计算机图形学课程作业-----画圆
Public Class Form1
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim G As Graphics = PictureBox1.CreateGraphics()
Dim Br As SolidBrush = New SolidBrush(Color.Blue)
Dim x0, y0, r, x, y As Integer
Dim d As Integer
d = 3 - 2 * r
x0 = Val(TextBox1.Text) : y0 = Val(TextBox2.Text) : r = Val(TextBox3.Text)
x = 0 : y = r
Do While x <= y
G.FillRectangle(Br, x0 + x, y0 + y, 1, 1)
G.FillRectangle(Br, x0 + y, y0 + x, 1, 1)
G.FillRectangle(Br, x0 - x, y0 - y, 1, 1)
G.FillRectangle(Br, x0 - y, y0 - x, 1, 1)
G.FillRectangle(Br, x0 - x, y0 + y, 1, 1)
G.FillRectangle(Br, x0 - y, y0 + x, 1, 1)
G.FillRectangle(Br, x0 + x, y0 - y, 1, 1)
G.FillRectangle(Br, x0 + y, y0 - x, 1, 1)
If d < 0 Then
d = d + 4 * x + 6
Else
d = d + 4 * (x - y) + 10
y = y - 1
End If
x = x + 1
End Sub
Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
Me.Refresh()
End Sub
Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
End
End Sub
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
TextBox1.Text = 150 : TextBox2.Text = 200 : TextBox3.Text = 100
End Sub
End Class