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const
escape=4.0;
{ escape value }
attract=0.0001;
{
attractor sensitivity }
const
Black = 0;
Blue = 1;
Green = 2;
Cyan = 3;
Red = 4;
Magenta = 5;
Brown = 6;
LightGray = 7;
DarkGray = 8;
LightBlue = 9;
LightGreen =10;
LightCyan =11;
LightRed =12;
LightMagenta =13;
Yellow =14;
White =15;
function GetRGBColor(color:byte):longint;
begin
case Color of
black : GetRGBColor := RGB(0,0,0);
blue : GetRGBColor := RGB(0,0,128);
green : GetRGBColor := RGB(0,128,0);
cyan : GetRGBColor := RGB(0,255,255);
red : GetRGBColor := RGB(128,0,0);
magenta : GetRGBColor := RGB(128,0,128);
brown : GetRGBColor := RGB(128,128,0);
lightgray : GetRGBColor := RGB(192,192,192);
darkgray : GetRGBColor := RGB(128,128,128);
lightBlue : GetRGBColor := RGB(0,0,255);
lightGreen : GetRGBColor := RGB(0,255,0);
lightcyan : GetRGBColor := RGB(0,255,255);
lightRed : GetRGBColor := RGB(255,0,0);
lightmagenta : GetRGBColor := RGB(255,0,255);
yellow: GetRGBColor := RGB(255,255,0);
white : GetRGBColor := RGB(255,255,255);
else
GetRGBColor := RGB(0,0,255);
end;
end;
////////////////////////////////////////////////////////////////////////////////
procedure Fern(ABitmap: TBitmap);
var
x, y : double;
{ pixel coordinates }
i : integer;
{ loop counter}
q : integer;
{ random number }
k : integer;
{ row selector }
MaxY : integer;
xValue,
yValue : integer;
MaxY2,
MaxY10 : double; { Maximum Y screen coordinate}
d : array[1..4,1..6] of double;
{ holds data of IFS attractor }
Rect : TRect;
Iterations: integer;
begin
SetRect(Rect, 0, 0,
ABitmap.Width, ABitmap.Height);
with Rect do
begin
MaxY := bottom - top; { find maximum Y coordinate }
MaxY2 := MaxY/2;
maxY10 := MaxY/10;
{ initialize IFS data array }
d[1,1]:=0; d[1,2]:=0; d[1,3]:=0;
d[1,4]:=0.16; d[1,5]:=0; d[1,6]:=0;
d[2,1]:=0.85; d[2,2]:=0.04; d[2,3]:=-0.04; d[2,4]:=0.85; d[2,5]:=0; d[2,6]:=1.6;
d[3,1]:=0.2; d[3,2]:=-0.26; d[3,3]:=0.23; d[3,4]:=0.22; d[3,5]:=0; d[3,6]:=1.6;
d[4,1]:=-0.15; d[4,2]:=0.28; d[4,3]:=0.26; d[4,4]:=0.24; d[4,5]:=0; d[4,6]:=0.44;
x := 0;
{set starting coordinates}
y := 0;
Iterations := MaxY * 20; { iteration factor }
for i := 1 to 10 do
{ skip first 10 iterations }
begin
q := random(100) + 1;
{ pick random number from 1-100}
if q <= 85 then
{ assign row according to }
k := 2
{ probability }
else if q = 86 then
k := 1
else if (q > 86) and (q < 94) then
k := 3
else
k := 4;
x := d[k,1]*x + d[k,2]*y + d[k,5]; { transform coordinates }
y := d[k,3]*x +
d[k,4]*y + d[k,6];
end;
for i := 11 to Iterations do
begin
q := random(100) + 1;
{ pick random number from 1-100}
if q <= 85 then
{ assign row according to }
k := 2
{ probability }
else if q = 86 then
k := 1
else if (q > 86) AND (q < 94) then
k := 3
else
k := 4;
x := d[k,1]*x + d[k,2]*y + d[k,5]; { transform coordinates }
y := d[k,3]*x +
d[k,4]*y + d[k,6];
xValue := round(MaxY2 + MaxY10*x) + Left;
yValue := round(MaxY10*y) + Top;
ABitmap.Canvas.Pixels[xValue,yValue] :=
ABitmap.Canvas.Pen.Color;
end;
{ scale for screen }
end;
end;
////////////////////////////////////////////////////////////////////////////////
� 2004 Jim Valavanis