Poligon adalah geometri dengan banyak sudut seperti segitiga, segi empat dan nonagon dan lainnya. poligon terdiri atas beberapa titik atau vertex yang terhubung menjadi sebuah bentuk geometri. Poligon memiliki penamaan khusus sesuai jumlah sudutnya.
Poligon merupakan geometri yang dapat dikembangkan secara luas sehingga digunakan di berbagai bidang.
Untuk memudahkan mengenal atau memperkenalkan polygon, salah satu media yang bisa digunakan adalah pc/laptop. Fitur dasar seperti create dan modify adalah sebagai langkah awal untuk membangun sebuah media pembelajaran geometri. Selanjutnya bisa dikembangkan menjadi lebih fungsional sesuai kebutuhan pengembangannya.
Screenshoot media pembelajaran polygin menggunakan delphi :
Kode delphi pengembangan media belajar geometri polygon :
unit Unit1;
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls, ExtCtrls, Buttons, Grids;
type
TForm1 = class(TForm)
Panel1: TPanel;
Panel2: TPanel;
Image1: TImage;
GroupBox1: TGroupBox;
GroupBox3: TGroupBox;
GroupBox2: TGroupBox;
LabelPosisi: TLabel;
ButtonClose: TButton;
LabelVertex: TLabel;
GroupBox4: TGroupBox;
StringGrid1: TStringGrid;
ButtonDelete: TButton;
ButtonDraw: TButton;
ButtonEdit: TButton;
ButtonInsert: TButton;
ButtonClear: TButton;
ButtonSave: TButton;
ButtonOpen: TButton;
Label1: TLabel;
procedure ButtonDrawClick(Sender: TObject);
procedure ButtonEditClick(Sender: TObject);
procedure Image1MouseMove(Sender: TObject; Shift: TShiftState; X,
Y: Integer);
procedure Image1Click(Sender: TObject);
procedure FormCreate(Sender: TObject);
procedure ButtonCloseClick(Sender: TObject);
procedure ButtonSaveClick(Sender: TObject);
procedure ButtonLoadClick(Sender: TObject);
procedure refreshCanvas();
procedure StringGrid1SelectCell(Sender: TObject; ACol, ARow: Integer;
var CanSelect: Boolean);
procedure ButtonDeleteClick(Sender: TObject);
procedure FormResize(Sender: TObject);
procedure ButtonInsertClick(Sender: TObject);
procedure ButtonClearClick(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;
type Point = record
X : integer;
Y : integer;
end;
var
Form1: TForm1;
modeOperasi : integer;
posisi : Point;
tinggiCanvas : integer;
startPolygon : boolean;
polygon : array[0..20] of Point;
polygonCount : integer;
editIndex : integer;
const
modeIdle = 0;
modeDraw = 1;
modeEdit = 3;
modeInsert = 4;
implementation
{$R *.dfm}
procedure TForm1.refreshCanvas();
var
i : integer;
begin
StringGrid1.RowCount := polygonCount + 1;
i := 0;
while true do
begin
if polygon[i].X = -1 then
break;
StringGrid1.Cells[0,i+1] := inttostr(i+1);
StringGrid1.Cells[1,i+1] := inttostr(polygon[i].X);
StringGrid1.Cells[2,i+1] := inttostr(polygon[i].Y);
if i = 0 then
begin
image1.Canvas.rectangle(0,0,image1.width-1, image1.height-1);
image1.Canvas.MoveTo(polygon[0].X, tinggiCanvas - polygon[0].Y);
end
else
begin
if (modeOperasi = modeInsert) and (editIndex = i) then
begin
Image1.Canvas.Pen.Color := clRed;
end
else
begin
Image1.Canvas.Pen.Color := clBlack;
end;
image1.Canvas.LineTo(polygon[i].X, tinggiCanvas - polygon[i].Y);
end;
i := i + 1;
if i = 20 then
break;
end;
if modeOperasi = modeEdit then
begin
image1.Canvas.Rectangle(polygon[editIndex].X-5, tinggiCanvas - polygon[editIndex].Y - 5,
polygon[editIndex].X+5, tinggiCanvas - polygon[editIndex].Y + 5);
end;
end;
procedure TForm1.FormCreate(Sender: TObject);
begin
StringGrid1.Cells[0,0] := 'No';
StringGrid1.Cells[1,0] := 'X';
StringGrid1.Cells[2,0] := 'Y';
end;
procedure TForm1.FormResize(Sender: TObject);
begin
tinggiCanvas := Image1.Height;
end;
procedure TForm1.ButtonDrawClick(Sender: TObject);
begin
