CUGL 2.3
Cornell University Game Library
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Public Member Functions | Static Public Member Functions | Public Attributes | Static Public Attributes | List of all members
cugl::Color4 Class Reference

#include <CUColor4.h>

Public Member Functions

 Color4 ()
 
 Color4 (Uint8 r, Uint8 g, Uint8 b, Uint8 a=255)
 
 Color4 (Uint32 color)
 
 Color4 (const float *array)
 
 Color4 (const std::string color)
 
Color4operator= (Uint32 color)
 
Color4operator= (const float *array)
 
Color4operator= (const std::string name)
 
Color4set (Uint8 r, Uint8 g, Uint8 b, Uint8 a=255)
 
Color4set (const float *array)
 
Color4set (Uint32 color)
 
Color4set (const Color4 c)
 
Color4set (const std::string name)
 
Color4setHSV (float h, float s, float v, Uint8 a=255)
 
Color4setHSL (float h, float s, float l, Uint8 a=255)
 
Color4clamp (Color4 min, Color4 max)
 
Color4 getClamp (Color4 min, Color4 max) const
 
Color4add (Color4 c, bool alpha=false)
 
Color4add (Uint8 r, Uint8 g, Uint8 b, Uint8 a=0)
 
Color4subtract (Color4 c, bool alpha=false)
 
Color4subtract (Uint8 r, Uint8 g, Uint8 b, Uint8 a=0)
 
Color4scale (float s, bool alpha=false)
 
Color4scale (float sr, float sg, float sb, float sa=1)
 
Color4scale (Color4 c, bool alpha=false)
 
Color4map (std::function< Uint8(Uint8)> func, bool alpha=false)
 
Color4 getMap (std::function< Uint8(Uint8)> func, bool alpha=false) const
 
Color4complement (bool alpha=false)
 
Color4 getComplement (bool alpha=false) const
 
Color4lerp (const Color4f other, float alpha)
 
Color4blend (Color4 other)
 
Color4blendPre (Color4 other)
 
Color4premultiply ()
 
Color4unpremultiply ()
 
Color4 getLerp (Color4 other, float alpha) const
 
Color4 getBlend (Color4 other) const
 
Color4 getBlendPre (Color4 other) const
 
Color4 getPremultiplied () const
 
Color4 getUnpremultiplied () const
 
Color4operator+= (Color4 c)
 
Color4operator-= (Color4 c)
 
Color4operator*= (float s)
 
Color4operator*= (Color4 c)
 
const Color4 operator+ (Color4 c) const
 
const Color4 operator- (Color4 c) const
 
const Color4 operator* (float s) const
 
const Color4 operator* (Color4 c) const
 
bool operator< (Color4 c) const
 
bool operator<= (Color4 c) const
 
bool operator> (Color4 c) const
 
bool operator>= (Color4 c) const
 
bool operator== (Color4 c) const
 
bool operator!= (Color4 c) const
 
bool darkerThan (Color4 c) const
 
bool lighterThan (Color4 c) const
 
std::string toString (bool verbose=false) const
 
 operator std::string () const
 
 operator Vec4 () const
 
 Color4 (const Vec4 vector)
 
Color4operator= (const Vec4 vector)
 
 operator Vec3 () const
 
 Color4 (const Vec3 vector)
 
Color4operator= (const Vec3 vector)
 
 operator Color4f () const
 
 Color4 (const Color4f color)
 
Color4operator= (const Color4f color)
 
float * get (float *array) const
 
Uint32 getRGBA () const
 
Uint32 getPacked () const
 

Static Public Member Functions

static Color4lerp (Color4 c1, Color4 c2, float alpha, Color4 *dst)
 
static Color4blend (Color4 c1, Color4 c2, Color4 *dst)
 
static Color4blendPre (Color4 c1, Color4 c2, Color4 *dst)
 

Public Attributes

union {
   struct {
      Uint8   r
 
      Uint8   g
 
      Uint8   b
 
      Uint8   a
 
   } 
 
   Uint32   rgba
 
}; 
 

Static Public Attributes

static const Color4 CLEAR
 
static const Color4 WHITE
 
static const Color4 BLACK
 
static const Color4 YELLOW
 
static const Color4 BLUE
 
static const Color4 GREEN
 
static const Color4 RED
 
static const Color4 MAGENTA
 
static const Color4 CYAN
 
static const Color4 ORANGE
 
static const Color4 GRAY
 
static const Color4 CORNFLOWER
 
static const Color4 PAPYRUS
 

Detailed Description

This class is a RGBA color composed of 4 unsigned bytes.

