WeixiangYan/CodeTransOcean huggingface dataset:
Task: Greyscale bars_Display


C++: #ifndef MYWIDGET_H
#define MYWIDGET_H
#include <QWidget>

class QPaintEvent ;

class MyWidget : public QWidget {
public :
   MyWidget( ) ;

protected :
   void paintEvent( QPaintEvent * ) ;
} ;
#endif


C#: using System;
using System.Drawing;
using System.Windows.Forms;
static class Program { static void Main() { Application.Run(new FullScreen()); } }
public sealed class FullScreen : Form
{
    const int ColorCount = 256;
    public FullScreen()
    {
        FormBorderStyle = FormBorderStyle.None;
        WindowState = FormWindowState.Maximized;
        KeyPress += (s, e) => Application.Exit();
        BackgroundImage = ColorBars(Screen.FromControl(this).Bounds);
    }
    private static Bitmap ColorBars(Rectangle size)
    {
        var colorBars = new Bitmap(size.Width, size.Height);
        Func<int, int, int> forwardColor = (x, divs) => (int)(x * ((float)divs / size.Width)) * ColorCount / divs;
        Func<int, int, int> reverseColor = (x, divs) => ColorCount - 1 - forwardColor(x, divs);
        Action<int, int, int> setGray = (x, y, gray) => colorBars.SetPixel(x, y, Color.FromArgb(gray, gray, gray));
        Action<int, int, int> setForward = (x, y, divs) => setGray(x, y, forwardColor(x, divs));
        Action<int, int, int> setReverse = (x, y, divs) => setGray(x, y, reverseColor(x, divs));
        int verticalStripe = size.Height / 4;
        for (int x = 0; x < size.Width; x++)
        {
            for (int y = 0; y < verticalStripe; y++) setForward(x, y, 8);
            for (int y = verticalStripe; y < verticalStripe * 2; y++) setReverse(x, y, 16);
            for (int y = verticalStripe * 2; y < verticalStripe * 3; y++) setForward(x, y, 32);
            for (int y = verticalStripe * 3; y < verticalStripe * 4; y++) setReverse(x, y, 64);
        }
        return colorBars;
    }
}
Task: Greyscale bars_Display


C++: #ifndef MYWIDGET_H
#define MYWIDGET_H
#include <QWidget>

class QPaintEvent ;

class MyWidget : public QWidget {
public :
   MyWidget( ) ;

protected :
   void paintEvent( QPaintEvent * ) ;
} ;
#endif



Go: package main

import (
    "github.com/fogleman/gg"
    "math"
)

func greyBars(dc *gg.Context) {
    run := 0
    colorComp := 0.0 
    for colCount := 8; colCount < 128; colCount *= 2 {
        
        colorGap := 255.0 / float64(colCount-1)
        colWidth := float64(dc.Width() / colCount)
        colHeight := float64(dc.Height() / 4)
        
        if run%2 == 0 {
            colorComp = 0.0
        } else {
            colorComp = 255.0
            colorGap = -colorGap
        }
        xstart, ystart := 0.0, colHeight*float64(run)
        for i := 0; i < colCount; i++ {
            icolor := int(math.Round(colorComp)) 
            dc.SetRGB255(icolor, icolor, icolor)
            dc.DrawRectangle(xstart, ystart, colWidth, colHeight)
            dc.Fill()
            xstart += colWidth
            colorComp += colorGap
        }
        run++
    }
}

func main() {
    dc := gg.NewContext(640, 320)
    greyBars(dc)
    dc.SavePNG("greybars.png")
}
Task: Greyscale bars_Display


