#include "l_bitmap.h"

L_LTDIS_API L_INT L_SetBitmapRgnRect(pBitmap, pXForm, pRect, uCombineMode)


pointer to the bitmap handle


pointer to a coordinate-translation structure

L_RECT* pRect;

pointer to the rectangular region

L_UINT uCombineMode;

action to take regarding the existing region

Creates or updates the bitmap region by adding a rectangular region.




Pointer to the bitmap handle referencing the bitmap where the region is to be created or updated.


Pointer to an RGNXFORM structure that LEADTOOLS uses to translate between display coordinates and bitmap coordinates.


If you specify NULL in this parameter, the scalar fields default to 1, the offsets default to 0, and the view perspective defaults to the bitmap's view perspective.


Pointer to the windows RECT structure that specifies the rectangular region. You specify the structure using device context coordinates, and LEADTOOLS translates the coordinates using the values specified in the pXForm parameter.


The action to take regarding the existing bitmap region, if one is defined. For descriptions of the possible values, refer to Creating a Bitmap Region.



The function was successful.

< 1

An error occurred. Refer to Return Codes.


Before calling this function, you must declare an RGNXFORM structure and set its values, which LEADTOOLS uses to translate between device context coordinates and bitmap coordinates. For details about how the structure works refer to the RGNXFORM structure description. For a description of common usage, refer to Translating Coordinates for a Bitmap Region.

To update an existing region, you specify how the new region is to be combined with the existing one. For descriptions of the possibilities, refer to Creating a Bitmap Region.

Required DLLs and Libraries


For a listing of the exact DLLs and Libraries needed, based on the toolkit version, refer to Files To Be Included With Your Application.


Win32, x64, Linux.

See Also


L_SetBitmapRgnColor, L_SetBitmapRgnEllipse, L_SetBitmapRgnPolygon, L_SetBitmapRgnRoundRect


Raster Image Functions: Creating and Using a Region


Raster Image Functions: Region Processing


Defining and Using a Bitmap Region


Saving a Region


For complete sample code, refer to the CHILD.C module of the DEMO example. This example creates a rectangular region and lightens the part of the bitmap that is in the region.

L_INT SetBitmapRgnRectExample(L_HWND          hWnd, 
                                             pBITMAPHANDLE pBitmap) 
   L_INT nRet; 
   RGNXFORM    XForm;         /* Structure for transforming display coordinates */ 
   HDC         hWindowDC;     /* Device context of the current window */ 
   RECT        rClientArea;   /* Client area of the current window */ 
   RECT        rRgnRect;      /* Rectangle that defines the region */ 
   /* Get the device context of the current window */ 
   hWindowDC = GetDC (hWnd); 
   /* Get the client area of the current window */ 
   /* Load a bitmap */ 
   nRet = L_LoadBitmap (MAKE_IMAGE_PATH(TEXT("ImageProcessingDemo\\Image3.cmp")), pBitmap, sizeof(BITMAPHANDLE), 0, ORDER_BGR, NULL, NULL); 
   if(nRet != SUCCESS) 
      return nRet; 
   /* Set RGNXFORM fields, assuming that the display rectangle is the same 
   as the client area of the current window */ 
   XForm.uViewPerspective = TOP_LEFT; 
   XForm.nXScalarNum = BITMAPWIDTH(pBitmap); 
   XForm.nXScalarDen = rClientArea.right; 
   XForm.nYScalarNum = BITMAPHEIGHT(pBitmap); 
   XForm.nYScalarDen = rClientArea.bottom; 
   XForm.nXOffset = 0; 
   XForm.nYOffset = 0; 
   /* Specify a rectangle to define the region */ 
   SetRect(&rRgnRect, rClientArea.right/8, rClientArea.bottom/8,  
      rClientArea.right/2, rClientArea.bottom/2); 
   /* Create a rectangular region */ 
   nRet = L_SetBitmapRgnRect(pBitmap, &XForm, &rRgnRect, L_RGN_SET); 
   if(nRet != SUCCESS) 
      return nRet; 
   /* Lighten the region so that we will see it */ 
   nRet = L_ChangeBitmapIntensity(pBitmap,500, 0); 
   if(nRet != SUCCESS) 
      return nRet; 
   /* Free the region */ 
   return SUCCESS; 

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