Apophysis-AV/Variations/varEscher.pas
2022-03-08 20:25:51 +03:00

147 lines
4.2 KiB
ObjectPascal

{
Apophysis Copyright (C) 2001-2004 Mark Townsend
Apophysis Copyright (C) 2005-2006 Ronald Hordijk, Piotr Borys, Peter Sdobnov
Apophysis Copyright (C) 2007-2008 Piotr Borys, Peter Sdobnov
Apophysis "3D hack" Copyright (C) 2007-2008 Peter Sdobnov
Apophysis "7X" Copyright (C) 2009-2010 Georg Kiehne
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
}
unit varEscher;
interface
uses
BaseVariation, XFormMan;
type
TVariationEscher = class(TBaseVariation)
private
escher_beta, bc, bd: double;
public
constructor Create;
class function GetName: string; override;
class function GetInstance: TBaseVariation; override;
function GetNrVariables: integer; override;
function GetVariableNameAt(const Index: integer): string; override;
function SetVariable(const Name: string; var value: double): boolean; override;
function GetVariable(const Name: string; var value: double): boolean; override;
function ResetVariable(const Name: string): boolean; override;
procedure Prepare; override;
procedure CalcFunction; override;
end;
implementation
uses
Math;
///////////////////////////////////////////////////////////////////////////////
procedure TVariationEscher.Prepare;
begin
sincos(escher_beta, bd, bc);
bc := 0.5 * (1.0 + bc);
bd := 0.5 * bd;
end;
procedure TVariationEscher.CalcFunction;
var sn, cs, ang, lnr, m : double;
begin
ang := arctan2(FTy^, FTx^); // Angular polar dimension
lnr := 0.5 * ln(FTx^*FTx^ + FTy^*FTy^); // Natural logarithm of the radial polar dimension.
m := VVAR * exp(bc * lnr - bd * ang);
sincos(bc * ang + bd * lnr, sn, cs);
FPx^ := FPx^ + m * cs;
FPy^ := FPy^ + m * sn;
FPz^ := FPz^ + vvar * FTz^;
end;
///////////////////////////////////////////////////////////////////////////////
constructor TVariationEscher.Create;
begin
escher_beta := 0;
end;
///////////////////////////////////////////////////////////////////////////////
class function TVariationEscher.GetInstance: TBaseVariation;
begin
Result := TVariationEscher.Create;
end;
///////////////////////////////////////////////////////////////////////////////
class function TVariationEscher.GetName: string;
begin
Result := 'escher';
end;
///////////////////////////////////////////////////////////////////////////////
function TVariationEscher.GetVariableNameAt(const Index: integer): string;
begin
case Index Of
0: Result := 'escher_beta';
else
Result := '';
end
end;
///////////////////////////////////////////////////////////////////////////////
function TVariationEscher.SetVariable(const Name: string; var value: double): boolean;
begin
Result := False;
if Name = 'escher_beta' then begin
value := frac((value + PI) / PI2) * PI2 - PI; // AV: added 2*pi precalc
escher_beta := Value;
Result := True;
end
end;
function TVariationEscher.ResetVariable(const Name: string): boolean;
begin
Result := False;
if Name = 'escher_beta' then begin
escher_beta := 0;
Result := True;
end;
end;
///////////////////////////////////////////////////////////////////////////////
function TVariationEscher.GetNrVariables: integer;
begin
Result := 1
end;
///////////////////////////////////////////////////////////////////////////////
function TVariationEscher.GetVariable(const Name: string; var value: double): boolean;
begin
Result := False;
if Name = 'escher_beta' then begin
Value := escher_beta;
Result := True;
end
end;
///////////////////////////////////////////////////////////////////////////////
initialization
RegisterVariation(TVariationClassLoader.Create(TVariationEscher), true, false);
end.