C++: #ifndef MYWIDGET_H
#define MYWIDGET_H
#include <QWidget>

class QPaintEvent ;

class MyWidget : public QWidget {
public :
   MyWidget( ) ;

protected :
   void paintEvent( QPaintEvent * ) ;
} ;
#endif




Java: import javax.swing.* ;
import java.awt.* ;

public class Greybars extends JFrame {
   private int width ;
   private int height ;

   public Greybars( )  {
      super( "grey bars example!" ) ;
      width = 640 ;
      height = 320 ;
      setSize( width , height ) ;
      setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE ) ;
      setVisible( true ) ;
    }

    public void paint ( Graphics g ) {
      int run = 0 ;
      double colorcomp = 0.0 ; 
      for ( int columncount = 8 ; columncount < 128 ; columncount *= 2 ) {
	 double colorgap = 255.0 / (columncount - 1) ; 
	 int columnwidth = width / columncount ;
	 int columnheight = height / 4 ;
	 if ( run % 2 == 0 ) 
	    colorcomp = 0.0 ;
	 else {
	    colorcomp = 255.0 ;
	    colorgap *= -1.0 ;
	 }
	 int ystart = 0 + columnheight * run ;
	 int xstart = 0 ;
	 for ( int i = 0 ; i < columncount ; i++ ) {
            int icolor = (int)Math.round(colorcomp) ; 
	    Color nextColor = new Color( icolor , icolor, icolor ) ;
	    g.setColor( nextColor ) ;
	    g.fillRect( xstart , ystart , columnwidth , columnheight ) ;
	    xstart += columnwidth ;
	    colorcomp += colorgap ;
	 }
	 run++ ;
      }
    }

    public static void main( String[ ] args ) {
       Greybars gb = new Greybars( ) ;
    }
}
Task: Greyscale bars_Display


C++: #ifndef MYWIDGET_H
#define MYWIDGET_H
#include <QWidget>

class QPaintEvent ;

class MyWidget : public QWidget {
public :
   MyWidget( ) ;

protected :
   void paintEvent( QPaintEvent * ) ;
} ;
#endif







VB: Declare Sub PaintCanvas

Create Form as Qform
    Caption = "Rosetta Greyscale"
    Center
    create Canv as QCanvas
        align = 5
        onPaint = PaintCanvas
    end create
end create

Sub PaintCanvas
    NumRows = 4 
    for curbar = 0 to NumRows-1
        Bars = 2^(curbar+3)
        for x = 0 to (Bars -1)
            x1=Canv.Width/Bars*x
            y1=Canv.Height/NumRows*CurBar 
            x2=Canv.Width/Bars*(x+1)
            y2=Canv.Height/NumRows*(CurBar+1) 
            c=(255/(Bars-1))*x
            c=iif(curbar mod 2, 255-c, c)
            Canv.FillRect(x1, y1, x2, y2, rgb(c, c, c))
        next x
    next curbar 
end sub    

Form.showmodal
Task: Greyscale bars_Display



C#: using System;
using System.Drawing;
using System.Windows.Forms;
static class Program { static void Main() { Application.Run(new FullScreen()); } }
public sealed class FullScreen : Form
{
    const int ColorCount = 256;
    public FullScreen()
    {
        FormBorderStyle = FormBorderStyle.None;
        WindowState = FormWindowState.Maximized;
        KeyPress += (s, e) => Application.Exit();
        BackgroundImage = ColorBars(Screen.FromControl(this).Bounds);
    }
    private static Bitmap ColorBars(Rectangle size)
    {
        var colorBars = new Bitmap(size.Width, size.Height);
        Func<int, int, int> forwardColor = (x, divs) => (int)(x * ((float)divs / size.Width)) * ColorCount / divs;
        Func<int, int, int> reverseColor = (x, divs) => ColorCount - 1 - forwardColor(x, divs);
        Action<int, int, int> setGray = (x, y, gray) => colorBars.SetPixel(x, y, Color.FromArgb(gray, gray, gray));
        Action<int, int, int> setForward = (x, y, divs) => setGray(x, y, forwardColor(x, divs));
        Action<int, int, int> setReverse = (x, y, divs) => setGray(x, y, reverseColor(x, divs));
        int verticalStripe = size.Height / 4;
        for (int x = 0; x < size.Width; x++)
        {
            for (int y = 0; y < verticalStripe; y++) setForward(x, y, 8);
            for (int y = verticalStripe; y < verticalStripe * 2; y++) setReverse(x, y, 16);
            for (int y = verticalStripe * 2; y < verticalStripe * 3; y++) setForward(x, y, 32);
            for (int y = verticalStripe * 3; y < verticalStripe * 4; y++) setReverse(x, y, 64);
        }
        return colorBars;
    }
}



