Errata for Metaprogramming GPUs with Sh

Page 18: missing word

The first sentence on the page is missing a word: "Basically, sequences of calls into an API can be interpreted as a ..."

Page 28: wrong z convention noted

Second paragraph from the bottom:
"Values of z at the near plane are mapped to 0, those close to the far plane are mapped to 1. This follows OpenGL conventions."
should be
"Values of z at the near plane are mapped to -1, those close to the far plane are mapped to 1. This follows OpenGL conventions."

Page 29: our->are

In middle of first full paragraph on page:
"Therefore, some simplifications to our shaders our possible in the ..."
should be
"Therefore, some simplifications to our shaders are possible in the ..."

Listing 5.3:

The last line of the listing,

ShProgram update_state = p << state;

Should be

ShProgram update_state = update << state;

Page 168: faceforward

The math should be

      /  b if dot(a, b) > 0,
 r <- |
      \ -b otherwise

Rather than

      /  a if dot(a, b) > 0,
 r <- |
      \ -a otherwise

(ie. return b instead of a).

Page 219: result.depth

result.depth is mapped to SH_POSITION, not SH_ATTRIB.

index:

"ShInterpolate modifier" should be "ShInterp modifier"

Copyright 2003-2005 Serious Hack Inc.