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https://git.sr.ht/~rabbits/macintosh_cookbook
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51 lines
1.2 KiB
ObjectPascal
51 lines
1.2 KiB
ObjectPascal
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program ExampleFractal;
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{ Program to play the Chaos Game }
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{ Algorithm: }
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{ 1. Pick a point in a triangle at random & plot it }
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{ 2. Pick a vertex of the triangle at random }
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{ 3. Move 1/2 way from present point to this vertex }
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{ 4. Plot point and loop from (2) until mouse pressed.}
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var
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xp, yp, i: integer;
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x, y: array[1..3] of real;
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function Rndint (n: integer): integer;
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{Function to return random integer on range 1 --> n}
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var
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rr: longint;
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r: real;
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begin
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rr := random; {Intrinsic routine}
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r := (rr + 32767) / (32767 + 32768);
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Rndint := trunc(n * r) + 1;
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end;
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begin
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ShowDrawing;
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{Set corners of triangle centered at (110,125),}
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{with sides 200 pixels long}
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x[1] := 110 - 100;
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y[1] := 125 + 57.73503;
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x[2] := 110;
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y[2] := 125 - 115.470;
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x[3] := 110 + 100;
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y[3] := y[1];
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{Pick first point at random in box containing triangle}
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xp := Rndint(200) + 10;
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yp := Rndint(173) + 10;
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DrawLine(xp, yp, xp, yp); {Plot point}
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repeat {until Mouse button is pressed}
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i := Rndint(3); {Pick random corner}
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xp := round((x[i] - xp) / 2 + xp); {Go half way}
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yp := round((y[i] - yp) / 2 + yp); {Go half way}
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DrawLine(xp, yp, xp, yp); {Plot point}
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until button;
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end.
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