#include "l_bitmap.h"
L_LTDIS_API L_INT L_PaintRgnDCBuffer (hDC, pBitmap, pSrc, pClipSrc, pDst, pClipDst, uROP3, pBuffer, nRow, nCount)
Paints image data into a device context from a buffer. This function works the same as L_PaintDCBuffer, except that only the bitmap region is painted.
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.
Pointer to the bitmap handle referencing the bitmap that has the region to paint.
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.
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.
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.
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.
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.
Pointer to the buffer that contains the image data to paint.
The first row to paint. The painted portion of any row may be limited by the RECT parameters.
The number of rows to paint. The painted portion of any row may be limited by the RECT parameters.
Value | Meaning |
---|---|
SUCCESS | The function was successful. |
< 1 | An error occurred. Refer to Return Codes. |
The bitmap must be allocated before you can create a region for it. Therefore, if you use this function in a paint-while-load routine, you must use your callback function to create the region after the bitmap is allocated.
Required DLLs and Libraries
Win32, x64.
Creates a region in the image, then gets the data one line at a time and paints it.
L_INT PaintRgnDCBufferExample(L_HWND hWnd, pBITMAPHANDLE pBitmap)
{
L_INT nRet=SUCCESS;
HDC hdc; /* Device context for the current window */
RECT rcDest; /* 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 */
RECT rcRgn;
L_INT x;
SetRect(&rcRgn, BITMAPWIDTH(pBitmap)*1/4, BITMAPHEIGHT(pBitmap)*1/4,
BITMAPWIDTH(pBitmap)*3/4, BITMAPHEIGHT(pBitmap)*3/4);
L_SetBitmapRgnEllipse(pBitmap, NULL, &rcRgn, L_RGN_SET);
/* Get the device context */
hdc = GetDC (hWnd);
/* Set the destination rectangle to be the same as the bitmap.
Other painting rectangles can take defaults. */
GetClientRect(hWnd, &rcDest);
/* Create the palette that we will use to paint */
hOurPalette = L_CreatePaintPalette (hdc, pBitmap);
/* Select our palette and save the old one */
hSavedPalette = SelectPalette (hdc, hOurPalette, FALSE);
/* Realize our palette */
RealizePalette (hdc);
/* Paint the image */
L_AccessBitmap(pBitmap);
for(x=0; x<pBitmap->Height; x++)
{
L_UCHAR *pBuf = (L_UCHAR*)malloc(pBitmap->BytesPerLine);
L_GetBitmapRow(pBitmap, pBuf, x, pBitmap->BytesPerLine);
nRet = L_PaintRgnDCBuffer(hdc, pBitmap, NULL, NULL, &rcDest, NULL, SRCCOPY, pBuf, x, 1);
}
L_ReleaseBitmap(pBitmap);
/* Restore the old palette */
SelectPalette (hdc, hSavedPalette, FALSE);
/* Delete the newly created palette */
DeleteObject (hOurPalette);
/* Release the device context */
ReleaseDC(hWnd, hdc);
return nRet;
}
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