Q5

touchgfx/widgets/canvas/CWRUtil.hpp

Defines a "floating point number" with 5 bits reserved for the fractional part of the decimal number. Q5 implements some simple arithmetic operations, most yielding a Q5 number and some yielding a Q10 number as a result. Other operations also work with Q15 numbers.

See: Q10, Q15

Public Functions

int	ceil() const
	Convert the Q5 value to an integer by removing the 5 bits used for the fraction.
int	floor() const
	Convert the Q5 value to an integer by removing the 5 bits used for the fraction.
	operator int() const
	Gets the Q5 as an integer without conversion.
Q5	operator%(const Q5 q5) const
	Modulus operator.
Q5 &	operator%=(const Q5 q5)
	Modulus operator.
Q5	operator*(const int i) const
	Multiplication operator.
Q5	operator*(const Q15 & q15) const
	Multiplication operator.
Q10	operator*(const Q5 & q5) const
	Multiplication operator.
Q5	operator+(const Q5 & q5) const
	Addition operator.
Q5 &	operator+=(const Q5 & q5)
	Addition operator.
Q5	operator-() const
	Negation operator.
Q5	operator-(const Q5 & q5) const
	Subtraction operator.
Q5 &	operator-=(const Q5 & q5)
	Subtraction operator.
Q5	operator/(const int i) const
	Division operator.
Q5	operator/(const Q5 q5) const
	Division operator.
	Q5()
	Initializes a new instance of the Q5 class.
	Q5(const Q10 q10)
	Constructor from Q10.
	Q5(int i)
	Constructor from integer.
int	round() const
	Round the Q5 value to the nearest integer value.
template <typename T > T	to() const
	Convert the Q5 value to an integer by removing the 5 bits used for the fraction, or to a floating point value by dividing by 32, depending on the type specified as T.

Public Functions Documentation

ceil

int ceil	(			)	const

Convert the Q5 value to an integer by removing the 5 bits used for the fraction.

The number is rounded up to the nearest integer.

Returns:

The first integer value higher than (or equal to) the Q5 value.

See also:

floor

floor

int floor	(			)	const

Convert the Q5 value to an integer by removing the 5 bits used for the fraction.

The number is rounded down to the nearest integer.

Returns:

The first integer value higher than (or equal to) the Q5 value.

See also:

ceil

operator int

operator int	(			)	const

Gets the Q5 as an integer without conversion.

Returns:

The unconverted Q5 value.

operator%

Q5 operator%	(	const Q5	q5	)

Modulus operator.

Parameters:

q5	The Q5 to modulus this by.

Returns:

The result of the operation.

operator%=

Q5 & operator%=	(	const Q5	q5	)

Modulus operator.

Parameters:

q5	The Q5 to modulus this by.

Returns:

The result of the operation.

operator*

Q5 operator*	(	const int	i	)

Multiplication operator.

Parameters:

i	The integer to multiply this with.

Returns:

The result of the operation.

operator*

Q5 operator*	(	const Q15 &	q15	)

Multiplication operator.

Often used in relation with sine and cosine calculation which are pre-calculated as Q15. As the result is needed as a Q5, this operator multiplies with the given Q15 and converts the result to a Q5.

Parameters:

q15	The Q15 to multiply this with.

Returns:

The result of the operation.

See also:

Q15

operator*

Q10 operator*	(	const Q5 &	q5	)

Multiplication operator.

The result is a Q10, not a Q5, for increased precision.

Parameters:

q5	The Q5 to multiply this with.

Returns:

The result of the operation.

See also:

Q10

operator+

Q5 operator+	(	const Q5 &	q5	)

Addition operator.

Parameters:

q5	The Q5 to add to this.

Returns:

The result of the operation.

operator+=

Q5 & operator+=	(	const Q5 &	q5	)

Addition operator.

Parameters:

q5	The Q5 to add to this.

Returns:

The result of the operation.

operator-

Q5 operator-	(			)	const

Negation operator.

Returns:

The negative value of this.

operator-

Q5 operator-	(	const Q5 &	q5	)

Subtraction operator.

Parameters:

q5	The Q5 to subtract from this.

Returns:

The result of the operation.

operator-=

Q5 & operator-=	(	const Q5 &	q5	)

Subtraction operator.

Parameters:

q5	The Q5 to subtract from this.

Returns:

The result of the operation.

operator/

Q5 operator/	(	const int	i	)

Division operator.

Parameters:

i	The integer to divide this by.

Returns:

The result of the operation.

operator/

Q5 operator/	(	const Q5	q5	)

Division operator.

Internally this Q5 is converted to Q10 before the division to increased precision.

Parameters:

q5	The Q5 to divide this by.

Returns:

The result of the operation.

See also:

Q10

Q5

Q5	(			)

Initializes a new instance of the Q5 class.

Q5

Q5	(	const Q10	q10	)

Constructor from Q10.

The Q10 is shifted down to convert it to Q5, thus the value is rounded down in the conversion.

Parameters:

q10	The Q10 value to convert to a Q5 value.

See also:

Q10

Q5

explicit Q5	(	int	i	)

Constructor from integer.

No conversion is done - the integer is assumed to already be in Q5 format.

Parameters:

i	Integer pre-formattet in Q5 format.

round

int round	(			)	const

Round the Q5 value to the nearest integer value.

Returns:

The integer closest to the Q5 value.

to

T to	(			)	const

Convert the Q5 value to an integer by removing the 5 bits used for the fraction, or to a floating point value by dividing by 32, depending on the type specified as T.

Template Parameters:

T	Either int or float.

Returns:

Q5 value as a type T.

Note

Using "to<int16_t>()" result in loss of precision. Use "(int16_t)to<int>()" instead.