GDI + Zooming?

[pWnd711]

Hey Guys i have a question.

I draw a Picture and its possible to zoom into the image? 

Thanks to all

[UEZ]

3 hours ago, pWnd711 said:

I draw a Picture and its possible to zoom into the image? 

Yes, it is.

[pWnd711]

Can you explain me? 

[UEZ]

Here an example code which you can analyze. There are more ways to zoom an image, this is one of them:

#include <GDIPlus.au3>
#include <GUIConstantsEx.au3>

Global $sImage = FileOpenDialog("Select an image", "", "Images (*.jpg;*.png;*.bmp;*.gif;*.tif)")
If @error Then Exit MsgBox(16, "Error", "No file selected!", 10)

Global $fZoom = 2.5
_GDIPlus_Startup()
Global $hImage = _GDIPlus_ImageLoadFromFile($sImage)
Global $aDim = _GDIPlus_ImageGetDimension($hImage)
Global $hGUI = GUICreate("GDI+ Image Zoom", $aDim[0], $aDim[1])
GUISetState()
Global $hCanvas = _GDIPlus_GraphicsCreateFromHWND($hGUI)
_GDIPlus_GraphicsSetInterpolationMode($hCanvas, $GDIP_INTERPOLATIONMODE_NearestNeighbor)
_GDIPlus_GraphicsDrawImageRectRect($hCanvas, $hImage, 0, 0, $aDim[0], $aDim[1], _
                                                                                                    ($aDim[0] - $aDim[0] * $fZoom) / 2, ($aDim[1] - $aDim[1] * $fZoom) / 2, _
                                                                                                    $aDim[0] * $fZoom, $aDim[1] * $fZoom)

Do
Until GUIGetMsg() = $GUI_EVENT_CLOSE

_GDIPlus_GraphicsDispose($hCanvas)
_GDIPlus_ImageDispose($hImage)
_GDIPlus_Shutdown()

It will zoom the image by factor 2.5 and center the display.

[pWnd711]

Yes this freeze the Image but i want to zoom in with mouse scrolling and hold right mouse button to navigate on the image 🙂 Can you explain too? I have seen this method already but its freeze the image but i want to move the image to see the rest of the image to by holding rmb and move it

y

[UEZ]

This is an old script which I coded a while ago.

expandcollapse popup

#include <GUIConstantsEx.au3>
#include <Misc.au3>
#include <Screencapture.au3>
#include <WindowsConstants.au3>

Global $sx, $z = 10, $sy, $mc2, $f, $scroll_x, $scroll_y
Global Const $gdip_x = 0, $gdip_y = 0, $zmin = 5, $zmax = 15, $bg_c = "404040"
Global Const $gdip_w = 800, $gdip_h = 600
Global $bW = $gdip_w, $bH = $gdip_h
Global Const $hGUI = GUICreate("GDI+ Test", $gdip_w, $gdip_h)
GUISetState()

Global Const $dll = DllOpen("user32.dll")
_GDIPlus_Startup()
Global Const $hGraphic = _GDIPlus_GraphicsCreateFromHWND($hGUI)
Global Const $hBuffer_Bmp = _GDIPlus_BitmapCreateFromGraphics($gdip_w, $gdip_h, $hGraphic)
Global Const $hContext = _GDIPlus_ImageGetGraphicsContext($hBuffer_Bmp)
_GDIPlus_GraphicsSetPixelOffsetMode($hContext, 2)
;~ _GDIPlus_GraphicsSetCompositingQuality($hContext, 2)
_GDIPlus_GraphicsSetInterpolationMode($hContext, 5)

Global $hMatrix = _GDIPlus_MatrixCreate()
_GDIPlus_MatrixTranslate($hMatrix, $gdip_w / 2, $gdip_h / 2)

Global Const $hHBitmap = _ScreenCapture_Capture("", 0, 0, $gdip_w, $gdip_h)
Global Const $hBmp = _GDIPlus_BitmapCreateFromHBITMAP($hHBitmap)


Draw2Graphic($hBmp)
Zoom(2)

GUIRegisterMsg($WM_MOUSEWHEEL, "_Mousewheel")