This is the preferred (non-transparent) color class for storage. It is slightly slower on calculations, because it often has to shift to 0..1 for all its values. It is also slower to cast to Vec3.

Constructor & Destructor Documentation

◆ Color4() [1/8]

cugl::Color4::Color4 ( )
inline

Constructs a new clear color (all zeros).

◆ Color4() [2/8]

cugl::Color4::Color4 ( Uint8  r,
Uint8  g,
Uint8  b,
Uint8  a = 255 
)
inline

Constructs a new color initialized to the specified values.

Parameters
rThe red color.
gThe green color.
bThe blue color.
aThe alpha value (optional).

◆ Color4() [3/8]

cugl::Color4::Color4 ( Uint32  color)
inline

Creates a new color from an integer interpreted as an RGBA value.

This representation assigned is native to the platform, but the integer parameter is interpreted in network order, which matches the way web colors are specified. In this order, red will always be the highest order byte and alpha will always be the lowest order byte. Hence
0x00ff00ff represents green or the color (0, 1, 0, 1).

Parameters
colorThe integer to interpret as an RGBA value.

◆ Color4() [4/8]

cugl::Color4::Color4 ( const float *  array)

Constructs a new color from the values in the specified array.

The color values must all be in the range 0..1. They are multiplied by 255.0 and rounded up.

Parameters
arrayAn array containing the color values in the order r, g, b, a.

◆ Color4() [5/8]

cugl::Color4::Color4 ( const std::string  color)

Creates a new color from an string represenation

A string representation may either be an explicit name or a (modified) HTML code. The supported color names are the classic TCL/TK colors, which are listed here:

https://www.tcl.tk/man/tcl8.6/TkCmd/colors.htm

An HTML code is a string that starts with #, followed by the characters 0-9, A-F. This is the hex representation of the color, as specified here:

https://htmlcolorcodes.com

We support 3, 4, 6, and 8 character codes (not including the #). The standard code is 6 characters, but that does not specify the alpha value.
If you specify eight characters, the last two characters specify the byte values for alpha, following the same rules for red, green, blue.

Finally, the 3 and 4 character versions are the abbreviated 6 and 8 character versions, respectively. In these versions, the byte values are repeated. So #fa2 becomes #ffaa22 and #fad3 becomes #ffaadd33.

Parameters
colorThe integer to interpret as an RGBA value.

◆ Color4() [6/8]

cugl::Color4::Color4 ( const Vec4  vector)
explicit

Creates a color from the given vector.

The attributes are read in the order x,y,z,w. They are all multiplied by 255.0f and rounded up before assignment.

Parameters
vectorThe vector to convert

◆ Color4() [7/8]

cugl::Color4::Color4 ( const Vec3  vector)
explicit

Creates a color from the given vector.

The attributes are read in the order x,y,z. They are all multiplied by 255.0f and rounded up before assignment. The alpha value is 255.

Parameters
vectorThe vector to convert

◆ Color4() [8/8]

cugl::Color4::Color4 ( const Color4f  color)
explicit

Creates a byte-based color from the given float-based color.

The attributes are read in the order r,g,b,a. They are all multiplied by 255.0f and rounded up before assignment.

Parameters
colorThe color to convert

Member Function Documentation

◆ add() [1/2]

Color4 & cugl::Color4::add ( Color4  c,
bool  alpha = false 
)
inline

Adds the given color to this one in place.

This operation is functionally identical to additive blending. The addition is clamped so that this remains a valid color.

Parameters
cThe color to add
alphaWhether to add the alpha values (optional)
Returns
A reference to this (modified) Color4 for chaining.

◆ add() [2/2]

Color4 & cugl::Color4::add ( Uint8  r,
Uint8  g,
Uint8  b,
Uint8  a = 0 
)
inline

Adds the given values to this color.

The addition is clamped so that this remains a valid color.

