#include "BIDISP.H"
WORD CALLBACK RefreshDIB ( HWND hWnd,
HDIB hDIB,
LPRECT lprScroll,
LPRECT lprScale,
UINT wDisplayFormat,
LPDISPLAYSTRUCT cb)
Description
This function displays the image passed as a device independent bitmap. This function should be used any time the DIB changes or display mode changes. The DPI resolution is part of the BITMAPINFOHEADER data structure. The LPDISPLAYSTRUCT structure will be filled automatically. This structure is used internally for scrolling and to format the image to display. The Flag of DISP_NEWDIB should be set whenever the DIB changes physically. That includes the first time one calls RefreshDIB(). Each time one changes the DIB, such as rotate, invert, or replace, one must set the DISP_NEWDIB flag. This function can be used instead of the DisplayDIBStart function.
Parameters
|
HWND |
hWnd |
Window handle to get client parameters. |
|
|
HDIB |
hDIB |
Device independent bitmap handle. |
|
|
LPRECT |
lprScroll |
Describes which part of the bitmap is displayed. |
|
|
LPRECT |
lprScale |
Scaling factor for X and Y axis. (left:top and right:bottom) |
|
|
UINT |
wDisplayFormat |
Display format. |
|
|
LPDISPLAYSTRUCT |
cb |
Display information structure. |
|
Return values
0 on failures, display format on success.
Programming notes
The scaling factor is stored in the RECT data structure where one can define the ratio for scaling for the X or Y coordinate by two integers as 3:4 or 13:19 in the lprScale->left and lprScale->top field for X coordinate and lprScale->right and lprScale->bottom for the Y coordinate. For code example:
Scaling in X axis = left;top 1:3 increases the image width by three times
Scaling in Y axis = right;bottom 1:3 increases the image height by three times
UINT wDisplayFormat can be set to:
DISP_NEWDIB - Regenerate the a new BITMAP internally.
DISP_NORMAL - Display image pixel by pixel.
DISP_PREVIEW - Forces the image to fit into the window client area using DPI information and unique scaling factors in both the vertical and horizontal direction.
DISP_INVERT - Displays the image an inverted image.
DISP_SCALED - Use DPI information for displaying image.
DISP_CENTER - Forces the image to be aligned centered onto the window.
DISP_FITTOWIDTH - Forces the image to fit into the window client area using unique scaling factors in the horizontal direction.
DISP_FITTOHEIGHT - Forces the image to fit into the window client area using unique scaling factors in the vertical direction.
DISP_FITSCREEN - Forces the image to fit into the window client area using unique scaling factors in both the vertical and horizontal direction.
DISP_NOVERTSCROLL - Prevents the vertical scroll bar to be shown.
DISP_NOHORZSCROLL - Prevents the horizontal scroll bar to be shown.
The display formats can be combined by the “|” binary “OR” operator. For example, DISP_INVERT | DISP_NORMAL is valid.
In the case of, DISP_NORMAL | DISP_SCALED. The DISP_SCALED takes precedence over DISP_NORMAL.
Requirements
Header : Declared in BIDisp.h; include BIDisp.h.
Library : Use BIDisp.lib.
DLLs : BIDisp.dll, BiDIB.dll.
Code example
See sample code at DisplayWmCreate().