前两讲,讲了图像的相关内容,图像相关还有很多,比如多帧图像,这在我以前的GIF相关源码中已经有例子了,对于TIFF的多帧图像我没有TIFF图像,所以也不懂
对于图像方面还有很多,我也不清楚,用到再研究了
本讲,我想讲一下GDI+特有的 ALPHA通道(透明度)
GDI+的颜色是ARGB格式,A就是指alpha透明度,0为全透明,255指不透明
那是否设置了就是透明了呢?透明到哪层呢?
_GDIPlus_GraphicsSetCompositingMode($hGraphics, $iCompositionMode)
$iCompositionMode = 0,指合成模式--指同一个画布上,同一个地方,上层的能通过通明度看到下一层
$iCompositionMode = 1,指覆盖模式--指同一个画布上,同一个地方,上层直接穿过下层,相当于在这个位置没有下层的内容
这个还是用例子来看效果吧
#include <APIConstants.au3>
#include <WinAPIEx.au3>
#include <GDIPlus.au3>
#include <GDIPlusEx.au3>
#include <GuiSlider.au3>
Global $alphaOfBack = 0, $alphaOfRed = 0x80, $alphaOfGreen = 0x80
GUICreate("第十七讲 GDI+混合模式透明度", 300, 300)
$nCtrlId = GUICtrlCreatePic("", 0, 0, 300, 200)
$hPicWnd = GUICtrlGetHandle($nCtrlId)
Global $rect[3][2]
init()
GUIRegisterMsg($WM_HSCROLL, "onHSCROLL")
GUISetState()
update()
While 1
$Msg = GUIGetMsg()
Switch $Msg
Case -3
ExitLoop
EndSwitch
WEnd
GUIDelete()
Exit
Func init()
GUICtrlCreateLabel("黄色透明度", 5, 205)
$rect[0][0] = GUICtrlCreateSlider(65, 205, 100)
GUICtrlSetLimit(-1, 0xFF, 0)
GUICtrlSetData(-1, $alphaOfBack)
_GUICtrlSlider_SetTicFreq(-1, 16)
$rect[0][1] = GUICtrlCreateLabel("", 175, 205, 40, 25)
GUICtrlSetData(-1, $alphaOfBack)
GUICtrlCreateLabel("红色透明度", 5, 235)
$rect[1][0] = GUICtrlCreateSlider(65, 235, 100)
GUICtrlSetLimit(-1, 0xFF, 0)
GUICtrlSetData(-1, $alphaOfRed)
_GUICtrlSlider_SetTicFreq(-1, 16)
$rect[1][1] = GUICtrlCreateLabel("", 175, 235, 40, 25)
GUICtrlSetData(-1, $alphaOfRed)
GUICtrlCreateLabel("绿色透明度", 5, 265)
$rect[2][0] = GUICtrlCreateSlider(65, 265, 100)
GUICtrlSetLimit(-1, 0xFF, 0)
GUICtrlSetData(-1, $alphaOfGreen)
_GUICtrlSlider_SetTicFreq(-1, 16)
$rect[2][1] = GUICtrlCreateLabel("", 175, 265, 40, 25)
GUICtrlSetData(-1, $alphaOfGreen)
EndFunc ;==>init
Func onHSCROLL($hWnd, $iMsg, $wParam, $lParam)
Switch _WinAPI_GetDlgCtrlID($lParam)
Case $rect[0][0]
$alphaOfBack = GUICtrlRead($rect[0][0])
GUICtrlSetData($rect[0][1], $alphaOfBack)
Case $rect[1][0]
$alphaOfRed = GUICtrlRead($rect[1][0])
GUICtrlSetData($rect[1][1], $alphaOfRed)
Case $rect[2][0]
$alphaOfGreen = GUICtrlRead($rect[2][0])
GUICtrlSetData($rect[2][1], $alphaOfGreen)
EndSwitch
update()
EndFunc ;==>onHSCROLL
Func update()
Local $HWND_CX = _WinAPI_GetWindowWidth($hPicWnd)
Local $HWND_CY = _WinAPI_GetWindowHeight($hPicWnd)
_GDIPlus_Startup()
Local $hGraphics = _GDIPlus_GraphicsCreateFromHWND($hPicWnd)
Local $hBitmap = _GDIPlus_BitmapCreateFromGraphics($HWND_CX, $HWND_CY, $hGraphics)
Local $hBackbuffer = _GDIPlus_ImageGetGraphicsContext($hBitmap)
_GDIPlus_GraphicsSetSmoothingMode($hBackbuffer, 2)
DoubleDraw($hBackbuffer)
_GDIPlus_GraphicsDrawImageRect($hGraphics, $hBitmap, 0, 0, $HWND_CX, $HWND_CY)
_GDIPlus_BitmapDispose($hBitmap)
_GDIPlus_GraphicsDispose($hBackbuffer)
_GDIPlus_GraphicsDispose($hGraphics)
_GDIPlus_Shutdown()
EndFunc ;==>update
Func DoubleDraw($hGraphics)
Local $hBitmap
BackColor($hGraphics);绘制背景竖条纹
;~ ;========================生成混合模式为合成的图片,并与背景竖条纹分别用合成和覆盖方式,在左侧显示===================================================
$hBitmap = myImage($hGraphics, 0)
_GDIPlus_GraphicsDrawImageRect($hGraphics, $hBitmap, 0, 0, 100, 80)
_GraphicsDrawString($hGraphics, "图片合成背景", 5, 80)
_GDIPlus_GraphicsTranslateTransform($hGraphics, 0, 100)
_GDIPlus_GraphicsSetCompositingMode($hGraphics, 1)
