扇形の描画          <TOP>

扇形を描画します。

Pie 扇形を描画する

　

例では、座標を変て描画される図形の確認をしています。

扇を形成する円（楕円）は、・1と・2で表される矩形領域に内接します。

扇の開始位置は、円（楕円）の中心と・3を結ぶ延長線上の交点、扇の終了位置は、中心と・4を結ぶ延長線上の交点です。

起動時

値を変えてみます

　

'================================================================
'= 扇形の描画
'=    (Pie.bas)
'================================================================
#include "Windows.bi"

' 扇形を描画する
Declare Function Api_Pie& Lib "gdi32" Alias "Pie" (ByVal hDC&, ByVal X1&, ByVal Y1&, ByVal X2&, ByVal Y2&, ByVal X3&, ByVal Y3&, ByVal X4&, ByVal Y4&)

' 指定されたウィンドウのクライアント領域または画面全体を表すディスプレイデバイスコンテキストのハンドルを取得
Declare Function Api_GetDC& Lib "user32" Alias "GetDC" (ByVal hWnd&)

' デバイスコンテキストを解放
Declare Function Api_ReleaseDC& Lib "user32" Alias "ReleaseDC" (ByVal hWnd&, ByVal hDC&)

Var Shared Text(6) As Object
Var Shared Edit(7) As Object
Var Shared Picture1 As Object
Var Shared Group1 As Object
Var Shared Timer1 As Object

For i = 0 To 7
    If i < 6 Then
        Text(i).Attach GetDlgItem("Text" & Trim$(Str$(i + 1))) : Text(i).SetFontSize 14
    End If
    Edit(i).Attach GetDlgItem("Edit" & Trim$(Str$(i + 1))) : Edit(i).SetFontSize 14
Next
Picture1.Attach GetDlgItem("Picture1")
Group1.Attach GetDlgItem("Group1") : Group1.SetFontSize 14
Timer1.Attach GetDlgItem("Timer1")

Var Shared hDC As Long

'================================================================
'=
'================================================================
Declare Sub MainForm_Start edecl ()
Sub MainForm_Start()
    ShowWindow -1
    Cls

    hDC = Api_GetDC(Picture1.GethWnd)

    Timer1.SetInterval 100
    Timer1.Enable -1
End Sub

'================================================================
'=
'================================================================
Declare Sub Timer1_Timer edecl ()
Sub Timer1_Timer()
    Var x(3) As Long
    Var y(3) As Long
    Var Ret As Long

    Picture1.Cls

    For i = 0 To 3
        x(i) = Val(GetDlgItemText("Edit" & Trim$(Str$(i + 1))))
        y(i) = Val(GetDlgItemText("Edit" & Trim$(Str$(i + 5))))
    Next

    Picture1.Line(x(0), y(0)) - (x(1), y(1)), , 14, b

    Ret = Api_Pie(hDC, x(0), y(0), x(1), y(1), x(2), y(2), x(3), y(3))

    For i = 0 To 3
        Picture1.SetDrawWidth 4
        Picture1.Pset(x(i), y(i)), 5
        Picture1.SetDrawWidth 0
        Picture1.Symbol(x(i) - 1, y(i) + 1), Trim$(Str$(i + 1)), 1, 1, 2
    Next
End Sub

'================================================================
'=
'================================================================
Declare Sub MainForm_QueryClose edecl ()
Sub MainForm_QueryClose()
    Var Ret As Long

    Ret = Api_ReleaseDC(Picture1.GethWnd, hDC)
    End 
End Sub

'================================================================
'=
'================================================================
While 1
    WaitEvent
Wend
Stop
End