QParameter Class

class Qt3DRender ::QParameter

Provides storage for a name and value pair. This maps to a shader uniform. 更多...

头：	#include <Qt3DRender/QParameter>
qmake:	QT += 3drender
实例化：	参数
继承：	Qt3DCore::QNode

所有成员列表，包括继承成员

特性

name : QString
value : QVariant

公共函数

	QParameter (const QString & name , Qt3DRender::QAbstractTexture * texture , Qt3DCore::QNode * parent = nullptr)
	QParameter (const QString & name , const QVariant & value , Qt3DCore::QNode * parent = nullptr)
	QParameter (Qt3DCore::QNode * parent = nullptr)
QString	name () const
QVariant	value () const

公共槽

void	setName (const QString & name )
void	setValue (const QVariant & dv )

信号

void	nameChanged (const QString & name )
void	valueChanged (const QVariant & value )

详细描述

A QParameter can be referenced by a QRenderPass , QTechnique , QEffect , QMaterial , QTechniqueFilter , QRenderPassFilter . At runtime, depending on which shader is selected for a given step of the rendering, the value contained in a QParameter will be converted and uploaded if the shader contains a uniform with a name matching that of the QParameter.

QParameter *param = new QParameter();
param->setName(QStringLiteral("diffuseColor"));
param->setValue(QColor::fromRgbF(0.0f, 0.0f, 1.0f, 1.0f));
// Alternatively you can create and set a QParameter this way
QParameter *param2 = new QParameter(QStringLiteral("diffuseColor"), QColor::fromRgbF(0.0f, 0.0f, 1.0f, 1.0f));
// Such QParameters will work with the following GLSL uniform shader declarations
// uniform vec4 diffuseColor;
// uniform vec3 diffuseColor;
// uniform vec2 diffuseColor;
// uniform float diffuseColor;

注意： some care must be taken to ensure the value wrapped by a QParameter can actually be converted to what the real uniform expect. Giving a value stored as an int where the actual shader uniform is of type float could result in undefined behaviors.

注意： when the targeted uniform is an array, the name should be the name of the uniform with [0] appended to it.

注意： QParameter node can not be disabled.

QParameter *param = new QParameter();
QVariantList values = QVariantList() << 0.0f << 1.0f << 2.0f << 3.0f << 4.0f << 883.0f << 1340.0f << 1584.0f;
param->setName(QStringLiteral("diffuseValues[0]"));
param->setValue(values);
// Matching GLSL shader uniform  declaration
// uniform float diffuseValues[8];

When it comes to texture support, the QParameter value should be set to the appropriate QAbstractTexture subclass that matches the sampler type of the shader uniform.

QTexture2D *texture = new QTexture2D();
...
QParameter *param = new QParameter();
param->setName(QStringLiteral("diffuseTexture"));
param->setValue(QVariant::fromValue(texture));
// Works with the following GLSL uniform shader declaration
// uniform sampler2D diffuseTexture

另请参阅 QAbstractTexture .

特性文档编制

name : QString

Specifies the name of the parameter

访问函数：

QString	name () const
void	setName (const QString & name )

通知程序信号：

void	nameChanged (const QString & name )

value : QVariant

Specifies the value of the parameter

访问函数：

QVariant	value () const
void	setValue (const QVariant & dv )

通知程序信号：

void	valueChanged (const QVariant & value )

成员函数文档编制

QParameter:: QParameter (const QString & name , Qt3DRender::QAbstractTexture * texture , Qt3DCore::QNode * parent = nullptr)

Constructs a new QParameter with the specified parent name and takes its value from texture .

QParameter:: QParameter (const QString & name , const QVariant & value , Qt3DCore::QNode * parent = nullptr)

Constructs a new QParameter with the specified parent name and value .

QParameter:: QParameter ( Qt3DCore::QNode * parent = nullptr)

Constructs a new QParameter with the specified parent .