Task: Julia set


C++: #include <windows.h>
#include <string>
#include <complex>

const int BMP_SIZE = 600, ITERATIONS = 512;
const long double FCT = 2.85, hFCT = FCT / 2.0;

class myBitmap {
public:
    myBitmap() : pen( NULL ), brush( NULL ), clr( 0 ), wid( 1 ) {}
    ~myBitmap() {
        DeleteObject( pen ); DeleteObject( brush );
        DeleteDC( hdc ); DeleteObject( bmp );
    }
    bool create( int w, int h ) {
        BITMAPINFO bi;
        ZeroMemory( &bi, sizeof( bi ) );
        bi.bmiHeader.biSize        = sizeof( bi.bmiHeader );
        bi.bmiHeader.biBitCount    = sizeof( DWORD ) * 8;
        bi.bmiHeader.biCompression = BI_RGB;
        bi.bmiHeader.biPlanes      = 1;
        bi.bmiHeader.biWidth       =  w;
        bi.bmiHeader.biHeight      = -h;
        HDC dc = GetDC( GetConsoleWindow() );
        bmp = CreateDIBSection( dc, &bi, DIB_RGB_COLORS, &pBits, NULL, 0 );
        if( !bmp ) return false;
        hdc = CreateCompatibleDC( dc );
        SelectObject( hdc, bmp );
        ReleaseDC( GetConsoleWindow(), dc );
        width = w; height = h;
        return true;
    }
    void clear( BYTE clr = 0 ) {
        memset( pBits, clr, width * height * sizeof( DWORD ) );
    }
    void setBrushColor( DWORD bClr ) {
        if( brush ) DeleteObject( brush );
        brush = CreateSolidBrush( bClr );
        SelectObject( hdc, brush );
    }
    void setPenColor( DWORD c ) {
        clr = c; createPen();
    }
    void setPenWidth( int w ) {
        wid = w; createPen();
    }
    void saveBitmap( std::string path ) {
        BITMAPFILEHEADER fileheader;
        BITMAPINFO       infoheader;
        BITMAP           bitmap;
        DWORD            wb;
        GetObject( bmp, sizeof( bitmap ), &bitmap );
        DWORD* dwpBits = new DWORD[bitmap.bmWidth * bitmap.bmHeight];
        ZeroMemory( dwpBits, bitmap.bmWidth * bitmap.bmHeight * sizeof( DWORD ) );
        ZeroMemory( &infoheader, sizeof( BITMAPINFO ) );
        ZeroMemory( &fileheader, sizeof( BITMAPFILEHEADER ) );
        infoheader.bmiHeader.biBitCount = sizeof( DWORD ) * 8;
        infoheader.bmiHeader.biCompression = BI_RGB;
        infoheader.bmiHeader.biPlanes = 1;
        infoheader.bmiHeader.biSize = sizeof( infoheader.bmiHeader );
        infoheader.bmiHeader.biHeight = bitmap.bmHeight;
        infoheader.bmiHeader.biWidth = bitmap.bmWidth;
        infoheader.bmiHeader.biSizeImage = bitmap.bmWidth * bitmap.bmHeight * sizeof( DWORD );
        fileheader.bfType    = 0x4D42;
        fileheader.bfOffBits = sizeof( infoheader.bmiHeader ) + sizeof( BITMAPFILEHEADER );
        fileheader.bfSize    = fileheader.bfOffBits + infoheader.bmiHeader.biSizeImage;
        GetDIBits( hdc, bmp, 0, height, ( LPVOID )dwpBits, &infoheader, DIB_RGB_COLORS );
        HANDLE file = CreateFile( path.c_str(), GENERIC_WRITE, 0, NULL, CREATE_ALWAYS, 
            FILE_ATTRIBUTE_NORMAL, NULL );
        WriteFile( file, &fileheader, sizeof( BITMAPFILEHEADER ), &wb, NULL );
        WriteFile( file, &infoheader.bmiHeader, sizeof( infoheader.bmiHeader ), &wb, NULL );
        WriteFile( file, dwpBits, bitmap.bmWidth * bitmap.bmHeight * 4, &wb, NULL );
        CloseHandle( file );
        delete [] dwpBits;
    }
    HDC getDC() const     { return hdc; }
    int getWidth() const  { return width; }
    int getHeight() const { return height; }
    DWORD* bits() const { return ( DWORD* )pBits; }
private:
    void createPen() {
        if( pen ) DeleteObject( pen );
        pen = CreatePen( PS_SOLID, wid, clr );
        SelectObject( hdc, pen );
    }
    HBITMAP bmp; HDC    hdc;
    HPEN    pen; HBRUSH brush;
    void    *pBits; int    width, height, wid;
    DWORD    clr;
};
class julia {
public:
    void draw( std::complex<long double> k ) {
        bmp.create( BMP_SIZE, BMP_SIZE );
        DWORD* bits = bmp.bits();
        int res, pos;
        std::complex<long double> c, factor( FCT / BMP_SIZE, FCT / BMP_SIZE ) ;

        for( int y = 0; y < BMP_SIZE; y++ ) {
            pos = y * BMP_SIZE;

            c.imag( ( factor.imag() * y ) + -hFCT );

            for( int x = 0; x < BMP_SIZE; x++ ) {
                c.real( factor.real() * x + -hFCT );
                res = inSet( c, k );
                if( res ) {
                    int n_res = res % 255;
                    if( res < ( ITERATIONS >> 1 ) ) res = RGB( n_res << 2, n_res << 3, n_res << 4 );
                    else res = RGB( n_res << 4, n_res << 2, n_res << 5 );
                }
                bits[pos++] = res;
            }
        }
        bmp.saveBitmap( "./js.bmp" );
    }
private:
    int inSet( std::complex<long double> z, std::complex<long double> c ) {
        long double dist;
        for( int ec = 0; ec < ITERATIONS; ec++ ) {
            z = z * z; z = z + c;
            dist = ( z.imag() * z.imag() ) + ( z.real() * z.real() );
            if( dist > 3 ) return( ec );
        }
        return 0;
    }
    myBitmap bmp;
};
int main( int argc, char* argv[] ) {
    std::complex<long double> c;
    long double factor = FCT / BMP_SIZE;
    c.imag( ( factor * 184 ) + -1.4 );
    c.real( ( factor * 307 ) + -2.0 );
    julia j; j.draw( c ); return 0;    
}










Ada: with Ada.Numerics.Generic_Complex_Types;

with SDL.Video.Windows.Makers;
with SDL.Video.Renderers.Makers;
with SDL.Video.Palettes;
with SDL.Events.Events;

procedure Julia_Set is

   Width      : constant := 1_200;
   Height     : constant := 900;

   type Real is new Float;
   package Complex_Real is
      new Ada.Numerics.Generic_Complex_Types (Real);
   use Complex_Real;

   Iter   : constant         := 100;
   C      : constant Complex := (Re => -0.70000, Im => 0.27015);
   Move   : constant Complex := (Re => 0.000,    Im => 0.000);
   Zoom   : constant         := 0.800;

   Window   : SDL.Video.Windows.Window;
   Renderer : SDL.Video.Renderers.Renderer;
   Event    : SDL.Events.Events.Events;

   function Map (Width, Height : in Integer;
                 X, Y          : in Integer) return Complex
   is
      C : Complex;
      L : constant Real := Real (Integer'Max (Width, Height));
   begin
      C := (2.0 * Real (X - Width  / 2) / (L * Zoom),
            2.0 * Real (Y - Height / 2) / (L * Zoom));
      return C + Move;
   end Map;

   procedure Draw_Julia_Set is
      use type SDL.C.int;
      use SDL.Video.Palettes;
      Z : Complex;
   begin
      for Y in 0 .. Height loop
         for X in 0 .. Width loop
            Z := Map (Width, Height, X, Y);
            for N in 1 .. Iter loop
               Z := Z ** 2 + C;
               if abs (Z) > 2.0 then
                  Renderer.Set_Draw_Colour ((Red   => 2 * Colour_Component (N),
                                             Green => 255 - 2 * Colour_Component (N),
                                             Blue  => 150, Alpha => 255));
                  Renderer.Draw (Point => (X => SDL.C.int (X),
                                           Y => SDL.C.int (Y)));
                  exit;
               end if;
            end loop;
         end loop;
      end loop;
   end Draw_Julia_Set;

   procedure Wait is
      use type SDL.Events.Event_Types;
   begin
      loop
         while SDL.Events.Events.Poll (Event) loop
            if Event.Common.Event_Type = SDL.Events.Quit then
               return;
            end if;
         end loop;
      end loop;
   end Wait;

begin
   if not SDL.Initialise (Flags => SDL.Enable_Screen) then
      return;
   end if;

   SDL.Video.Windows.Makers.Create (Win      => Window,
                                    Title    => "Julia set",
                                    Position => SDL.Natural_Coordinates'(X => 10, Y => 10),
                                    Size     => SDL.Positive_Sizes'(Width, Height),
                                    Flags    => 0);
   SDL.Video.Renderers.Makers.Create  (Renderer, Window.Get_Surface);
   Renderer.Set_Draw_Colour ((0, 0, 0, 255));
   Renderer.Fill (Rectangle => (0, 0, Width, Height));

   Draw_Julia_Set;
   Window.Update_Surface;

   Wait;
   Window.Finalize;
   SDL.Finalise;
end Julia_Set;