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

x | 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

x | 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

x | the value to be rounded. |

### SQR()

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

This macro squares its argument `x` .

#### Parameters

x | 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

a | 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

a | 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. |