JUCE  v6.1.6 (6.0.8-1114)
JUCE API
Looking for a senior C++ dev?
I'm looking for work. Hire me!
juce::PixelAlpha Class Reference

Represents an 8-bit single-channel pixel, and can perform compositing operations on it. More...

#include <juce_PixelFormats.h>

Collaboration diagram for juce::PixelAlpha:

Public Types

enum  { indexA = 0 }
 The indexes of the different components in the byte layout of this type of colour. More...
 

Public Member Functions

 PixelAlpha () noexcept=default
 Creates a pixel without defining its colour. More...
 
template<class Pixel >
forcedinline void blend (const Pixel &src) noexcept
 Blends another pixel onto this one. More...
 
template<class Pixel >
forcedinline void blend (const Pixel &src, uint32 extraAlpha) noexcept
 Blends another pixel onto this one, applying an extra multiplier to its opacity. More...
 
forcedinline void desaturate () noexcept
 
forcedinline uint8 getAlpha () const noexcept
 
forcedinline uint8 getBlue () const noexcept
 
forcedinline uint32 getEvenBytes () const noexcept
 Return channels with an even index and insert zero bytes between them. More...
 
forcedinline uint8 getGreen () const noexcept
 
forcedinline uint32 getInARGBMaskOrder () const noexcept
 Returns a uint32 which will be in argb order as if constructed with the following mask operation ((alpha << 24) | (red << 16) | (green << 8) | blue). More...
 
uint32 getInARGBMemoryOrder () const noexcept
 Returns a uint32 which when written to memory, will be in the order a, r, g, b. More...
 
forcedinline uint32 getNativeARGB () const noexcept
 Returns a uint32 which represents the pixel in a platform dependent format which is compatible with the native format of a PixelARGB. More...
 
forcedinline uint32 getOddBytes () const noexcept
 Return channels with an odd index and insert zero bytes between them. More...
 
forcedinline uint8 getRed () const noexcept
 
forcedinline void multiplyAlpha (float multiplier) noexcept
 
forcedinline void multiplyAlpha (int multiplier) noexcept
 Multiplies the colour's alpha value with another one. More...
 
forcedinline void premultiply () noexcept
 Premultiplies the pixel's RGB values by its alpha. More...
 
template<class Pixel >
forcedinline void set (const Pixel &src) noexcept
 Copies another pixel colour over this one. More...
 
forcedinline void setAlpha (uint8 newAlpha) noexcept
 Replaces the colour's alpha value with another one. More...
 
forcedinline void setARGB (uint8 a_, uint8, uint8, uint8) noexcept
 Sets the pixel's colour from individual components. More...
 
template<class Pixel >
forcedinline void tween (const Pixel &src, uint32 amount) noexcept
 Blends another pixel with this one, creating a colour that is somewhere between the two, as specified by the amount. More...
 
forcedinline void unpremultiply () noexcept
 Unpremultiplies the pixel's RGB values. More...
 

Private Member Functions

 PixelAlpha (uint32 internal) noexcept
 

Private Attributes

uint8 a
 

Detailed Description

Represents an 8-bit single-channel pixel, and can perform compositing operations on it.

This is used internally by the imaging classes.

See also
PixelARGB, PixelRGB

@tags{Graphics}

Member Enumeration Documentation

◆ anonymous enum

anonymous enum

The indexes of the different components in the byte layout of this type of colour.

Enumerator
indexA 

Constructor & Destructor Documentation

◆ PixelAlpha() [1/2]

juce::PixelAlpha::PixelAlpha ( )
defaultnoexcept

Creates a pixel without defining its colour.

◆ PixelAlpha() [2/2]

juce::PixelAlpha::PixelAlpha ( uint32  internal)
inlineprivatenoexcept

Member Function Documentation

◆ blend() [1/2]

template<class Pixel >
forcedinline void juce::PixelAlpha::blend ( const Pixel &  src)
inlinenoexcept

Blends another pixel onto this one.

This takes into account the opacity of the pixel being overlaid, and blends it accordingly.

References juce::gl::a, and juce::gl::src.

◆ blend() [2/2]

template<class Pixel >
forcedinline void juce::PixelAlpha::blend ( const Pixel &  src,
uint32  extraAlpha 
)
inlinenoexcept

Blends another pixel onto this one, applying an extra multiplier to its opacity.

