Is GDI+ just a layer on top of GDI, or something new?

Question

When GDI+ came out, I remember all the brouhaha about how it was the \"new, faster, better\" way to display stuff in Windows. But everytime I looked at it, it seemed to me that

Answer 1

Many GDI functions are accelerated by the graphics hardware, and some GDI+ routines may use GDI underneath. But most of GDI+ is independant of GDI.

An important, and telling, example is text rendering. In GDI+ text rendering is done completely in software; the anti-aliasing, glyph pixel-fitting and other effects is done without the video card.

_{(source: microsoft.com)}

Microsoft's Chris Jackson had an interesting blog post where he profiled the speed difference between text rendering in GDI and GDI+:

...my GDI code path was rendering approximately 99,000 glyphs per second, while my GDI+ code path was rendering approximately 16,000 glyphs per second.

Another example is line drawing. GDI+ supports anti-aliased line/polygon and circle/ellipse drawing, while GDI does not:

<sub>(source: microsoft.com)

(source: microsoft.com)</sub>

_{(source: microsoft.com)}