#include "l_bitmap.h"

L_LTIMGSFX_API L_INT L_LightBitmap(pBitmap, pLightInfo, uLightNo, uBright, uAmbient, crAmbientClr, uFlags)

Adds many spots of directed light sources to the bitmap.



Pointer to the bitmap handle that references the bitmap on which to apply the effect.


Pointer to an array of LIGHTINFO structures that contains information on each light source.

L_UINT uLightNo

The number of light sources.

L_UINT uBright

Value that represents the brightness of the ambient light of the entire image. This can be any number that is 0 or greater. If it is 0 the image will be black. This value is divided internally by 100.

L_UINT uAmbient

Factor used when mixing the ambient color with the image.

COLORREF crAmbientClr

The COLORREF value that specifies the ambient color of the light sources in the pLightInfo array.

L_UINT32 uFlags

Reserved for future use. Must be 0.


Value Meaning
SUCCESS The function was successful.
< 1 An error occurred. Refer to Return Codes.


This function does not support signed data images. It returns the error code ERROR_SIGNED_DATA_NOT_SUPPORTED if a signed data image is passed to this function.

The pLIGHTINFO->uStructSize must be set to sizeof(LIGHTINFO) before calling this function. For an array of structures, only the first structure in the array needs to have uStructSize member set.

This function supports 12 and 16-bit grayscale and 48 and 64-bit color images. Support for 12 and 16-bit grayscale and 48 and 64-bit color images is available in the Document and Medical Imaging toolkits.

To update a status bar or detect a user interrupt during execution of this function, refer to L_SetStatusCallback.

For an example, click here

To obtain this effect, the following settings were used with the function:

   ptCenter = (pBitmap->Width/2, pBitmap->Height/2); 
   uWidth = pBitmap->Width; 
   uHeight = pBitmap->Width * 4/3; 
   nAngle = 13500; 
   uBright = 100; 
   uEdge = 75; 
   crFill = RGB(0,0,255); 
   uOpacity = 100; 
   uFlag = LGT_SPOTLIGHT; 
uLightNo = 1; 
uBright = 100; 
uAmbient = 100; 
crAmbientClr = RGB(255,255,0); 

This function does not support 32-bit grayscale images. It returns the error code ERROR_GRAY32_UNSUPPORTED if a 32-bit grayscale image is passed to this function.

Required DLLs and Libraries


Win32, x64.

See Also




L_INT LightBitmapExample(L_VOID) 
   L_INT nRet; 
   BITMAPHANDLE LeadBitmap;   /* Bitmap handle for the image */ 
   LIGHTINFO LightInfo; 
   /* Load a bitmap at its own bits per pixel  */ 
   nRet = L_LoadBitmap(MAKE_IMAGE_PATH(TEXT("sample5.cmp")), &LeadBitmap, sizeof(BITMAPHANDLE), 0, ORDER_BGR, NULL, NULL); 
   if(nRet !=SUCCESS) 
      return nRet; 
   LightInfo.uStructSize = sizeof(LIGHTINFO); 
   LightInfo.crFill = RGB(255, 255, 255); 
   LightInfo.nAngle = 0; 
   LightInfo.ptCenter.x  = LeadBitmap.Width/2; 
   LightInfo.ptCenter.y  = LeadBitmap.Height/2; 
   LightInfo.uEdge = 0; 
   LightInfo.uBright  = 100; 
   LightInfo.uFlag = LGT_SPOTLIGHT; 
   LightInfo.uHeight = min(LeadBitmap.Height, LeadBitmap.Width)/2; 
   LightInfo.uWidth  = max(LeadBitmap.Height, LeadBitmap.Width)/2; 
   LightInfo.uOpacity  = 100; 
   nRet = L_LightBitmap(&LeadBitmap, &LightInfo, 1, 100, 100, RGB(255,255,255), 0); 
   if(nRet !=SUCCESS) 
      return nRet; 
   nRet = L_SaveBitmap(MAKE_IMAGE_PATH(TEXT("Result.BMP")), &LeadBitmap, FILE_BMP, 24, 0, NULL); 
   if(nRet !=SUCCESS) 
      return nRet; 
   //free bitmap  
   return SUCCESS; 
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LEADTOOLS Raster Imaging C API Help

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© 1991-2022 LEAD Technologies, Inc. All Rights Reserved.