Parameters
rThe red color to add.
gThe green color to add.
bThe blue color to add.
aThe alpha value (optional).
Returns
A reference to this (modified) Color4 for chaining.

◆ blend() [1/2]

static Color4 * cugl::Color4::blend ( Color4  c1,
Color4  c2,
Color4 dst 
)
static

Blends the two colors c1 and c2, assuming they are not premultiplied.

The blending is the standard over operation with color c1 as the source and c2 as the destination. It assumes that the color values are not premultiplied.

Parameters
c1The source color.
c2The destination color.
dstThe color to store the result in
Returns
A reference to dst for chaining

◆ blend() [2/2]

Color4 & cugl::Color4::blend ( Color4  other)

Blends this color with the other one, storing the new value in place.

The blending is the standard over operation with this color as the destination. It assumes that the color values are not premultiplied.

Parameters
otherThe color to interpolate with.
Returns
This color, after the blending.

◆ blendPre() [1/2]

static Color4 * cugl::Color4::blendPre ( Color4  c1,
Color4  c2,
Color4 dst 
)
static

Blends the two colors c1 and c2, assuming they are premultiplied.

The blending is the standard over operation with color c1 as the source and c2 as the destination. It assumes that the color values are premultiplied.

Parameters
c1The source color.
c2The destination color.
dstThe color to store the result in
Returns
A reference to dst for chaining

◆ blendPre() [2/2]

Color4 & cugl::Color4::blendPre ( Color4  other)

Blends this color with the other one, storing the new value in place.

The blending is the standard over operation with this color as the destination. It assumes that this color is premultiplied.

Parameters
otherThe color to interpolate with.
Returns
This color, after the blending.

◆ clamp()

Color4 & cugl::Color4::clamp ( Color4  min,
Color4  max 
)

Clamps this color within the given range.

Parameters
minThe minimum value.
maxThe maximum value.
Returns
A reference to this (modified) Color4 for chaining.

◆ complement()

Color4 & cugl::Color4::complement ( bool  alpha = false)
inline

Complements this color.

The complement of the color is the (255-v) for each value v.

Parameters
alphaWhether to complement the alpha value (optional)
Returns
A reference to this (modified) Color4f for chaining.

◆ darkerThan()

bool cugl::Color4::darkerThan ( Color4  c) const
inline

Returns true if this color is dominated by the given color.

Domination means that all components of the given color are greater than or equal to the components of this one. However, alpha is reversed for this computation, as a greater value means more opaque (and hence darker).

Parameters
cThe color to compare against.
Returns
True if this color is dominated by the given color.

◆ get()

float * cugl::Color4::get ( float *  array) const

Writes the color values into a float array.

The attributes are read into the array in the order r,g,b,a. All values are divided by 255.0f (so they are between 0 and 1) before assignment.

Parameters
arrayThe array to store the color values.
Returns
A reference to the array for chaining.

◆ getBlend()

Color4 cugl::Color4::getBlend ( Color4  other) const

Returns a blend of this color with the other one.

The blending is the standard over operation with this color as the destination. It assumes that the color values are not premultiplied.

Note: this does not modify this color.

Parameters
otherThe color to interpolate with.
Returns
The newly blended color

◆ getBlendPre()

Color4 cugl::Color4::getBlendPre ( Color4  other) const

Returns a blend of this color with the other one.

The blending is the standard over operation with this color as the destination. It assumes that this color is premultiplied.

Note: this does not modify this color.

Parameters
otherThe color to interpolate with.
Returns
The newly blended color

◆ getClamp()

Color4 cugl::Color4::getClamp ( Color4  min,
Color4  max 
) const
inline

Returns a copy of this color clamped within the given range.

Note: this does not modify this color.

Parameters
minThe minimum value.
maxThe maximum value.
Returns
A copy of this color clamped within the given range.

◆ getComplement()

Color4 cugl::Color4::getComplement ( bool  alpha = false) const
inline

Returns the complement of this color.

The complement of the color is the (255-v) for each value v.

Parameters
alphaWhether to complement the alpha value (optional)

Note: this does not modify this color.

Returns
The complement of this color

◆ getLerp()

Color4 cugl::Color4::getLerp ( Color4  other,
float  alpha 
) const
inline

Returns the linear interpolation of this color with other.