Java: import javax.swing.* ;
import java.awt.* ;

public class Greybars extends JFrame {
   private int width ;
   private int height ;

   public Greybars( )  {
      super( "grey bars example!" ) ;
      width = 640 ;
      height = 320 ;
      setSize( width , height ) ;
      setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE ) ;
      setVisible( true ) ;
    }

    public void paint ( Graphics g ) {
      int run = 0 ;
      double colorcomp = 0.0 ; 
      for ( int columncount = 8 ; columncount < 128 ; columncount *= 2 ) {
	 double colorgap = 255.0 / (columncount - 1) ; 
	 int columnwidth = width / columncount ;
	 int columnheight = height / 4 ;
	 if ( run % 2 == 0 ) 
	    colorcomp = 0.0 ;
	 else {
	    colorcomp = 255.0 ;
	    colorgap *= -1.0 ;
	 }
	 int ystart = 0 + columnheight * run ;
	 int xstart = 0 ;
	 for ( int i = 0 ; i < columncount ; i++ ) {
            int icolor = (int)Math.round(colorcomp) ; 
	    Color nextColor = new Color( icolor , icolor, icolor ) ;
	    g.setColor( nextColor ) ;
	    g.fillRect( xstart , ystart , columnwidth , columnheight ) ;
	    xstart += columnwidth ;
	    colorcomp += colorgap ;
	 }
	 run++ ;
      }
    }

    public static void main( String[ ] args ) {
       Greybars gb = new Greybars( ) ;
    }
}
Task: Greyscale bars_Display



C#: using System;
using System.Drawing;
using System.Windows.Forms;
static class Program { static void Main() { Application.Run(new FullScreen()); } }
public sealed class FullScreen : Form
{
    const int ColorCount = 256;
    public FullScreen()
    {
        FormBorderStyle = FormBorderStyle.None;
        WindowState = FormWindowState.Maximized;
        KeyPress += (s, e) => Application.Exit();
        BackgroundImage = ColorBars(Screen.FromControl(this).Bounds);
    }
    private static Bitmap ColorBars(Rectangle size)
    {
        var colorBars = new Bitmap(size.Width, size.Height);
        Func<int, int, int> forwardColor = (x, divs) => (int)(x * ((float)divs / size.Width)) * ColorCount / divs;
        Func<int, int, int> reverseColor = (x, divs) => ColorCount - 1 - forwardColor(x, divs);
        Action<int, int, int> setGray = (x, y, gray) => colorBars.SetPixel(x, y, Color.FromArgb(gray, gray, gray));
        Action<int, int, int> setForward = (x, y, divs) => setGray(x, y, forwardColor(x, divs));
        Action<int, int, int> setReverse = (x, y, divs) => setGray(x, y, reverseColor(x, divs));
        int verticalStripe = size.Height / 4;
        for (int x = 0; x < size.Width; x++)
        {
            for (int y = 0; y < verticalStripe; y++) setForward(x, y, 8);
            for (int y = verticalStripe; y < verticalStripe * 2; y++) setReverse(x, y, 16);
            for (int y = verticalStripe * 2; y < verticalStripe * 3; y++) setForward(x, y, 32);
            for (int y = verticalStripe * 3; y < verticalStripe * 4; y++) setReverse(x, y, 64);
        }
        return colorBars;
    }
}





