I was happily recoding a software renderer from scratch (in java for beginners student), reusing some opengl mathematics.
I used the formulas in the opengl redbook (I bought it 6 or 7 years ago), to get the orthographic projection matrix.
It is the one that is written here , at the end of the page :
http://glprogramming.com/red/appendixf.html
And guess what? That is incorrect ! It misses a few minus in the formula... I had hard time to believe it.
The worse is that you can find this wrong formula in many tutorials over the internet.
The correct formula is written in the opengl specification, though, and in many other places.
http://www.opengl.org/sdk/docs/man/xhtml/glOrtho.xml
That redbook broke my heart
! Did you experience such problems too with other technical books ?
Best regards,
Pierre