_GDIPlus_GraphicsDrawImageRect($hGraphics, $hBitmap, 0, 0, 100, 80)
_GraphicsDrawString($hGraphics, "图片覆盖背景", 5, 80)
_GDIPlus_BitmapDispose($hBitmap)
;~ ;========================左侧显示结束===================================================
;~ ;========================生成混合模式为覆盖的图片,并与背景竖条纹分别用合成和覆盖方式,在右侧显示===================================================
$hBitmap = myImage($hGraphics, 1)
_GDIPlus_GraphicsResetTransform($hGraphics)
_GDIPlus_GraphicsTranslateTransform($hGraphics, 150, 0)
_GDIPlus_GraphicsSetCompositingMode($hGraphics, 0)
_GDIPlus_GraphicsDrawImageRect($hGraphics, $hBitmap, 0, 0, 100, 80)
_GraphicsDrawString($hGraphics, "图片合成背景", 5, 80)
_GDIPlus_GraphicsTranslateTransform($hGraphics, 0, 100)
_GDIPlus_GraphicsSetCompositingMode($hGraphics, 1)
_GDIPlus_GraphicsDrawImageRect($hGraphics, $hBitmap, 0, 0, 100, 80)
_GraphicsDrawString($hGraphics, "图片覆盖背景", 5, 80)
_GDIPlus_BitmapDispose($hBitmap)
;~ ;========================右侧显示结束===================================================
EndFunc ;==>DoubleDraw
Func myImage($hGraphics, $i)
Local $hBitmap = _GDIPlus_BitmapCreateFromGraphics(100, 80, $hGraphics)
Local $hBackbuffer = _GDIPlus_ImageGetGraphicsContext($hBitmap)
_GDIPlus_GraphicsSetSmoothingMode($hBackbuffer, 2)
_GDIPlus_GraphicsClear($hBackbuffer, BitOR(BitShift($alphaOfBack, -24), 0xFFFF00))
Local $hBrushback = _GDIPlus_BrushCreateSolid(BitOR(BitShift($alphaOfGreen, -24), 0x00FF00))
Local $hBrushtop = _GDIPlus_BrushCreateSolid(BitOR(BitShift($alphaOfRed, -24), 0xFF0000))
_GDIPlus_GraphicsSetCompositingMode($hBackbuffer, $i)
_GDIPlus_GraphicsFillEllipse($hBackbuffer, 0, 0, 100, 80, $hBrushback)
_GDIPlus_GraphicsFillEllipse($hBackbuffer, 20, 10, 50, 60, $hBrushtop)
If $i = 0 Then
_GraphicsDrawString($hBackbuffer, "图片合成模式", 5, 40)
Else
_GraphicsDrawString($hBackbuffer, "图片覆盖模式", 5, 40)
EndIf
;释放画笔
_GDIPlus_BrushDispose($hBrushback)
_GDIPlus_BrushDispose($hBrushtop)
_GDIPlus_GraphicsDispose($hBackbuffer)
Return $hBitmap
EndFunc ;==>myImage
Func BackColor($hGraphics)
Local $hPen = _GDIPlus_PenCreate(0xFF000000)
Local $r, $g, $b, $color
For $i = 0 To 300
$r = Random(0, 255)
$g = Random(0, 255)
$b = Random(0, 255)
$color = BitOR(0xFF000000, _;Alpha
BitShift($r, -16), _;Red
BitShift($g, -8), _;Green
$b);Blue
_GDIPlus_PenSetColor($hPen, $color)
_GDIPlus_GraphicsDrawLine($hGraphics, $i, 0, $i, 200, $hPen)
Next
;释放画笔
_GDIPlus_PenDispose($hPen)
EndFunc ;==>BackColor
Func _GraphicsDrawString($hGraphics, $sString, $nX, $nY, $hBrush = 0, $sFont = "Arial", $nSize = 10, $iFormat = 0)
Local $hFormat = _GDIPlus_StringFormatCreate($iFormat)
Local $hFamily = _GDIPlus_FontFamilyCreate($sFont)
Local $hFont = _GDIPlus_FontCreate($hFamily, $nSize)
Local $tLayout = _GDIPlus_RectFCreate($nX, $nY, 0, 0)
Local $aInfo = _GDIPlus_GraphicsMeasureString($hGraphics, $sString, $hFont, $tLayout, $hFormat)
__GDIPlus_BrushDefCreate($hBrush)
Local $aResult = _GDIPlus_GraphicsDrawStringEx($hGraphics, $sString, $hFont, $aInfo[0], $hFormat, $hBrush)
Local $iError = @error
__GDIPlus_BrushDefDispose()
_GDIPlus_FontDispose($hFont)
_GDIPlus_FontFamilyDispose($hFamily)
_GDIPlus_StringFormatDispose($hFormat)
Return SetError($iError, 0, $aResult)
EndFunc ;==>_GraphicsDrawString
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