GSoC 2012: Week 5+6

[Ivan Vučica]

Hi,

Since I've now begun real work on the GSoC project, and I've obviously
started occasionally running into things I need to patch in other
parts of GNUstep, it may be interesting if I also sent reports
publicly. Up to now I sent them to Fred, David and Gregory. If sending
them to the list doesn't seem like a good idea, send me a note and
I'll stop.

So here's what I did.

* I've explored my options for getting pixel data out of Opal.
* I've picked cairo_image_surface_get_data() and feeding the data into
a GL texture when updated.
* I wrote a demo that makes use of Opal to create an image, and then
uses the above method to create an OpenGL texture, which is then
painted onscreen. (See: dev-libs/quartzcore/Tests/hello_opal.m).
* To get hello_opal to run, I patched/worked around Opal's NSFont
conflict with gnustep-gui.
* I wrote basic implementation of CALayer and CARenderer, supporting
painting of background color specified via backgroundColor property of
a layer, and supporting painting of content drawn via -drawToContext:.
* I'm trying to stick to OpenGL ES compatible API, so that once I get
around to porting QuartzCore to ES there is minimum effort needed. I
expect that some features like masking and shadowing will only be
supported via shaders, but that's not carved into stone. (Both might
be doable via Cairo instead.)
* Additional notes: For now, CARenderer only paints into
NSOpenGLContext. No transforms or layers nor sublayers. No animation
support yet (hence no separate model and presentation layer).
* I wrote a demo that makes use of CALayer and CARenderer, combining
image previously drawn in hello_opal with a background color. (See:
dev-libs/quartzcore/Tests/hello_carenderer.m).

-- 
Ivan Vučica - ivan@vucica.net