Sets the current gamma correction value for the class objects bitmap. This value issued by painting operations and can be retrieved using the LBitmapBase::GetPaintGamma function.


#include "ltwrappr.h"

virtual L_INT LBitmapWindow::SetPaintGamma(uValue)


L_UINT uValue

Unsigned integer that represents the gamma value. It can be any number greater than 0. The default value is 100.

Because this is an unsigned integer, it is 100 times the actual gamma value. For example, use 235 to set a gamma value of 2.35.


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


This is the local paint gamma for the class object and is used when painting the bitmap.

Setting the gamma correction that is used for painting lets you adjust the displayed brightness of all images without changing the bitmap data.

Intensity values ideally follow a logarithmic progression, because the eye perceives changes in intensity as being equal when the ratio of change is equal. For example, we would see a change from 0.1 to 0.2 as being equal to a change from 0.2 to 0.4.

Gamma is a standard constant that is used to calculate the progression. For most CRTs the gamma constant is in the range of 2.2 to 2.5.

This sets the paint gamma for the floater bitmap to the passed value.

Required DLLs and Libraries


Win32, x64.

See Also




L_INT LBitmapWindow__SetPaintGammaExample() 
   L_INT nRet; 
   LBitmapWindow MyBitmap; 
   nRet =MyBitmap.Load(MAKE_IMAGE_PATH(TEXT("image1.cmp")),24); 
   if(nRet !=SUCCESS) 
      return nRet; 
   nRet =MyBitmap.SetPaintGamma(150); 
   if(nRet !=SUCCESS) 
      return nRet; 
   return SUCCESS; 
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