Python: 


from livewires import *

horiz=640; vert=480; pruh=vert/4; dpp=255.0
begin_graphics(width=horiz,height=vert,title="Gray stripes",background=Colour.black)

def ty_pruhy(each):
	hiy=each[0]*pruh; loy=hiy-pruh
	krok=horiz/each[1]; piecol=255.0/(each[1]-1)
	for x in xrange(0,each[1]):
		barva=Colour(piecol*x/dpp,piecol*x/dpp,piecol*x/dpp ); set_colour(barva)
		if each[2]:
			box(x*krok,hiy,x*krok+krok,loy,filled=1)
		else:
			box(horiz-x*krok,hiy,horiz-((x+1)*krok),loy,filled=1)


source=[[4,8,True],[3,16,False],[2,32,True],[1,64,False]]
for each in source:
	ty_pruhy(each)

while keys_pressed() != [' ']: 
	pass
Task: Greyscale bars_Display





Java: import javax.swing.* ;
import java.awt.* ;

public class Greybars extends JFrame {
   private int width ;
   private int height ;

   public Greybars( )  {
      super( "grey bars example!" ) ;
      width = 640 ;
      height = 320 ;
      setSize( width , height ) ;
      setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE ) ;
      setVisible( true ) ;
    }

    public void paint ( Graphics g ) {
      int run = 0 ;
      double colorcomp = 0.0 ; 
      for ( int columncount = 8 ; columncount < 128 ; columncount *= 2 ) {
	 double colorgap = 255.0 / (columncount - 1) ; 
	 int columnwidth = width / columncount ;
	 int columnheight = height / 4 ;
	 if ( run % 2 == 0 ) 
	    colorcomp = 0.0 ;
	 else {
	    colorcomp = 255.0 ;
	    colorgap *= -1.0 ;
	 }
	 int ystart = 0 + columnheight * run ;
	 int xstart = 0 ;
	 for ( int i = 0 ; i < columncount ; i++ ) {
            int icolor = (int)Math.round(colorcomp) ; 
	    Color nextColor = new Color( icolor , icolor, icolor ) ;
	    g.setColor( nextColor ) ;
	    g.fillRect( xstart , ystart , columnwidth , columnheight ) ;
	    xstart += columnwidth ;
	    colorcomp += colorgap ;
	 }
	 run++ ;
      }
    }

    public static void main( String[ ] args ) {
       Greybars gb = new Greybars( ) ;
    }
}



Python: 


from livewires import *

horiz=640; vert=480; pruh=vert/4; dpp=255.0
begin_graphics(width=horiz,height=vert,title="Gray stripes",background=Colour.black)

def ty_pruhy(each):
	hiy=each[0]*pruh; loy=hiy-pruh
	krok=horiz/each[1]; piecol=255.0/(each[1]-1)
	for x in xrange(0,each[1]):
		barva=Colour(piecol*x/dpp,piecol*x/dpp,piecol*x/dpp ); set_colour(barva)
		if each[2]:
			box(x*krok,hiy,x*krok+krok,loy,filled=1)
		else:
			box(horiz-x*krok,hiy,horiz-((x+1)*krok),loy,filled=1)


source=[[4,8,True],[3,16,False],[2,32,True],[1,64,False]]
for each in source:
	ty_pruhy(each)

while keys_pressed() != [' ']: 
	pass
Task: Greyscale bars_Display







Python: 


from livewires import *

horiz=640; vert=480; pruh=vert/4; dpp=255.0
begin_graphics(width=horiz,height=vert,title="Gray stripes",background=Colour.black)

def ty_pruhy(each):
	hiy=each[0]*pruh; loy=hiy-pruh
	krok=horiz/each[1]; piecol=255.0/(each[1]-1)
	for x in xrange(0,each[1]):
		barva=Colour(piecol*x/dpp,piecol*x/dpp,piecol*x/dpp ); set_colour(barva)
		if each[2]:
			box(x*krok,hiy,x*krok+krok,loy,filled=1)
		else:
			box(horiz-x*krok,hiy,horiz-((x+1)*krok),loy,filled=1)


source=[[4,8,True],[3,16,False],[2,32,True],[1,64,False]]
for each in source:
	ty_pruhy(each)

while keys_pressed() != [' ']: 
	pass


VB: Declare Sub PaintCanvas

Create Form as Qform
    Caption = "Rosetta Greyscale"
    Center
    create Canv as QCanvas
        align = 5
        onPaint = PaintCanvas
    end create
end create

