Changes

Painting/rendering/rasterizing is the step where graphical primitives (such as a command to fill an [https://developer.mozilla.org/en-US/docs/Web/SVG SVG] circle, or a [https://developer.mozilla.org/en-US/docs/Web/Guide/Graphics/Drawing_graphics_with_canvas canvas] command to stroke a path between x, y, z, or the internally produced command to draw the edge of an HTML div's bordera rounded rectangle) are used to color in the pixels of a surface so that the surface "displays" those rasterized primitives.

The platform independent library that gecko uses to render is [http://dxr.mozilla.org/mozilla-central/source/gfx/2d/2D.h Moz2D]. Gecko code paints into Moz2D DrawTarget objects (the DrawTarget baseclass base class having multiple platform dependent subclasses). (At least this is where gecko is going - for now there is still significant amounts of code that uses [http://dxr.mozilla.org/mozilla-central/source/gfx/thebes/gfxContext.h Thebes gfxContext] objects or the even older nsRenderingContext objects. Objects of these types now always wrap a DrawTarget so all painting does now go through Moz2D, but conversion to use the wrapped DrawTargets directly is taking time since consumer code can sometimes need to be radically rewritten to fit the Moz2D API and immediate mode paradigm.)