Hi Jim,
On 2/11/14 4:12 AM, Jim Graham wrote:
Just out of curiosity, on a Mac there is support for @2x images where
they get loaded and used (at half scale to preserve layout size)
automatically for you. In that respect, the added resolution is
hidden from the regular APIs and the developer doesn't really have to
deal with the meaning of "size" as it relates to HiDPI.
But, when you buy into HiDPI for your rendering, it looks like their
system requires you to ask them to calculate the proper extents for
the back buffer to render it and you are supposed to render it into
that rectangle (FX is calling convertRectToBacking and then using the
bounds to control the eventual blit of the back buffers).
If that is the case, then it looks like we have some precedence there
to have them buy into HiDPI backing stores or compatible images where
the images report their pixel sizes and they need to manage the
display size directly (i.e. by using drawImage(x,y,w,h) as we do
internally). I think we could make it a little more friendly than
their "convertRectToBacking" system, but it would mean we wouldn't
have to pollute the getWidth/Height APIs with conditional return values.
For example, if we added getLayoutWH() or getScaleFactor() to image or
bimg, then the normal ways of constructing those objects would simply
return objects where the answers were unscaled and unsurprising. If
they went out of their way to request one that was scaled, then those
new APIs (available on all images, but not very interesting except on
the specially constructed DPI-aware versions) would have new values to
help them manage the scaled image. Unaware code would simply see
these as overly large images, but it would be up to the developer to
manage hiding any HiDPI images from any code that they had not
converted to be DPI aware (just as we are doing here with our internal
Swing buffer).
Ok, you're still against those "conditional return values" :) I already
tried to convey my thoughts describing the reason why I couldn't simply
throw them away. But Ok, let's do it eventually, then look at the new
version and judge it...
One thing to keep in mind, though, is that Windows appears to allow
non-integer scales so I think we should not assume integer scale
factors in whatever new API we create...
I just sticked to the type of the scale factor returned by
SurfaceData.getDefaultScale() which was int.
Thanks,
Anton.
...jim
On 2/10/14 3:37 PM, Jim Graham wrote:
On 2/10/14 6:11 AM, Anton V. Tarasov wrote:
On 2/3/14 6:36 AM, Anton V. Tarasov wrote:
In SG2D, the drawHiDPIImage, for instance, makes a call to
op.filter(img, null); where the img is expected to return its layout
size. That's why I still prefer to use the setReturnLayoutSize
"switcher", in order not to go deep into the 2D rendering code,
casting
here and there to OffscreenImage and calling getLayoutWidth/Height.
Would we expect one of these images to have the BufferedImageOp
version of drawImage be used on it? (It could happen if we ever leak
the object into developers hands, but I'm not sure if that can happen
or not - I'm pretty sure we don't use those Ops internally ourselves,
do we?)
We don't use it internally. Originally, I had an option in the fix with
which a developer could create a HiDPI BufferedImage. Then, I
implemented the last SG2D.drawImage method which didn't have hidpi
support, and created a 2D test for it. In the test I drew some 2D
primitives into a HiDPI image, using a BufferedImageOp transform. So, I
just tested the ability to use it externally.
In the current version of the fix there's no option to get a HiDPI
image
from the outside, so this code is not really used. I can eliminate
it if
we think we don't need it in the nearest future.
It might make sense to leave it in for now. I'm not happy with that
design conceptually in the long term, but I don't think there is a 100%
pure/simple/obvious solution to the issues we are facing and it's not
really hurting anything in the short term...
...jim
