Re: [Plib-devel] Re: [PATCH] fntBitmapFont::puts(): set negative coordinates correctly (Part II)

[Steve B. <sjb...@ai...>]

Melchior FRANZ wrote:
> * Bram Stolk -- Tuesday 05 July 2005 12:56:
> 
>>If z-test is off, and z-buffer writes are off, my guess is that
>>the z coord does not matter.
>
> I don't think that z is useful for fntBitmapFonts at all. Their main
> advantage is the non-blurry, sharp look. They would probably become
> illegible with any non-zero z.

No - that's not how glBitmaps work.

You give it *one* vertex position in x,y,z - which is then transformed
as if it was an ordinary vertex (and culled if it's off-screen).

When you render the bitmap, it's positioned at that vertex and rendered
at 1:1 pixel size and parallel to the edges of the screen no matter what.

So the size and resolution of the bitmap are independent of Z - perspective
only affects the position of the corner of the bitmap - not the size of
the bits when rendered onscreen.

The only time Z might matter would be if you still had perspective
enabled (which you don't in PUI) - then it's possible for the Z coord
to come out closer than Znear or further than Zfar - which would result
in the position command being set 'offscreen' and the bitmap not being
drawn.

---------------------------- Steve Baker -------------------------
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