hello,i know this post is 2007 but i am very interesting how eidolon engine works.I tried contact with Heaven/TQA but it doesnt allow me send pm.
I am new on atari,my machine was a cpc ,but any info is welcome.
I was searching on net and also contacted with loren carpeten with facebook.He told me he has not have the sources,but he remember ome things i would like share with you.
"The visibility/hidden line part was done with what's called a "height field algorithm". Basically you draw the scene from near to far, keeping track of the "highest" point at each horizontal screen coordinate in the picture. Then when you are to draw in a new line (or pixel) you check to see if it is higher than anything drawn before. If so, then you draw it and update the height for that screen column, otherwise you skip it. Another thing that speeds it up is that perspective is only calculated for the horizontal axis. The vertical axis is scaled by a simple distance multiplier. The high and low points in the landscape were computed from scratch when the program started. Drawing fractal lines was done with midpoint subdivision (randomly displace the midpoint up or down an amount proportional to the length of the line). Keep doing that until the lines were 1 pixel long."
do you found more things with your disasm code?
thanks
dani