legato_math.h File Reference

Defines common math functions for general use. More...

#include "gfx/legato/common/legato_common.h"

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Data Structures
struct	leArcQuadrantQuery
struct	leResolvedAngleRanges

Typedefs
typedef struct leResolvedAngleRanges	leResolvedAngleRanges

Enumerations
enum	LE_TRIG_FUNCTION_TYPE { LE_TRIG_SINE_TYPE, LE_TRIG_COSINE_TYPE }
	Used to define the types of trig functions. More...
enum	LE_QUADRANT { LE_Q1, LE_Q2, LE_Q3, LE_Q4 }
	Used to define the basic four quandrants of a coordinate plane. More...
enum	leArcDir { LE_CCW, LE_CW }
	Used to define arc direction. More...

Functions
LIB_EXPORT int32_t	leMini (int32_t l, int32_t r)
	Calculate minimum of two integers. More...
LIB_EXPORT int32_t	leMaxi (int32_t l, int32_t r)
	Calculate maximum of two integers. More...
LIB_EXPORT float	leMinf (float l, float r)
	Calculate minimum of two floats. More...
LIB_EXPORT float	leMaxf (float l, float r)
	Calculate maximum of two floats. More...
LIB_EXPORT int32_t	leClampi (int32_t min, int32_t max, int32_t i)
	Calculates clamp of an integer. More...
LIB_EXPORT float	leClampf (float min, float max, float f)
	Calculate clamp of a float. More...
LIB_EXPORT uint32_t	lePercent (uint32_t l, uint32_t r)
	Calculate percent of number. More...
LIB_EXPORT uint32_t	lePercentWholeRounded (uint32_t l, uint32_t r)
	Calculate percent whole rounded. More...
LIB_EXPORT uint32_t	lePercentOf (uint32_t num, uint32_t percent)
	Calculate percent of a number. More...
LIB_EXPORT void	lePercentOfDec (uint32_t num, uint32_t percent, uint32_t *whl, uint32_t *dec)
	Calculate percent of a decimal. More...
LIB_EXPORT uint32_t	leScaleInteger (uint32_t num, uint32_t oldMax, uint32_t newMax)
	Calculate the scale of an integer. More...
LIB_EXPORT int32_t	leScaleIntegerSigned (int32_t num, int32_t oldMax, int32_t newMax)
	Calculate the scale of signed integer. More...
LIB_EXPORT uint32_t	leAbsoluteValue (int32_t val)
	Calculates the absolute value of a signed integer. More...
LIB_EXPORT int32_t	leLerp (int32_t x, int32_t y, uint32_t per)
	Calculates a linear interpolation of an integer based on a percentage between two signed points. More...
LIB_EXPORT int32_t	leDivideRounding (int32_t num, int32_t denom)
	Performs a linear interpolation of an integer based on a percentage between two signed points. More...
LIB_EXPORT leResult	lePolarToXY (int32_t r, int32_t a, lePoint *p)
	Generate points in an arc. More...
LIB_EXPORT int32_t	leNormalizeAngle (int32_t t)
	Normalize an angle between 0 - 360. More...
LIB_EXPORT int32_t	leSin (int32_t v)
	Calculate sin of a number. More...
LIB_EXPORT int32_t	leCos (int32_t v)
	Calculate cosine of a number. More...
LIB_EXPORT leResult	leEllipsePoint (int32_t t, int32_t a, int32_t b, int32_t theta, lePoint *p)
	Calculates points in an arc. More...
LIB_EXPORT double	leAtan (double val)
	Calculate atan of points. More...
leBool	lePointOnLineSide (lePoint *pt, lePoint *linePt, lePoint *sign)
void	leSortPointsX (lePoint *p1, lePoint *p2)
	Sorts two points on the X axis. More...
void	leSortPointsY (lePoint *p1, lePoint *p2)
	Sorts two points on the Y axis. More...
int32_t	leGetXGivenYOnLine (lePoint p1, lePoint p2, int32_t y)
	Project point. More...
int32_t	leGetYGivenXOnLine (lePoint p1, lePoint p2, int32_t x)
	Project Y give X. More...
lePoint	leRotatePoint (lePoint pos, lePoint org, int32_t ang)
	Rotates point. More...
leRect	leRotatedRectBounds (leRect rect, int32_t ang)
	Calculate bounding rectangle. More...
float	leSqrt (const float x)
lePoint	lePointOnCircle (uint32_t radius, int32_t angle)
uint32_t	leDegreesFromPercent (uint32_t percent, int32_t centerAngle, int32_t startAngle)
uint32_t	lePercentFromDegrees (uint32_t degrees, int32_t centerAngle, int32_t startAngle)
void	leNormalizeAngles (int32_t startAngle, int32_t spanAngle, int32_t *normalizedStartAngle, int32_t *normalizedEndAngle)
leResolvedAngleRanges	leResolveAngles (int32_t startAngle, int32_t spanAngle)
float	leRound (float flt)

