In the first call, the Point object defines the upper-left corner of the BitmapData object, which is not opaque, and
in the second call, the Point object defines the center of the BitmapData object, which is opaque.
import flash.display.BitmapData;
import flash.geom.Rectangle;
import flash.geom.Point;
var bmd1:BitmapData = new BitmapData(80, 80, true, 0x00000000);
var rect:Rectangle = new Rectangle(20, 20, 40, 40);
bmd1.fillRect(rect, 0xFF0000FF);
var pt1:Point = new Point(1, 1);
trace(bmd1.hitTest(pt1, 0xFF, pt1)); // false
var pt2:Point = new Point(40, 40);
trace(bmd1.hitTest(pt1, 0xFF, pt2)); // true
public function lock():void
Language version: | ActionScript 3.0
|
Locks an image so that any objects that reference the BitmapData object, such as Bitmap objects,
are not updated when this BitmapData object changes. To improve performance, use this method
along with the unlock()
method before and after numerous calls to the
setPixel()
or setPixel32()
method.
See also
Example
The following example creates a BitmapData object based on the
bitmapData
property of a Bitmap object,
picture
.
It then calls the
lock()
method before calling a complicated custom function,
complexTransformation()
, that modifies the BitmapData object. (The
picture
object
and the
complexTransformation()
function are not defined in this example.) Even if the
complexTransformation()
function updates the
bitmapData
property of
the
picture
object, changes are not reflected until the code calls the
unlock()
method on the
bitmapData
object:
import flash.display.BitmapData;
var bitmapData:BitmapData = picture.bitmapData;
bitmapData.lock();
bitmapData = complexTransformation(bitmapData);
bitmapData.unlock();
picture.bitmapData = bitmapData;
public function merge(sourceBitmapData:BitmapData, sourceRect:Rectangle, destPoint:Point, redMultiplier:uint, greenMultiplier:uint, blueMultiplier:uint, alphaMultiplier:uint):void
Language version: | ActionScript 3.0
|
Performs per-channel blending from a source image to a destination image. For each channel
and each pixel, a new value is computed based on the channel values of the source and destination
pixels. For example, in the red channel, the new value is computed as follows (where redSrc
is the red channel value for a pixel in the source image and redDest
is the red channel
value at the corresponding pixel of the destination image):
new redDest = [(redSrc * redMultiplier) + (redDest * (256 - redMultiplier))] / 256;
The redMultiplier
, greenMultiplier
, blueMultiplier
, and
alphaMultiplier
values are the multipliers used for each color channel. Use a hexadecimal
value ranging from 0
to 0x100
(256) where 0
specifies the full
value from the destination is used in the result, 0x100
specifies the full value from the
source is used, and numbers in between specify a blend is used (such as 0x80
for 50%).
Parameters
| sourceBitmapData:BitmapData — The input bitmap image to use. The source image can be a different
BitmapData object, or it can refer to the current BitmapData object.
|
|
| sourceRect:Rectangle — A rectangle that defines the area of the source image to use as input.
|
|
| destPoint:Point — The point within the destination image (the current BitmapData
instance) that corresponds to the upper-left corner of the source rectangle.
|
|
| redMultiplier:uint — A hexadecimal uint value by which to multiply the red channel value.
|
|
| greenMultiplier:uint — A hexadecimal uint value by which to multiply the green channel value.
|
|
| blueMultiplier:uint — A hexadecimal uint value by which to multiply the blue channel value.
|
|
| alphaMultiplier:uint — A hexadecimal uint value by which to multiply the alpha transparency value.
|
Throws
| TypeError — The sourceBitmapData, sourceRect or destPoint are null.
