Sciter v.2 technology preview

Posted on by c-smile

You can download Sciter v.2 SDK preview from here http://terrainformatica.com/sciter/sciter2-tech-preview.zip

/bin/sciter.exe in the archive is a demo application to play with. Its sources are in /demos/sciter/ folder. After start you should see something like this:
article2

Note: this version works only on Vista/W7 as it uses Direct2D/Write graphics backend. Aero and W7 Basic DWMs only for a while.

New features in this version:

  • Direct2D/Write graphics backend – pretty fast on some operations. Expect animations to work faster.
  • Support of CSS 2D Transforms Module Level 3: http://www.w3.org/TR/css3-2d-transforms/ – everything except matrix() function. Will add it later if needed.
  • Internal DOM representation was redesigned to avoid need of that ugly <text> element injected by the parser. DOM is more standard now and in principle H-SMILE core can pass ACID2 test (if I will have a time to tweak it for that). DOM is represented by Element and Node entities. Node wraps text and comment nodes in HTML.
  • TIScript got support of "tagged n-tuples" data type. http://en.wikipedia.org/wiki/N-tuple with optional tag (a.k.a. name).

Some observations about Direct2D/Write:

Font rendering

Font rendering as I’ve mentioned already is significantly different in GDI and DW. Small an basic UI fonts looks better in GDI mode. Larger fonts are better in DW. For white text on black background with small and medium font sizes the GDI rendering is the only option I think. Just load /samples/basics/test-font-rendering.htm into the Sciter and you will see what I mean.

I was forced to introduce font-rendering-mode proprietary property for applications to be able to tweak this aspect.

Direct2D performance

While it is good on medium/high-end graphic cards it may behave very badly on low-end graphic cards or when there are applications on desktop that do graphic intense operations. Notably running Adobe Flash may affect speed of rendereing of other applications. That is not only about Sciter per se but other applications. Windows Live application suite is an example of graphics sensitive application. You may notice frame drops in animations inside Windows Live Mail or Messenger.

It appears as Direct2D/Write is a foundation for future high-DPI displays. As for now that font-rendering-mode workaround is the must I believe.