If alpha is 0, the color is unchanged. If alpha is 1, the color is other. Otherwise it is a value in between. If alpha is outside of the range 0 to 1, it is clamped to the nearest value.

This method just implements standard linear interpolation. It does not attempt to give any blending semantics to it.

Note: this does not modify this color.

Parameters
otherThe color to interpolate with.
alphaThe interpolation value in 0..1
Returns
The linear interpolation of this color with other.

◆ getMap()

Color4 cugl::Color4::getMap ( std::function< Uint8(Uint8)>  func,
bool  alpha = false 
) const
inline

Returns a copy of this color with func applied to each component.

This method supports any function that has the signature Glubyte func(Glubyte). If you wish to use float-oriented function, use Color4f instead.

Parameters
funcThe function to map on the color values.
alphaWhether to modify the alpha value (optional)
Returns
A copy of this color with func applied to each component.

◆ getPacked()

Uint32 cugl::Color4::getPacked ( ) const
inline

Returns the packed integer representation of this color

This representation returned is native to the platform. In other words, it is guaranteed to be the same value as if you were to access the rgba attribute directly. That makes this value the correct one to send to OpenGL (which always uses client order).

However, this value is not necessarily the same value that you assigned the constructor, because of endianness issues. To get that value, you should call getRGBA instead.

Returns
the packed integer representation of this color

◆ getPremultiplied()

Color4 cugl::Color4::getPremultiplied ( ) const
inline

Returns the premultiplied version of this color, using its current alpha.

This class does not store whether the color is already premultiplied. Hence premultiplying an already premultiplied color will have a compounding effect.

Note: this does not modify this color.

Returns
The newly premultiplied color

◆ getRGBA()

Uint32 cugl::Color4::getRGBA ( ) const
inline

Returns the canonical integer representation of this color

This method returns the color as an integer in network order, which matches the way web colors are specified. In this order, red will always be the highest order byte and alpha will always be the lowest order byte. Hence 0x00ff00ff represents green or the color (0, 1, 0, 1).

The value returned by this method is guaranteed to be the same value that you assigned the constructor, or via setter. However, it is not guaranteed to be a value recognizable by OpenGL. For that value you will need to call getPacked instead.

Returns
the canonical integer representation of this color

◆ getUnpremultiplied()

Color4 cugl::Color4::getUnpremultiplied ( ) const
inline

Returns the unpremultiplied version of this color, using its current alpha.

This class does not store whether the color is already premultiplied. Hence unpremultiplying an non-premultiplied color will have a compounding effect.

If the alpha value is 0, the copy is equal to the original color.

Note: this does not modify this color.

Returns
The newly premultiplied color

◆ lerp() [1/2]

static Color4 * cugl::Color4::lerp ( Color4  c1,
Color4  c2,
float  alpha,
Color4 dst 
)
static

Interpolates the two colors c1 and c2, and stores the result in dst.

If alpha is 0, the result is c1. If alpha is 1, the color is c2. Otherwise it is a value in c1..c2. If alpha is outside of the range 0 to 1, it is clamped to the nearest value.

This method just implements standard linear interpolation. It does not attempt to give any blending semantics to it.

Parameters
c1The first color.
c2The second color.
alphaThe interpolation value in 0..1
dstThe color to store the result in
Returns
A reference to dst for chaining

◆ lerp() [2/2]

Color4 & cugl::Color4::lerp ( const Color4f  other,
float  alpha 
)

Modifies this color to be the linear interpolation with other.

If alpha is 0, the color is unchanged. If alpha is 1, the color is other. Otherwise it is a value in between. If alpha is outside of the range 0 to 1, it is clamped to the nearest value.

This method just implements standard linear interpolation. It does not attempt to give any blending semantics to it.

Parameters
otherThe color to interpolate with.
alphaThe interpolation value in 0..1
Returns
This color, after the interpolation.

◆ lighterThan()

bool cugl::Color4::lighterThan ( Color4  c) const
inline

Returns true if this color dominates the given color.

Domination means that all components of this color are greater than or equal to the components of the given color. However, alpha is reversed for this computation, as a lesser value means more transparent (and hence lighter).

Parameters
cThe color to compare against.
Returns
True if this color is dominated by the given color.