|
Example
The following example creates two BitmapData objects. Both are 100 x 80 pixels in size. The first
is filled with green and the second is filled with red. The code calls the
merge()
method, merging
the second BitmapData pixels into the first BitmapData object, but only on a specified rectangular area:
import flash.display.Bitmap;
import flash.display.BitmapData;
import flash.geom.Rectangle;
import flash.geom.Point;
var bmd1:BitmapData = new BitmapData(100, 80, true, 0xFF00FF00);
var bmd2:BitmapData = new BitmapData(100, 80, true, 0xFFFF0000);
var rect:Rectangle = new Rectangle(0, 0, 20, 20);
var pt:Point = new Point(20, 20);
var mult:uint = 0x80; // 50%
bmd1.merge(bmd2, rect, pt, mult, mult, mult, mult);
var bm1:Bitmap = new Bitmap(bmd1);
addChild(bm1);
var bm2:Bitmap = new Bitmap(bmd2);
addChild(bm2);
bm2.x = 110;
public function noise(randomSeed:int, low:uint = 0, high:uint = 255, channelOptions:uint = 7, grayScale:Boolean = false):void
Language version: | ActionScript 3.0
|
Fills an image with pixels representing random noise.
Parameters
| randomSeed:int — The random seed number to use. If you keep all other parameters
the same, you can generate different pseudo-random results by varying the random seed value. The noise
function is a mapping function, not a true random-number generation function, so it creates the same
results each time from the same random seed.
|
|
| low:uint (default = 0 ) — The lowest value to generate for each channel (0 to 255).
|
|
| high:uint (default = 255 ) — The highest value to generate for each channel (0 to 255).
|
|
| channelOptions:uint (default = 7 ) — A number that can be a combination of any of
the four color channel values (BitmapDataChannel.RED ,
BitmapDataChannel.BLUE , BitmapDataChannel.GREEN , and
BitmapDataChannel.ALPHA ). You can use the logical OR
operator (| ) to combine channel values.
|
|
| grayScale:Boolean (default = false ) — A Boolean value. If the value is true , a grayscale image is created by setting
all of the color channels to the same value.
The alpha channel selection is not affected by
setting this parameter to true .
|
See also
Example
The following example creates two BitmapData objects and calls the
noise()
method on both. However, the
grayscale
parameter is set to
false
for the
call to the
noise()
method of the first object, and it is set to
true
for the
call to the
noise()
method of the second object:
import flash.display.Bitmap;
import flash.display.BitmapData;
import flash.display.BitmapDataChannel;
var bmd1:BitmapData = new BitmapData(80, 80);
var bmd2:BitmapData = new BitmapData(80, 80);
var seed:int = int(Math.random() * int.MAX_VALUE);
bmd1.noise(seed, 0, 0xFF, BitmapDataChannel.RED, false);
bmd2.noise(seed, 0, 0xFF, BitmapDataChannel.RED, true);
var bm1:Bitmap = new Bitmap(bmd1);
this.addChild(bm1);
var bm2:Bitmap = new Bitmap(bmd2);
this.addChild(bm2);
bm2.x = 90;
public function paletteMap(sourceBitmapData:BitmapData, sourceRect:Rectangle, destPoint:Point, redArray:Array = null, greenArray:Array = null, blueArray:Array = null, alphaArray:Array = null):void
Language version: | ActionScript 3.0
|
Remaps the color channel values in an image that has up to four arrays of color palette data, one
for each channel.
Flash runtimes use the following steps to
generate the resulting image:
- After the red, green, blue, and alpha
values are computed, they are added together using standard 32-bit-integer arithmetic.
- The red, green, blue, and alpha channel values of each pixel are extracted into separate 0 to 255 values.
These values are used to look up new color values in the appropriate array:
redArray
,
greenArray
, blueArray
, and alphaArray
.
Each of these four arrays should contain 256 values.
- After all four of the new channel values are retrieved, they are combined into a standard
ARGB value that is applied to the pixel.
Cross-channel effects can be supported with this method.
Each input array can contain full 32-bit values, and no shifting occurs when the
values are added together. This routine does not support per-channel
clamping.
If no array is specified for a channel,
the color channel is copied from the source image to the
destination image.
You can use this method for a variety of effects such as
general palette mapping (taking one channel and converting it
to a false color image). You can also use this method for a variety of advanced color
manipulation algorithms, such as gamma, curves, levels, and quantizing.
Parameters
| sourceBitmapData:BitmapData — The input bitmap image to use. The source image can be a different
BitmapData object, or it can refer to the current BitmapData instance.
|
|
| sourceRect:Rectangle — A rectangle that defines the area of the source image to use as input.
|
|
| destPoint:Point — The point within the destination image (the current BitmapData
object) that corresponds to the upper-left corner of the source rectangle.
|
|
| redArray:Array (default = null ) — If redArray is not null , red = redArray[source red value]
else red = source rect value .
|
|
| greenArray:Array (default = null ) — If greenArray is not null , green = greenArray[source
green value] else green = source green value.
|
|
| blueArray:Array (default = null ) — If blueArray is not null , blue = blueArray[source blue
value] else blue = source blue value .
|
|
| alphaArray:Array (default = null ) — If alphaArray is not null , alpha = alphaArray[source
alpha value] else alpha = source alpha value .
|
Throws
| TypeError — The sourceBitmapData, sourceRect or destPoint are null.
|
Example
The following example creates a green BitmapData object with a red center square, and then
uses the
paletteMap()
method to swap red with green in the bottom rectangular half of the
BitmapData object:
import flash.display.Bitmap;
import flash.display.BitmapData;
import flash.geom.Rectangle;
import flash.geom.Point;
var myBitmapData:BitmapData = new BitmapData(80, 80, false, 0x00FF0000);
myBitmapData.fillRect(new Rectangle(20, 20, 40, 40), 0x0000FF00);
var redArray:Array = new Array(256);
var greenArray:Array = new Array(256);
for(var i:uint = 0; i < 255; i++) {
redArray[i] = 0x00000000;
greenArray[i] = 0x00000000;
}
redArray[0xFF] = 0x0000FF00;
greenArray[0xFF] = 0x00FF0000;
var bottomHalf:Rectangle = new Rectangle(0, 0, 100, 40);
var pt:Point = new Point(0, 0);
myBitmapData.paletteMap(myBitmapData, bottomHalf, pt, redArray, greenArray);
var bm1:Bitmap = new Bitmap(myBitmapData);
addChild(bm1);
public function perlinNoise(baseX:Number, baseY:Number, numOctaves:uint, randomSeed:int, stitch:Boolean, fractalNoise:Boolean, channelOptions:uint = 7, grayScale:Boolean = false, offsets:Array = null):void
Language version: | ActionScript 3.0
|
Generates a Perlin noise image.
The Perlin noise generation algorithm interpolates and combines individual random noise functions (called octaves)
into a single function that generates more natural-seeming random noise. Like musical octaves, each octave function is twice the
frequency of the one before it. Perlin noise has been described as a "fractal sum of noise" because it combines multiple sets of noise data
with different levels of detail.
You can use Perlin noise functions to simulate natural
phenomena and landscapes, such as wood grain, clouds, and mountain ranges. In most cases, the output of a Perlin noise function
is not displayed directly but is used to enhance other images and give them pseudo-random variations.
Simple digital random noise functions often produce images with harsh, contrasting points. This kind of harsh contrast
is not often found in nature. The Perlin noise algorithm blends multiple noise functions that operate at different levels of detail.
This algorithm results in smaller variations among neighboring pixel values.
Parameters
| baseX:Number — Frequency to use in the x direction. For example, to generate a noise that
is sized for a 64 x 128 image, pass 64 for the baseX value.
|
|
| baseY:Number — Frequency to use in the y direction. For example, to generate a noise that
is sized for a 64 x 128 image, pass 128 for the baseY value.
|
|
| numOctaves:uint — Number of octaves or individual noise functions to combine to create this noise. Larger numbers of octaves create
images with greater detail. Larger numbers of octaves also require more processing time.
|
|
| randomSeed:int — The random seed number to use. If you keep all other parameters the same, you can generate different
pseudo-random results by varying the random seed value. The Perlin noise function is a mapping function, not a
true random-number generation function, so it creates the same results each time from the same random seed.
|
|
| stitch:Boolean — A Boolean value. If the value is true , the method attempts to smooth the transition edges of the image to create seamless textures for
tiling as a bitmap fill.
