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Sierpinski arrowhead curve: Difference between revisions

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Sierpinski arrowhead curve (view source)

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Line 34:
V size = 600
V iterations = 8
V outfile = File(‘sierpinski_arrowhead.svg’, ‘w’WRITE)
 
outfile.write(‘<svg xmlns='http://www.w3.org/2000/svg' width='’size‘' height='’size"'>\n")
Line 120:
Doc.Close;
end Arrowhead_Curve;</syntaxhighlight>
 
=={{header|ALGOL 68}}==
{{libheader|ALGOL 68-l-system}}
Generates an SVG file containing the curve using the L-System. Very similar to the Algol 68 Sierpinski square curve sample. Note the Algol 68 L-System library source code is on a separate page on Rosetta Code - follow the above link and then to the Talk page.
<syntaxhighlight lang="algol68">
BEGIN # Sierpinski Arrowhead Curve in SVG #
# uses the RC Algol 68 L-System library for the L-System evaluation & #
# interpretation #
 
PR read "lsystem.incl.a68" PR # include L-System utilities #
 
PROC sierpinski arrowhead curve = ( STRING fname, INT size, length, order, init x, init y )VOID:
IF FILE svg file;
BOOL open error := IF open( svg file, fname, stand out channel ) = 0
THEN
# opened OK - file already exists and #
# will be overwritten #
FALSE
ELSE
# failed to open the file #
# - try creating a new file #
establish( svg file, fname, stand out channel ) /= 0
FI;
open error
THEN # failed to open the file #
print( ( "Unable to open ", fname, newline ) );
stop
ELSE # file opened OK #
 
REAL x := init x;
REAL y := init y;
INT angle := 0;
put( svg file, ( "<svg xmlns='http://www.w3.org/2000/svg' width='"
, whole( size, 0 ), "' height='", whole( size, 0 ), "'>"
, newline, "<rect width='100%' height='100%' fill='white'/>"
, newline, "<path stroke-width='1' stroke='black' fill='none' d='"
, newline, "M", whole( x, 0 ), ",", whole( y, 0 ), newline
)
);
 
LSYSTEM ssc = ( "XF"
, ( "X" -> "YF+XF+Y"
, "Y" -> "XF-YF-X"
)
);
STRING curve = ssc EVAL order;
curve INTERPRET ( ( CHAR c )VOID:
IF c = "F" THEN
x +:= length * cos( angle * pi / 180 );
y +:= length * sin( angle * pi / 180 );
put( svg file, ( " L", whole( x, 0 ), ",", whole( y, 0 ), newline ) )
ELIF c = "+" THEN
angle +:= 60 MODAB 360
ELIF c = "-" THEN
angle -:= 60 MODAB 360
FI
);
put( svg file, ( "'/>", newline, "</svg>", newline ) );
close( svg file )
FI # sierpinski square # ;
 
sierpinski arrowhead curve( "sierpinski_arrowhead.svg", 1200, 12, 6, 200, 700 )
 
END
</syntaxhighlight>
 
=={{header|ALGOL W}}==
Line 459 ⟶ 525:
 
{{out}}
[[Media:Sierpinski_arrowhead_c.svg]]
See: [https://slack-files.com/T0CNUL56D-F016A6S357Z-dde1d67b8c sierpinski_arrowhead.svg] (offsite SVG image)
 
=={{header|C++}}==
Line 531 ⟶ 597:
 
{{out}}
[[Media:Sierpinski_arrowhead_cpp.svg]]
See: [https://slack-files.com/T0CNUL56D-F016A6S357Z-dde1d67b8c sierpinski_arrowhead.svg] (offsite SVG image)
 