Sub PaintCanvas
    NumRows = 4 
    for curbar = 0 to NumRows-1
        Bars = 2^(curbar+3)
        for x = 0 to (Bars -1)
            x1=Canv.Width/Bars*x
            y1=Canv.Height/NumRows*CurBar 
            x2=Canv.Width/Bars*(x+1)
            y2=Canv.Height/NumRows*(CurBar+1) 
            c=(255/(Bars-1))*x
            c=iif(curbar mod 2, 255-c, c)
            Canv.FillRect(x1, y1, x2, y2, rgb(c, c, c))
        next x
    next curbar 
end sub    

Form.showmodal
Task: Greyscale bars_Display

C: #include <gtk/gtk.h>

void gsplot (cairo_t *cr,int x,int y,double s) {
    cairo_set_source_rgb (cr,s,s,s);
    cairo_move_to (cr,x+0.5,y);
    cairo_rel_line_to (cr,0,1);
    cairo_stroke (cr);
}

gboolean expose_event (GtkWidget *widget,GdkEventExpose *event,gpointer data) {
    int r,c,x=0;
    cairo_t *cr;
    cr = gdk_cairo_create (widget->window);
    cairo_scale (cr,5,50);
    cairo_set_line_width (cr,1);
    for (r=0;r<4;r++) {
        c = (r&1)*64-(r%2);
        do gsplot (cr,x++%64,r,c/(1<<(3-r))/(8*(1<<r)-1.0));
        while ((c+=2*!(r%2)-1)!=(!(r%2))*64-(r%2));
    } cairo_destroy (cr);
    return FALSE;
}

int main (int argc, char *argv[]) {
    GtkWidget *window;
    gtk_init (&argc, &argv);
    window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
    g_signal_connect (window, "expose-event",G_CALLBACK (expose_event), NULL);
    g_signal_connect (window, "delete-event", G_CALLBACK(gtk_main_quit), NULL);
    gtk_window_set_default_size (GTK_WINDOW(window), 320, 200);
    gtk_widget_set_app_paintable (window, TRUE);
    gtk_widget_show_all (window);
    gtk_main ();
    return 0;
}








VB: Declare Sub PaintCanvas

Create Form as Qform
    Caption = "Rosetta Greyscale"
    Center
    create Canv as QCanvas
        align = 5
        onPaint = PaintCanvas
    end create
end create

Sub PaintCanvas
    NumRows = 4 
    for curbar = 0 to NumRows-1
        Bars = 2^(curbar+3)
        for x = 0 to (Bars -1)
            x1=Canv.Width/Bars*x
            y1=Canv.Height/NumRows*CurBar 
            x2=Canv.Width/Bars*(x+1)
            y2=Canv.Height/NumRows*(CurBar+1) 
            c=(255/(Bars-1))*x
            c=iif(curbar mod 2, 255-c, c)
            Canv.FillRect(x1, y1, x2, y2, rgb(c, c, c))
        next x
    next curbar 
end sub    

Form.showmodal
Task: Greyscale bars_Display


C++: #ifndef MYWIDGET_H
#define MYWIDGET_H
#include <QWidget>

class QPaintEvent ;

class MyWidget : public QWidget {
public :
   MyWidget( ) ;

protected :
   void paintEvent( QPaintEvent * ) ;
} ;
#endif






Python: 


from livewires import *

horiz=640; vert=480; pruh=vert/4; dpp=255.0
begin_graphics(width=horiz,height=vert,title="Gray stripes",background=Colour.black)

def ty_pruhy(each):
	hiy=each[0]*pruh; loy=hiy-pruh
	krok=horiz/each[1]; piecol=255.0/(each[1]-1)
	for x in xrange(0,each[1]):
		barva=Colour(piecol*x/dpp,piecol*x/dpp,piecol*x/dpp ); set_colour(barva)
		if each[2]:
			box(x*krok,hiy,x*krok+krok,loy,filled=1)
		else:
			box(horiz-x*krok,hiy,horiz-((x+1)*krok),loy,filled=1)