|
|
| fractalNoise:Boolean — A Boolean value. If the value is true , the method generates fractal noise; otherwise,
it generates turbulence. An image with turbulence has visible discontinuities in the gradient
that can make it better approximate sharper visual effects like flames and ocean waves.
|
|
| channelOptions:uint (default = 7 ) — A number that can be a combination of any of
the four color channel values (BitmapDataChannel.RED ,
BitmapDataChannel.BLUE , BitmapDataChannel.GREEN , and
BitmapDataChannel.ALPHA ). You can use the logical OR
operator (| ) to combine channel values.
|
|
| grayScale:Boolean (default = false ) — A Boolean value. If the value is true , a grayscale image is created by setting
each of the red, green, and blue color channels to
identical values. The alpha channel value is not affected if this value is
set to true .
|
|
| offsets:Array (default = null ) — An array of points that correspond to x and y offsets for each octave.
By manipulating the offset values you can smoothly scroll the layers of a perlinNoise image.
Each point in the offset array affects a specific octave noise function.
|
Example
The following example creates a 200 x 200 pixel BitmapData object that calls the
perlinNoise()
method to generate a red and blue watercolor effect:
import flash.display.Bitmap;
import flash.display.BitmapData;
var bmd:BitmapData = new BitmapData(200, 200, false, 0x00CCCCCC);
var seed:Number = Math.floor(Math.random() * 10);
var channels:uint = BitmapDataChannel.RED | BitmapDataChannel.BLUE;
bmd.perlinNoise(100, 80, 6, seed, false, true, channels, false, null);
var bm:Bitmap = new Bitmap(bmd);
addChild(bm);
public function pixelDissolve(sourceBitmapData:BitmapData, sourceRect:Rectangle, destPoint:Point, randomSeed:int = 0, numPixels:int = 0, fillColor:uint = 0):int
Language version: | ActionScript 3.0
|
Performs a pixel dissolve either from a source image to a destination image or by using the same image.
Flash runtimes use a randomSeed
value
to generate a random pixel dissolve. The return value
of the function must be passed in on subsequent calls to
continue the pixel dissolve until it is finished.
If the source image does not equal the destination image,
pixels are copied from the source to the destination by using all of the
properties. This process allows dissolving from a blank image into a
fully populated image.
If the source and destination images are equal, pixels are
filled with the color
parameter. This process allows dissolving away
from a fully populated image. In this mode, the destination
point
parameter is ignored.
Parameters
| sourceBitmapData:BitmapData — The input bitmap image to use. The source image can be a different
BitmapData object, or it can refer to the current BitmapData instance.
|
|
| sourceRect:Rectangle — A rectangle that defines the area of the source image to use as input.
|
|
| destPoint:Point — The point within the destination image (the current BitmapData
instance) that corresponds to the upper-left corner of the source rectangle.
|
|
| randomSeed:int (default = 0 ) — The random seed to use to start the pixel dissolve.
|
|
| numPixels:int (default = 0 ) — The default is 1/30 of the source area (width x height).
|
|
| fillColor:uint (default = 0 ) — An ARGB color value that you use to fill pixels whose
source value equals its destination value.
|
Returns
| int —
The new random seed value to use for subsequent calls.
|
Throws
| TypeError — The sourceBitmapData, sourceRect or destPoint are null.
|
|
| TypeError — The numPixels value is negative
|
Example
The following example uses the
pixelDissolve()
method to convert a grey BitmapData object to a red one by dissolving
40 pixels at a time until all pixels have changed colors:
import flash.display.BitmapData;
import flash.display.Bitmap;
import flash.geom.Point;
import flash.geom.Rectangle;
import flash.utils.Timer;
import flash.events.TimerEvent;
var bmd:BitmapData = new BitmapData(100, 80, false, 0x00CCCCCC);
var bitmap:Bitmap = new Bitmap(bmd);
addChild(bitmap);
var tim:Timer = new Timer(20);
tim.start();
tim.addEventListener(TimerEvent.TIMER, timerHandler);
function timerHandler(event:TimerEvent):void {
var randomNum:Number = Math.floor(Math.random() * int.MAX_VALUE);
dissolve(randomNum);
}
function dissolve(randomNum:Number):void {
var rect:Rectangle = bmd.rect;
var pt:Point = new Point(0, 0);
var numberOfPixels:uint = 100;
var red:uint = 0x00FF0000;
bmd.pixelDissolve(bmd, rect, pt, randomNum, numberOfPixels, red);
var grayRegion:Rectangle = bmd.getColorBoundsRect(0xFFFFFFFF, 0x00CCCCCC, true);
if(grayRegion.width == 0 && grayRegion.height == 0 ) {
tim.stop();
}
}
public function scroll(x:int, y:int):void
Language version: | ActionScript 3.0
|
Scrolls an image by a certain (x, y) pixel amount. Edge
regions outside the scrolling area are left unchanged.