Detailed Description

Defines common math functions for general use.

This is an array implementation that is used internally by the Legato user interface library.

Enumeration Type Documentation

LE_QUADRANT

enum LE_QUADRANT

Used to define the basic four quandrants of a coordinate plane.

LE_TRIG_FUNCTION_TYPE

enum LE_TRIG_FUNCTION_TYPE

Used to define the types of trig functions.

Trigonomtry is used in Legato.

leArcDir

enum leArcDir

Used to define arc direction.

The parameters CW and CCW enable you to define the direction of the arc.

Enumerator
LE_CCW	counter clock wise.
LE_CW	clock wise.

Function Documentation

leAbsoluteValue()

LIB_EXPORT uint32_t leAbsoluteValue

(

int32_t

val

)

Calculates the absolute value of a signed integer.

Calculates the absolute value of val.

uint32_t absl = leAbsoluteValue(val);

Parameters

param1

val is an integer.

Returns

the absolute value

leAtan()

LIB_EXPORT double leAtan

(

double

val

)

Calculate atan of points.

Calculate atan of x and y.

double val;
double angle = leAtan(val);

Parameters

param1

val is value.

Returns

the angle in radians

leClampf()

LIB_EXPORT float leClampf	(	float	min,
		float	max,
		float	f
	)

Calculate clamp of a float.

Calculates the clamp value of i constrained to the range min to max.

float val = leClampf(min, max, i);

Parameters

param1	min is an float.
param2	max is an float.
param3	f is an float.

Returns

a clamp integer

leClampi()

LIB_EXPORT int32_t leClampi	(	int32_t	min,
		int32_t	max,
		int32_t	i
	)

Calculates clamp of an integer.

Calculates the clamp value of i constrained to the range min to max.

int32_t val = leClampi(min, max, i);

Parameters

param1	min is an integer.
param2	max is an integer.
param3	i is an integer.

Returns

a clamp integer

leCos()

LIB_EXPORT int32_t leCos

(

int32_t

v

)

Calculate cosine of a number.

Calculates cosine of angle.

Remarks

- result of cosine fixed point value (times 256), calling function needs to divide by 256 to get good result. ex. "a * cos(v)" would be "a * leCos(v) / 256";

int32_t val = leCos(v);

Parameters

param1

v is the value in degrees.

Returns

cosine fixed point value

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leDivideRounding()

LIB_EXPORT int32_t leDivideRounding	(	int32_t	num,
		int32_t	denom
	)

Performs a linear interpolation of an integer based on a percentage between two signed points.

Calculates integer division of num divided by denom.

int32_t val = leDivideRounding(num, denom);

Parameters

param1	num is an integer.
param2	denom is the denom.
param3	per is the percent to apply.

Returns

equivalent to int32_t( ((float)num)/((float)denom) + 0.5 ) without using floating point

leEllipsePoint()

LIB_EXPORT leResult leEllipsePoint	(	int32_t	t,
		int32_t	a,
		int32_t	b,
		int32_t	theta,
		lePoint *	p
	)

Calculates points in an arc.

@bold Help

Generates points in an arc at radius and angle.

leEllipsePoint(angle, endAngleArc0, dir, points);

Parameters

param1	startAngleArc0 is point to rotate.
param2	endAngleArc0 of the rotation.
param2	dir of the rotation.
param2	quadrant of the rotation.