◆ map()

Color4 & cugl::Color4::map ( std::function< Uint8(Uint8)>  func,
bool  alpha = false 
)
inline

Maps the given function to the color values in place.

This method supports any function that has the signature Glubyte func(Glubyte). If you wish to use float-oriented function, use Color4f instead.

Parameters
funcThe function to map on the color values.
alphaWhether to modify the alpha value (optional)
Returns
A reference to this (modified) Color4f for chaining.

◆ operator Color4f()

cugl::Color4::operator Color4f ( ) const

Cast from Color4f to a float-based Color4.

◆ operator std::string()

cugl::Color4::operator std::string ( ) const
inline

Cast from Color4f to a string.

◆ operator Vec3()

cugl::Color4::operator Vec3 ( ) const

Cast from Color4f to a vector.

The attributes are all divided by 255.0. The alpha value is dropped.

◆ operator Vec4()

cugl::Color4::operator Vec4 ( ) const

Cast from Color4 to a vector.

The attributes are all divided by 255.0.

◆ operator!=()

bool cugl::Color4::operator!= ( Color4  c) const
inline

Returns true if this color is not equal to the given color.

Comparison is exact, which may be unreliable given that the attributes are floats.

Parameters
cThe color to compare against.
Returns
True if this color is not equal to the given color.

◆ operator*() [1/2]

const Color4 cugl::Color4::operator* ( Color4  c) const
inline

Returns the scalar product of this color with the given color.

This operation is functionally identical to multiplicative blending.

Note: this does not modify this color.

Parameters
cThe color to scale by.
Returns
The scalar product of this color with the given color.

◆ operator*() [2/2]

const Color4 cugl::Color4::operator* ( float  s) const
inline

Returns the scalar product of this color with the given color.

The scaling is clamped so that this remains a valid color.

This version of scaling always multiplies alpha values.

Note: this does not modify this color.

Parameters
sThe value to scale by.
Returns
The scalar product of this color with the given value.

◆ operator*=() [1/2]

Color4 & cugl::Color4::operator*= ( Color4  c)
inline

Scales this color nonuniformly by the given color.

This operation is functionally identical to multiplicative blending.

Parameters
cThe color to scale by
Returns
A reference to this (modified) Color4 for chaining.

◆ operator*=() [2/2]

Color4 & cugl::Color4::operator*= ( float  s)
inline

Scales this color in place by the given factor.

The scaling is clamped so that this remains a valid color.

This version of scaling always multiplies alpha values.

Parameters
sThe value to scale by
Returns
A reference to this (modified) Color4 for chaining.

◆ operator+()

const Color4 cugl::Color4::operator+ ( Color4  c) const
inline

Returns the sum of this color with the given color.

This operation is functionally identical to additive blending. The addition is clamped so that this remains a valid color.

This version of addition always adds alpha values.

Note: this does not modify this color.

Parameters
cThe color to add.
Returns
The sum of this color with the given color.

◆ operator+=()

Color4 & cugl::Color4::operator+= ( Color4  c)
inline

Adds the given color to this one in place.

This operation is functionally identical to additive blending. The addition is clamped so that this remains a valid color.

This version of addition always adds alpha values.

Parameters
cThe color to add
Returns
A reference to this (modified) Color4 for chaining.

◆ operator-()

const Color4 cugl::Color4::operator- ( Color4  c) const
inline

Returns the difference of this color with the given color.

This operation is functionally identical to subtractive blending. The subtraction is clamped so that this remains a valid color.

This version of subraction always subtracts alpha values.

Note: this does not modify this color.

Parameters
cThe color to subtract.
Returns
The difference of this color with the given color.

◆ operator-=()

Color4 & cugl::Color4::operator-= ( Color4  c)
inline

Subtracts the given color from this one in place.

This operation is functionally identical to subtractive blending. The subtraction is clamped so that this remains a valid color.

This version of subraction always subtracts alpha values.

Parameters
cThe color to subtract
Returns
A reference to this (modified) Color4 for chaining.

◆ operator<()

bool cugl::Color4::operator< ( Color4  c) const

Returns true if this color is less than the given color.

This comparison uses lexicographical order of rgba. To test if all components in this color are less than those of c, use the method darkerThan().