Parameters
| x:int — The amount by which to scroll horizontally.
|
|
| y:int — The amount by which to scroll vertically.
|
Example
The following example shows the effect of scrolling a Bitmap data object 40 pixels to the right:
import flash.display.Bitmap;
import flash.display.BitmapData;
import flash.geom.Rectangle;
var bmd:BitmapData = new BitmapData(80, 80, true, 0xFFCCCCCC);
var rect:Rectangle = new Rectangle(0, 0, 40, 40);
bmd.fillRect(rect, 0xFFFF0000);
var bm:Bitmap = new Bitmap(bmd);
addChild(bm);
trace (bmd.getPixel32(50, 20).toString(16)); // ffcccccccc
bmd.scroll(30, 0);
trace (bmd.getPixel32(50, 20).toString(16)); // ffff0000
public function setPixel(x:int, y:int, color:uint):void
Language version: | ActionScript 3.0
|
Sets a single pixel of a BitmapData object. The current
alpha channel value of the image pixel is preserved during this
operation. The value of the RGB color parameter is treated as an unmultiplied color value.
Note: To increase performance, when you use the setPixel()
or
setPixel32()
method repeatedly, call the lock()
method before
you call the setPixel()
or setPixel32()
method, and then call
the unlock()
method when you have made all pixel changes. This process prevents objects
that reference this BitmapData instance from updating until you finish making
the pixel changes.
Parameters
| x:int — The x position of the pixel whose value changes.
|
|
| y:int — The y position of the pixel whose value changes.
|
|
| color:uint — The resulting RGB color for the pixel.
|
See also
Example
The following example uses the
setPixel()
method to draw a red line in a BitmapData object:
import flash.display.Bitmap;
import flash.display.BitmapData;
var bmd:BitmapData = new BitmapData(80, 80, false, 0xCCCCCC);
for (var i:uint = 0; i < 80; i++) {
var red:uint = 0xFF0000;
bmd.setPixel(i, 40, red);
}
var bm:Bitmap = new Bitmap(bmd);
addChild(bm);
public function setPixel32(x:int, y:int, color:uint):void
Language version: | ActionScript 3.0
|
Sets the color and alpha transparency values of a single pixel of a BitmapData
object. This method is similar to the setPixel()
method; the main difference is
that the setPixel32()
method takes an
ARGB color value that contains alpha channel information.
All pixels in a BitmapData object are stored as premultiplied color values.
A premultiplied image pixel has the red, green, and blue
color channel values already multiplied by the alpha data. For example, if the
alpha value is 0, the values for the RGB channels are also 0, independent of their unmultiplied
values. This loss of data can cause some problems when you perform operations. All BitmapData
methods take and return unmultiplied values. The internal pixel representation is converted
from premultiplied to unmultiplied before it is returned as a value. During a set operation,
the pixel value is premultiplied before the raw image pixel is set.
Note: To increase performance, when you use the setPixel()
or
setPixel32()
method repeatedly, call the lock()
method before
you call the setPixel()
or setPixel32()
method, and then call
the unlock()
method when you have made all pixel changes. This process prevents objects
that reference this BitmapData instance from updating until you finish making
the pixel changes.
