Function

CGGetDisplayTransferByFormula(_:_:_:_:_:_:_:_:_:_:)

Gets the coefficients of the gamma transfer formula for a display.

Declaration

func CGGetDisplayTransferByFormula(_ display: CGDirectDisplayID, _ redMin: UnsafeMutablePointer<CGGammaValue>?, _ redMax: UnsafeMutablePointer<CGGammaValue>?, _ redGamma: UnsafeMutablePointer<CGGammaValue>?, _ greenMin: UnsafeMutablePointer<CGGammaValue>?, _ greenMax: UnsafeMutablePointer<CGGammaValue>?, _ greenGamma: UnsafeMutablePointer<CGGammaValue>?, _ blueMin: UnsafeMutablePointer<CGGammaValue>?, _ blueMax: UnsafeMutablePointer<CGGammaValue>?, _ blueGamma: UnsafeMutablePointer<CGGammaValue>?) -> CGError

Parameters

display

The identifier of the display to be accessed.

redMin

The minimum value of the red channel in the gamma table. The value is a number in the interval [0, redMax).

redMax

The maximum value of the red channel in the gamma table. The value is a number in the interval (redMin, 1].

redGamma

A positive value used to compute the red channel in the gamma table.

greenMin

The minimum value of the green channel in the gamma table. The value is a number in the interval [0, greenMax).

greenMax

The maximum value of the green channel in the gamma table. The value is a number in the interval (greenMin, 1].

greenGamma

A positive value used to compute the green channel in the gamma table.

blueMin

The minimum value of the blue channel in the gamma table. The value is a number in the interval [0, blueMax).

blueMax

The maximum value of the blue channel in the gamma table. The value is a number in the interval (blueMin, 1].

blueGamma

A positive value used to compute the blue channel in the gamma table.

Return Value

A result code. See Core Graphics Data Types and Constants.

Discussion

For information about the gamma transfer formula, see the description of the function CGSetDisplayTransferByFormula(_:_:_:_:_:_:_:_:_:_:).