Parameters
cThe color to compare against.
Returns
True if this color is less than the given color.

◆ operator<=()

bool cugl::Color4::operator<= ( Color4  c) const
inline

Returns true if this color is less than or equal the given color.

This comparison uses lexicographical order of rgba. To test if all components in this color are less than those of c, use the method darkerThan().

Parameters
cThe color to compare against.
Returns
True if this color is less than or equal the given color.

◆ operator=() [1/6]

Color4 & cugl::Color4::operator= ( const Color4f  color)

Sets the attributes of this color from the given float-based color.

The attributes are read in the order r,g,b,a. They are all multiplied by 255.0f and rounded up before assignment.

Parameters
colorThe color to convert.
Returns
A reference to this (modified) Color4f for chaining.

◆ operator=() [2/6]

Color4 & cugl::Color4::operator= ( const float *  array)
inline

Sets the elements of this color from the values in the specified array.

The color values must all be in the range 0..1. They are multiplied by 255.0 and rounded up

Parameters
arrayAn array containing the color values in the order r, g, b, a
Returns
A reference to this (modified) Color4 for chaining.

◆ operator=() [3/6]

Color4 & cugl::Color4::operator= ( const std::string  name)
inline

Sets the elements of this color to match the string represenation

A string representation may either be an explicit name or a (modified) HTML code. The supported color names are the classic TCL/TK colors, which are listed here:

https://www.tcl.tk/man/tcl8.6/TkCmd/colors.htm

An HTML code is a string that starts with #, followed by the characters 0-9, A-F. This is the hex representation of the color, as specified here:

https://htmlcolorcodes.com

We support 3, 4, 6, and 8 character codes (not including the #). The standard code is 6 characters, but that does not specify the alpha value.
If you specify eight characters, the last two characters specify the byte values for alpha, following the same rules for red, green, blue.

Finally, the 3 and 4 character versions are the abbreviated 6 and 8 character versions, respectively. In these versions, the byte values are repeated. So #fa2 becomes #ffaa22 and #fad3 becomes #ffaadd33.

Parameters
nameThe string name
Returns
A reference to this (modified) Color4f for chaining.

◆ operator=() [4/6]

Color4 & cugl::Color4::operator= ( const Vec3  vector)

Sets the coordinates of this color to those of the given vector.

The attributes are read in the order x,y,z. They are all multiplied by 255.0f and rounded up before assignment. The alpha value is 255.

Parameters
vectorThe vector to convert
Returns
A reference to this (modified) Color4f for chaining.

◆ operator=() [5/6]

Color4 & cugl::Color4::operator= ( const Vec4  vector)

Sets the coordinates of this color to those of the given vector.

The attributes are read in the order x,y,z,w. They are all multiplied by 255.0f and rounded up before assignment.

Parameters
vectorThe vector to convert
Returns
A reference to this (modified) Color4f for chaining.

◆ operator=() [6/6]

Color4 & cugl::Color4::operator= ( Uint32  color)
inline

Sets this color to the integer interpreted as an RGBA value.

This representation assigned is native to the platform, but the integer parameter is interpreted in network order, which matches the way web colors are specified. In this order, red will always be the highest order byte and alpha will always be the lowest order byte. Hence
0x00ff00ff represents green or the color (0, 1, 0, 1).

Parameters
colorThe integer to interpret as an RGBA value.
Returns
A reference to this (modified) Color4 for chaining.

◆ operator==()

bool cugl::Color4::operator== ( Color4  c) const
inline

Returns true if this color is equal to the given color.

Parameters
cThe color to compare against.
Returns
True if this color is equal to the given color.

◆ operator>()

bool cugl::Color4::operator> ( Color4  c) const

Returns true if this color is greater than the given color.

This comparison uses lexicographical order of rgba. To test if all components in this color are greater than those of c, use the method lighterThan().

Parameters
cThe color to compare against.
Returns
True if this color is greater than the given color.

◆ operator>=()

bool cugl::Color4::operator>= ( Color4  c) const
inline

Returns true if this color is greater than or equal the given color.

This comparison uses lexicographical order of rgba. To test if all components in this color are greater than those of c, use the method lighterThan().

Parameters
cThe color to compare against.
Returns
True if this color is greater than or equal the given color.

