Sierpinski square curve: Difference between revisions
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Output is similar to C++. |
Output is similar to C++. |
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=={{header|ALGOL 68}}== |
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Generates an SVG file. The SVG generating code is translated from the FreeBASIC sample (which is a translation of the 11l sample which is translated from the C++). Uses the Algol 68 library for L-System related Tasks on Rosetta Code. |
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{{libheader|ALGOL 68-l-system}} |
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Note: The source of the Algol 68 L-System library is available on a separate page on Rosetta Code - see the above link and follow the link to the Talk (Discussion) page. |
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<syntaxhighlight lang="algol68"> |
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BEGIN # Sierpinski Square Curve in SVG - SVG generation translated from the # |
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# FreeBASIC sample (which is a translation of C++) # |
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# uses the RC Algol 68 L-System library for the L-System evaluation & # |
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# interpretation # |
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PR read "lsystem.incl.a68" PR # include L-System utilities # |
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PROC sierpinski square curve = ( STRING fname, INT size, length, order )VOID: |
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IF FILE svg file; |
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BOOL open error := IF open( svg file, fname, stand out channel ) = 0 |
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THEN |
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# opened OK - file already exists and # |
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# will be overwritten # |
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FALSE |
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ELSE |
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# failed to open the file # |
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# - try creating a new file # |
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establish( svg file, fname, stand out channel ) /= 0 |
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FI; |
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open error |
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THEN # failed to open the file # |
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print( ( "Unable to open ", fname, newline ) ); |
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stop |
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ELSE # file opened OK # |
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REAL x := ( size - length ) / 2; |
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REAL y := length; |
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INT angle := 0; |
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put( svg file, ( "<svg xmlns='http://www.w3.org/2000/svg' width='" |
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, whole( size, 0 ), "' height='", whole( size, 0 ), "'>" |
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, newline, "<rect width='100%' height='100%' fill='white'/>" |
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, newline, "<path stroke-width='1' stroke='black' fill='none' d='" |
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, newline, "M", whole( x, 0 ), ",", whole( y, 0 ), newline |
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) |
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); |
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LSYSTEM ssc = ( "F+XF+F+XF" |
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, ( "X" -> "XF-F+F-XF+F+XF-F+F-X" |
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) |
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); |
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STRING curve = ssc EVAL order; |
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curve INTERPRET ( ( CHAR c )VOID: |
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IF c = "F" THEN |
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x +:= length * cos( angle * pi / 180 ); |
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y +:= length * sin( angle * pi / 180 ); |
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put( svg file, ( " L", whole( x, 0 ), ",", whole( y, 0 ), newline ) ) |
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ELIF c = "+" THEN |
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angle +:= 90 MODAB 360 |
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ELIF c = "-" THEN |
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angle +:= 270 MODAB 360 |
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FI |
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); |
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put( svg file, ( "'/>", newline, "</svg>", newline ) ); |
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close( svg file ) |
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FI # sierpinski square # ; |
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sierpinski square curve( "sierpinski_square.svg", 635, 5, 5 ) |
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END |
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</syntaxhighlight> |
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{{out}} |
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Same as FreeBasic, 11l, C++, etc. |
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=={{header|ALGOL W}}== |
=={{header|ALGOL W}}== |