http://t3x.org/t3x/0/exam-mandel.html

# T3X/0

## Example Programs

T3X/0 homepage
Examples: bubblesort | mandelbrot | ntoa | strings

Draw a Mandelbrot set using ASCII characters. See the program output here.

 use t3x: t; ! Denominator for fixed-point computations const SCALE = 100; ! ASCII renditions of filled rectangles: const FULL = 'M', ! completely filled UPPER = '"', ! upper half filled LOWER = 'm', ! lower half filled EMPTY = '\s'; ! empty ! Compute the color of a point x+yi f(x, y) do var cr, ci, zr, zi, ir; var i; zr := 0; ! z = 0+0i zi := 0; cr := x*SCALE/25; ! c = x+yi ci := y*SCALE/20; ! try 100 iterations for (i=0, 100) do ! z := z^2+c ir := zr*zr/SCALE - zi*zi/SCALE; zi := zr*zi/SCALE + zi*zr/SCALE + ci; zr := ir + cr; ! if |z| > 2+2i, x+yi is not a member ! of the Mandelbrot set M if (zi > 2*SCALE \/ zr > 2*SCALE \/ zi < -2*SCALE\/ zr < -2*SCALE ) return 0; end ! |z| <= 2+2i after 100 iterations, ! so x+yi is probably in M return %1; end do var x, y, r; ! coordinates, point color var line::79; ! line buffer var even; ! even line flag even := 0; for (y=-24, 25) do ! lines for (x=-59, 20) do ! columns r := \f(x,y); ! When drawing an even line, ! merge the color of r into the ! current rectangle ... ie (even) line::(x+59) := line::(x+59)-> ! odd point was on r-> FULL: UPPER: ! odd point was off r-> LOWER: EMPTY; ! ... else just memorize the color else line::(x+59) := r; end ! Even line completed, print it if (even) do t.write(T3X.SYSOUT, line, 79); t.write(T3X.SYSOUT, "\n", 1); end even := \even; end end

## Program Output

 MMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM MMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM MMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMmMMMMMMMMMMMMMMMMMMM MMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM" MM"MMMMMMMMMMMMMMMMMMM MMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM" "MMMMMMMMMMMMMMMMMMM MMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM"MMM" MM"MMMMMMMMMMMMMMMMM MMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM "" """""MMMMMMMMMMM MMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM"" MMMMMMMMMMM MMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM" "MMMMMMMMM MMMMMMMMMMMMMMMMMMMMMMMMMMMMMM""M" """"MM MMMMMMMMMM MMMMMMMMMMMMMMMMMMMMMMMMMMMM"" "" mMMMMMMMMM MMMMMMMMMMMMMMMMMMMMMM"MM" mMMMMMMMMMM MMMMMMMMMmmmmmmmmmmmmm mm ""MMMMMMMMMMM MMMMMMMMMMMMMMMMMMMMMMMMMMmm MMMMMMMMMM MMMMMMMMMMMMMMMMMMMMMMMMMMMMMM m MM mMMMMMMMMM MMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMmMMMMMMm "MMMMMMMMM MMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM mMMMMMMMMMM MMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMm MMMMMMMMMMM MMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMmmM"mmm mm mMMMMMMMMMMMMMMMM MMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM" "MMMMMMMMMMMMMMMMMMM MMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMm mm"MMMMMMMMMMMMMMMMMMM MMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMmMMMMMMMMMMMMMMMMMMMMMM MMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMmMMMMMMMMMMMMMMMMMMM MMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM