Task: Barnsley fern


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

const int BMP_SIZE = 600, ITERATIONS = static_cast<int>( 15e5 );

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; }
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 fern {
public:
    void draw() {
        bmp.create( BMP_SIZE, BMP_SIZE );
        float x = 0, y = 0; HDC dc = bmp.getDC();
        int hs = BMP_SIZE >> 1;
        for( int f = 0; f < ITERATIONS; f++ ) {
            SetPixel( dc, hs + static_cast<int>( x * 55.f ), 
                      BMP_SIZE - 15 - static_cast<int>( y * 55.f ), 
                      RGB( static_cast<int>( rnd() * 80.f ) + 20, 
                           static_cast<int>( rnd() * 128.f ) + 128, 
                           static_cast<int>( rnd() * 80.f ) + 30 ) ); 
            getXY( x, y );
        }
        bmp.saveBitmap( "./bf.bmp" );
    }
private:
    void getXY( float& x, float& y ) {
        float g, xl, yl;
        g = rnd();
        if( g < .01f ) { xl = 0; yl = .16f * y; } 
        else if( g < .07f ) {
            xl = .2f * x - .26f * y;
            yl = .23f * x + .22f * y + 1.6f;
        } else if( g < .14f ) {
            xl = -.15f * x + .28f * y;
            yl = .26f * x + .24f * y + .44f;
        } else {
            xl = .85f * x + .04f * y;
            yl = -.04f * x + .85f * y + 1.6f;
        }
        x = xl; y = yl;
    }
    float rnd() {
        return static_cast<float>( rand() ) / static_cast<float>( RAND_MAX );
    }
    myBitmap bmp;
};
int main( int argc, char* argv[]) {
    srand( static_cast<unsigned>( time( 0 ) ) );
    fern f; f.draw(); return 0;    
}










Ada: with Ada.Numerics.Discrete_Random;

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

procedure Barnsley_Fern is

   Iterations : constant := 1_000_000;
   Width      : constant := 500;
   Height     : constant := 750;
   Scale      : constant := 70.0;

   type Percentage is range 1 .. 100;
   package Random_Percentages is
      new Ada.Numerics.Discrete_Random (Percentage);

   Gen      : Random_Percentages.Generator;
   Window   : SDL.Video.Windows.Window;
   Renderer : SDL.Video.Renderers.Renderer;
   Event    : SDL.Events.Events.Events;

   procedure Draw_Barnsley_Fern is
      use type SDL.C.int;
      subtype F1_Range is Percentage range Percentage'First  .. Percentage'First;
      subtype F2_Range is Percentage range F1_Range'Last + 1 .. F1_Range'Last + 85;
      subtype F3_Range is Percentage range F2_Range'Last + 1 .. F2_Range'Last + 7;
      subtype F4_Range is Percentage range F3_Range'Last + 1 .. F3_Range'Last + 7;

      X0, Y0 : Float := 0.00;
      X1, Y1 : Float;
   begin
      for I in 1 .. Iterations loop
         case Random_Percentages.Random (Gen) is

            when F1_Range =>
               X1 := 0.00;
               Y1 := 0.16 * Y0;

            when F2_Range =>
               X1 :=  0.85 * X0 + 0.04 * Y0;
               Y1 := -0.04 * X0 + 0.85 * Y0 + 1.60;

            when F3_Range =>
               X1 := 0.20 * X0 - 0.26 * Y0;
               Y1 := 0.23 * X0 + 0.22 * Y0 + 1.60;

            when F4_Range =>
               X1 := -0.15 * X0 + 0.28 * Y0;
               Y1 :=  0.26 * X0 + 0.24 * Y0 + 0.44;

         end case;
         Renderer.Draw (Point => (X => Width / 2 + SDL.C.int (Scale * X1),
                                  Y => Height    - SDL.C.int (Scale * Y1)));
         X0 := X1; Y0 := Y1;

      end loop;
   end Draw_Barnsley_Fern;

   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    => "Barnsley Fern",
                                    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));
   Renderer.Set_Draw_Colour ((0, 220, 0, 255));

   Random_Percentages.Reset (Gen);
   Draw_Barnsley_Fern;
   Window.Update_Surface;

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