This evening, Lexx handed me a small object made by a fellow named Petr Brandenburg, that alternately flashed yellow and cyan. She couldn’t read the script inside it, so she didn’t know how it worked. She asked if I could figure it out.
Within a few minutes, I had handed her this:
// Neon Flasher Script
// Erbo Evans - 3/23/2008
/////////////////////////////////
// List of colors to cycle through, specified as tuples.
list colors = [<0.0,1.0,1.0>, <1.0,1.0,0.0>];
float delay = 0.5; // how long to wait between color changes
integer index; // counter used to keep track of color state
default
{
state_entry()
{ // initialize the color index and display the first color
index = 0;
llSetColor(llList2Vector(colors,0),ALL_SIDES);
// set up the timer to flash colors
llSetTimerEvent(delay);
} // end state_entry
timer()
{ // advance to next color and display it
if (++index>=llGetListLength(colors))
index = 0; // wrap around back to beginning if we run off the end
llSetColor(llList2Vector(colors,index),ALL_SIDES);
} // end timer
} // end state default
Simple enough to understand. The script itself is basically a timer-driven state machine, using a table (the colors list) to specify the colors to be displayed on the prim (which uses a blank texture on all faces to better show the effect).
As an exercise, I asked her, “How would you extend the script to flash more than two colors?” Because of the way I wrote the code, it’s very easy (just extend the colors list). However, she stared at it and felt her brain begin to melt. I think it was mostly due to the fact that she was running on only four hours sleep, though. 🙂
Evans Avenue Exit 