=={{header|Delphi}}==
{{works with|Delphi|6.0}}
{{libheader|SysUtils,StdCtrls}}
 
[[File:DelphiSierpinskiArrowhead.png|frame|none]]
<syntaxhighlight lang="Delphi">
 
type T2DVector=packed record
X,Y: double;
end;
 
var Pos: T2DVector;
var CurAngle: double;
 
 
procedure Turn(Angle: double);
{Turn current angle by specified degrees}
begin
CurAngle:=CurAngle+Angle;
end;
 
 
procedure DrawLine(Canvas: TCanvas; Len: double);
{Draw current line, rotated by the current angle}
var P2: T2DVector;
begin
Canvas.Pen.Mode:=pmCopy;
Canvas.Pen.Style:=psSolid;
P2.X:= Pos.X + Len*Cos(DegToRad(CurAngle));
P2.Y:= Pos.Y - Len*Sin(DegToRad(CurAngle));
Canvas.MoveTo(Round(Pos.X),Round(Pos.Y));
Canvas.LineTo(Round(P2.X),Round(P2.Y));
Pos:=P2;
end;
 
procedure Curve(Canvas: TCanvas; Order: integer; Length: double; Angle: integer);
{Recursively draw curve of specified order and based specified Angle}
begin
if 0 = Order then DrawLine(Canvas,Length)
else
begin
Curve(Canvas,Order - 1, Length / 2, -Angle);
Turn(angle);
curve(Canvas,Order - 1, Length / 2, Angle);
Turn(angle);
Curve(Canvas,Order - 1, Length / 2, -Angle);
end;
end;
 
 
procedure SierpinskiArrowheadCurve(Image: TImage; Order: integer; Length: double);
{Draw arrowhead curve of specified order.}
{Length controls the width of one side of the arrowhead }
begin
Pos.X:=10; Pos.Y:=10;
if (Order and 1)=0 then Curve(Image.Canvas, Order, Length, +60)
else
begin
{Order is odd}
Turn(+60);
Curve(Image.Canvas, Order, Length, -60);
end;
end;
 
 
procedure ShowSierpinskiArrowhead(Image: TImage);
var Size: double;
begin
if Image.Width>Image.Height then Size:=Image.Height/0.9
else Size:=Image.Width;
{Super impose three different orders, colors and line-widths}
Image.Canvas.Pen.Color:=clBlack;
Image.Canvas.Pen.Width:=3;
SierpinskiArrowheadCurve(Image,4, Size);
Image.Canvas.Pen.Color:=clBlue;
Image.Canvas.Pen.Width:=2;
SierpinskiArrowheadCurve(Image,6, Size);
Image.Canvas.Pen.Color:=clRed;
Image.Canvas.Pen.Width:=1;
SierpinskiArrowheadCurve(Image,8, Size);
end;
 
</syntaxhighlight>
{{out}}
<pre>
Elapsed Time: 50.555 ms.
 
</pre>
 
=={{header|EasyLang}}==
 
[https://easylang.dev/show/#cod=hZBNDgIhDIX3PcVL3PgTEE3GiQsOQxCVBMEMOs7c3qKMi9nYBen7Wl6bDtBoaOR3p8jECycHRcFH9/KnxxVKNrQA3btkYZ9dj4QAAwlJAPyZtYYqOceAjYZNGcVojVDxWHD2cYbLEP4yFulCdhUnCF5m6sFWY1/Fb/5SmFVlxZLdzbzF/KlPFpIk3VL/XeRTbXFUEHyENw== Run it]
 
<syntaxhighlight lang="easylang">
x = 5
y = 10
ang = 60
linewidth 0.5
#
proc curv o l a . .
if o = 0
x += cos ang * l
y += sin ang * l
line x y
else
o -= 1
l /= 2
curv o l (-a)
ang += a
curv o l a
ang += a
curv o l (-a)
.
.
move x y
curv 7 90 -60
</syntaxhighlight>
 
=={{header|Factor}}==
Line 578 ⟶ 762:
| x || iterate L-system
|}
 
 
=={{header|Forth}}==
Line 711 ⟶ 894:
5 arrowhead</syntaxhighlight>
 
=={{header|FreeBASIC}}==
{{trans|XPL0}}
<syntaxhighlight lang="vb">#define pi 4 * Atn(1)
#define yellow Rgb(255,255,0)
 
