8Bit Colors
lazarus / 39-Graphics

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Gigatron · 2025-04-09 23:16

Hi,

Another nice shader fx from Coldberg Shadertoy called nes-ify;

The goal is replacing image colors by the 8 bit computers or consoles
like cpc464 ,zx-spectrum, CGA
gameboy, c64 ....

Try to start with CPC464, EGA, and GAME BOY;
The used picture is a game Hybris from Amiga ; You can load your image
, please
resize it to power of 2 size; eg 128x128 ; 256x256; 512*512.


Good Luck

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, BGRAOpenGL,
BGRABitmapTypes, BGRAOpenGL3D, BGLVirtualScreen; type  { TForm1 }  
TForm1 = class(TForm)    ega_btn: TButton;    gboy_btn: TButton;   
cpc_btn: TButton;    shader_on: TButton;    ShaderScreen1:
TBGLVirtualScreen;    FragMemo: TMemo;    SpinEdit1: TSpinEdit;   
Timer1: TTimer;    VertexMemo: TMemo;     procedure
cpc_btnClick(Sender: TObject);    procedure ega_btnClick(Sender:
TObject);    procedure gboy_btnClick(Sender: TObject);    procedure
ShaderScreen1LoadTextures(Sender: TObject; BGLContext: TBGLContext); 
 procedure ShaderScreen1Redraw(Sender: TObject; BGLContext:
TBGLContext);    procedure ShaderScreen1UnloadTextures(Sender:
TObject; BGLContext: TBGLContext);    procedure FormCreate(Sender:
TObject);    procedure shader_onClick(Sender: TObject);    procedure
Timer1Timer(Sender: TObject);     procedure ResetUniforms;   
procedure UpdateUniforms;    procedure RunShader;   private   public 
    gl_surface : IBGLTexture; shader3 : TBGLShader3D;       ctx  :
TBGLContext;       cpc,ega,gboy,normal_img : boolean ;       fshader :
string ; vshader : string; // fragment and vertex  end; var   Form1:
TForm1; implementation {$R *.lfm} { TForm1 } procedure
TForm1.FormCreate(Sender: TObject);begin  cpc := false;  ega :=
false;  gboy := false;  normal_img := false;  fshader :=
FragMemo.text;  vshader := VertexMemo.Text; end; procedure
TForm1.ShaderScreen1Redraw(Sender: TObject; BGLContext:
TBGLContext);begin   if gl_surface <> nil then   
 BGLContext.Canvas.StretchPutImage(0, 0, ShaderScreen1.Width,
ShaderScreen1.Height, gl_surface);   if shader3 <> nil then  begin   
BGLContext.Canvas.Lighting.ActiveShader := shader3; 
end;end; procedure TForm1.ShaderScreen1LoadTextures(Sender: TObject;
BGLContext: TBGLContext);begin   try     gl_surface :=
BGLTexture(ResourceFile('hybris.png'));    // Create shader    shader3
:= TBGLShader3D.Create(      BGLContext.Canvas,      vshader,   //
Vertex shader      fshader,   // Fragment shader      'varying vec2
texCoord;',      '130');    // Version GLSL       ctx := BGLContext; 
except    on E: Exception do      raise exception.Create('Shader Error
: ' + E.Message);  end;end; procedure TForm1.RunShader;begin  try   
fshader := FragMemo.Text;    vshader := VertexMemo.Text;     if
Assigned(shader3) then    begin      ctx.Canvas.Lighting.ActiveShader
:= nil;      FreeAndNil(shader3);    end;     shader3 :=
TBGLShader3D.Create(ctx.Canvas, vshader, fshader, 'varying vec2
texCoord;', '130');    // if shader error,  exception raised by
BGRAOpenGLD3 nice :);     Timer1.Enabled := True; // timer1  except  
on E: Exception do      ShowMessage('Shader Error : ' + E.Message); 
end;end; procedure TForm1.ShaderScreen1UnloadTextures(Sender:
TObject;  BGLContext: TBGLContext);begin  gl_surface  := nil; 
FreeAndNil(shader3);  BGLContext.Canvas.Lighting.ActiveShader :=
nil;end; procedure TForm1.cpc_btnClick(Sender: TObject);begin     
ResetUniforms;      RunShader;      cpc := true;end; procedure
TForm1.ega_btnClick(Sender: TObject);begin  ResetUniforms; 
RunShader;  ega := true; end; procedure TForm1.gboy_btnClick(Sender:
TObject);begin  ResetUniforms;  RunShader;  gboy :=
true;end; procedure TForm1.shader_onClick(Sender: TObject);begin 
ResetUniforms;  RunShader;  normal_img := true;end; procedure
TForm1.Timer1Timer(Sender: TObject);begin  if shader3 <> nil then 
begin    shader3.UniformPointF['resolution'].Value :=
Pointf(Round(ShaderScreen1.Width),Round(ShaderScreen1.Height));   //
shader3.UniformSingle['NORMAL_IMAGE'].Value := 1.0;    
shader3.UniformSingle['rez'].Value := SpinEdit1.Value;   
UpdateUniforms;    ShaderScreen1.Invalidate;  end;end; procedure
TForm1.ResetUniforms;begin  if shader3 <> nil then  begin   
normal_img := false;    cpc := false;    ega := false;    gboy :=
false;   end;end; procedure TForm1.UpdateUniforms;begin  if shader3 <>
nil then  begin     if ega then shader3.UniformSingle['EGA'].Value :=
1.0;    if cpc then shader3.UniformSingle['CPC'].Value := 1.0;    if
gboy then shader3.UniformSingle['GAMEBOY'].Value := 1.0;    if
normal_img then shader3.UniformSingle['NORMAL_IMAGE'].Value := 1.0;  
end;end;  end.

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Gigatron · 2025-04-10 16:23

Hi,

It seems I've worked on this project before; however this one uses a
pixel shader and is easier to use, so here is the latest version with
support for c64, zx-spectrum, cga and msx palettes.

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Lulu · 2025-04-10 18:26

Hi, Hybris remember me its successor, Battle Squadron, which I played
a lot when I was 20!

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Gigatron · 2025-04-10 18:34

Quote from: Lulu on April 10, 2025, 08:26:50 pmHi, Hybris remember me
its successor, Battle Squadron, which I played a lot when I was 20! 

I was shocked by this game, first the trackloader routine, then the
music and finally the fluidity of the game.

Vraiement impéccable