Parameters
| x:int — The x position of the pixel whose value changes.
|
|
| y:int — The y position of the pixel whose value changes.
|
|
| color:uint — The resulting ARGB color for the pixel. If the bitmap is opaque
(not transparent), the alpha transparency portion of this color value is ignored.
|
See also
Example
The following example uses the
setPixel32()
method to draw a transparent (alpha == 0x60) red line in a BitmapData object:
import flash.display.Bitmap;
import flash.display.BitmapData;
var bmd:BitmapData = new BitmapData(80, 80, true, 0xFFCCCCCC);
for (var i:uint = 0; i < 80; i++) {
var red:uint = 0x60FF0000;
bmd.setPixel32(i, 40, red);
}
var bm:Bitmap = new Bitmap(bmd);
addChild(bm);
public function setPixels(rect:Rectangle, inputByteArray:ByteArray):void
Language version: | ActionScript 3.0
|
Converts a byte array into a rectangular region of pixel data. For each
pixel, the ByteArray.readUnsignedInt()
method is called and the return value is
written into the pixel. If the byte array ends before the full rectangle
is written, the function returns. The data in the byte array is
expected to be 32-bit ARGB pixel values. No seeking is performed
on the byte array before or after the pixels are read.
Parameters
| rect:Rectangle — Specifies the rectangular region of the BitmapData object.
|
|
| inputByteArray:ByteArray — A ByteArray object that consists of 32-bit unmultiplied pixel values
to be used in the rectangular region.
|
Throws
| Error — The inputByteArray object does not include enough data
to fill the area of the rect rectangle. The method fills as many pixels as
possible before throwing the exception.
|
|
| TypeError — The rect or inputByteArray are null.
|
See also
Example
The following example uses the
getPixels()
and
setPixels()
methods to copy pixels from one BitmapData object to another:
import flash.display.Bitmap;
import flash.display.BitmapData;
import flash.utils.ByteArray;
import flash.geom.Rectangle;
var bmd1:BitmapData = new BitmapData(100, 100, true, 0xFFCCCCCC);
var bmd2:BitmapData = new BitmapData(100, 100, true, 0xFFFF0000);
var rect:Rectangle = new Rectangle(0, 0, 100, 100);
var bytes:ByteArray = bmd1.getPixels(rect);
bytes.position = 0;
bmd2.setPixels(rect, bytes);
var bm1:Bitmap = new Bitmap(bmd1);
addChild(bm1);
var bm2:Bitmap = new Bitmap(bmd2);
addChild(bm2);
bm2.x = 110;
public function setVector(rect:Rectangle, inputVector:Vector.<uint>):void
Language version: | ActionScript 3.0
|
Converts a Vector into a rectangular region of pixel data. For each pixel, a Vector element is read
and written into the BitmapData pixel. The data in the Vector is expected to be 32-bit ARGB pixel values.
Parameters
| rect:Rectangle — Specifies the rectangular region of the BitmapData object.
|
|
| inputVector:Vector.<uint> — A Vector object that consists of 32-bit unmultiplied pixel values to be used
in the rectangular region.
|
Throws
| RangeError — The vector array is not large enough to read all the pixel data.
|
public function threshold(sourceBitmapData:BitmapData, sourceRect:Rectangle, destPoint:Point, operation:String, threshold:uint, color:uint = 0, mask:uint = 0xFFFFFFFF, copySource:Boolean = false):uint
Language version: | ActionScript 3.0
|
Tests pixel values in an image against a specified threshold and sets pixels that pass the test to new color values.
Using the threshold()
method, you can isolate and replace color ranges in an image and perform other
logical operations on image pixels.
The threshold()
method's test logic is as follows:
- If
((pixelValue & mask) operation (threshold & mask))
, then
set the pixel to color
;
- Otherwise, if
copySource == true
, then
set the pixel to corresponding pixel value from sourceBitmap
.
The operation
parameter specifies the comparison operator to use for the threshold test.
For example, by using "==" as the operation
parameter, you
can isolate a specific color value in an image. Or by using {operation:
"<", mask: 0xFF000000, threshold: 0x7F000000, color:
0x00000000}
, you can set all destination pixels to be fully transparent
when the source image pixel's alpha is less than 0x7F. You can use this technique
for animated transitions and other effects.
