Foundry::Katana::FnExpressionMath Class Reference

#include <FnExpressionMath.h>

List of all members.

Static Public Member Functions
static int	clamp (int value, int a, int b)
static float	lerp (float mix, float a, float b)
static float	smoothstep (float t)
static float	fit (float value, float oldmin, float oldmax, float newmin, float newmax)
static float	cfit (float value, float oldmin, float oldmax, float newmin, float newmax)
static float	softcfit (float value, float oldmin, float oldmax, float newmin, float newmax)
static float	randval (float min, float max, int seed)
static float	noise (float x)
static float	snoise (float x)
static int32_t	stablehash (const std::string &cacheID)

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Detailed Description

Class providing range common utility functions used in expression math.

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Member Function Documentation

static float Foundry::Katana::FnExpressionMath::cfit	(	float	value,
		float	oldmin,
		float	oldmax,
		float	newmin,
		float	newmax
	)		[static]

Same as fit(), but clamps to new borders, works on both increasing / decreasing segments

See also:

fit()

static int Foundry::Katana::FnExpressionMath::clamp	(	int	value,
		int	a,
		int	b
	)		[static]

Clamp the value between a and b. This function works for a>b and a<b.

Parameters:

value	the value to be clamped
a	lower bound to clamp value to
b	upper bound to clamp value to.

Returns:

a if value is less than a, b if value is greater than value else value.

static float Foundry::Katana::FnExpressionMath::fit	(	float	value,
		float	oldmin,
		float	oldmax,
		float	newmin,
		float	newmax
	)		[static]

Example:

 fit(0.8, 0, 1, 0, 255) = 204.
 fit(3,1,4,5,20) = 15

Returns:

a number between newmin and newmax, which is relative to val in the range between oldmin and oldmax.

static float Foundry::Katana::FnExpressionMath::lerp	(	float	mix,
		float	a,
		float	b
	)		[static]

Linearly interpolate between a and b using the specified mix Mix values outside of [0,1] are not clamped. Mix value of zero returns 'a'. This argument order is such to make it similar to fit and cfit

Returns:

the value between a and b, using the specified mix

static float Foundry::Katana::FnExpressionMath::noise

(

float

x

)

[static]

Improved Perlin noise (Siggraph 2002) Ranges from [0,1]

static float Foundry::Katana::FnExpressionMath::randval	(	float	min,
		float	max,
		int	seed
	)		[static]

Returns:

a random value between [min,max]

static float Foundry::Katana::FnExpressionMath::smoothstep

(

float

t

)

[static]

Compute a smoothstep (ease in, ease out) version of t: [0,1] This will clamp the output to between 0 and 1

static float Foundry::Katana::FnExpressionMath::snoise

(

float

x

)

[static]

Signed Improved Perlin noise (Siggraph 2002) Ranges from [-1,1] Results are just a rescaled version of noise

static float Foundry::Katana::FnExpressionMath::softcfit	(	float	value,
		float	oldmin,
		float	oldmax,
		float	newmin,
		float	newmax
	)		[static]

Like regular cfit(), only softer, specifically, uses SmoothStep to ease in and out of the fit.

See also:

cfit() fit()

static int32_t Foundry::Katana::FnExpressionMath::stablehash

(

const std::string &

cacheID

)

[static]

We always return a 32-bit integer, no matter which architecture we're on.

Note:

Uses MD5 internally.

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

• FnExpressionMath.h