Canvas API Feedback.

[joe andresen]

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/