Canvas API Feedback.

[joe andresen]

Also, note that we have discussed 3,4, and 5 and have some ideas on how 
to implement them, but also some issues we would need to work through. 
None of them could be fully vetted in the 2.2 time frame and all of them 
we felt could be added in future releases without much trouble so we 
reserve the possibility of adding any of them in a future release when 
we have more time to get them right.

On 5/11/2012 11:32 AM, joe andresen wrote:
> On 5/11/2012 11:12 AM, joe andresen wrote:
>> On 5/11/2012 10:38 AM, Josh Marinacci wrote:
>>>> 4. We are sticking with an application controlled immediate mode 
>>>> drawing
>>>> API for Canvas, similar to the likes of HTML 5 canvas. The rendering
>>>> will be triggered by the application, and not by a paint callback.
>>>
>>> Will this enable developers to handle the infinite scrolling area 
>>> use case? For example: a control which draws the an audio 
>>> waveform.   It would only actually draw the visible area, letting 
>>> the user pan to the area they choose.  It seems like the canvas 
>>> needs some indication of when part of the canvas has been revealed 
>>> and must be repainted.
>> There really isn's such a thing as "part" of the canvas (or really it 
>> is just not a good idea to). You must think of canvas as an image 
>> where the GraphicsContext will issue a bunch of draw calls to it. It 
>> is up to the developer to choose which draw calls to issue (ie 
>> transform your calls for scrolling events, etc.)
>>
> there are already several html 5 canvas examples that could help 
> inform your solution.
>
> http://dougx.net/plunder/
>
> http://www.html5gamedevs.com/2012/01/10/parallax-scrolling-html5-canvas-iphone/ 
>