Make the line thinner than 1 in GDI plus

[topten]

I have a ine drawn with GDI

_GDIPlus_PenSetColor($g_hPen, 0xE5FFFFFF) ;set pen color for inner lines
 _GDIPlus_PenSetWidth($g_hPen, 1) ;set pen size for outer lines
_GDIPlus_GraphicsDrawLine($g_hGfxCtxt, 730,0, 730, 400, $g_hPen)
_WinAPI_BitBlt($g_hDC, 0, 0, $iWidth, $iHeight, $g_hDC_Backbuffer, 0, 0, $SRCCOPY)

I find this line thick, but even if I set the thickness

_GDIPlus_PenSetWidth($g_hPen, 0.1)

nothing changes and the line stays as thick as it was before. Is there any possibility to reduce line thickness?

[UEZ]

Afaik there is no possibility to draw less than 1 pixel dimension. How should this be displayed?

Might be an issue with anti aliasing that the line looks taller than 1 pixel.

[JohnOne]

Or a crappy monitor.

[topten]

Or a crappy monitor.

I attach the image to show what I mean (I am not speaking about dotted line- just only the thickness of it)

[JohnOne]

Looks like some sort of smoothing is going on because of the inclination of the line.

[JohnOne]

When creating the pen try 2 in third parameter.

[UEZ]

As mentioned in my previous post anti aliasing (smoothness) is enabled (_GDIPlus_GraphicsSetSmoothingMode).

Disabled it and you will see the difference.

[topten]

You are right, JohnOne

I have smoothing mode switched on

$g_hGUI = GUICreate("GDI+ Example (" & @ScriptName & ")", $iWidth, $iHeight) ;create a test GUI
    GUISetBkColor($iBgColor, $g_hGUI) ;set GUI background color
    GUISetState(@SW_SHOW)

    ;create a faster buffered graphics frame set for smoother gfx object movements
    Local $hBitmap = _GDIPlus_BitmapCreateFromScan0($iWidth, $iHeight) ;create an empty bitmap
    $g_hHBITMAP = _GDIPlus_BitmapCreateHBITMAPFromBitmap($hBitmap) ;convert GDI+ bitmap to GDI bitmap
    _GDIPlus_BitmapDispose($hBitmap) ;delete GDI+ bitmap because not needed anymore

    $g_hDC = _WinAPI_GetDC($g_hGUI) ;get device context from GUI
    $g_hDC_Backbuffer = _WinAPI_CreateCompatibleDC($g_hDC) ;creates a memory device context compatible with the specified device
    $g_oDC_Obj = _WinAPI_SelectObject($g_hDC_Backbuffer, $g_hHBITMAP) ;selects an object into the specified device context
 Global   $g_hGfxCtxt = _GDIPlus_GraphicsCreateFromHDC($g_hDC_Backbuffer) ;create a graphics object from a device context (DC)
    _GDIPlus_GraphicsSetSmoothingMode($g_hGfxCtxt, $GDIP_SMOOTHINGMODE_HIGHQUALITY) ;set smoothing mode (8 X 4 box filter)
   _GDIPlus_GraphicsSetPixelOffsetMode($g_hGfxCtxt, $GDIP_PIXELOFFSETMODE_HIGHQUALITY)

Does it mean that if I switch off smoothing mode- the static part will become thin, but  the dynamic part will be not so smooth though

[topten]

Yes, UEZ,  I have disabled it- the line looks a bit thinner now. Thanx!

 

JohnOne, which parameter do you mean?

$g_hPen = _GDIPlus_PenCreate() ;create a pen object

or something different? Didnt get it

[JohnOne]

I meant _GDIPlus_PenCreate(whatever, whatever, 2) ; the unit is a pixel

Don't suppose it matters now, UEZ is in, he is the Emperor of GDI

[UEZ]

In the help file there is an example which shows both mode -> _GDIPlus_GraphicsSetSmoothingMode.

 

Btw, a horizontal / vertical line looks thinner than a diagonal line at smaller pen width sizes when smoothing (anti aliasing) is activated.

Edited November 3, 2015 by UEZ

[topten]

Great thanx, people, its really helpfull