Copper Chunky Pixel
lazarus / 39-Graphics

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Gigatron · 2025-05-11 00:48

Hi,

A nice fx from amiga called copper chunky;
Working with grid cells , code from a javascript version not optimized
yet !

example of this code on Scoopex Cracktro :
https://youtu.be/urhCo_3Khd4?si=0viz1GNDdnYe0X6v&t=14
Or Digital A maze intro
https://youtu.be/fcB-v8D3i6s?si=8soBKLQwBaIIakbA&t=72

Explanation of Copper Chunky :
https://www.youtube.com/watch?v=ste_ejNVvDk

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
Unit1; {$mode objfpc}{$H+} interface uses  Classes, SysUtils, Forms,
Controls, Graphics, Dialogs, ExtCtrls, StdCtrls,  BGRAVirtualScreen,
BGRABitmap, BGRABitmapTypes; type  { TForm1 }  TForm1 = class(TForm) 
 BGRAVirtualScreen1: TBGRAVirtualScreen;    Button1: TButton;   
Panel1: TPanel;    Timer1: TTimer;    procedure
BGRAVirtualScreen1Redraw(Sender: TObject; Bitmap: TBGRABitmap);   
procedure Button1Click(Sender: TObject);    procedure
FormCreate(Sender: TObject);    procedure Timer1Timer(Sender:
TObject);  private    ZoomFactor: Single;    MaxZoom: Single;   
MinZoom: Single;    CellSize: Integer;    Angle: Single;    RotSpeed:
Single;    Tmr: Single;    ZoomCenter: Single;    ZoomAmp: Single; 
public  end; var  Form1: TForm1;  tex :
TBGRABitmap; implementation {$R *.lfm} { TForm1 } procedure
TForm1.FormCreate(Sender: TObject);begin  // texture  tex :=
TBGRABitmap.Create('gl.png');  MaxZoom :=  5.0;  MinZoom := 2.0; 
CellSize := 8;  Angle := 0;  RotSpeed := 0.6;  Tmr := 0;  ZoomCenter
:= (MaxZoom + MinZoom) / 2;  ZoomAmp := (MaxZoom - MinZoom) / 2; 
ZoomFactor := ZoomCenter / 8; end; procedure
TForm1.BGRAVirtualScreen1Redraw(Sender: TObject; Bitmap:
TBGRABitmap);var  x, y: Integer;  bx, by: Integer;  dx, dy: Single; 
sx, sy: Integer;  centerX, centerY: Single;  zoom: Single;  col:
TBGRAPixel;  angleRad: Single;  sinVal, cosVal: Single;  rotX, rotY:
Single;begin   centerX := tex.Width / 2;  centerY := tex.Height / 2; 
zoom := 1 / ZoomFactor;  angleRad := Angle * Pi / 180;  sinVal :=
Sin(angleRad);  cosVal := Cos(angleRad);  Bitmap.Fill(BGRABlack);  //
pixel fx ok with pascal  for y := 0 to (BGRAVirtualScreen1.Height - 1)
div CellSize do  begin    for x := 0 to (BGRAVirtualScreen1.Width - 1)
div CellSize do    begin      dx := (x * CellSize -
BGRAVirtualScreen1.Width/2) * zoom;      dy := (y * CellSize -
BGRAVirtualScreen1.Height/2) * zoom;      rotX := dx * cosVal - dy *
sinVal;      rotY := dx * sinVal + dy * cosVal;      sx :=
Round(centerX + rotX);      sy := Round(centerY + rotY);      //
Replace pixel on each cells adapted from js;      if (sx >= 0) and (sx
< tex.Width) and (sy >= 0) and (sy < tex.Height) then      begin     
 // get pixel source        col := tex.GetPixel(sx, sy);        //
cells block        for by := 0 to CellSize - 1 do        begin       
 for bx := 0 to CellSize - 1 do          begin            if (x *
CellSize + bx < BGRAVirtualScreen1.Width) and            (y * CellSize
+ by < BGRAVirtualScreen1.Height) then            begin             
Bitmap.SetPixel(x * CellSize + bx, y * CellSize + by, col);          
end;          end;        end;       end;    end;  end; end; procedure
TForm1.Button1Click(Sender: TObject);begin  RotSpeed :=
-RotSpeed;end; procedure TForm1.Timer1Timer(Sender: TObject);begin 
Tmr := Tmr + 0.01;  // counter timer  ZoomFactor := ZoomCenter +
(ZoomAmp * Sin(Tmr * 0.5));  Angle := Angle + RotSpeed; 
BGRAVirtualScreen1.RedrawBitmap;end; end.
Base code js :
Code: Javascript  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i function
rotozoom() {    const centerX = srcWidth / 2;    const centerY =
srcHeight / 2;    const zoom = 1 / config.zoom;    const angleRad =
config.angle * Math.PI / 180;    const sin = Math.sin(angleRad);   
const cos = Math.cos(angleRad);        const bufferData =
bufferCtx.createImageData(config.width, config.height);    const
pixels = bufferData.data;    const step = config.blockSize;          
    clearCanvas();        for (let y = 0; y < config.height; y +=
step) {        for (let x = 0; x < config.width; x += step) {        
  // Transformation            const dx = (x - config.width/2) *
zoom;            const dy = (y - config.height/2) * zoom;           
const sx = Math.floor(centerX + dx * cos - dy * sin);            const
sy = Math.floor(centerY + dx * sin + dy * cos);             if (sx >=
0 && sx < srcWidth && sy >= 0 && sy < srcHeight) {               
const srcPos = (sy * srcWidth + sx) << 2;                            
  for (let by = 0; by < step && y + by < config.height; by++) {      
            for (let bx = 0; bx < step && x + bx < config.width; bx++)
{                        const destPos = ((y + by) * config.width + (x
+ bx)) << 2;                        pixels[destPos] = srcData[srcPos];
      // R                        pixels[destPos+1] =
srcData[srcPos+1];   // G                        pixels[destPos+2] =
srcData[srcPos+2];   // B                        pixels[destPos+3] =
255;                 // A                    }                }      
    }        }    }        bufferCtx.putImageData(bufferData, 0, 0); 
 ctx.drawImage(buffer, 0, 0);}

