76 lines
2.2 KiB
ObjectPascal
76 lines
2.2 KiB
ObjectPascal
program ChaosGame;
|
|
|
|
// FPC 3.0.2
|
|
uses
|
|
Graph, windows, math;
|
|
|
|
// Return a point on a circle defined by angle and the circles radius
|
|
// Angle 0 = Radius points to the left
|
|
// Angle 90 = Radius points upwards
|
|
Function PointOfCircle(Angle: SmallInt; Radius: integer): TPoint;
|
|
var Ia: Double;
|
|
begin
|
|
Ia:=DegToRad(-Angle);
|
|
result.x:=round(cos(Ia)*Radius);
|
|
result.y:=round(sin(Ia)*Radius);
|
|
end;
|
|
|
|
{ Main }
|
|
|
|
var
|
|
GraphDev,GraphMode: smallint;
|
|
Triangle: array[0..2] of Tpoint; // Corners of the triangle
|
|
TriPnt: Byte; // Point in ^^^^
|
|
Origin: TPoint; // Defines center of triangle
|
|
Itterations: integer; // Number of Itterations
|
|
Radius: Integer;
|
|
View: viewPorttype;
|
|
CurPnt: TPoint;
|
|
Rect: TRect;
|
|
Counter: integer;
|
|
begin
|
|
|
|
Repeat {forever}
|
|
|
|
// Get the Itteration count 0=exit
|
|
Write('Itterations: ');
|
|
ReadLn(Itterations);
|
|
|
|
if Itterations=0 then halt;
|
|
|
|
// Set Up Graphics screen (everythings Auto detect)
|
|
GraphDev:=Detect;
|
|
GraphMode:=0;
|
|
InitGraph(GraphDev,GraphMode,'');
|
|
if GraphResult<>grok then
|
|
begin
|
|
Writeln('Graphics doesn''t work');
|
|
Halt;
|
|
end;
|
|
|
|
// set Origin to center of the _Triangle_ (Not the creen)
|
|
GetViewSettings(View);
|
|
Rect.Create(View.x1,View.y1+10,View.x2,View.y2-10);
|
|
Origin:=Rect.CenterPoint;
|
|
Origin.Offset(0,Rect.Height div 6); // Center Triangle on screen
|
|
|
|
// Define Equilateral triangle,
|
|
Radius:=Origin.y; // Radius of Circumscribed circle
|
|
for Counter:=0 to 2 do
|
|
Triangle[Counter]:=PointOfCircle((Counter*120)+90,Radius)+Origin;
|
|
|
|
// Choose random starting point, in the incsribed circle of the triangle
|
|
Radius:=Radius div 2; // Radius of inscribed circle
|
|
CurPnt:=PointOfCircle(random(360),random(Radius div 2))+Origin;
|
|
|
|
// Play the Chaos Game
|
|
for Counter:=0 to Itterations do
|
|
begin
|
|
TriPnt:=Random(3); // Select Triangle Point
|
|
Rect.Create(Triangle[TriPnt],CurPnt);; // Def. rect. between TriPnt and CurPnt
|
|
CurPnt:=Rect.CenterPoint; // New CurPnt is center of rectangle
|
|
putPixel(CurPnt.x,CurPnt.y,cyan); // Plot the new CurPnt
|
|
end;
|
|
|
|
until False;
|
|
end.
|