help: i want to draw polygon in pascal

[zanghaohieu]

I want to draw polygons with coordinates had been entered from the keyboard into one-dimensional array. Now that the coordinates used to draw polygons.
Should I use google translate expressions incoherent

[typo]

Use Canvas.Polygon(ArrayOfTPoint). Only be sure that the user enters valid points (by asking him/her to pick the point with the mouse, for instance).

[zanghaohieu]

retrieve data from array coordinates to draw

[zanghaohieu]

for example
type coordinates=record
  x,y:integer ;
  end;
 mang=array[0..30] of coordinates;
{Added polygon vertices}
 procedure nhapdinh(var n:byte;var p:mang);
 var i:byte;
 begin
      write('verticles :n= ');readln(n);
      for i:=1 to n do
      begin
           write('p[',i,'].x=  ');readln(p.x);
           write('p[',i,'].y=  ');readln(p.y);
      end;
 end;
typed arrays used to draw polygons

[User137]

Just change this line to:

Code: [Select]

mang=array[0..30] of TPoint;You can then use ......Canvas.Polygon(mang);  where Canvas can be from any graphical component like TForm, TImage, TImage.Picture.Bitmap, TPaintBox etc.

[howardpc]

From his code snippet it seems zanghaohieu wants to draw polygons in console window, not in a GUI environment.

[zanghaohieu]

I want to enter data in console windowns, and then draw in the graphical environment

[taazz]

I want to enter data in console windowns, and then draw in the graphical environment

Go all graphical and forget about the console window.

[zanghaohieu]

so as not to draw polygons by taking the data from the array to draw?

[taazz]

As to get the input from a graphical interface too instead of a console window.

[zanghaohieu]

please give me examples

[Bart]

You coud use a TStringGrid with ColCount = 2, FixedRows = 1, RowCount = Nr of points you want + 1 and set the text of the top cells to 'x' and 'y'.
You will have to validate the input (but you would also need to do that when using readln() on the console (your current code (in the example) will crash the program if someone enters a non-valid value).

[edit]Attached demo, which lets you input coordinates in a stringgrid[/edit]

Bart

[typo]

Here a simple example (attached). Click on the form to set points.

[howardpc]

And another example to show how to use a different mouse event. This example draws just the polygon perimeter.

[zanghaohieu]

thanks typo
but i have problem, you can see in this picture