Do
    $mc2 = MouseGetPos()
    While _IsPressed("01", $dll)
        $mc3 = MouseGetPos()
        If $mc2[0] <> $mc3[0] Or $mc2[1] <> $mc3[1] Then
            $scroll_x = ($sx + ($mc3[0] - $mc2[0]) / ($z ^ 2 / 32))
            $scroll_y = ($sy + ($mc3[1] - $mc2[1]) / ($z ^ 2 / 32))
            Draw2Graphic($hBmp)
            Zoom(2)
        EndIf
        Sleep(10)
    WEnd
    $sx = $scroll_x
    $sy = $scroll_y
Until GUIGetMsg() = $GUI_EVENT_CLOSE

_GDIPlus_MatrixDispose($hMatrix)
_WinAPI_DeleteObject($hHBitmap)
_GDIPlus_GraphicsDispose($hGraphic)
_GDIPlus_GraphicsDispose($hContext)
_GDIPlus_BitmapDispose($hBuffer_Bmp)
_GDIPlus_BitmapDispose($hBmp)
_GDIPlus_Shutdown()
GUIDelete()
DllClose($dll)
Exit

Func Draw2Graphic($hImage)
    Local $w, $h
    _GDIPlus_GraphicsClear($hContext, "0xFF" & $bg_c)
    If $bW <= $gdip_w And $bH <= $gdip_h Then
        $f = 1
        _GDIPlus_GraphicsDrawImageRect($hContext, $hImage, $gdip_w / 2 - $bW / 2 - $scroll_x, $gdip_h / 2 - $bH / 2 - $scroll_y, $bW, $bH)
    Else
        If $bW >= $bH Then
            $f = $bW / $gdip_w
        Else
            $f = $bH / $gdip_h
        EndIf
        $w = Floor($bW / $f)
        $h = Floor($bH / $f)
        If $w > $gdip_w Then
            $f = $bW / $gdip_w
        ElseIf $h > $gdip_h Then
            $f = $bH / $gdip_h
        EndIf
        _GDIPlus_GraphicsDrawImageRect($hContext, $hImage, $gdip_w / 2 - $w / 2 - $scroll_x, $gdip_h / 2 - $h / 2 - $scroll_y, $w, $h)
    EndIf
EndFunc   ;==>Draw2Graphic

Func Zoom($zoom_dir)
    Switch $zoom_dir
        Case -1
            _GDIPlus_MatrixDispose($hMatrix)
            $hMatrix = _GDIPlus_MatrixCreate()
            _GDIPlus_MatrixTranslate($hMatrix, $gdip_w / 2, $gdip_h / 2)
            _GDIPlus_MatrixScale($hMatrix, 1 / $f, 1 / $f)
            $scroll_x = 0
            $scroll_y = 0
        Case 0
            If $z > $zmin Then
                _GDIPlus_MatrixScale($hMatrix, 0.95, 0.95)
                $z -= 0.05
            EndIf
        Case 1
            If $z <= $zmax Then
                _GDIPlus_MatrixScale($hMatrix, 1.05, 1.05)
                $z += 0.05
            EndIf
        Case 2
            _GDIPlus_MatrixScale($hMatrix, 1, 1)
    EndSwitch
    _GDIPlus_GraphicsSetTransform($hContext, $hMatrix)
    _GDIPlus_GraphicsClear($hContext, "0xFF" & $bg_c)
;~  _GDIPlus_GraphicsDrawImage($hContext, $hBmp, -$bW / 2 + $scroll_x, -$bH / 2 + $scroll_y)
    _GDIPlus_GraphicsDrawImageRect($hContext, $hBmp, -$bW / 2 + $scroll_x, -$bH / 2 + $scroll_y, $gdip_w, $gdip_h)
    _GDIPlus_GraphicsDrawImageRect($hGraphic, $hBuffer_Bmp, $gdip_x, $gdip_y, $gdip_w, $gdip_h)
EndFunc   ;==>Zoom

Func _Mousewheel($hWnd, $iMsg, $wParam, $lParam)
    Switch $wParam
        Case 0xFF880000 ;mouse wheel up
            Zoom(0)
            Return 0
        Case 0x00780000
            Zoom(1)
            Return 0
    EndSwitch
    Return $GUI_RUNDEFMSG
EndFunc   ;==>_Mousewheel

Zoom with mouse wheel, move picture around by pressing the lmb and moving mouse.

Edited July 7, 2020 by UEZ

[pWnd711]

perfect thanks to you!