If FLAG_HIGH_QUALITY_SCALING is used, we should use
SurfaceCache::LookupBestMatch just like how it is done in RasterImage.
This may provide an alternative size at which we should rasterize the
SVG instead of the requested size. Since SurfaceCache imposes a maximum
size for which it will permit rasterized SVGs, we should also bypass the
cache entirely if we are well above that and simply draw directly to the
draw target in such cases.
With WebRender, it is somewhat more complicated. We will now return
NOT_SUPPORTED if the size is too big, and this should trigger fallback
to blob images. This should only produce drawing commands for the
relevant region and save us the high cost of rasterized a very large
surface on the main thread, which at the same time, looking as crisp as
a user would expect.
If FLAG_HIGH_QUALITY_SCALING is used, we should use
SurfaceCache::LookupBestMatch just like how it is done in RasterImage.
This may provide an alternative size at which we should rasterize the
SVG instead of the requested size. Since SurfaceCache imposes a maximum
size for which it will permit rasterized SVGs, we should also bypass the
cache entirely if we are well above that and simply draw directly to the
draw target in such cases.
With WebRender, it is somewhat more complicated. We will now return
NOT_SUPPORTED if the size is too big, and this should trigger fallback
to blob images. This should only produce drawing commands for the
relevant region and save us the high cost of rasterized a very large
surface on the main thread, which at the same time, looking as crisp as
a user would expect.
Andrew Osmond
Andreea Pavel
Jonathan Watt