ImageGear Professional v18.1 > API Reference Guide > Core Component API Reference > Core Component Functions Reference > Display Functions > IG_dspl_image_calc |
This function calculates DisplayedImageRect, which is the exact rectangle in which the image is to be scaled.
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AT_ERRCOUNT ACCUAPI IG_dspl_image_calc( [IN] HIGEAR hIGear, [IN] DWORD dwGrpID, [IN] HWND hWnd, [IN] HDC hDC, [OUT] LPAT_RECTANGLE lpActualDeviceRect ); |
Name | Type | Description |
hIGear | HIGEAR | ImageGear handle from which to get options and pixel data. |
dwGrpID | DWORD | Identifier of group from which to get display options. |
hWnd | HWND | Handle of window where image is to be displayed. Can be NULL, but in this case some display options may be calculated incorrectly if they are not set explicitly. |
hDC | HDC | Handle of the device context where image is to be drawn. |
lpActualDeviceRect | LPAT_RECTANGLE | Pointer to the rectangle in which to copy DisplayedImageRect. This rectangle is calculated no matter whether hDC=NULL or not. If NULL, then this parameter is ignored. |
Returns the number of ImageGear errors that occurred during this function call.
All pixel formats supported by ImageGear Professional.
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HIGEAR hIGear; /* HIGEAR handle of image */ DWORD nGrpID; /* Display group identifier */ AT_RECTANGLE DisplayedRect; ... case WM_PAINT: BeginPaint(hWnd, &ps); if (IG_image_is_valid(hIGear)) IG_dspl_image_calc( hIGear, nGrpID, hWnd, ps.hdc, &DisplayedRect ); EndPaint(hWnd, &ps); break; |
All options for drawing the image are taken from the dwGrpID group. This function does not perform any drawing, whether hDC is NULL or not.