About Trigonometry

[Jex]

If i know x , y, ( blue dot ) angle and length can i find x2 and y2 ( green dot ) for create line ? ( I know that question answer is yes but how ? )

Example i know blue dot x : 150 y : 200 and green dot angle 45 and that line length ( hip ) 100.

I'm tried that but not work

#include <GuiConstantsEx.au3>
#include <GDIPlus.au3>

$hGUI = GUICreate("GDI+", 500, 500)
$hWnd = WinGetHandle("GDI+")
GUISetState()
_GDIPlus_Startup()
$hGraphic = _GDIPlus_GraphicsCreateFromHWND($hWnd)
$hPen = _GDIPlus_PenCreate()
Global $x = 150, $y = 200
$Deg = Angle($x, $y, 35, 100)
_GDIPlus_GraphicsDrawLine($hGraphic, $x, $y, $Deg[1], $Deg[2], $hPen)
Do
Until GUIGetMsg() = $GUI_EVENT_CLOSE
_GDIPlus_PenDispose($hPen)
_GDIPlus_GraphicsDispose($hGraphic)
_GDIPlus_Shutdown()

Func Angle($x1, $y1, $Ang, $Length)
    Local $Return[3]
    $Return[1] = $x1 + ($Length * Sin($Ang / 180 * 3.14159265358979))
    $Return[2] = $y1 + ($Length * Cos($Ang / 180 * 3.14159265358979))
    Return $Return
EndFunc   ;==>Angle

I think my angle function completely wrong but i can't figure out how can i do

Edited January 14, 2008 by Jex

[JerryD]

Sorry, I don't have an immediate answer for you, but two things.

First, in your example above don't you want line 12 to be "$Deg = Angle($x, $y, 45, 100)" ?

Second, for your test run, why not use a 30/60/90 triangle with a hypotenuse of 50 and an angle of either 30 or 60 - then you know the X measurement (either 3 or 4) and the Y measurement (3 or 4)?

[weaponx]

You can check your answers here if you are unsure:

http://www.webmath.com/rtri.html

I don't think you can use sin for the X value.

Angle = 60 degrees

Length = 100 px

100 sin 60 = 86.6 <--- Wrong. This is the Y value

Check out this example I put together:

expandcollapse popup

#include <GUIConstants.au3>

Dim $GuiSize = 400
Dim $lineSize = 100
Dim $GuiCenter = $GuiSize / 2

GUICreate("My GUI", $GuiSize, $GuiSize)  ; will create a dialog box that when displayed is centered

$sandBox = GUICtrlCreateGraphic (0, 0, $GuiSize, $GuiSize)

;Draw centered circle with radius = line length
GUICtrlSetGraphic(-1,$GUI_GR_COLOR, 0x000000)
GUICtrlSetGraphic(-1,$GUI_GR_ELLIPSE, $GuiCenter - $lineSize, $GuiCenter - $lineSize, $lineSize * 2, $lineSize * 2)

;Draw line at 0 degrees (from GUI center)
drawLine(0)

;Draw line at 30 degrees (from GUI center)
drawLine(30)

;Draw line at 90 degrees (from GUI center)
drawLine(90)

;Draw line at 180 degrees (from GUI center)
drawLine(180)

GUISetState (@SW_SHOW)

; Run the GUI until the dialog is closed
While 1
    $msg = GUIGetMsg()
    If $msg = $GUI_EVENT_CLOSE Then ExitLoop
    Wend
    
Func Angle($x1, $y1, $Ang, $Length)
    Local $Return[2]
    $Return[0] = $x1 + ($Length * Cos($Ang / 180 * 3.14159265358979))
    $Return[1] = $y1 - ($Length * Sin($Ang / 180 * 3.14159265358979))
    Return $Return
EndFunc   ;==>Angle

Func drawLine($angle)
    $Deg = Angle($GuiCenter, $GuiCenter, $angle, $lineSize)
    GUICtrlSetGraphic(-1,$GUI_GR_MOVE, $GuiCenter,$GuiCenter)
    GUICtrlSetGraphic(-1,$GUI_GR_LINE, $Deg[0],$Deg[1])
EndFunc

Edited January 14, 2008 by weaponx

[weaponx]

Here is the fixed version of your code. I made a few changes so that the line is drawn from the center of the gui, this makes it easier to verify that it is correct.

#include <GuiConstantsEx.au3>
#include <GDIPlus.au3>

Dim $GuiSize = 500
Global $x = $GuiSize / 2, $y = $GuiSize / 2

$hGUI = GUICreate("GDI+", $GuiSize, $GuiSize)
$hWnd = WinGetHandle("GDI+")
GUISetState()
_GDIPlus_Startup()
$hGraphic = _GDIPlus_GraphicsCreateFromHWND($hWnd)
$hPen = _GDIPlus_PenCreate()

;Draw 30 degree angle
$Deg = Angle($x, $y, 30, 100)
_GDIPlus_GraphicsDrawLine($hGraphic, $x, $y, $Deg[1], $Deg[2], $hPen)

Do
Until GUIGetMsg() = $GUI_EVENT_CLOSE

_GDIPlus_PenDispose($hPen)
_GDIPlus_GraphicsDispose($hGraphic)
_GDIPlus_Shutdown()

Func Angle($x1, $y1, $Ang, $Length)
    Local $Return[3]
    $Return[1] = $x1 + ($Length * Cos($Ang / 180 * 3.14159265358979))
    $Return[2] = $y1 - ($Length * Sin($Ang / 180 * 3.14159265358979))
    Return $Return
EndFunc   ;==>Angle

[Jex]

Very thanks for your help weaponx.

I'm tried create more simple example :

#include <GUIConstants.au3>

Dim $GuiSize = 400, $LineSize = 150, $GuiCenter = $GuiSize / 2

GUICreate("GUI", $GuiSize, $GuiSize)
GUICtrlCreateGraphic(0, 0, $GuiSize, $GuiSize)
GUICtrlSetGraphic(-1, $GUI_GR_ELLIPSE, $GuiCenter - $LineSize, $GuiCenter - $LineSize, $LineSize * 2, $LineSize * 2)

For $i = 1 To 72
    DrawLine($GuiCenter, $GuiCenter, $i * 5, $LineSize)
Next

GUISetState()

Do
Until GUIGetMsg() = -3

Func DrawLine($x1, $y1, $Angle, $Length)
    $x2 = $x1 + ($Length * Cos($Angle / 180 * 3.14159265358979))
    $y2 = $y1 - ($Length * Sin($Angle / 180 * 3.14159265358979))
    GUICtrlSetGraphic(-1, $GUI_GR_MOVE, $x1, $y1)
    GUICtrlSetGraphic(-1, $GUI_GR_LINE, $x2, $y2)
EndFunc   ;==>DrawLine