Returns

void.

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leGetXGivenYOnLine()

int32_t leGetXGivenYOnLine	(	lePoint	p1,
		lePoint	p2,
		int32_t	y
	)

Project point.

Project point p1 onto p2 on y coordinate.

lePoint p1;
lePoint p2;
int32_t y;
int32_t x = leGetYGivenXOnLine(p1, p2, y);

Parameters

param1	p1 is point to rotate.
param2	p2 of the rotation.
param3	y is the angle in degrees.

Returns

the x coordinate.

leGetYGivenXOnLine()

int32_t leGetYGivenXOnLine	(	lePoint	p1,
		lePoint	p2,
		int32_t	x
	)

Project Y give X.

Project point p1 onto p2 on x coordinate.

lePoint p1;
lePoint p2;
int32_t x;
int32_t y = leGetYGivenXOnLine(p1, p2, x);

Parameters

param1	p1 is point to rotate.
param2	p2 of the rotation.
param3	x is the angle in degrees.

Returns

the y coordinate.

leLerp()

LIB_EXPORT int32_t leLerp	(	int32_t	x,
		int32_t	y,
		uint32_t	per
	)

Calculates a linear interpolation of an integer based on a percentage between two signed points.

Calculates a linear interpolation between x and y based on per.

uint32_t scale = leLerp(l, percent);

Parameters

param1	x is point.
param2	y is point.
param2	per is the percent to apply.

Returns

the interpolated value

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leMaxf()

LIB_EXPORT float leMaxf	(	float	l,
		float	r
	)

Calculate maximum of two floats.

Calculates the maximum of two floats l and r.

float larger = leMaxf(l, r);

Parameters

param1	l is an float.
param2	r is an float.

Returns

the maximum of l and r.

leMaxi()

LIB_EXPORT int32_t leMaxi	(	int32_t	l,
		int32_t	r
	)

Calculate maximum of two integers.

Calculates the maximum of integers l and r.

uint32_t larger = leMaxi(l, r);

Parameters

param1	l is an integer.
param2	r is an integer.

Returns

the maximum of l and r.

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leMinf()

LIB_EXPORT float leMinf	(	float	l,
		float	r
	)

Calculate minimum of two floats.

Calculates the minimum of two floats l and r.

float smaller = leMinf(l, r);

Parameters

param1	l is an float.
param2	r is an float.

Returns

the minimum of l and r.

leMini()

LIB_EXPORT int32_t leMini	(	int32_t	l,
		int32_t	r
	)

Calculate minimum of two integers.

Calculates the lessor of integers l and r.

uint32_t smaller = leMini(l, r);

Parameters

param1	l is an integer.
param2	r is an integer.

Returns

the lessor of l and r.

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leNormalizeAngle()

LIB_EXPORT int32_t leNormalizeAngle

(

int32_t

t

)

Normalize an angle between 0 - 360.

Normalizes angle. Example: t = -5, return value is 355 t = 450, return value is 90

int32_t val = leNormalizeAngle(angle);

Parameters

param1	x is an integer.
param2	y is the percent to apply.
param2	per is the percent to apply.

Returns

normalize an angle in degrees.

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lePercent()

LIB_EXPORT uint32_t lePercent	(	uint32_t	l,
		uint32_t	r
	)

Calculate percent of number.

Calculates the decimal percent of l and r. Integer based. Accuracy for higher numbers is not guaranteed.The result is the decimal percentage multiplied by 100.

uint32_t pc = lePercent(l, r);

Parameters

param1	l is an integer.
param2	r is an integer.

Returns

percentage represented as a whole number

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lePercentOf()

LIB_EXPORT uint32_t lePercentOf	(	uint32_t	num,
		uint32_t	percent
	)

Calculate percent of a number.

Calculate the whole number percentage of num and percent.

uint32_t whole = lePercentOf(l, percent);

Parameters

param1	num is an integer.
param2	percent is the percent to apply.

Returns

the percentage of the number.

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lePercentOfDec()

LIB_EXPORT void lePercentOfDec	(	uint32_t	num,
		uint32_t	percent,
		uint32_t *	whl,
		uint32_t *	dec
	)

Calculate percent of a decimal.

