MapleTang / androidsvg

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Support for hardware acceleration #52

Open GoogleCodeExporter opened 9 years ago

GoogleCodeExporter commented 9 years ago
I know that, as explained in your FAQ, when displaying an SVG using an 
(SVG)ImageView, or using something else that requires a Picture or 
(Picture)Drawable, it is probably always going to be necessary to disable HWA 
because rendering would always(?) involve a call to Canvas#drawPicture() -- 
which will likely never be supported on a hardware-accelerated canvas.

However, when rendering an SVG straight to a Canvas using SVG#renderToCanvas(), 
I think we may actually be able to increase performance by allowing for HWA. If 
I'm not mistaken this would require that SVGAndroidRenderer does not call any 
drawing methods on either Canvas or Paint which are unsupported when HWA is 
enabled.
So have you perhaps already been trying to (completely?) avoid calling such 
methods? And if not, do you think it would be possible at all?
Note this may also require some Canvas.isHardwareAccelerated() checks to 
trigger alternative rending strategies.
Also note that the list of HWA-supported drawing methods has been growing with 
each new Android release 
(http://developer.android.com/guide/topics/graphics/hardware-accel.html#unsuppor
ted), so complete avoidance would perhaps only be possible on recent Android 
releases.

If such HWA support is possible it would perhaps also make sense to provide an 
additional (Image)View subclass which does not rely on SVG#renderToPicture() 
but instead uses SVG#renderToCanvas() and does not force HWA to be disabled.

Original issue reported on code.google.com by matthias...@gmail.com on 27 Jan 2015 at 9:02