Ball soll treu dem Reflexionsgesetz an etwas abprallen.

;coded by UEZ 2009
#include <GUIConstantsEx.au3>
#include <GDIplus.au3>
#include <WindowsConstants.au3>

Global Const $width = @DesktopWidth / 2
Global Const $height = @DesktopHeight / 2

Opt("GUIOnEventMode", 1)
Global $hwnd = GUICreate("Border Collision!", $width, $height, -1, -1, Default, BitOR($WS_EX_TOPMOST, $WS_EX_TOOLWINDOW))
GUISetOnEvent($GUI_EVENT_CLOSE, "close")
GUISetState()

_GDIPlus_Startup()
Global $graphics = _GDIPlus_GraphicsCreateFromHWND($hWnd)
Global $bitmap = _GDIPlus_BitmapCreateFromGraphics($width, $height, $graphics)
Global $backbuffer = _GDIPlus_ImageGetGraphicsContext($bitmap)
_GDIPlus_GraphicsClear($backbuffer)
_GDIPlus_GraphicsSetSmoothingMode($backbuffer, 4)
Global $brush_color
Global $brush = _GDIPlus_BrushCreateSolid()
_GDIPlus_BrushSetSolidColor($brush, $brush_color)
Global $max_dots = 1
Global $max_speed = 5
Global $iWidth = 60
Global $iHeight = 60
Dim $coordinates[$max_dots][5], $angle
Dim $brush[$max_dots]
Initialize()

Do
_GDIPlus_GraphicsClear($backbuffer, 0xFF000000)
Draw_Dots()
Calculate_New_Position()
_GDIPlus_GraphicsDrawImageRect($graphics, $bitmap, 0, 0, $width, $height)
Sleep(5)
Until False

Func Initialize()
For $k = 0 To $max_dots - 1
$r = Random(64, 255, 1)
$g = Random(64, 255, 1)
$b = Random(64, 255, 1)
$brush_color = "0xAF" & Hex($r, 2) & Hex($g, 2) & Hex($b, 2)
$brush[$k] = _GDIPlus_BrushCreateSolid($brush_color)
New_Coordinates($k)
Next
EndFunc ;==>Initialize

Func Draw_Dots()
Local $i, $temp_x, $temp_y
For $i = 0 To $max_dots - 1
_GDIPlus_GraphicsFillEllipse($backbuffer, $coordinates[$i][0], $coordinates[$i][1], $iWidth, $iHeight, $brush[$i])
Next
EndFunc ;==>Draw_Dots

Func New_Coordinates($k)
$coordinates[$k][0] = $width / 2 ;Random($width / 20, $width - $width / 20, 1);start x position
$coordinates[$k][1] = $height / 2 ;Random($height / 20, $height - $height / 20, 1) ;start y position
$coordinates[$k][2] = Random(1, $max_speed, 1) ;speed of pixel
$angle = Random(0, 359, 1)
ConsoleWrite("Angle: " & $angle & "°" & @CRLF)
$coordinates[$k][3] = $coordinates[$k][2] * Cos($angle * 3.141592653 / 180)
$coordinates[$k][4] = $coordinates[$k][2] * Sin($angle * 3.141592653 / 180)
EndFunc ;==>New_Coordinates

Func Calculate_New_Position()
Local $k
For $k = 0 To $max_dots - 1
$coordinates[$k][0] += $coordinates[$k][3] ;increase x coordinate with appropriate slope
$coordinates[$k][1] += $coordinates[$k][4] ;increase y coordinate with appropriate slope
If $coordinates[$k][0] <= 0 Then ;border collision x left
$coordinates[$k][0] = 1
$coordinates[$k][3] *= -1
ElseIf $coordinates[$k][0] >= $width - $iWidth Then ;border collision x right
$coordinates[$k][0] = $width - ($iWidth + 1)
$coordinates[$k][3] *= -1
EndIf
If $coordinates[$k][1] <= 0 Then ;border collision y top
$coordinates[$k][1] = 1
$coordinates[$k][4] *= -1
ElseIf $coordinates[$k][1] >= $height - $iHeight Then ;border collision y bottom
$coordinates[$k][1] = $height - ($iHeight + 1)
$coordinates[$k][4] *= -1
EndIf
Next
EndFunc ;==>Calculate_New_Position

Func close()
_GDIPlus_BrushDispose($brush)
_GDIPlus_BitmapDispose($bitmap)
_GDIPlus_GraphicsDispose($graphics)
_GDIPlus_GraphicsDispose($backbuffer)
_GDIPlus_Shutdown()
Exit
EndFunc ;==>close

Func _GDIPlus_BrushSetSolidColor($hBrush, $iARGB = 0xFF000000)
Local $aResult
$aResult = DllCall($ghGDIPDll, "int", "GdipSetSolidFillColor", "hwnd", $hBrush, "int", $iARGB)
If @error Then Return SetError(@error, @extended, 0)
Return SetError($aResult[0], 0, $aResult[0] = 0)
EndFunc ;==>_GDIPlus_BrushSetSolidColor