Dim Shared As Integer posX, posY
Dim Shared As Single direc
 
Sub Curva(orden As Byte, largo As Single, angulo As Integer)
If orden = 0 Then
posX += Fix(largo * Cos(direc))
posY -= Fix(largo * Sin(direc))
Line - (posX, posY), yellow
Else
Curva(orden-1, largo/2, -angulo)
direc += angulo
Curva(orden-1, largo/2, +angulo)
direc += angulo
Curva(orden-1, largo/2, -angulo)
End If
End Sub
 
Screenres 640, 480, 32
 
Dim As Integer x, y
Dim As Byte orden = 5
Dim As Integer tam = 2^orden
Dim As Single largo = 300
Dim As Single sixty = pi/3
 
direc = 0
posX = 640/4
posY = 3*480/4
Pset (posX, posY)
 
If (orden And 1) = 0 Then
Curva(orden, largo, +sixty)
Else
direc += sixty
Curva(orden, largo, -sixty)
End If
 
Windowtitle "Hit any key to end program"
Sleep</syntaxhighlight>
 
=={{header|Fōrmulæ}}==
 
{{FormulaeEntry|page=https://formulae.org/?script=examples/L-system}}
 
'''Solution'''
 
It can be done using an [[wp:L-system|L-system]]. There are generic functions written in Fōrmulæ to compute an L-system in the page [[L-system#Fōrmulæ | L-system]].
 
The program that creates a Sierpiński arrowhead is:
 
[[File:Fōrmulæ - L-system - Sierpiński triangle (rounded) 01.png]]
 
[[File:Fōrmulæ - L-system - Sierpiński triangle (rounded) 02.png]]
 
=={{header|Go}}==
Line 783 ⟶ 1,023:
dc.SavePNG("sierpinski_arrowhead_curve.png")
}</syntaxhighlight>
 
=={{header|IS-BASIC}}==
<syntaxhighlight lang="is-basic">100 PROGRAM "Sierpin2.bas"
110 LET LEVEL=5
120 OPTION ANGLE DEGREES
130 SET VIDEO MODE 1:SET VIDEO COLOUR 0:SET VIDEO X 40:SET VIDEO Y 27
140 OPEN #101:"video:"
150 SET PALETTE BLACK,YELLOW
160 DISPLAY #101:AT 1 FROM 1 TO 27
170 PLOT 1180,20,ANGLE 180;
180 CALL SIERP(560,LEVEL)
190 DEF CURVE(D,A,LEV)
200 IF LEV=0 THEN
210 PLOT FORWARD D;
220 ELSE
230 CALL CURVE(D/2,-A,LEV-1)
240 PLOT RIGHT A;
250 CALL CURVE(D/2,A,LEV-1)
260 PLOT RIGHT A;
270 CALL CURVE(D/2,-A,LEV-1)
280 END IF
290 END DEF
300 DEF SIERP(D,LEV)
310 CALL CURVE(D,60,LEV)
320 PLOT LEFT 60;
330 CALL CURVE(D,-60,LEV)
340 PLOT LEFT 60;
350 CALL CURVE(D,60,LEV)
360 END DEF</syntaxhighlight>
 