◆ premultiply()

Color4 & cugl::Color4::premultiply ( )
inline

Premultiplies this color with its current alpha.

This class does not store whether the color is already premultiplied. Hence premultiplying an already premultiplied color will have a compounding effect.

Returns
This color, after premultiplication.

◆ scale() [1/3]

Color4 & cugl::Color4::scale ( Color4  c,
bool  alpha = false 
)
inline

Scales this color nonuniformly by the given color.

This operation is functionally identical to multiplicative blending.

Parameters
cThe color to scale by
alphaWhether to scale the alpha value (optional)
Returns
A reference to this (modified) Color4 for chaining.

◆ scale() [2/3]

Color4 & cugl::Color4::scale ( float  s,
bool  alpha = false 
)
inline

Scales this color in place by the given factor.

The scaling is clamped so that this remains a valid color.

Parameters
sThe scalar to multiply by
alphaWhether to scale the alpha value (optional)
Returns
A reference to this (modified) Color4 for chaining.

◆ scale() [3/3]

Color4 & cugl::Color4::scale ( float  sr,
float  sg,
float  sb,
float  sa = 1 
)
inline

Scales this color nonuniformly by the given factors.

The scaling is clamped so that this remains a valid color.

Parameters
srThe scalar to multiply the red value
sgThe scalar to multiply the green value
sbThe scalar to multiply the blue value
saThe scalar to multiply the alpha value (optional)
Returns
A reference to this (modified) Color4 for chaining.

◆ set() [1/5]

Color4 & cugl::Color4::set ( const Color4  c)
inline

Sets the values of this color to those in the specified color.

Parameters
cThe color to copy.
Returns
A reference to this (modified) Color4f for chaining.

◆ set() [2/5]

Color4 & cugl::Color4::set ( const float *  array)

Sets the elements of this color from the values in the specified array.

The color values must all be in the range 0..1. They are multiplied by 255.0 and rounded up

Parameters
arrayAn array containing the color values in the order r, g, b, a
Returns
A reference to this (modified) Color4 for chaining.

◆ set() [3/5]

Color4 & cugl::Color4::set ( const std::string  name)

Sets the elements of this color to match the string represenation

A string representation may either be an explicit name or a (modified) HTML code. The supported color names are the classic TCL/TK colors, which are listed here:

https://www.tcl.tk/man/tcl8.6/TkCmd/colors.htm

An HTML code is a string that starts with #, followed by the characters 0-9, A-F. This is the hex representation of the color, as specified here:

https://htmlcolorcodes.com

We support 3, 4, 6, and 8 character codes (not including the #). The standard code is 6 characters, but that does not specify the alpha value.
If you specify eight characters, the last two characters specify the byte values for alpha, following the same rules for red, green, blue.

Finally, the 3 and 4 character versions are the abbreviated 6 and 8 character versions, respectively. In these versions, the byte values are repeated. So #fa2 becomes #ffaa22 and #fad3 becomes #ffaadd33.

Parameters
nameThe string name
Returns
A reference to this (modified) Color4f for chaining.

◆ set() [4/5]

Color4 & cugl::Color4::set ( Uint32  color)

Sets this color to the integer interpreted as an RGBA value.

This representation assigned is native to the platform, but the integer parameter is interpreted in network order, which matches the way web colors are specified. In this order, red will always be the highest order byte and alpha will always be the lowest order byte. Hence
0x00ff00ff represents green or the color (0, 1, 0, 1).

Parameters
colorThe integer to interpret as an RGBA value.
Returns
A reference to this (modified) Color4 for chaining.

◆ set() [5/5]

Color4 & cugl::Color4::set ( Uint8  r,
Uint8  g,
Uint8  b,
Uint8  a = 255 
)
inline

Sets the elements of this color to the specified values.

Parameters
rThe red color.
gThe green color.
bThe blue color.
aThe alpha value (optional).
Returns
A reference to this (modified) Color43 for chaining.

◆ setHSL()

Color4 & cugl::Color4::setHSL ( float  h,
float  s,
float  l,
Uint8  a = 255 
)

Sets this color to have the given hue-saturation-lightness

This method will apply the formula given on this page:

 https://en.wikipedia.org/wiki/HSL_and_HSV
Parameters
hThe hue (in radians)
sThe saturation (in range 0..1)
lThe lightness (in range 0..1)
aThe alpha component (in range 0..255)
Returns
A reference to this (modified) Color4f for chaining.