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Gigatron · 2025-05-11 12:57

Hi

A new version of this nice chunky copper effect , Pascal version is
near 95% of the original amiga
effet version. https://www.youtube.com/watch?v=ste_ejNVvDk

Source bird image from : https://powerprograms.nl/amiga/copper-
chunky.html

You can change cellsize, speed, zoom factor and reverse rotation.
This demo is running fullscreen to see how BGRA and Pascal code is
faster !!

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
Unit1; {$mode objfpc}{$H+} interface uses  Classes, SysUtils, Forms,
Controls, Graphics, Dialogs, ExtCtrls, StdCtrls,  Spin,
BGRAVirtualScreen, BGRABitmap, BGRABitmapTypes; type  { TForm1 } 
TForm1 = class(TForm)    BGRAVirtualScreen1: TBGRAVirtualScreen;   
Button1: TButton;    FloatSpinEdit1: TFloatSpinEdit;   
FloatSpinEdit2: TFloatSpinEdit;    Panel1: TPanel;    SpinEdit1:
TSpinEdit;    Timer1: TTimer;    procedure
BGRAVirtualScreen1Redraw(Sender: TObject; Bitmap: TBGRABitmap);   
procedure Button1Click(Sender: TObject);    procedure
FormCreate(Sender: TObject);    procedure Timer1Timer(Sender:
TObject);  private    ZoomFactor, MaxZoom, MinZoom, Angle, RotSpeed,
Tmr, ZoomCenter, ZoomAmp: Single;    CellSize: Integer;  public 
end; var  Form1: TForm1;  tex : TBGRABitmap; implementation {$R
*.lfm} { TForm1 } procedure TForm1.FormCreate(Sender: TObject);begin 
// texture  tex := TBGRABitmap.Create('bird.jpg');  MaxZoom :=  4.0; 
MinZoom := 1.5;  CellSize := 12;  Angle := 0;  RotSpeed := 0.6;  Tmr
:= 0;  ZoomCenter := (MaxZoom + MinZoom) / 2;  ZoomAmp := (MaxZoom -
MinZoom) / 2;  ZoomFactor := ZoomCenter / 8;end; procedure
TForm1.BGRAVirtualScreen1Redraw(Sender: TObject; Bitmap:
TBGRABitmap);var  x, y: Integer;  bx, by: Integer;  dx, dy: Single; 
sx, sy: Integer;  centerX, centerY: Single;  zoom: Single;  col:
TBGRAPixel;  angleRad: Single;  sinVal, cosVal: Single;  rotX, rotY:
Single;begin   centerX := tex.Width / 2;  centerY := tex.Height / 2; 
zoom := 1 / ZoomFactor;  angleRad := Angle * Pi / 180;  sinVal :=
Sin(angleRad);  cosVal := Cos(angleRad);  Bitmap.Fill(BGRABlack);  //
pixel fx ok with pascal  for y := 0 to (BGRAVirtualScreen1.Height - 1)
div CellSize do  begin    for x := 0 to (BGRAVirtualScreen1.Width - 1)
div CellSize do    begin      dx := (x * CellSize -
BGRAVirtualScreen1.Width/2) * zoom;      dy := (y * CellSize -
BGRAVirtualScreen1.Height/2) * zoom;      rotX := dx * cosVal - dy *
sinVal;      rotY := dx * sinVal + dy * cosVal;      sx :=
Round(centerX + rotX);      sy := Round(centerY + rotY);      //
Replace pixel on each cells inside limits adapted from js;      if (sx
>= 0) and (sx < tex.Width) and (sy >= 0) and (sy < tex.Height) then  
  begin        // get pixel source        col := tex.GetPixel(sx,
sy);        // fill cells block        for by := 0 to CellSize - 1 do 
      begin          for bx := 0 to CellSize - 1 do          begin   
       if (x * CellSize + bx < BGRAVirtualScreen1.Width) and         
 (y * CellSize + by < BGRAVirtualScreen1.Height) then           
begin              Bitmap.SetPixel(x * CellSize + bx, y * CellSize +
by, col);            end;          end;        end;      end;    
end;  end; end; procedure TForm1.Button1Click(Sender: TObject);begin 
FloatSpinEdit1.Value := -FloatSpinEdit1.Value;end; procedure
TForm1.Timer1Timer(Sender: TObject);begin  Tmr := Tmr + 0.01;  //
counter timer  ZoomFactor := ZoomCenter + (ZoomAmp * Sin(Tmr * 0.5)); 
Angle := Angle + RotSpeed;  CellSize := SpinEdit1.Value;  RotSpeed :=
FloatSpinEdit1.Value;  ZoomFactor := FloatSpinEdit2.Value; // never
negative ! div / 0  BGRAVirtualScreen1.RedrawBitmap;end;end.