楕円形の円弧の描画          <TOP>

ArcTo 楕円形の円弧の描画

　

X1〜X4、Y1〜Y4の数値および時計回り、反時計回り描画を変えて変化を確認しています。

　

　

X1 LeftRect

Y1 TopRect

X2 RightRect

Y2 BottomRect

X3 xStartArc

Y3 yStartArc

X4 xEndArc

Y4 yEndAr

　

'================================================================
'= 楕円形の円弧の描画
'=    (ArcTo.bas)
'================================================================
#include "Windows.bi"

#define AD_CLOCKWISE 2             '時計回り
#define AD_COUNTERCLOCKWISE 1      '反時計回り

' 楕円弧を描画
Declare Function Api_ArcTo& Lib "gdi32" Alias "ArcTo" (ByVal hDC&, ByVal X1&, ByVal Y1&, ByVal X2&, ByVal Y2&, ByVal X3&, ByVal Y3&, ByVal X4&, ByVal Y4&)

' デバイスコンテキストに設定されている、円弧の現在の方向を設定
Declare Function Api_SetArcDirection& Lib "gdi32" Alias "SetArcDirection" (ByVal hDC&, ByVal ArcDirection&)

' デバイスコンテキストに設定されている、円弧の現在の方向を取得
Declare Function Api_GetArcDirection& Lib "gdi32" Alias "GetArcDirection" (ByVal hDC&)

' 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 x(3) As Long
Var Shared y(3) As Long

'================================================================
'=
'================================================================
Declare Function Index bdecl () As Integer
Function Index()
    Index = Val(Mid$(GetDlgRadioSelect("Radio1"), 6)) -1
End Function

'================================================================
'=
'================================================================
Declare Sub Button1_on edecl ()
Sub Button1_on()
    Var Ret As Long
    Var hDC As Long

    x(0) = Val(GetDlgItemText("Edit1"))                'LeftRect
    y(0) = Val(GetDlgItemText("Edit2"))                'TopRect
    x(1) = Val(GetDlgItemText("Edit3"))                'RightRect
    y(1) = Val(GetDlgItemText("Edit4"))                'BottomRect
    x(2) = Val(GetDlgItemText("Edit5"))                'xStartArc
    y(2) = Val(GetDlgItemText("Edit6"))                'yStartArc
    x(3) = Val(GetDlgItemText("Edit7"))                'xEndArc
    y(3) = Val(GetDlgItemText("Edit8"))                'yEndArc
    
    cls
    hDC = Api_GetDC(GethWnd)

    If Index = 0 Then
        Ret = Api_SetArcDirection(hDC, AD_CLOCKWISE)
    Else
        Ret = Api_SetArcDirection(hDC, AD_COUNTERCLOCKWISE)
    End If

    Line(x(0), y(0)) - (x(1), y(1)), , 5, b, Dot
    Ret = Api_ArcTo(hDC, x(0), y(0), x(1), y(1), x(2), y(2), x(3), y(3))
    SetDrawWidth 3
    Pset(x(2), y(2)),9
    Pset(x(3), y(3)),11
    SetDrawWidth 0
    Ret = Api_ReleaseDC(GethWnd, hDC)
End Sub

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