as usual — long time, no blog.
my only excuse is that I was busy with other things: new job, new office, holidays… you know, whatever happens between coding.
it’s that time of year again, and we’re nearing another Clutter release — this time it’s a special one, though, as it is 1.0.0. which also means that the API will be frozen for the entire duration of the 1.x branch: only additions and deprecations will be allowed1.
since we’re in the process of finalizing the 1.0 API I thought about writing something about what changed, what was added and what has been removed for good.
let’s start with the Effects API. the Effects were meant to provide a high level API for simple, fire-and-forget animations2. they were sub-obtimal in the memory management — you had to keep around the EffectTemplate, the effects copied the timelines — and they weren’t extensible — writing your own effect would have been impossible without reimplementing the whole machinery. after the experiments done by Øyvind and myself, and after looking at what the high-level languages provided, I implemented a new implicit animation API — all based around a single object, with the most automagic memory management possible:
/* resize the actor in 250 milliseconds using a cubic easing * and attach a callback at the end of the animation */ ClutterAnimation *animation = clutter_actor_animate (actor, 250, CLUTTER_EASE_IN_CUBIC, "width", 200, "height", 200, "color", &new_color, NULL); g_signal_connect (animation, "completed", G_CALLBACK (on_animation_complete), NULL);
what might make some people slightly less happy is the big API churn that removed both ClutterLabel and ClutterEntry and added ClutterText. the trade-off, though, is clearly in favour of ClutterText, as this is a base class for both editable and non-editable text displays; it supports pointer and keyboard selection, and multi-line as well as single-line editing.
another big changed happened on the low level COGL API, with the introduction of vertex buffers — which allow you to efficiently store arrays of vertex attributes; and, more importantly, with the introduction of the Materials which decouple the drawing operations with the fill operations. it also adds support for multi-texturing, colors and other GL features — on both GL and GLES.
after unifying Label and Entry, we also decided to unify BehaviourPath and BehaviourBspline; after that we added support for creating paths using SVG-like descriptions and for “replaying” a Path on a
cairo_t. well, the Cairo integration is also another feature — clutter-cairo has been deprecated and its functionality moved inside ClutterCairoTexture.
one of the last minute additions has been ClutterClone, an efficient way to clone generic actors without using FBOs — which also supercedes the CloneTexture actor.
the Pango integration has been extended, and the internal Pango API exposed and officially supported — now you can display text using the Pango renderer and glyphs cache inside your own custom actors without using internal/unstable API.
thanks to Johan Dahlin and Owen Taylor, Clutter now generates GObject-Introspection data at compile time, so that runtime language bindings will be ready as soon as 1.0.0 hits the internets.
finally, there’s a ton of bug fixes in how we use GL, how we render text, how we relayout actors, etc.
hope you’ll have fun with Clutter!