Could someone please help with this Rotating RECT [Resolved]

[Electroman]

Can someone please help me with the code below? I'm trying to rotate a RECT structure (Sprite(iSpriteIndex1).dstRect) and then create a new RECT (S1) that will be just the right size to contain the rotated RECT. I thought I had it but I'm getting some strange results and I can't figure out why.

Dim Angle As Single
Dim XCenter As Single
Dim YCenter As Single
Dim BL As POINTAPI
Dim TL As POINTAPI
Dim BR As POINTAPI
Dim TR As POINTAPI
 
 
If Sprite(iSpriteIndex1).Angle = 0 Then
    S1 = Sprite(iSpriteIndex1).dstRect
Else
    TempRect = Sprite(iSpriteIndex1).dstRect
    XCenter = TempRect.Left + ((TempRect.Right - TempRect.Left - 1) / 2)
    YCenter = TempRect.Top + ((TempRect.Bottom - TempRect.Top - 1) / 2)
    Angle = Sprite(iSpriteIndex1).Angle + (Pi / 2)
    If Angle >= 2 * Pi Then Angle = Angle - ((2 * Pi) * CInt(Angle / (2 * Pi)))
    If Angle < 4.714 And Angle > 4.71 Then
        Angle = 3 * Pi / 2
    ElseIf Angle < 3.143 And Angle > 3.14 Then
        Angle = Pi
    ElseIf Angle < 6.284 And Angle > 6.282 Then
        Angle = 2 * Pi
    End If
    
    'Bottom Left
    BL.x = XCenter + (TempRect.Left - XCenter) * Sin(Angle) + (TempRect.Bottom - YCenter) * Cos(Angle)
    BL.y = YCenter + (TempRect.Bottom - YCenter) * Sin(Angle) - (TempRect.Left - XCenter) * Cos(Angle)
    'Top Left
    TL.x = XCenter + (TempRect.Left - XCenter) * Sin(Angle) + (TempRect.Top - YCenter) * Cos(Angle)
    TL.y = YCenter + (TempRect.Top - YCenter) * Sin(Angle) - (TempRect.Left - XCenter) * Cos(Angle)
 
    'Bottom Right
    BR.x = XCenter + (TempRect.Right - XCenter) * Sin(Angle) + (TempRect.Bottom - YCenter) * Cos(Angle)
    BR.y = YCenter + (TempRect.Bottom - YCenter) * Sin(Angle) - (TempRect.Right - XCenter) * Cos(Angle)
    'Top Right
    TR.x = XCenter + (TempRect.Right - XCenter) * Sin(Angle) + (TempRect.Top - YCenter) * Cos(Angle)
    TR.y = YCenter + (TempRect.Top - YCenter) * Sin(Angle) - (TempRect.Right - XCenter) * Cos(Angle)
    'Set S1...
    SetRect R1, TL.x, TL.y, BL.x, BL.y
    SetRect R2, BL.x, BL.y, BR.x, BR.y
    SetRect R3, BR.x, BR.y, TR.x, TR.y
    SetRect R4, TR.x, TR.y, TL.x, TL.y
    UnionRect S1, R1, R2
    UnionRect S1, R3, S1
    UnionRect S1, R4, S1
    'S1 is now the RECT for the area needed to paint the first sprite
End If

I'd greatly appreciate any help anyone has.

[Electroman]

I sorted it out with this code instead:

If Sprite(iSpriteIndex1).Angle = 0 Then
    S1 = Sprite(iSpriteIndex1).dstRect
Else
    TempRect = Sprite(iSpriteIndex1).dstRect
    XCenter = TempRect.Left + ((TempRect.Right - TempRect.Left - 1) / 2)
    YCenter = TempRect.Top + ((TempRect.Bottom - TempRect.Top - 1) / 2)
    Angle = Sprite(iSpriteIndex1).Angle + (Pi / 2)
    If Angle >= 2 * Pi Then Angle = Angle - ((2 * Pi) * CInt(Angle / (2 * Pi)))
    If Angle < 4.714 And Angle > 4.71 Then
        Angle = 3 * Pi / 2
    ElseIf Angle < 3.143 And Angle > 3.14 Then
        Angle = Pi
    ElseIf Angle < 6.284 And Angle > 6.282 Then
        Angle = 2 * Pi
    End If
    
    'Bottom Left
    BL.x = XCenter + (TempRect.Left - XCenter) * Sin(Angle) + (TempRect.Bottom - YCenter) * Cos(Angle)
    BL.y = YCenter + (TempRect.Bottom - YCenter) * Sin(Angle) - (TempRect.Left - XCenter) * Cos(Angle)
    'Top Left
    TL.x = XCenter + (TempRect.Left - XCenter) * Sin(Angle) + (TempRect.Top - YCenter) * Cos(Angle)
    TL.y = YCenter + (TempRect.Top - YCenter) * Sin(Angle) - (TempRect.Left - XCenter) * Cos(Angle)
    'Bottom Right
    BR.x = XCenter + (TempRect.Right - XCenter) * Sin(Angle) + (TempRect.Bottom - YCenter) * Cos(Angle)
    BR.y = YCenter + (TempRect.Bottom - YCenter) * Sin(Angle) - (TempRect.Right - XCenter) * Cos(Angle)
    'Top Right
    TR.x = XCenter + (TempRect.Right - XCenter) * Sin(Angle) + (TempRect.Top - YCenter) * Cos(Angle)
    TR.y = YCenter + (TempRect.Top - YCenter) * Sin(Angle) - (TempRect.Right - XCenter) * Cos(Angle)
    'Set S1...
    'R1 is made from TL and BR...
    If TL.y < BR.y Then
        R1.Top = TL.y
        R1.Bottom = BR.y
    Else
        R1.Top = BR.y
        R1.Bottom = TL.y
    End If
    If TL.x < BR.x Then
        R1.Left = TL.x
        R1.Right = BR.x
    Else
        R1.Left = BR.x
        R1.Right = TL.x
    End If
    
    'R2 is made from BL and TR...
    If TR.y < BL.y Then
        R2.Top = TR.y
        R2.Bottom = BL.y
    Else
        R2.Top = BL.y
        R2.Bottom = TR.y
    End If
    If BL.x < TR.x Then
        R2.Left = BL.x
        R2.Right = TR.x
    Else
        R2.Left = TR.x
        R2.Right = BL.x
    End If
    
    'S1 is made from R1 and R2...
    If R1.Top < R2.Top Then
        S1.Top = R1.Top
    Else
        S1.Top = R2.Top
    End If
    
    If R1.Left < R2.Left Then
        S1.Left = R1.Left
    Else
        S1.Left = R2.Left
    End If
    
    If R1.Bottom > R2.Bottom Then
        S1.Bottom = R1.Bottom
    Else
        S1.Bottom = R2.Bottom
    End If
    
    If R1.Right > R2.Right Then
        S1.Right = R1.Right
    Else
        S1.Right = R2.Right
    End If
    
    'S1 is now the RECT for the area needed to paint the first sprite
End If

It seems it was something to do with the fact that Left was sometimes greater than Right and when that happens the Union API doesn't work all that well. Well the main thing this is part of is still throwing errors out so looks like I still got quite a bit of work left on it.