◆ setHSV()

Color4 & cugl::Color4::setHSV ( float  h,
float  s,
float  v,
Uint8  a = 255 
)

Sets this color to have the given hue-saturation-value

This method will convert to hue-staturation-lightness and then apply the formula given on this page:

 https://en.wikipedia.org/wiki/HSL_and_HSV
Parameters
hThe hue (in radians)
sThe saturation (in range 0..1)
vThe brightness value (in range 0..1)
aThe alpha component (in range 0..255)
Returns
A reference to this (modified) Color4f for chaining.

◆ subtract() [1/2]

Color4 & cugl::Color4::subtract ( Color4  c,
bool  alpha = false 
)
inline

Subtracts the given color from this one in place.

This operation is functionally identical to subtractive blending. The subtraction is clamped so that this remains a valid color.

Parameters
cThe color to subtract
alphaWhether to subtract the alpha value (optional)
Returns
A reference to this (modified) Color4 for chaining.

◆ subtract() [2/2]

Color4 & cugl::Color4::subtract ( Uint8  r,
Uint8  g,
Uint8  b,
Uint8  a = 0 
)
inline

Subtracts the given values from this color.

The subtraction is clamped so that this remains a valid color.

Parameters
rThe red color to subtract.
gThe green color to subtract.
bThe blue color to subtract.
aThe alpha value (optional).
Returns
A reference to this (modified) Color4 for chaining.

◆ toString()

std::string cugl::Color4::toString ( bool  verbose = false) const

Returns a string representation of this vector for debuggging purposes.

If verbose is true, the string will include class information. This allows us to unambiguously identify the class.

Parameters
verboseWhether to include class information
Returns
a string representation of this vector for debuggging purposes.

◆ unpremultiply()

Color4 & cugl::Color4::unpremultiply ( )
inline

Undoes premultiplication this color with its current alpha.

This class does not store whether the color is already premultiplied. Hence unpremultiplying an non-premultiplied color will have a compounding effect.

If the alpha value is 0, the color is unchanged.

Returns
This color, after undoing premultiplication.

Member Data Documentation

◆ a

Uint8 cugl::Color4::a

The alpha value

◆ b

Uint8 cugl::Color4::b

The blue value

◆ BLACK

const Color4 cugl::Color4::BLACK
static

The Black color (0,0,0,1)

◆ BLUE

const Color4 cugl::Color4::BLUE
static

The Blue color (0,0,1,1)

◆ CLEAR

const Color4 cugl::Color4::CLEAR
static

The Clear color (0,0,0,0)

◆ CORNFLOWER

const Color4 cugl::Color4::CORNFLOWER
static

The classic XNA color (0.392,0.584,0.93,1)

◆ CYAN

const Color4 cugl::Color4::CYAN
static

The Cyan color (0,1,1,1)

◆ g

Uint8 cugl::Color4::g

The green value

◆ GRAY

const Color4 cugl::Color4::GRAY
static

The Gray color (0.65,0.65,0.65,1)

◆ GREEN

const Color4 cugl::Color4::GREEN
static

The Green color (0,1,0,1)

◆ MAGENTA

const Color4 cugl::Color4::MAGENTA
static

The Magenta color (1,0,1,1)

◆ ORANGE

const Color4 cugl::Color4::ORANGE
static

The Orange color (1,0.5,0,1)

◆ PAPYRUS

const Color4 cugl::Color4::PAPYRUS
static

The Playing Fields color (0.933f,0.99f,0.65f,1.0f)

◆ r

Uint8 cugl::Color4::r

The red value

◆ RED

const Color4 cugl::Color4::RED
static

The Red color (1,0,0,1)

◆ rgba

Uint32 cugl::Color4::rgba

The color as a packed integer (WARNING: Endian specific)

◆ WHITE

const Color4 cugl::Color4::WHITE
static

The White color (1,1,1,1)

◆ YELLOW

const Color4 cugl::Color4::YELLOW
static

The Yellow color (1,1,0,1)


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