JSL, attached below, modified a bit to make this video. Best when viewed. Intended for full screen. Inspired by Substrate screensaver.
https://www.youtube.com/watch?v=WP1moAuUKXo
this is a typical picture from the attached JSL.
Fantastic!
Wow Craige, you just turned JMP into a screensaver. What's next -- flying toasters?
Thanks! I was thinking about a scroller built with transparent bitmaps.
Great script! I don't see where in the code curved lines are generated. Is there a way to generate more curves?
I'm new to JSL.
Thank you.
Thanks! In my excitement to post, it looks like I forgot to write comments!
This program is using a JSL list named stack (which is misnamed, but ignore that.) Stack holds a list of active roads. Each element on the stack is a list of
There is also a veclen, which I believe is always .7, close to .707.
The driver loop, near the end, calls the doodle function N times with indexes to the N front-most items in stack. doodle draws one pixel for each of those roads, so it looks like N roads are built at the same time. Look at the code at the front of doodle and you'll see the code that implements the turn:
1 {row, col, angle, deltaangle, veclen} = stack[istack]; 2 {newrow, newcol, angle} = Eval List( {row + veclen * Sin( angle ), col + veclen * Cos( angle ), angle + deltaangle} ); 3 If( newrow >= 1 & newrow <= rowsiz & newcol >= 1 & newcol <= colsiz, 4 stack[istack] = Eval List( {newrow, newcol, angle, deltaangle, veclen} );
Line 1 grabs the state of the nth (istack) road. Line 2 computes a row and col for the next pixel AND a new angle (for next time.) Line 3 is testing if the row,col is still on the screen, and if so, line 4 updates the info for the road back into the stack.
If you are still following in the source, you'll see a black pixel set at row,col, or if off screen, you'll see the stack element removed...which will make a new road, further down the stack, start drawing next time.
You'll also see code that spawns new roads at right angles (by adding +/- pi/2 to the current angle), and code that sprays the lightly colored sand at right angles as well.
The code that spawns a new road
// new doodle at right angle stack[N Items( stack ) + 1] = Eval List({newrow, newcol, angle + If( Random Integer( 0, 1 ), Pi() / 2, -Pi() / 2 ), Random Normal( 0, .0001 ), .7});
is the answer to your question: random normal is generating a delta angle that is very close to zero, most of the time. Make the .0001 a shade larger and more of the lines will have more curvature.
Thanks for puzzling over the code, and ask again if the missing comments are a problem.
Thank you for the fast reply. I've had lots of fun generating images with different curvature and color combinations.
https://www.youtube.com/watch?v=WP1moAuUKXo
