int IMAPI ImgDrawImageFX ( hImage, hDC, pDstBound, pSrcBounds,T nEffect, dwFlags, dwExtra, pfnCallback, UINT nInterval, dwUserInfo, hPal )

This function displays the image referenced by hImage on the screen at the specified location and size using one of the special effects indicated.

 

Parameter	Type	Description
hImage	HANDLE	Identifies the image to be displayed. If NULL, the specified effect is applied using the DC's background brush.
hDC	HDC	Identifies the device context for the display.
pDstBounds	LPRECT	Points to a RECT data structure containing the logical screen coordinates to draw the image into.
pSrcBounds	LPRECT	Point to a RECT data structure specifying the portion of the source which will be displayed. If NULL, the entire image will be displayed in pDstBounds.
nEffect	UINT	Specifies the effect to use while drawing the image.

 

 

Valid values for nEffect are :

 

Values	Description
IMFX_WIPELEFT	wipes left from right edge
IMFX_WIPERIGHT	wipe right from left edge
IMFX_WIPEUP	wipe up from the bottom
IMFX_WIPEDOWN	wipe down from the top
IMFX_VCURTAIN_OUT	vertical curtain from the middle
IMFX_VCURTAIN_IN	vertical curtain to the middle
IMFX_HCURTAIN_OUT	horizontal curtain from the middle
IMFX_HCURTAIN_IN	horizontal curtain to the middle
IMFX_MOSAIC	rectangles spread over the entire area
IMFX_MOSAICLEFT	rectangles creeping from the right edge
IMFX_MOSAICRIGHT	rectangles creeping from the left edge
IMFX_MOSAICUP	rectangles creeping up from the bottom
IMFX_MOSAICDOWN	rectangles creeping down form the top
IMFX_BLUR_IN	image blurs in (from bad to good)
IMFX_BLUR_OUT	image blurs out (from good to bad)
IMFX_SHAPE_EXPLODE	image is drawn from the center out
IMFX_SHAPE_IMPLODE	image is drawn towards the center
IMFX_VBLIND_LEFT	vertical Venetian blinds open to the left
IMFX_VBLIND_RIGHT	vertical Venetian blinds open to the right
IMFX_VBLIND_UP	horizontal Venetian blinds open to the top
IMFX_VBLIND_DOWN	horizontal blinds open to the bottom

 

 

 

dwFlags

DWORD

Specifies an effect modifier.

 

Valid dwFlags values are:

 

Values	Description
IMDF_WIPE_IMGSLIDE	image slides into view
IMDF_WIPE_IMGEXPOSE	image is exposed in place
IMDF_WIPE_PUSHBKGND	image pushes the background out
IMDF_WIPE_OVERBKGND	new image floats above background
IMDF_CURTAIN_IMGSLIDE
IMDF_CURTAIN_IMGEXPOSE
IMDF_CURTAIN_PUSHBKGND
IMDF_CURTAIN_OVERBKGND
IMDF_SHAPE_RECTANGLE
IMDF_SHAPE_ROUNDRECTANGLE
IMDF_SHAPE_ELLIPSE
IMDF_VBLIND_IMGSLIDE
IMDF_VBLIND_IMGEXPOSE
IMDF_VBLIND_PUSHBKGND
IMDF_VBLIND_OVERBKGND

 

 

dwExtra	DWORD	Specifies additional effect specific information. See the Comments..
pfnCallback	IMFXCALLBACK	Specifies the address of the callback (status) function to be called between every effect operation. If NULL, no status call backs are made
nInterval	UINT	This is the percentage of effect completed points between each callback invocation.
dwUserInfo	DWORD	Specifies any user/programmer information that will be passed directly to your call back function.
hPal	HPALETTE	Specifies a palette that will be realized by the effect drawing routine. (Currently only the Blur effect uses this.)

 

 

Return Value

This function returns IMG_OK if successful. Otherwise IMG_ERR. If you are using a callback function and it does not return zero, then IMG_ERR will be returned and ImgGetStatus() will return IMG_CANCELLED.

 

Comments

By adjusting the values that make up the dwExtra modifier you have control over certain aspects of each special effect. For Wipes its value specifies the step increment. For a simple Mosaic (IMFX_MOSAIC), the low-word is the cell width and the high-word is the cell height. If you use small cells and it's a large image, it may take some time to completely draw the image. For the Creeping Mosaics, the low-word is the cell height and width and the high-word is the fill percent (0-100). For the Curtain and Venetian Blind effects the low-word specifies the step increment. For Venetian Blind, it also uses the high-word for slat size.

 

If no call back function is used, the ImgDrawImageFX function will not stop or return until it has completely drawn the image.

 

Be careful adjusting the value of the nInterval parameter. If you set this to zero, your function will be called in between every single effect drawing activity.

See Also

See the sections Having Fun With Special Effects and Using the Special Effects Callback for more information.

 

 

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