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From Frank Wienberg <>
Subject Re: [FalconJS] concepts
Date Fri, 30 Nov 2012 10:42:44 GMT
Btw, since only the "cacheAsBitmap" feature and the Graphics implementation
use canvas, it is completely possible to implement SVG rendering as an
alternative. The "cacheAsBitmap" flag of a flash.display.Bitmap object
could be used as the switch whether to use canvas or SVG.

On Fri, Nov 30, 2012 at 11:40 AM, Frank Wienberg <> wrote:

> On Thu, Nov 29, 2012 at 6:29 PM, Alex Harui <> wrote:
>> On 11/29/12 3:31 AM, "Frank Wienberg" <> wrote:
>> > Primarily, I also map DOs to DOM elements!
>> >
>> > Greetings
>> > -Frank-
>> Just curious, but how does this mapping work?  How many DOM objects are
>> being created and what does the drawing, SVG?
>> Usually only one DOM object, but that can be different in each
> DisplayObject subclass.
> The actual drawing (flash.display.Graphics) is always done through a
> canvas (which is, of course, also a DOM element!). Thus, in DOM-mode, a
> Sprite consists of a <div> container with a <canvas> for rendering and more
> DOM elements for all contained child-DOs.
> Because in typical gaming scenarios, this approach led to a lot of
> canvases being created and turned out to be slow and memory-consuming, I
> implemented a mode where a complete DisplayList-subtree (well, the thing
> called DisplayList actually is a tree!) is rendered into a single canvas.
> This is the approach taken by DartFlash and works extremely well for games
> and animations where almost all DOs are graphics or simple text, but is not
> so good for interactive components like TextField, where you would have to
> emulate all the interactive behavior on a low-level basis (blinking cursor
> etc.).
> Since it seems none of the two solutions is always preferable, I now let
> the developer decide. Setting "cacheAsBitmap" to true on a DO-Container
> activates canvas mode for that DL-subtree, but other parts of the DL can
> still use DOM-mode, so you can mix-and-match graphics and interactive parts
> of your UI.
> Note however that the DOM-mode supports less Flash features and has
> several known bugs concerning scaling and rotation (it is really tough to
> map these on CSS3 transforms and it turned out to be much easier when using
> canvas 2D API). It might even be that after the canvas-refactoring,
> DOM-mode work worse than before...

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