Ron Parker wrote in message <37a1f578@news.povray.org>...
>
>POV already supports at least one true 16-bit image format: PNG.
>I think TIFF support would be a nice addition, though.  Maybe
>I'll see what's involved.

From just a quick look at the code in png_pov.c, I couldn't
find any plain 16-bit support; there's always some conversion
of color channels going on. But I'm not 100% sure; will
have to look closer at it.


I just realized that no caching scheme may be effective,
because there will always be a scene that makes it thrash.

Consider a scene with multiple objects (all using the
same imagemap) at various distances from the camera.
As the rendering scanline intersects more than one object,
the access pattern to the imagemap becomes more random.

The solution is probably to build a depth map of the
entire scene, and then iterate through the imagemap
looking for screen pixels that can be serviced by
the current imagemap chunk. One nice thing is that
the storage format of the image file doesn't have
to be block-based; we can make a chunk be a set
of scanlines, so reading it is just as fast as
reading a block.

Ray Gardener
Daylon Graphics Ltd.
http://www.daylongraphics.com/

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