HdcModeSetter Class Reference

Helper class for setting and resetting the ROP2 mode. More...

List of all members.

Public Member Functions
	HdcModeSetter (Canvas &canvas, int mode)
	Constructor setting the ROP2 of the given Device Context.
	~HdcModeSetter ()
	Automatically resets the ROP2.

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Detailed Description

Helper class for setting and resetting the ROP2 mode.

The ROP2 mode is used for telling windows which type of brush you want while painting.
this class ensures we reset the ROP2 mode after we have fiinished with it.
Used in combination with e.g. UpdateCanvas or PaintCanvas.
Supported modes are those supported in Windows API

• R2_BLACK Pixel is always 0.
• R2_COPYPEN Pixel is the pen color.
• R2_MASKNOTPEN Pixel is a combination of the colors common to both the screen and the inverse of the pen.
• R2_MASKPEN Pixel is a combination of the colors common to both the pen and the screen.
• R2_MASKPENNOT Pixel is a combination of the colors common to both the pen and the inverse of the screen.
• R2_MERGENOTPEN Pixel is a combination of the screen color and the inverse of the pen color.
• R2_MERGEPEN Pixel is a combination of the pen color and the screen color.
• R2_MERGEPENNOT Pixel is a combination of the pen color and the inverse of the screen color.
• R2_NOP Pixel remains unchanged.
• R2_NOT Pixel is the inverse of the screen color.
• R2_NOTCOPYPEN Pixel is the inverse of the pen color.
• R2_NOTMASKPEN Pixel is the inverse of the R2_MASKPEN color.
• R2_NOTMERGEPEN Pixel is the inverse of the R2_MERGEPEN color.
• R2_NOTXORPEN Pixel is the inverse of the R2_XORPEN color.
• R2_WHITE Pixel is always 1.
• R2_XORPEN Pixel is a combination of the colors in the pen and in the screen, but not in both.

Related classes

• UpdateCanvas
• PaintCanvas
• FreeCanvas
• Canvas
• Pen

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Constructor & Destructor Documentation

HdcModeSetter	(	Canvas &	canvas,
		int	mode
	)

Constructor setting the ROP2 of the given Device Context.

The mode is any of the above enums.

~HdcModeSetter

(

)

Automatically resets the ROP2.

Resets the mode back to what it was before this object was created. Note this object cannot have longer lifetime than the Canvas given to the Constructor since this will cause undefined behavior.

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