The demo units used by Microsoft employees to show off Windows Phone 7 all had a 800×480 screen – which can be considered the current pinnacle of high-definition screens for mobile devices. However, these screens also are expensive…
Shawn Hargreaves now disclosed further information which should be interesting to both users and developers:
The phone features an image scaler which allows games to render to any size backbuffer they like, and have it automatically stretched to fill the display, with black bars along the edges if the backbuffer and display have different aspect ratios (an idea that will be familiar to Xbox developers). This scaling is handled by dedicated hardware, so does not consume any GPU resources, and it uses a high quality image filter that gives much better results than bilinear filtering like you would get if you did this yourself on the GPU. The scaler is important for two reasons:
* At launch, all phones will have a 480×800 (WVGA) display resolution, but we will add 320×480 (HVGA) in a future update. Of course you can detect the native resolution and program your game to adapt to this if you want, but the scaler allows games to pick just one resolution, always render at that fixed size, and still run correctly on phones with different native screen sizes. For bonus points, we automatically scale touch input to match your chosen resolution.
* 480×800 is a lot of pixels! This is a great resolution for displaying text, browsing the web, etc, but it can be a challenge for intensive 3D games to render so much data at a good framerate. To boost performance, some games may prefer to render at a lower resolution, then scale up to fill the display.
Not much to add here…