Calculates the whole number percent of num and percent and stores the result in whl and dec

uint32_t whole = lePercentOf(num, percent, whl, dec);

Parameters

param1	l is an integer.
param2	percent is the percent to apply.

Returns

resultant percentage of the number.

lePercentWholeRounded()

LIB_EXPORT uint32_t lePercentWholeRounded	(	uint32_t	l,
		uint32_t	r
	)

Calculate percent whole rounded.

Calculates the whole number integer based percent of l and r. The difference between this and lePercent is that the decimal portion of the whole number is rounded off.

See also

lePercent

Note

Accuracy for higher numbers is not guaranteed.

uint32_t pc = lePercentWholeRounded(l, r);

Parameters

param1	l is an integer.
param2	r is an integer.

Returns

percentage represented as a whole number.

lePolarToXY()

LIB_EXPORT leResult lePolarToXY	(	int32_t	r,
		int32_t	a,
		lePoint *	p
	)

Generate points in an arc.

Generates points in an arc using radius and angle.

leResult res = lePolarToXY(l, percent);

Parameters

param1	radius is the radius of arc.
param2	angle is the angle of arc.
param3	points is the position to query.

Returns

resultant percentage of the number.

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leRotatedRectBounds()

leRect leRotatedRectBounds	(	leRect	rect,
		int32_t	ang
	)

Calculate bounding rectangle.

Calculates the bounding rectangle for the area rect rotated about origin at angle.

uint32_t whole = lePercentOf(l, percent);

Parameters

param1	rect is area to rotate.
param3	angle is the angle in degrees.

Returns

resultant percentage of the number.

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leRotatePoint()

lePoint leRotatePoint	(	lePoint	pos,
		lePoint	org,
		int32_t	ang
	)

Rotates point.

Rotates point around origin at angle degrees.

lePoint point;
lePoint origin;
int32_t angle;
lePoint rot = leRotatePoint(point, origin, angle);

Parameters

param1	point is point to rotate.
param2	origin of the rotation.
param3	angle is the angle in degrees.

Returns

the rotated point.

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leScaleInteger()

LIB_EXPORT uint32_t leScaleInteger	(	uint32_t	num,
		uint32_t	oldMax,
		uint32_t	newMax
	)

Calculate the scale of an integer.

Calculates the scale of num from oldMax to newMax

Note

one number range of 0 -> n0 to another range 0 -> n1 based on percentages.

uint32_t scale = leScaleInteger(num, oldMax, newMax);

Parameters

param1	num is an integer.
param2	oldMax is the old range maximum.
param3	newMax is the new range maximum.

Returns

resultant percentage of the number.

leScaleIntegerSigned()

LIB_EXPORT int32_t leScaleIntegerSigned	(	int32_t	num,
		int32_t	oldMax,
		int32_t	newMax
	)

Calculate the scale of signed integer.

Calculates the scale of num in range oldMax to range newMax.

uint32_t scale = leScaleIntegerSigned(l, percent);

Parameters

param1	num is an integer.
param2	oldMax is an integer.
param3	newMax is the percent to apply.

Returns

resultant percentage of the number.

leSin()

LIB_EXPORT int32_t leSin

(

int32_t

v

)

Calculate sin of a number.

Calculates sin of angle.

Remarks

- result of sine fixed point value (times 256), calling function needs to divide by 256 to get good result. ex. "a * sin(v)" would be "a * leSin(v) / 256";

int32_t val = leSin(v);

Parameters

param1

v is the value in degrees.

Returns

sine fixed point value

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leSortPointsX()

void leSortPointsX	(	lePoint *	p1,
		lePoint *	p2
	)

Sorts two points on the X axis.

Sort points p1 and p2 on the X axis.

leSortPointsX(p1, p2);

Parameters

param1	p1 is point.
param2	p2 is point.

Returns

void.

leSortPointsY()

void leSortPointsY	(	lePoint *	p1,
		lePoint *	p2
	)

Sorts two points on the Y axis.

Sort points p1 and p2 on the Y axis.

leSortPointsY(p1, p2);

Parameters

param1	p1 is a point.
param2	p2 is a point.

Returns

void.