source=[[4,8,True],[3,16,False],[2,32,True],[1,64,False]]
for each in source:
	ty_pruhy(each)

while keys_pressed() != [' ']: 
	pass
Task: Greyscale bars_Display



C#: using System;
using System.Drawing;
using System.Windows.Forms;
static class Program { static void Main() { Application.Run(new FullScreen()); } }
public sealed class FullScreen : Form
{
    const int ColorCount = 256;
    public FullScreen()
    {
        FormBorderStyle = FormBorderStyle.None;
        WindowState = FormWindowState.Maximized;
        KeyPress += (s, e) => Application.Exit();
        BackgroundImage = ColorBars(Screen.FromControl(this).Bounds);
    }
    private static Bitmap ColorBars(Rectangle size)
    {
        var colorBars = new Bitmap(size.Width, size.Height);
        Func<int, int, int> forwardColor = (x, divs) => (int)(x * ((float)divs / size.Width)) * ColorCount / divs;
        Func<int, int, int> reverseColor = (x, divs) => ColorCount - 1 - forwardColor(x, divs);
        Action<int, int, int> setGray = (x, y, gray) => colorBars.SetPixel(x, y, Color.FromArgb(gray, gray, gray));
        Action<int, int, int> setForward = (x, y, divs) => setGray(x, y, forwardColor(x, divs));
        Action<int, int, int> setReverse = (x, y, divs) => setGray(x, y, reverseColor(x, divs));
        int verticalStripe = size.Height / 4;
        for (int x = 0; x < size.Width; x++)
        {
            for (int y = 0; y < verticalStripe; y++) setForward(x, y, 8);
            for (int y = verticalStripe; y < verticalStripe * 2; y++) setReverse(x, y, 16);
            for (int y = verticalStripe * 2; y < verticalStripe * 3; y++) setForward(x, y, 32);
            for (int y = verticalStripe * 3; y < verticalStripe * 4; y++) setReverse(x, y, 64);
        }
        return colorBars;
    }
}


Go: package main

import (
    "github.com/fogleman/gg"
    "math"
)

func greyBars(dc *gg.Context) {
    run := 0
    colorComp := 0.0 
    for colCount := 8; colCount < 128; colCount *= 2 {
        
        colorGap := 255.0 / float64(colCount-1)
        colWidth := float64(dc.Width() / colCount)
        colHeight := float64(dc.Height() / 4)
        
        if run%2 == 0 {
            colorComp = 0.0
        } else {
            colorComp = 255.0
            colorGap = -colorGap
        }
        xstart, ystart := 0.0, colHeight*float64(run)
        for i := 0; i < colCount; i++ {
            icolor := int(math.Round(colorComp)) 
            dc.SetRGB255(icolor, icolor, icolor)
            dc.DrawRectangle(xstart, ystart, colWidth, colHeight)
            dc.Fill()
            xstart += colWidth
            colorComp += colorGap
        }
        run++
    }
}

func main() {
    dc := gg.NewContext(640, 320)
    greyBars(dc)
    dc.SavePNG("greybars.png")
}
Task: Greyscale bars_Display



C#: using System;
using System.Drawing;
using System.Windows.Forms;
static class Program { static void Main() { Application.Run(new FullScreen()); } }
public sealed class FullScreen : Form
{
    const int ColorCount = 256;
    public FullScreen()
    {
        FormBorderStyle = FormBorderStyle.None;
        WindowState = FormWindowState.Maximized;
        KeyPress += (s, e) => Application.Exit();
        BackgroundImage = ColorBars(Screen.FromControl(this).Bounds);
    }
    private static Bitmap ColorBars(Rectangle size)
    {
        var colorBars = new Bitmap(size.Width, size.Height);
        Func<int, int, int> forwardColor = (x, divs) => (int)(x * ((float)divs / size.Width)) * ColorCount / divs;
        Func<int, int, int> reverseColor = (x, divs) => ColorCount - 1 - forwardColor(x, divs);
        Action<int, int, int> setGray = (x, y, gray) => colorBars.SetPixel(x, y, Color.FromArgb(gray, gray, gray));
        Action<int, int, int> setForward = (x, y, divs) => setGray(x, y, forwardColor(x, divs));
        Action<int, int, int> setReverse = (x, y, divs) => setGray(x, y, reverseColor(x, divs));
        int verticalStripe = size.Height / 4;
        for (int x = 0; x < size.Width; x++)
        {
            for (int y = 0; y < verticalStripe; y++) setForward(x, y, 8);
            for (int y = verticalStripe; y < verticalStripe * 2; y++) setReverse(x, y, 16);
            for (int y = verticalStripe * 2; y < verticalStripe * 3; y++) setForward(x, y, 32);
            for (int y = verticalStripe * 3; y < verticalStripe * 4; y++) setReverse(x, y, 64);
        }
        return colorBars;
    }
}






