GimpMath: GIMP Math Library Reference Manual

+ + +

GimpMath

GimpMath — Mathematical definitions and macros.

Functions

++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +

#define	+RINT() +
#define	+ROUND() +
#define	+SIGNED_ROUND() +
#define	+SQR() +
#define	+MAX255() +
#define	+CLAMP0255() +
#define	+SAFE_CLAMP() +
#define	+gimp_deg_to_rad() +
#define	+gimp_rad_to_deg() +

Description

Mathematical definitions and macros for use both by the GIMP +application and plug-ins. These macros should be used rather than +the ones from <math.h> for enhanced portability.

Functions

RINT()

#define RINT(x) rint(x)
+

This macro rounds its argument x + to an integer value in floating +point format. Use RINT() instead of rint().

Parameters

+++++ + + + + + +

the value to be rounded

ROUND()

#define ROUND(x) ((int) ((x) + 0.5))
+

This macro rounds its positive argument x + to the nearest integer.

Parameters

+++++ + + + + + +

the value to be rounded.

SIGNED_ROUND()

#define SIGNED_ROUND(x) ((int) RINT (x))
+

This macro rounds its argument x + to the nearest integer.

Parameters

+++++ + + + + + +

the value to be rounded.

SQR()

#define SQR(x) ((x) * (x))
+

This macro squares its argument x +.

Parameters

+++++ + + + + + +

the value to be squared.

MAX255()

#define MAX255(a)  ((a) | (((a) & 256) - (((a) & 256) >> 8)))
+

This macro limits it argument a +, an (0-511) int, to 255.

Parameters

+++++ + + + + + +

the value to be limited.

CLAMP0255()

#define CLAMP0255(a)  CLAMP(a,0,255)
+

This macro clamps its argument a +, an int32-range int, between 0 +and 255 inclusive.

Parameters

+++++ + + + + + +

the value to be clamped.

SAFE_CLAMP()

#define SAFE_CLAMP(x, low, high)  ((x) > (low) ? (x) < (high) ? (x) : (high) : (low))
+

Ensures that x + is between the limits set by low + and high +, +even if x + is NaN. If low + is greater than high +, or if either +of them is NaN, the result is undefined.

Parameters

+++++ + + + + + + + + + + + + + + + + + +

x	the value to be limited.
low	the lower limit.
high	the upper limit.

Since: 2.10

gimp_deg_to_rad()

#define gimp_deg_to_rad(angle) ((angle) * (2.0 * G_PI) / 360.0)
+

This macro converts its argument angle + from degree to radian.

Parameters

+++++ + + + + + +

angle

the angle to be converted.

gimp_rad_to_deg()

#define gimp_rad_to_deg(angle) ((angle) * 360.0 / (2.0 * G_PI))
+

This macro converts its argument angle + from radian to degree.

Parameters

+++++ + + + + + +

angle

the angle to be converted.