Parameters
| sourceBitmapData:BitmapData — The input bitmap image to use. The source image can be a different
BitmapData object or it can refer to the current BitmapData instance.
|
|
| sourceRect:Rectangle — A rectangle that defines the area of the source image to use as input.
|
|
| destPoint:Point — The point within the destination image (the current BitmapData
instance) that corresponds to the upper-left corner of the source rectangle.
|
|
| operation:String — One of the following comparison operators, passed as a String: "<", "<=", ">", ">=", "==", "!="
|
|
| threshold:uint — The value that each pixel is tested against to see if it meets or exceeds the threshhold.
|
|
| color:uint (default = 0 ) — The color value that a pixel is set to if the threshold test succeeds. The default value is 0x00000000.
|
|
| mask:uint (default = 0xFFFFFFFF ) — The mask to use to isolate a color component.
|
|
| copySource:Boolean (default = false ) — If the value is true , pixel values from the source image are copied to the destination
when the threshold test fails. If the value is false , the source image is not copied when the
threshold test fails.
|
Returns
| uint —
The number of pixels that were changed.
|
Throws
| TypeError — The sourceBitmapData, sourceRect destPoint or operation are null.
|
|
| ArgumentError — The operation string is not a valid operation
|
Example
The following example uses the
perlinNoise()
method to
add a blue and red pattern to one BitmapData object, and then uses the
threshold()
method to copy those pixels from the first BitmapData object to a second one, replacing those pixels
in which the red value is greater than 0x80 (50%) with a pixel set to transparent red (0x20FF0000):
import flash.display.Bitmap;
import flash.display.BitmapData;
import flash.display.BitmapDataChannel;
import flash.geom.Point;
import flash.geom.Rectangle;
var bmd1:BitmapData = new BitmapData(200, 200, true, 0xFFCCCCCC);
var seed:int = int(Math.random() * int.MAX_VALUE);
var channels:uint = BitmapDataChannel.RED | BitmapDataChannel.BLUE;
bmd1.perlinNoise(100, 80, 12, seed, false, true, channels, false, null);
var bitmap1:Bitmap = new Bitmap(bmd1);
addChild(bitmap1);
var bmd2:BitmapData = new BitmapData(200, 200, true, 0xFFCCCCCC);
var pt:Point = new Point(0, 0);
var rect:Rectangle = new Rectangle(0, 0, 200, 200);
var threshold:uint = 0x00800000;
var color:uint = 0x20FF0000;
var maskColor:uint = 0x00FF0000;
bmd2.threshold(bmd1, rect, pt, ">", threshold, color, maskColor, true);
var bitmap2:Bitmap = new Bitmap(bmd2);
bitmap2.x = bitmap1.x + bitmap1.width + 10;
addChild(bitmap2);
public function unlock(changeRect:Rectangle = null):void
Language version: | ActionScript 3.0
|
Unlocks an image so that any objects that reference the BitmapData object, such as Bitmap objects,
are updated when this BitmapData object changes. To improve performance, use this method
along with the lock()
method before and after numerous calls to the
setPixel()
or setPixel32()
method.
Parameters
| changeRect:Rectangle (default = null ) — The area of the BitmapData object that has changed. If you do not specify a value for
this parameter, the entire area of the BitmapData object is considered
changed. This parameter requires Flash Player version 9.0.115.0 or later.
|
See also
Example
The following example creates a BitmapData object based on the
bitmapData
property of a Bitmap object,
picture
.
It then calls the
lock()
method before calling a complicated custom function,
complexTransformation()
, that modifies the BitmapData object. (The
picture
object
and the
complexTransformation()
function are not defined in this example.) Even if the
complexTransformation()
function updates the
bitmapData
property of
the
picture
object, changes are not reflected until the code calls the
unlock()
method on the
bitmapData
object:
import flash.display.BitmapData;
var bitmapData:BitmapData = picture.bitmapData;
bitmapData.lock();
bitmapData = complexTransformation(bitmapData);
bitmapData.unlock();
picture.bitmapData = bitmapData;
The following example uses the class BitmapDataExample to load the
image Image.gif into a DisplayObject in the default location (0, 0). A copy
of Image.gif is then placed to the right of the original, which has new colors applied to pixels
that pass a test using the
threshold()
method.