The opacity of the pixel being overlaid is scaled by the extraAlpha factor before being used, so this can blend semi-transparently from a PixelRGB argument.

References juce::gl::a, int(), juce::gl::src, and juce::gl::srcAlpha.

◆ desaturate()

forcedinline void juce::PixelAlpha::desaturate ( )
inlinenoexcept

◆ getAlpha()

forcedinline uint8 juce::PixelAlpha::getAlpha ( ) const
inlinenoexcept

References juce::gl::a.

◆ getBlue()

forcedinline uint8 juce::PixelAlpha::getBlue ( ) const
inlinenoexcept

◆ getEvenBytes()

forcedinline uint32 juce::PixelAlpha::getEvenBytes ( ) const
inlinenoexcept

Return channels with an even index and insert zero bytes between them.

This is useful for blending operations. The exact channels which are returned is platform dependent but compatible with the return value of getEvenBytes of the PixelARGB class.

See also
PixelARGB::getEvenBytes

References juce::gl::a.

◆ getGreen()

forcedinline uint8 juce::PixelAlpha::getGreen ( ) const
inlinenoexcept

◆ getInARGBMaskOrder()

forcedinline uint32 juce::PixelAlpha::getInARGBMaskOrder ( ) const
inlinenoexcept

Returns a uint32 which will be in argb order as if constructed with the following mask operation ((alpha << 24) | (red << 16) | (green << 8) | blue).

◆ getInARGBMemoryOrder()

uint32 juce::PixelAlpha::getInARGBMemoryOrder ( ) const
inlinenoexcept

Returns a uint32 which when written to memory, will be in the order a, r, g, b.

In other words, if the return-value is read as a uint8 array then the elements will be in the order of a, r, g, b

◆ getNativeARGB()

forcedinline uint32 juce::PixelAlpha::getNativeARGB ( ) const
inlinenoexcept

Returns a uint32 which represents the pixel in a platform dependent format which is compatible with the native format of a PixelARGB.

See also
PixelARGB::getNativeARGB

References juce::gl::a.

◆ getOddBytes()

forcedinline uint32 juce::PixelAlpha::getOddBytes ( ) const
inlinenoexcept

Return channels with an odd index and insert zero bytes between them.

This is useful for blending operations. The exact channels which are returned is platform dependent but compatible with the return value of getOddBytes of the PixelARGB class.

See also
PixelARGB::getOddBytes

References juce::gl::a.

◆ getRed()

forcedinline uint8 juce::PixelAlpha::getRed ( ) const
inlinenoexcept

◆ multiplyAlpha() [1/2]

forcedinline void juce::PixelAlpha::multiplyAlpha ( float  multiplier)
inlinenoexcept

References juce::gl::a.

◆ multiplyAlpha() [2/2]

forcedinline void juce::PixelAlpha::multiplyAlpha ( int  multiplier)
inlinenoexcept

Multiplies the colour's alpha value with another one.

References juce::gl::a.

◆ premultiply()

forcedinline void juce::PixelAlpha::premultiply ( )
inlinenoexcept

Premultiplies the pixel's RGB values by its alpha.

◆ set()

template<class Pixel >
forcedinline void juce::PixelAlpha::set ( const Pixel &  src)
inlinenoexcept

Copies another pixel colour over this one.

This doesn't blend it - this colour is simply replaced by the other one.

References juce::gl::a, and juce::gl::src.

◆ setAlpha()

forcedinline void juce::PixelAlpha::setAlpha ( uint8  newAlpha)
inlinenoexcept

Replaces the colour's alpha value with another one.

References juce::gl::a.

◆ setARGB()

forcedinline void juce::PixelAlpha::setARGB ( uint8  a_,
uint8  ,
uint8  ,
uint8   
)
inlinenoexcept

Sets the pixel's colour from individual components.

References juce::gl::a.

◆ tween()

template<class Pixel >
forcedinline void juce::PixelAlpha::tween ( const Pixel &  src,
uint32  amount 
)
inlinenoexcept

Blends another pixel with this one, creating a colour that is somewhere between the two, as specified by the amount.

References juce::gl::a, and juce::gl::src.

◆ unpremultiply()

forcedinline void juce::PixelAlpha::unpremultiply ( )
inlinenoexcept

Unpremultiplies the pixel's RGB values.

Member Data Documentation

◆ a

uint8 juce::PixelAlpha::a
private

The documentation for this class was generated from the following file: