donner Namespace Reference

Top-level Donner namespace, which is split into different sub-namespaces such as donner::svg and donner::css. More...

Namespaces
namespace	css
	Donner CSS library, a standalone composable CSS parser.
namespace	svg
	Donner SVG library, which can load, manipulate and render SVG files.

Classes
struct	AbsoluteLengthMetrics
	A container with ratios for converting absolute lengths, such as "cm" or "in", see https://www.w3.org/TR/css-values/#absolute-lengths. More...
struct	Box
	A 2D axis-aligned bounding box. More...
struct	CaseInsensitiveCharTraits
	Type traits for case-insensitive string comparison, usable with algorithms that accept an STL std::char_traits. More...
class	ElementTraversalGenerator
	Selectors may need to traverse the tree in different ways to match, and this is abstracted away using C++20 coroutines. More...
class	FakeElement
	A test fake for a type that satisfies the ElementLike concept. More...
struct	FontMetrics
	A container for font information relevant for computing font-relative lengths, per https://www.w3.org/TR/css-values/#font-relative-lengths. More...
struct	Length
	Parses a CSS <length-percentage> type as defined by https://www.w3.org/TR/css-values-3/#typedef-length-percentage. More...
struct	MathConstants
	Contains a set of math constants for the specified type (float or double). More...
struct	MathConstants< double >
	Math constants for double. More...
struct	MathConstants< float >
	Math constants for float. More...
class	OptionalRef
	A class that simulates an optional reference to a constant object of type T. More...
struct	QuadraticSolution
	Holds the solution of a quadratic equation, as returned by SolveQuadratic. More...
class	RcString
	A reference counted string, that is copy-on-write and implements the small-string optimization. More...
class	RcStringOrRef
	An in-transit type that can hold either an RcString or std::string_view, to enable transferring the RcString reference or also accepting a non-owning std::string_view from API surfaces. More...
class	SmallVector
	A vector with small-size optimization. More...
class	StringUtils
	A collection of string utils, such as case-insensitive comparison and StartsWith/EndsWith. More...
struct	Transform
	A 2D matrix representing an affine transformation. More...
struct	Vector2
	A 2D vector, (x, y). More...
struct	XMLQualifiedName
	Represents an XML attribute name with an optional namespace. More...
struct	XMLQualifiedNameRef
	Reference type for XMLQualifiedName, to pass the value to APIs without needing to allocate an RcString. More...

Concepts
concept	ElementLike
	Concept for types that can be matched against a selector, such as a donner::svg::SVGElement.
concept	StringLike
	A concept for types that are string-like, i.e.

Typedefs
typedef Box< double >	Boxd
	Shorthand for Box<double>.
typedef Length< double >	Lengthd
	Shorthand for Length<double>.
typedef Transform< float >	Transformf
	Shorthand for Transform<float>
typedef Transform< double >	Transformd
	Shorthand for Transform<double>
typedef Vector2< float >	Vector2f
	Shorthand for Vector2<float>
typedef Vector2< double >	Vector2d
	Shorthand for Vector2<double>
typedef Vector2< int >	Vector2i
	Shorthand for Vector2<int>

Enumerations
enum class	LengthUnit {   None ,   Percent ,   _ABSOLUTE ,   Cm ,   Mm ,   Q ,   In ,   Pc ,   Pt ,   Px ,   _RELATIVE ,   Em ,   Ex ,   Ch ,   Rem ,   Vw ,   Vh ,   Vmin ,   Vmax }
	The unit identifier for a length, corresponding to CSS unit identifiers. More...
enum class	StringComparison {   Default ,   IgnoreCase }
	String comparison options, e.g. case sensitivity. More...

Functions
template<ElementLike T>
ElementTraversalGenerator< T >	singleElementGenerator (T element)
	A generator that yields a single element, if it exists.
template<ElementLike T>
ElementTraversalGenerator< T >	parentsGenerator (T element)
	A generator that yields all parents of an element, repeatedly following parentElement() until reaching the root.
template<ElementLike T>
ElementTraversalGenerator< T >	previousSiblingsGenerator (T element)
	A generator that yields all siblings of an element, in reverse order.
template<ElementLike T>
ElementTraversalGenerator< T >	allChildrenRecursiveGenerator (T element)
	A generator that yields all children of an element recursively with pre-order traversal.
std::ostream &	operator<< (std::ostream &os, LengthUnit unit)
	OStream output operator, writes the enum value as a stream, e.g. Percent or Px.
float	NarrowToFloat (double from)
	Semantically represent a narrowing conversion, such as converting a double to a float, to make the conversion more visible.
template<typename T >
const T &	Min (const T &a, const T &b)
	Returns minimum of the provided values.
template<typename T , typename... Args>
const T &	Min (const T &a, const T &b, Args &&... args)
	Returns minimum of the provided values.
template<typename T >
const T &	Max (const T &a, const T &b)
	Returns maximum of the provided values.
template<typename T , typename... Args>
const T &	Max (const T &a, const T &b, Args &&... args)
	Returns maximum of the provided values.
float	Abs (float a)
	Returns the absolute value of the number.
double	Abs (double a)
	Returns the absolute value of the number.
template<typename T , typename = std::enable_if<std::is_integral<T>::value && std::is_signed<T>::value>>
T	Abs (T a)
	Returns the absolute value of the number.
template<typename T , typename = std::enable_if<std::is_floating_point<T>::value>>
T	Round (T orig)
	Round a floating point value to an integer.
template<typename T >
T	Lerp (T a, T b, const float t)
	Returns linear interpolation of a and b with ratio t.
template<typename T >
const T	Clamp (T value, T low, T high)
	Clamps a value between low and high.
template<typename T >
bool	NearEquals (T a, T b, T tolerance=std::numeric_limits< T >::epsilon())
	Returns if a equals b, taking possible rounding errors into account.
template<typename T >
bool	NearZero (T a, T tolerance=std::numeric_limits< T >::epsilon())
	Returns if a equals zero, taking rounding errors into account.
template<typename T , typename = std::enable_if<std::is_integral<T>::value>>
bool	InRange (T var, T start, T end)
	Test if a variable is in a specific range, using an optimized technique that requires only one branch.
template<typename T >
QuadraticSolution< T >	SolveQuadratic (T a, T b, T c)
	Solve a quadratic equation.
	MATCHER_P (ToStringIs, expected, "")
	Matches the string representation of an object, by calling testing::PrintToString and comparing the results with the expected value.
	MATCHER_P2 (Vector2Eq, xMatcher, yMatcher, "")
	Matches a Vector.
	MATCHER_P2 (Vector2Near, xValue, yValue, "")
	Matches a Vector2 with DoubleNear(0.01).
	MATCHER_P (NormalizedEq, expectedVector, "")
	Matches if two vectors are equal when both are normalized, within an error of 0.01.
	MATCHER_P (TransformEq, other, "transform eq "+testing::PrintToString(other))
	Matches a transform with near-equals comparison.
	MATCHER_P6 (TransformIs, d0, d1, d2, d3, d4, d5, "")
	Matches a transform per-element, with a near-equals comparison using a threshold of 0.0001.
	MATCHER (TransformIsIdentity, "")
	Matches if a transform is identity.
	MATCHER_P2 (BoxEq, topLeftMatcher, bottomRightMatcher, "")
	Matches a Box.
	MATCHER_P2 (LengthIs, valueMatcher, unitMatcher, "")
	Matches a Length.

Detailed Description

Top-level Donner namespace, which is split into different sub-namespaces such as donner::svg and donner::css.

---

Class Documentation

donner::MathConstants

struct donner::MathConstants

template<typename T>
struct donner::MathConstants< T >

Contains a set of math constants for the specified type (float or double).

Template Parameters

T

donner::QuadraticSolution

struct donner::QuadraticSolution

template<typename T>
struct donner::QuadraticSolution< T >

Holds the solution of a quadratic equation, as returned by SolveQuadratic.

Template Parameters

T

Collaboration diagram for donner::QuadraticSolution< T >:

Class Members
bool	hasSolution = false	True if the equation has solutions.
array< T, 2 >	solution	Solutions to the equation, valid if hasSolution is true.

Enumeration Type Documentation

LengthUnit

enum class donner::LengthUnit

strong

The unit identifier for a length, corresponding to CSS unit identifiers.

See https://www.w3.org/TR/css-values-3/#lengths for definitions.

Enumerator
None	Unitless.
Percent	Percentage, using the '%' symbol.
_ABSOLUTE	Absolute lengths, https://www.w3.org/TR/css-values-3/#absolute-lengths.
Cm	Centimeters, 1cm = 96px/2.54.
Mm	Millimeters, 1mm = 1/10th of 1cm.
Q	Quarter-millimeters, 1Q = 1/40th of 1cm.
In	Inches, 1in = 2.54cm = 96px.
Pc	Picas, 1pc = 1/6th of 1in.
Pt	Points, 1pt = 1/72nd of 1in.
Px	Pixels, 1px = 1/96th of 1in.
_RELATIVE	Relative lengths, https://www.w3.org/TR/css-values-3/#relative-lengths.
Em	Font size, 1em = current font size.
Ex	x-height of the current font, 1ex = x-height of current font.
Ch	Width of the glyph '0' in the current font, 1ch = width of '0' in current font.
Rem	Root font size, 1rem = font size of the root element.
Vw	Viewport width, 1vw = 1% of viewport width.
Vh	Viewport height, 1vh = 1% of viewport height.
Vmin	Smaller of viewport width and height, 1vmin = 1% of smaller of viewport width and height.
Vmax	Larger of viewport width and height, 1vmax = 1% of larger of viewport width and height.

StringComparison

enum class donner::StringComparison

strong

String comparison options, e.g. case sensitivity.

Enumerator
Default	The default case-sensitive string comparison.
IgnoreCase	Case-insensitive string comparison.

Function Documentation

InRange()

template<typename T , typename = std::enable_if<std::is_integral<T>::value>>

bool donner::InRange ( T var, T start, T end )

inline

Test if a variable is in a specific range, using an optimized technique that requires only one branch.

Some compilers do this automatically.

Example:

if (InRange(var, 'a', 'z')) // ...

Lerp()

template<typename T >

T donner::Lerp ( T a, T b, const float t )

inline

Returns linear interpolation of a and b with ratio t.

Returns

a if t == 0, b if t == 1, and the linear interpolation else.

MATCHER_P() [1/3]

donner::MATCHER_P	(	NormalizedEq	,
		expectedVector	,
		""	)

Matches if two vectors are equal when both are normalized, within an error of 0.01.

Example:

EXPECT_THAT(Vector2d(1.0, 2.0), NormalizedEq(Vector2d(2.0, 4.0)));

Parameters

expectedVector

Expected value vector, which will be normalized.

MATCHER_P() [2/3]

donner::MATCHER_P	(	ToStringIs	,
		expected	,
		""	)

Matches the string representation of an object, by calling testing::PrintToString and comparing the results with the expected value.

Example:

EXPECT_THAT(myObject, ToStringIs("MyObject(foo)"));

Parameters

expected

Expected string representation.

MATCHER_P() [3/3]

donner::MATCHER_P	(	TransformEq	,
		other	,
		"transform eq "+	testing::PrintToStringother )

Matches a transform with near-equals comparison.

Example:

EXPECT_THAT(result, TransformEq(Transformd::Scale({2.0, 2.0})));

Parameters

other

Transform object to compare.

MATCHER_P2() [1/4]

donner::MATCHER_P2	(	BoxEq	,
		topLeftMatcher	,
		bottomRightMatcher	,
		""	)

Matches a Box.

Parameters

topLeftMatcher	Matcher for topLeft field.
bottomRightMatcher	Matcher for bottomRight field.

MATCHER_P2() [2/4]

donner::MATCHER_P2	(	LengthIs	,
		valueMatcher	,
		unitMatcher	,
		""	)

Matches a Length.

Example:

EXPECT_THAT(Length(10.0, Lengthd::Unit::Cm), LengthIs(10.0, Lengthd::Unit::Cm));

Parameters

valueMatcher	Matcher for value field.
unitMatcher	Matcher for unit field.

MATCHER_P2() [3/4]

donner::MATCHER_P2	(	Vector2Eq	,
		xMatcher	,
		yMatcher	,
		""	)

Matches a Vector.

Example:

EXPECT_THAT(Vector2i(1, 2), Vector2Eq(1, 2));

Parameters

xMatcher	X coordinate matcher.
yMatcher	Y coordinate matcher.

MATCHER_P2() [4/4]

donner::MATCHER_P2	(	Vector2Near	,
		xValue	,
		yValue	,
		""	)

Matches a Vector2 with DoubleNear(0.01).

Parameters

xValue	X coordinate, note that this is not a matcher.
yValue	Y coordinate, note that this is not a matcher.

MATCHER_P6()

donner::MATCHER_P6	(	TransformIs	,
		d0	,
		d1	,
		d2	,
		d3	,
		d4	,
		d5	,
		""	)

Matches a transform per-element, with a near-equals comparison using a threshold of 0.0001.

Example:

EXPECT_THAT(result, TransformIs(1.0, 0.0, 0.0, 1.0, 0.0, 0.0));

Parameters

d0	Corresponds to Transform::data[0]
d1	Corresponds to Transform::data[1]
d2	Corresponds to Transform::data[2]
d3	Corresponds to Transform::data[3]
d4	Corresponds to Transform::data[4]
d5	Corresponds to Transform::data[5]

NarrowToFloat()

float donner::NarrowToFloat ( double from )

inline

Semantically represent a narrowing conversion, such as converting a double to a float, to make the conversion more visible.

For example: const float f = NarrowToFloat(1.0);

parentsGenerator()

template<ElementLike T>

ElementTraversalGenerator< T > donner::parentsGenerator

(

T

element

)

A generator that yields all parents of an element, repeatedly following parentElement() until reaching the root.

Parameters

element

The element to start from, which is not yielded.

previousSiblingsGenerator()

template<ElementLike T>

ElementTraversalGenerator< T > donner::previousSiblingsGenerator

(

T

element

)

A generator that yields all siblings of an element, in reverse order.

This repeatedly follows previousSibling().

Parameters

element

The element to start from, which is not yielded.

singleElementGenerator()

template<ElementLike T>

ElementTraversalGenerator< T > donner::singleElementGenerator

(

T

element

)

A generator that yields a single element, if it exists.

Parameters

element

The element to yield. If this is std::nullopt, the generator will yield nothing.

SolveQuadratic()

template<typename T >

QuadraticSolution< T > donner::SolveQuadratic	(	T	a,
		T	b,
		T	c )

Solve a quadratic equation.

\( a x^2 + b x + c = 0 \)

Parameters

a	First coefficient.
b	Second coefficient.
c	Third coefficient.

Returns

QuadraticSolution, containing 0-2 solutions.