The task is accomplished using the following steps:
- A
url
property is created, which is the location and name of the image file
- The class constructor creates a Loader object, which then instantiates an event listener,
which is dispatched when the
completeHandler()
method completes the image manipulation.
- The
request
URLRequest object is then passed to loader.load()
, which loads the image
into memory by using a display object.
- The image is then placed on the display list, which displays the image on screen at
coordinates x = 0, y = 0.
- The
completeHandler()
method then does the following:
- Creates a second Loader, along with a Bitmap object, which is initialized with the
Loader object.
- Creates a second Bitmap object,
duplicate
, which in turn calls the
duplicateImage()
method, which creates a duplicate of the original image.
- Creates a BitmapData object that is assigned to the
duplicate
object's
BitmapData object.
- Creates a new Rectangle object initialized with the same coordinates, width, and height
as the original image.
- Creates a new Point object, which defaults to x = 0, y = 0.
- Creates the following variables:
operation
Applies the new color when the threshold
value is greater than or equal to the original.
threshold
The value against which each pixel is compared (in this example,
light gray with an alpha of 0xCC).
color
The color that the pixels are set to that pass the threshold
test, which is solid yellow in this case.
mask
The exact opposite of color (transparent blue).
copySource
Set to false
, indicating the pixel values are
not copied if the threshold value does not pass. This value has no meaning because
the image is duplicated and only pixels that pass the threshold test are changed.
- Calls the
threshold()
method using the preceding variables. The resulting threshold
equation is as follows: if (current pixel Value & 0x000000FF) >=
(0xCCCCCCCC & 0x000000FF) then set pixel to 0xFFFFFF00
.
Notes:
- You will need to compile the SWF file with Local Playback Security set to Access Local Files Only.
- This example requires that a file named Image.gif be placed in the same directory as your SWF file.
- It is recommended that you use an image of up to approximately 80 pixels in width.
package {
import flash.display.Bitmap;
import flash.display.BitmapData;
import flash.display.Loader;
import flash.display.Sprite;
import flash.events.*;
import flash.geom.Point;
import flash.geom.Rectangle;
import flash.net.URLRequest;
public class BitmapDataExample extends Sprite {
private var url:String = "Image.gif";
private var size:uint = 80;
public function BitmapDataExample() {
configureAssets();
}
private function configureAssets():void {
var loader:Loader = new Loader();
loader.contentLoaderInfo.addEventListener(Event.COMPLETE, completeHandler);
loader.contentLoaderInfo.addEventListener(IOErrorEvent.IO_ERROR, ioErrorHandler);
var request:URLRequest = new URLRequest(url);
loader.x = size * numChildren;
loader.load(request);
addChild(loader);
}
private function duplicateImage(original:Bitmap):Bitmap {
var image:Bitmap = new Bitmap(original.bitmapData.clone());
image.x = size * numChildren;
addChild(image);
return image;
}
private function completeHandler(event:Event):void {
var loader:Loader = Loader(event.target.loader);
var image:Bitmap = Bitmap(loader.content);
var duplicate:Bitmap = duplicateImage(image);
var bitmapData:BitmapData = duplicate.bitmapData;
var sourceRect:Rectangle = new Rectangle(0, 0, bitmapData.width, bitmapData.height);
var destPoint:Point = new Point();
var operation:String = ">=";
var threshold:uint = 0xCCCCCCCC;
var color:uint = 0xFFFFFF00;
var mask:uint = 0x000000FF;
var copySource:Boolean = true;
bitmapData.threshold(bitmapData,
sourceRect,
destPoint,
operation,
threshold,
color,
mask,
copySource);
}
private function ioErrorHandler(event:IOErrorEvent):void {
trace("Unable to load image: " + url);
}
}
}
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Wed Jul 3 2024, 9:16 AM GMT+01:00