L_PaintDCOverlay
#include "l_bitmap.h"
L_INT EXT_FUNCTION L_PaintDCOverlay(hDC, pBitmap, nIndex, pSrc, pClipSrc, pDst, pClipDst, uROP3);
HDC hDC; |
/* handle to the target device context */ |
pBITMAPHANDLE pBitmap; |
/* pointer to the main bitmap handle containing the overlay */ |
L_INT nIndex; |
/* the index of the overlay bitmap used for painting */ |
LPRECT pSrc; |
/* the source rectangle (in pBitmap coordinates, not in overlay coordinates!) */ |
LPRECT pClipSrc; |
/* the source clipping rectangle (in pBitmap coordinates, not in overlay coordinates!) */ |
LPRECT pDst; |
/* the destination rectangle (in pBitmap coordinates, not in overlay coordinates) */ |
LPRECT pClipDst; |
/* the destination clipping rectangle (in pBitmap coordinates, not in overlay coordinates) */ |
L_UINT32 uROP3; |
/* windows ROP code for display */ |
Paints the overlay at the specified index. Use this function to paint overlays that are not automatically painted.
Parameter |
Description |
hDC |
Handle to a device context, such as a screen, to use as the display surface. The mapping mode of the device context must be MM_TEXT. |
pBitmap |
Pointer to the bitmap handle referencing the main bitmap. |
nIndex |
The index of the overlay used for painting. The overlay should have a bitmap. If the overlay is embedded into a bitmap bitplane, make sure you create an overlay bitmap prior to calling this function. This index is zero-based. |
pSrc |
Pointer to the Windows RECT structure that specifies the part of the bitmap to use as the display source. |
|
The coordinates in the RECT structure are relative to the main bitmap. You can pass NULL to use the default, which matches the main bitmap. |
pClipSrc |
Pointer to the Windows RECT structure that specifies the portion of the display source to paint. Generally, this is used for updating the display when part of the source bitmap has changed. |
|
The coordinates in the RECT structure are relative to the main bitmap. You can pass NULL to use the default, which matches the main bitmap. |
pDst |
Pointer to the Windows RECT structure that determines how the source rectangle is scaled and how the image is positioned in the device context. |
|
The coordinates in the RECT structure are relative to the device context. There is no default for this parameter. You must specify the RECT structure. |
pClipDst |
Pointer to the Windows RECT structure that specifies the portion of the display rectangle to paint. Generally, this is used for updating changes in the display surface, such as when a user moves another window, uncovering a part of the image that had been covered up. |
|
The coordinates in the RECT structure are relative to the device context. You can pass NULL to use the default, which matches the device context. In most cases, however, you should use the rectangle returned by the Windows WM_PAINT message. |
uFlags |
The Windows ROP code that determines how the destination rectangle is updated. This parameter takes the same codes as the Windows BitBlt function. For ordinary painting, use SRCCOPY. |
Returns
SUCCESS |
The function was successful. |
< 1 |
An error occurred. Refer to Return Codes. |
Comments
This function will paint an overlay bitmap. For more information on the paint rectangles, see L_PaintDC. L_PaintDC will paint all the overlays that have OVERLAY_AUTOPAINT set in the uFlags member of the OVERLAYATTRIBUTES structure. The overlays are painted in ascending index order: overlay 0 is painted first, then overlay 1, etc.
Use this function to manually paint an overlay. For example, to change the order in which the overlays are painted, clear the OVERLAY_AUTOPAINT flag from the uFlags member of the overlay's OVERLAYATTRIBUTES structure and call L_PaintDCOverlay directly.
To temporarily make an overlay top-most, call L_PaintDCOverlay after L_PaintDC. To permanently make an overlay top-most, change its index and give it the highest defined index.
The overlay bitmap’s 1 pixels are painted with the color set in the crColor member of the OVERLAYATTRIBUTES structure. The overlay bitmap’s 0 pixels are considered transparent.
For more information on the overlay attributes, including the OVERLAY_AUTOPAINT flag and crColor, refer to OVERLAYATTRIBUTES.
Required DLLs and Libraries
LTDIS For a listing of the exact DLLs and Libraries needed, based on the toolkit version, refer to Files To Be Included With Your Application. |
Platforms
Windows 95 / 98 / Me, Windows 2000 / XP.
See Also
Example
/* This example assumes pBitmap contains overlays. It will make it look as if overlay 0 is topmost */
/* The example also assumes hDC and pDest have been initialized elsewhere */
L_PaintDC(hDC, pBitmap, NULL, NULL, pDest, NULL, SRCCOPY);
L_PaintDCOverlay(hDC, pBitmap, 0, NULL, NULL, pDest, NULL, SRCCOPY);
/* Now overlay 0 is topmost (it covers all the other overlays) */