VB: Declare Sub PaintCanvas

Create Form as Qform
    Caption = "Rosetta Greyscale"
    Center
    create Canv as QCanvas
        align = 5
        onPaint = PaintCanvas
    end create
end create

Sub PaintCanvas
    NumRows = 4 
    for curbar = 0 to NumRows-1
        Bars = 2^(curbar+3)
        for x = 0 to (Bars -1)
            x1=Canv.Width/Bars*x
            y1=Canv.Height/NumRows*CurBar 
            x2=Canv.Width/Bars*(x+1)
            y2=Canv.Height/NumRows*(CurBar+1) 
            c=(255/(Bars-1))*x
            c=iif(curbar mod 2, 255-c, c)
            Canv.FillRect(x1, y1, x2, y2, rgb(c, c, c))
        next x
    next curbar 
end sub    

Form.showmodal
Task: Greyscale bars_Display





Java: import javax.swing.* ;
import java.awt.* ;

public class Greybars extends JFrame {
   private int width ;
   private int height ;

   public Greybars( )  {
      super( "grey bars example!" ) ;
      width = 640 ;
      height = 320 ;
      setSize( width , height ) ;
      setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE ) ;
      setVisible( true ) ;
    }

    public void paint ( Graphics g ) {
      int run = 0 ;
      double colorcomp = 0.0 ; 
      for ( int columncount = 8 ; columncount < 128 ; columncount *= 2 ) {
	 double colorgap = 255.0 / (columncount - 1) ; 
	 int columnwidth = width / columncount ;
	 int columnheight = height / 4 ;
	 if ( run % 2 == 0 ) 
	    colorcomp = 0.0 ;
	 else {
	    colorcomp = 255.0 ;
	    colorgap *= -1.0 ;
	 }
	 int ystart = 0 + columnheight * run ;
	 int xstart = 0 ;
	 for ( int i = 0 ; i < columncount ; i++ ) {
            int icolor = (int)Math.round(colorcomp) ; 
	    Color nextColor = new Color( icolor , icolor, icolor ) ;
	    g.setColor( nextColor ) ;
	    g.fillRect( xstart , ystart , columnwidth , columnheight ) ;
	    xstart += columnwidth ;
	    colorcomp += colorgap ;
	 }
	 run++ ;
      }
    }

    public static void main( String[ ] args ) {
       Greybars gb = new Greybars( ) ;
    }
}




VB: Declare Sub PaintCanvas

Create Form as Qform
    Caption = "Rosetta Greyscale"
    Center
    create Canv as QCanvas
        align = 5
        onPaint = PaintCanvas
    end create
end create

Sub PaintCanvas
    NumRows = 4 
    for curbar = 0 to NumRows-1
        Bars = 2^(curbar+3)
        for x = 0 to (Bars -1)
            x1=Canv.Width/Bars*x
            y1=Canv.Height/NumRows*CurBar 
            x2=Canv.Width/Bars*(x+1)
            y2=Canv.Height/NumRows*(CurBar+1) 
            c=(255/(Bars-1))*x
            c=iif(curbar mod 2, 255-c, c)
            Canv.FillRect(x1, y1, x2, y2, rgb(c, c, c))
        next x
    next curbar 
end sub    

Form.showmodal