How to rotate an image on key press in vb.net - vb.net

Question

I am making a lunar lander game, and want the spaceship to rotate when the left and right arrow keys are pressed.
I know how to move an image using a picture box and the keydown event, but there isn't anyway to directly rotate a picture box. Do i need to use the image a different way to be able to achieve what I want? Any help is much appreciated.

Answer 1

Make a new class inheriting from picturebox. Use that. You can edit the designer.vb to change the type.
This is pseudocode, untested, so it certainly won't run.
class RotateablePictureBox
inherits picturebox
public property RotationAngle as single
overrides onpaint(e as ...)
e.graphics.rotatetransform(rotationangle)
mybase.onpaint(e)
That's the idea that Hans Passant is talking about (might have to do the DrawImage yourself too and skip the mybase.onpaint - it's done like e.graphics.onpaint(TheImage,dimensions etc...))

Answer 2

This is my first time posting code so let me know how I can improve it for the group. I developed this class using code from http://www.devasp.net/net/articles/display/391.htmlenter code here
I hope this helps. This is the button code
Private Sub btnRotateLeft_Click(sender As Object, e As EventArgs) Handles btnRotateLeft.Click
' IMAGE IS THE NEW OBJECT FROM THE CLASS. PASS THE PICTUREBOX CONTROL(pbItems)
image.RotateLeft(pbItems)
End Sub
This is the class
Imports System.Math
Public Class clsImage
Private wid As Single
Private hgt As Single
Public Function RotateLeft(ByVal picSource As PictureBox) As PictureBox
'ROTATES THE IMAGE LEFT
Dim bm_in = New Bitmap(picSource.Image)
wid = bm_in.Width
hgt = bm_in.Height
Dim corners As Point() = {New Point(0, 0), New Point(wid, 0), New Point(0, hgt), New Point(wid, hgt)}
Dim cx As Single = wid / 2
Dim cy As Single = hgt / 2
Dim i As Long
'ROTATES LEFT
For i = 0 To 3
corners(i).X -= cx
corners(i).Y -= cy
Next i
'THE ROTATION ANGLE IS HARD CODED HERE BUT COULD BE PASS TO THE CLASS
Dim theta As Single = Single.Parse(90) * PI / 180.0
Dim sin_theta As Single = Sin(theta)
Dim cos_theta As Single = Cos(theta)
Dim X As Single
Dim Y As Single
For i = 0 To 3
X = corners(i).X
Y = corners(i).Y
corners(i).X = X * cos_theta + Y * sin_theta
corners(i).Y = -X * sin_theta + Y * cos_theta
Next i
Dim xmin As Single = corners(0).X
Dim ymin As Single = corners(0).Y
For i = 1 To 3
If xmin > corners(i).X Then xmin = corners(i).X
If ymin > corners(i).Y Then ymin = corners(i).Y
Next i
For i = 0 To 3
corners(i).X -= xmin
corners(i).Y -= ymin
Next i
Dim bm_out As New Bitmap(CInt(-2 * xmin), CInt(-2 * ymin))
Dim gr_out As Graphics = Graphics.FromImage(bm_out)
ReDim Preserve corners(2)
gr_out.DrawImage(bm_in, corners)
picSource.Image = bm_out
Return picSource
End Function
Public Function RotateRight(ByVal picSource As PictureBox) As PictureBox
'ROTATES THE IMAGE RIGHT
Dim bm_in = New Bitmap(picSource.Image)
wid = bm_in.Width
hgt = bm_in.Height
Dim corners As Point() = {New Point(0, 0), New Point(wid, 0), New Point(0, hgt), New Point(wid, hgt)}
Dim cx As Single = wid / 2
Dim cy As Single = hgt / 2
Dim i As Long
'ROTATES RIGHT
For i = 0 To 3
corners(i).X -= cx
corners(i).Y -= cy
Next i
'THE ROTATION ANGLE IS HARD CODED HERE BUT COULD BE PASS TO THE CLASS
Dim theta As Single = Single.Parse(-90) * PI / 180.0
Dim sin_theta As Single = Sin(theta)
Dim cos_theta As Single = Cos(theta)
Dim X As Single
Dim Y As Single
For i = 0 To 3
X = corners(i).X
Y = corners(i).Y
corners(i).X = X * cos_theta + Y * sin_theta
corners(i).Y = -X * sin_theta + Y * cos_theta
Next i
Dim xmin As Single = corners(0).X
Dim ymin As Single = corners(0).Y
For i = 1 To 3
If xmin > corners(i).X Then xmin = corners(i).X
If ymin > corners(i).Y Then ymin = corners(i).Y
Next i
For i = 0 To 3
corners(i).X -= xmin
corners(i).Y -= ymin
Next i
Dim bm_out As New Bitmap(CInt(-2 * xmin), CInt(-2 * ymin))
Dim gr_out As Graphics = Graphics.FromImage(bm_out)
ReDim Preserve corners(2)
gr_out.DrawImage(bm_in, corners)
picSource.Image = bm_out
Return picSource
End Function
End Class