XMCOLOR::XMCOLOR(float,float,float,float) function (directxpackedvector.h)

Artículo
07/12/2022
Tiempo de lectura: 2 minutos

Initializes a new instance of XMCOLOR from four float arguments.

This constructor initializes a new instance of XMCOLOR from four float arguments.

Note This constructor is only available under C++.

Syntax

void XMCOLOR(
  float _r,
  float _g,
  float _b,
  float _a
) noexcept;

Parameters

_r

Normalized value for the red channel of a 32-bit ARGB color stored in the new instance of XMCOLOR. The value of this argument should be in the range [0.0 - 1.0].

_g

Normalized value for the green channel of a 32-bit ARGB color stored in the new instance of XMCOLOR. The value of this argument should be in the range [0.0 - 1.0].

_b

Normalized value for the blue channel of a 32-bit ARGB color stored in the new instance of XMCOLOR. The value of this argument should be in the range [0.0 - 1.0].

_a

Normalized value for the alpha channel of a 32-bit ARGB color stored in the new instance of XMCOLOR. The value of this argument should be in the range [0.0 - 1.0].

Return value

None

Remarks

During the instantiation of an instance of XMCOLOR, all input arguments to this constructor are clamped to a range of [0.0, 1.0], multiplied by 255.0f, as well as rounded, and before being stored in the appropriate structure member.

The following pseudocode demonstrates the operation of this constructor, which takes advantage of the union of the four components of the XMCOLOR vector with an instance of uint32_t in the definition of the structure:


        XMCOLOR instance;        
	_a1 = min( max( _a, 0.0 ), 1.0 );
	_r1 = min( max( _r, 0.0 ), 1.0 );
	_g1 = min( max( _g, 0.0 ), 1.0 );
	_b1 = min( max( _b, 0.0 ), 1.0 );

	_a1 = round ( _a1 * 255.0f );
	_r1 = round ( _r1 * 255.0f );
	_g1 = round ( _g1 * 255.0f );
	_b1 = round ( _b1 * 255.0f );

	instance.v =  ( (uint32_t)_a1  << 24) |
                      ( (uint32_t)_r1  << 16) |
                      ( (uint32_t)_g1  <<  8) |
                      ( (uint32_t)_b1 );

Requirements


Target Platform	Windows
Header	directxpackedvector.h