buttonDraw.Font.Style := [fsBold];
ButtonEdit.Font.Style := [];
ButtonInsert.Font.Style := [];
modeOperasi := modeDraw;
startPolygon := true;
polygonCount := 0;
polygon[polygonCount].X := -1;
refreshCanvas();
end;
procedure TForm1.ButtonCloseClick(Sender: TObject);
begin
if (modeOperasi = modeDraw) and (polygonCount > 1) then
begin
polygon[polygonCount] := polygon[0];
polygonCount := polygonCount + 1;
polygon[polygonCount].X := -1;
LabelVertex.Caption := 'Vertex ' + inttostr(polygonCount);
refreshCanvas();
buttonDraw.Font.Style := [];
ButtonEdit.Font.Style := [];
ButtonInsert.Font.Style := [];
modeOperasi := modeIdle;
end;
end;
procedure TForm1.ButtonEditClick(Sender: TObject);
begin
buttonDraw.Font.Style := [];
ButtonEdit.Font.Style := [fsBold];
ButtonInsert.Font.Style := [];
modeOperasi := modeEdit;
editIndex := 1;
refreshCanvas();
end;
procedure TForm1.ButtonInsertClick(Sender: TObject);
begin
buttonDraw.Font.Style := [];
ButtonEdit.Font.Style := [];
ButtonInsert.Font.Style := [fsBold];
modeOperasi := modeInsert;
editIndex := 1;
refreshCanvas();
end;
procedure TForm1.ButtonClearClick(Sender: TObject);
begin
polygonCount := 0;
polygon[polygonCount].X := -1;
refreshCanvas();
end;
procedure TForm1.ButtonDeleteClick(Sender: TObject);
var
i : integer;
begin
if editIndex <> 0 then
begin
for i := editIndex to polygonCount do
begin
polygon[i].X := polygon[i+1].X;
polygon[i].Y := polygon[i+1].Y;
end;
polygonCount := polygonCount - 1;
refreshCanvas();
end;
end;
procedure TForm1.Image1MouseMove(Sender: TObject; Shift: TShiftState; X,
Y: Integer);
begin
posisi.X := X;
posisi.Y := tinggiCanvas - Y;
LabelPosisi.Caption := 'Posisi ' + inttostr(posisi.X) + ', ' + inttostr(posisi.Y);
end;
procedure TForm1.Image1Click(Sender: TObject);
var
i : integer;
begin
if (modeOperasi = modeDraw) and (polygonCount < 20) then
begin
polygon[polygonCount].X := posisi.X;
polygon[polygonCount].Y := posisi.Y;
polygonCount := polygonCount + 1;
polygon[polygonCount].X := -1;
LabelVertex.Caption := 'Vertex ' + inttostr(polygonCount);
refreshCanvas();
end
else if (modeOperasi = modeEdit) and (editIndex > 0)then
begin
if (editIndex = 1) or (editIndex = polygonCount-1) then
begin
polygon[1].X := posisi.X;
polygon[1].Y := posisi.Y;
polygon[polygonCount-1].X := posisi.X;
polygon[polygonCount-1].Y := posisi.Y;
end
else if (editIndex > 0) then
begin
polygon[editIndex].X := posisi.X;
polygon[editIndex].Y := posisi.Y;
end;
refreshCanvas();
end
else if (modeOperasi = modeInsert) and (editIndex > 0) and (polygonCount < 20) then
begin
for i := polygonCount downto editIndex do
begin
polygon[i+1].X := polygon[i].X;
polygon[i+1].Y := polygon[i].Y;
end;
polygon[editIndex].X := posisi.X;
polygon[editIndex].Y := posisi.Y;
polygonCount := polygonCount + 1;
refreshCanvas();
end;
end;
procedure TForm1.ButtonSaveClick(Sender: TObject);
var
Stream: TStream;
begin
Stream:= TFileStream.Create('polygon.bin', fmCreate);
Stream.WriteBuffer(polygonCount, SizeOf(integer));
Stream.WriteBuffer(polygon, (polygonCount+1) * SizeOf(Point));
Stream.Free;
end;
procedure TForm1.ButtonLoadClick(Sender: TObject);
var
Stream: TStream;
begin
Stream:= TFileStream.Create('polygon.bin', fmOpenRead);
Stream.ReadBuffer(polygonCount, SizeOf(integer));
Stream.ReadBuffer(polygon, (polygonCount+1) * SizeOf(Point));
Stream.Free;
refreshCanvas();
LabelVertex.Caption := 'Vertex ' + inttostr(polygonCount);
end;
procedure TForm1.StringGrid1SelectCell(Sender: TObject; ACol,
ARow: Integer; var CanSelect: Boolean);
begin
editIndex := ARow - 1;
refreshCanvas();
end;
end.
code lengkap media pengajaran geometri poligon:
library :
