Peter de Jong Attractor: Bgrabmp Colouring Help Needed ?
lazarus / 39-Graphics

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Boleeman · 2025-04-16 08:19

I made a Lazarus program that creates Peter de Jong Attractors.

I am trying to get a smooth high coloured rainbow effect like at
https://richardrosenman.com/shop/peter-de-jong-attractor/


I used a TBgrabmap for the rendering but have been struggling to get a
high coloured rendering."

Up to version 4, after making a basic rendering and then extending it.

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Thaddy · 2025-04-16 12:14

Wow. Made me think to apply it to audio:
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i unit
PeterDeJongAttractor;{$mode objfpc}interface uses  Math, Types;type 
TDoublePoint = record    X, Y: Double;    constructor Create(AX, AY:
Double);  end; constructor TDoublePoint.Create(AX, AY: Double);begin 
X := AX;  Y := AY;end;   TPDJAttractor = class  private    Fx, Fy:
Double;    FParamA, FParamB, FParamC, FParamD: Double;  public   
constructor Create(a, b, c, d: Double);    /// Returns the next point
in the attractor sequence    function Iterate: TDoublePoint;inline;  
/// Reset to initial state (optional)    procedure Reset;inline; 
end; implementation constructor TPDJAttractor.Create(a, b, c, d:
Double);begin  FParamA := a;  FParamB := b;  FParamC := c;  FParamD :=
d;  Fx := 0;  Fy := 0;end; function TPDJAttractor.Iterate:
TDoublePoint;var  newX, newY: Double;begin  newX := Sin(FParamA * Fy)
- Cos(FParamB * Fx);  newY := Sin(FParamC * Fx) - Cos(FParamD * Fy); 
Fx := newX;  Fy := newY;  Result := TDoublePoint.Create(newX,
newY);end; procedure TPDJAttractor.Reset;begin  Fx := 0;  Fy :=
0;end; end.Then:Code: Pascal  [Select][+][-]window.onload =
function(){var x1 = document.getElementById("main_content_section");
if (x1) { var x = document.getElementsByClassName("geshi");for (var i
= 0; i procedure TMyVSTModule.ProcessAudioBlock(Buffer: PSingle;
SampleCount: Integer);var  i: Integer;  AttractorPoint: TDoublePoint; 
ModulationValue: Single;begin  for i := 0 to SampleCount - 1 do 
begin    // Retrieve the current attractor values (could be at a
slower modulation rate)    AttractorPoint := FMyAttractor.Iterate;   
// Map the output to a useful modulation range. For example, normalize
and scale:    ModulationValue := (CSng(AttractorPoint.X) + 2) / 4; //
maps from [-2,2] to [0,1]        // Use ModulationValue to influence a
parameter in your DSP code:    // For example, adjust oscillator
frequency, filter cutoff, etc.   
ApplyModulationToYourDSP(ModulationValue);     // Continue processing
audio...    Buffer[i] := ProcessSample(Buffer[i]);  end;end;I think I
have a VST to write....This is just a scetch.
You can probably also use this simple unit for your graphics purpose.

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Boleeman · 2025-04-16 23:44

Wondered how that audio version would sound ?


There are lots of graphic versions about , written in other languages
but never thought of audio versions.