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 <fr...@jangaroo.net> wrote: > On Thu, Nov 29, 2012 at 6:29 PM, Alex Harui <aha...@adobe.com> wrote: > >> >> On 11/29/12 3:31 AM, "Frank Wienberg" <fr...@jangaroo.net> 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... > >
