D3DXColorAdjustContrast Function

Adjusts the contrast value of a color.

Syntax

D3DXCOLOR *D3DXColorAdjustContrast(      

    D3DXCOLOR *pOut,
    D3DXCOLOR *pC,
    FLOAT c
);

Parameters

pOut

[in, out] Pointer to a D3DXCOLOR structure that is the result of the operation.

pC

[in] Pointer to a source D3DXCOLOR structure.

c

[in] Contrast value. This parameter linearly interpolates between 50 percent gray and the color, pC. There are not limits on the value of c. If this parameter is zero, then the returned color is 50 percent gray. If this parameter is 1, then the returned color is the original color.

Return Value

This function returns a pointer to a D3DXCOLOR structure that is the result of the contrast adjustment.

Remarks

The input alpha channel is copied, unmodified, to the output alpha channel.

The return value for this function is the same value returned in the pOut parameter. In this way, this function can be used as a parameter for another function.

This function interpolates the red, green, and blue color components of a D3DXCOLOR structure between 50 percent gray and a specified contrast value, as shown in the following example.

pOut->r = 0.5f + c * (pC->r - 0.5f);

If c is greater than 0 and less than 1, the contrast is decreased. If c is greater than 1, the contrast is increased.

Function Information

Header	d3dx9math.h
Import library	d3dx9.lib
Minimum operating systems	Windows 98

See Also

D3DXColorAdjustSaturation