The SetDeviceGammaRamp function sets the gamma ramp on direct color display boards having drivers that support downloadable gamma ramps in hardware.
BOOL SetDeviceGammaRamp( HDC hdc, LPVOID lpRamp );
Specifies the device context of the direct color display board in question.
Pointer to a buffer containing the gamma ramp to be set. The gamma ramp is specified in three arrays of 256 WORD elements each, which contain the mapping between RGB values in the frame buffer and digital-analog-converter (DAC ) values. The sequence of the arrays is red, green, blue. The RGB values must be stored in the most significant bits of each WORD to increase DAC independence.
If this function succeeds, the return value is TRUE.
If this function fails, the return value is FALSE.
Direct color display modes do not use color lookup tables and are usually 16, 24, or 32 bit. Not all direct color video boards support loadable gamma ramps. SetDeviceGammaRamp succeeds only for devices with drivers that support downloadable gamma ramps in hardware.
|Minimum supported client||Windows 2000 Professional [desktop apps only]|
|Minimum supported server||Windows 2000 Server [desktop apps only]|