The BitmapRenderer draws particles onto a single Bitmap display object. The
region of the particle system covered by this bitmap object must be defined
in the canvas property of the BitmapRenderer. Particles outside this region
are not drawn.
The image to be used for each particle is the particle's image property.
This is a DisplayObject, but this DisplayObject is not used directly. Instead
it is copied into the bitmap with the various properties of the particle
applied. Consequently each particle may be represented by the same
DisplayObject instance and the SharedImage initializer can be used with this
renderer.
The BitmapRenderer allows the use of BitmapFilters to modify the appearance
of the bitmap. Every frame, under normal circumstances, the Bitmap used to
display the particles is wiped clean before all the particles are redrawn.
However, if one or more filters are added to the renderer, the filters are
applied to the bitmap instead of wiping it clean. This enables various trail
effects by using blur and other filters.
The BitmapRenderer has mouse events disabled for itself and any
display objects in its display list. To enable mouse events for the renderer
or its children set the mouseEnabled or mouseChildren properties to true.
This class has been modified in version 1.0.1 of Flint to fix various
limitations in the previous version. Specifically, the canvas for drawing
the particles on must now be specified by the developer (it previously
defaulted to the size and position of the stage).
The previous behaviour, while still flawed, has been improved and
given its own renderer, the FullStageBitmapRenderer. To retain the previous
behaviour, please use the FullStageBitmapRenderer.
canvas:Rectangle [read-write]
The canvas is the area within the renderer on which particles can be drawn.
Particles outside this area will not be drawn.
Implementation
public function get canvas():Rectangle
public function set canvas(value:Rectangle):void
protected static var ZERO_POINT:Point
public function BitmapRenderer(canvas:Rectangle, smoothing:Boolean = false)
The constructor creates a BitmapRenderer. After creation it should be
added to the display list of a DisplayObjectContainer to place it on
the stage and should be applied to an Emitter using the Emitter's
renderer property.
Parameters
| canvas:Rectangle — The area within the renderer on which particles can be drawn.
Particles outside this area will not be drawn.
|
| |
| smoothing:Boolean (default = false) |
See also
public function addFilter(filter:BitmapFilter, postRender:Boolean = false):void
The addFilter method adds a BitmapFilter to the renderer. These filters
are applied each frame, before or after the new particle positions are
drawn, instead of wiping the display clear. Use of a blur filter, for
example, will produce a trail behind each particle as the previous images
blur and fade more each frame.
Parameters
| filter:BitmapFilter — The filter to apply
|
| |
| postRender:Boolean (default = false) |
public function addParticle(particle:Particle):void
The addParticle method is called when a particle is added to the emitter that
this renderer is assigned to.
Parameters
public function clearPaletteMap():void
Clears any palette map that has been set for the renderer.
protected function createBitmap():void
Create the Bitmap and BitmapData objects
public function dispose():void
When the renderer is no longer required, this method must be called by the
user to free up memory used by the renderer. If you don't call this method
then the renderer's bitmap data will remain in memory.
protected function drawParticle(particle:Particle):void
Used internally here and in derived classes to alter the manner of
the particle rendering.
Parameters
| particle:Particle — The particle to draw on the bitmap.
|
public function removeFilter(filter:BitmapFilter):void
Removes a BitmapFilter object from the Renderer.
Parameters
| filter:BitmapFilter — The BitmapFilter to remove
|
See also
addFilter()
public function removeParticle(particle:Particle):void
The removeParticle method is called when a particle is removed from the
emitter that this renderer is assigned to.
Parameters
public function renderParticles(particles:Array):void
The renderParticles method is called every frame so the renderer can
draw the particles that are in the emitter that this renderer is
assigned to.
Parameters
| particles:Array — The particles to draw.
|
public function setPaletteMap(red:Array = null, green:Array = null, blue:Array = null, alpha:Array = null):void
Sets a palette map for the renderer. See the paletteMap method in flash's BitmapData object for
information about how palette maps work. The palette map is applied to the full canvas of the
renderer after all filters have been applied and the particles have been drawn.
Parameters
| red:Array (default = null) |
| |
| green:Array (default = null) |
| |
| blue:Array (default = null) |
| |
| alpha:Array (default = null) |
© Big Room Ventures Ltd. 2008
flash.display.Sprite