=={{header|Java}}==
<syntaxhighlight lang="java">
 
import java.awt.Point;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
 
public final class SierpinskiArrowhead {
 
public static void main(String[] aArgs) throws IOException {
List<Point> points = initialStraightLine();
for ( int i = 1; i < 8; i++ ) {
points = nextIteration(points);
}
String text = sierpinskiArrowheadText(points, IMAGE_SIZE);
Files.write(Paths.get("sierpinkskiArrowhead.svg"), text.getBytes());
}
private static List<Point> initialStraightLine() {
final int margin = 50;
final int boxSize = IMAGE_SIZE - 2 * margin;
final int x = margin;
final int y = Math.round(( IMAGE_SIZE + SQRT3_2 * boxSize ) / 2.0F);
List<Point> points = Arrays.asList( new Point(x, y), new Point(x + boxSize, y) );
return points;
}
private static List<Point> nextIteration(List<Point> aPoints) {
List<Point> result = new ArrayList<Point>();
for ( int i = 0; i < aPoints.size() - 1; i++ ) {
final int x0 = aPoints.get(i).x;
final int y0 = aPoints.get(i).y;
final int x1 = aPoints.get(i + 1).x;
final int y1 = aPoints.get(i + 1).y;
final int dx = x1 - x0;
result.add( new Point(x0, y0) );
if ( y0 == y1 ) {
final float d = Math.abs(dx) * SQRT3_2 / 2;
result.add( new Point(x0 + dx / 4, Math.round(y0 - d)) );
result.add( new Point(x1 - dx / 4, Math.round(y0 - d)) );
} else if ( y1 < y0 ) {
result.add( new Point(x1, y0));
result.add( new Point(x1 + dx / 2, ( y0 + y1 ) / 2) );
} else {
result.add( new Point(x0 - dx / 2, ( y0 + y1 ) / 2) );
result.add( new Point(x0, y1) );
}
}
result.add(aPoints.get(aPoints.size() - 1));
return result;
}
private static String sierpinskiArrowheadText(List<Point> aPoints, int aSize) {
StringBuilder text = new StringBuilder();
text.append("<svg xmlns='http://www.w3.org/2000/svg'");
text.append(" width='" + aSize + "' height='" + aSize + "'>\n");
text.append("<rect width='100%' height='100%' fill='white'/>\n");
text.append("<path stroke-width='1' stroke='black' fill='white' d='");
for ( int i = 0; i < aPoints.size(); i++ ) {
text.append(( i == 0 ? "M" : "L" ) + aPoints.get(i).x + ", " + aPoints.get(i).y + " ");
}
text.append("'/>\n</svg>\n");
return text.toString();
}
private static final float SQRT3_2 = (float) Math.sqrt(3.0F) / 2.0F;
private static final int IMAGE_SIZE = 700;
 
}
</syntaxhighlight>
{{out}}
[[Media:SierpinskiArrowheadJava.svg]]
 
=={{header|jq}}==
Line 1,268 ⟶ 1,620:
 
{{out}}
[[Media:Sierpinski_arrowhead_prolog.svg]]
See: [https://slack-files.com/T0CNUL56D-F01DPA9DNFP-53faf39637 sierpinski_arrowhead.svg] (offsite SVG image)
 
=={{header|Quackery}}==
Line 1,302 ⟶ 1,654:
turtle
10 frames
witheach
[ switch
[ char L case [ -1 6 turn ]
char R case [ 1 6 turn ]
otherwise [ 4 1 walk ] ] ]</syntaxhighlight>
1 frames</syntaxhighlight>
 
{{output}}
 
[[File:Quackery Sierpinski arrowhead.png]]
https://imgur.com/Qaz37ds
 
=={{header|Raku}}==
Line 1,603 ⟶ 1,957:
 
{{out}}
[[Media:Sierpinski_arrowhead_rust.svg]]
See: [https://slack-files.com/T0CNUL56D-F0173HHBYL9-af5ef387c5 sierpinski_arrowhead.svg] (offsite SVG image)
 
=={{header|Sidef}}==
Line 1,631 ⟶ 1,985:
{{trans|Go}}
{{libheader|DOME}}
<syntaxhighlight lang="ecmascriptwren">import "graphics" for Canvas, Color, Point
import "dome" for Window
 
Line 1,690 ⟶ 2,044:
}
}</syntaxhighlight>
 
{{out}}
[[File:Wren-Sierpinski_arrowhead_curve.png|400px]]
 
=={{header|XPL0}}==
Tigerofdarkness
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