Re: [AD] Additional graphics primitives API

[Elias Pschernig <elias@xxxxxxxxxx>]

> Shapes such as triangles, rectangles, and lines are almost trivial to
> draw in memory and opengl. They'll be pretty small functions on all
> systems and they should probably be in the core.
> 
> Curved ones such as circle are really hard to do in opengl (with
> precision) but rather easy to do in memory. Maybe the best option for
> circle is to draw a rectangle and then map a "texture" of a circle.
> Some sort of mip-map or caching system would be useful.

A way as "trivial" as for triangle to draw a circle is like in 4.2.x,
calculate the left and right outlines and connect them with horizontal
spans.

> A question for later.. but does the glx and d3d drawing routines still
> get used even without a hardware driver? ie: does d3d and ogl default
> to software rendering?

No. They only get used when drawing to the main display or to bitmaps
which are not forced into memory mode with the ALLEGRO_MEMORY flag. They
also are used as fallback when drawing to a bitmap, but the driver does
not support offscreen surfaces (e.g. no framebuffer object extension in
the case of OpenGL).

The way we use no anti-aliasing and subpixel precision, software and
hardware results are supposed to be 100% identical, pixel-by-pixel,
though.

-- 
Elias Pschernig <elias@xxxxxxxxxx>