L_PaintRgnDC

#include "l_bitmap.h"

L_INT EXT_FUNCTION L_PaintRgnDC(hDC, pBitmap, pSrc, pClipSrc, pDst, pClipDst, uROP3)

HDC hDC;

/* handle to the target device context */

pBITMAPHANDLE pBitmap;

/* pointer to the bitmap handle */

LPRECT pSrc;

/* pointer to the display source rectangle */

LPRECT pClipSrc;

/* pointer to the display source clipping rectangle */

LPRECT pDst;

/* pointer to the display destination rectangle */

LPRECT pClipDst;

/* pointer to the display destination clipping rectangle */

L_UINT32 uROP3;

/* windows ROP code for display */

Paints the bitmap region to a device context. This function works the same as L_PaintDC, except that only the bitmap region is 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 bitmap that has the region.

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 bitmap. You can pass NULL to use the default, which matches the 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 bitmap. You can pass NULL to use the default, which matches the 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.

uROP3

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.

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

Functions:

L_FrameBitmapRgn, L_PaintRgnDCBuffer, L_PaintRgnDCEffect, L_WindowLevel, L_RectToBitmap, L_RectFromBitmap

Topics:

Raster Image Functions: Displaying Images

 

Raster Image Functions: Palettes

 

Defining and Using a Bitmap Region

 

Handling Palette Changes

 

Implementing Transparency

Example

For complete sample code, refer to the FEATURE3 example.

/* This example shows the minimum requirements for painting 
the current region of a bitmap using the bitmap’s palette */
BITMAPHANDLE LeadBitmap;   /* Bitmap handle for the image */
void TestFunction(HWND hWnd)
{
   HDC hdc; /* Device context for the current window */
   RECT rLeadDest; /* Destination rectangle for painting */
   HPALETTE hSavedPalette = NULL; /* Temporary copy of the current system palette */
   HPALETTE hOurPalette = NULL; /* The palette that we will use to paint */
   /* Get the device context */
   hdc = GetDC (hWnd);
   /* Set the destination rectangle to be the same as the bitmap.
   Other painting rectangles can take defaults. */
   SetRect(&rLeadDest, 0, 0, BITMAPWIDTH(&LeadBitmap), BITMAPHEIGHT(&LeadBitmap));
   /* Create the palette that we will use to paint */
   hOurPalette = L_CreatePaintPalette (hdc, &LeadBitmap);
   /* Select our palette and save the old one */
   hSavedPalette = SelectPalette (hdc, hOurPalette, FALSE);
   /* Realize our palette */
   RealizePalette (hdc); 
   /* Paint the image */
   L_PaintRgnDC ( hdc,        /* Device context */
               &LeadBitmap,/* Bitmap handle */
               NULL,       /* Default source rectangle */
               NULL,       /* Default source clip area */
               &rLeadDest, /* Destination rectangle */
               NULL,       /* Default destination clipping rectangle */
               SRCCOPY);   /*  ROP3 code for a Normal Paint */
   /* Restore the old palette */
   SelectPalette (hdc, hSavedPalette, FALSE);
/* Release the device context */
   ReleaseDC(hWnd, hdc);
   return;
}