module1.bas

VB开发的不错的旋转位图程序

Attribute VB_Name = "Module1"
Option Explicit
Private Declare Function SetPixel Lib "GDI32" (ByVal hDC As Integer, ByVal X As Integer, ByVal Y As Integer, ByVal crColor As Long) As Long
Private Declare Function GetPixel Lib "GDI32" (ByVal hDC As Integer, ByVal X As Integer, ByVal Y As Integer) As Long
Global Const Pi = 3.14159265359
Global abc As Double

Sub bmp_rotate(pic1 As PictureBox, pic2 As PictureBox, ByVal theta!) '自定义旋转位图函数
Dim c1x, c1y, c2x, c2y, p1x, p1y, p2x, p2y, n, r, pic1hDC, pic2hDC As Integer
Dim a As Single
Dim t, c0, c1, c2, c3, xret
c1x = pic1.ScaleWidth \ 2
c1y = pic1.ScaleHeight \ 2
c2x = pic2.ScaleWidth \ 2
c2y = pic2.ScaleHeight \ 2
If c2x < c2y Then n = c2y Else n = c2x
n = n - 1
pic1hDC = pic1.hDC
pic2hDC = pic2.hDC
For p2x = 0 To n
For p2y = 0 To n
If p2x = 0 Then a = Pi / 2 Else a = Atn(p2y / p2x)
r = Sqr(1& * p2x * p2x + 1& * p2y * p2y)
p1x = r * Cos(a + theta!)
p1y = r * Sin(a + theta!)
c0 = GetPixel(pic1hDC, c1x + p1x, c1y + p1y)
c1 = GetPixel(pic1hDC, c1x - p1x, c1y - p1y)
c2 = GetPixel(pic1hDC, c1x + p1y, c1y - p1x)
c3 = GetPixel(pic1hDC, c1x - p1y, c1y + p1x)
If c0 <> -1 Then xret = SetPixel(pic2hDC, c2x + p2x, c2y + p2y, c0)
If c1 <> -1 Then xret = SetPixel(pic2hDC, c2x - p2x, c2y - p2y, c1)
If c2 <> -1 Then xret = SetPixel(pic2hDC, c2x + p2y, c2y - p2x, c2)
If c3 <> -1 Then xret = SetPixel(pic2hDC, c2x - p2y, c2y + p2x, c3)
Next
t = DoEvents()
Next
End Sub