# [−][src]Module pbrt::core::pbrt

Type definitions of Float and Spectrum, otherwise constants and functions which can be used almost everywhere else in the code.

## Constants

 INV_2_PI INV_4_PI INV_PI MACHINE_EPSILON PI_OVER_2 PI_OVER_4 SHADOW_EPSILON SQRT_2

## Functions

 bits_to_float Use unsafe std::mem::transmute_copy to convert u32 to f32. clamp_t Clamp the given value val to lie between the values low and high. degrees Convert from angles expressed in radians to degrees. erf erf_inv find_interval Helper function which emulates the behavior of std::upper_bound(). float_to_bits Use unsafe std::mem::transmute_copy to convert f32 to u32. gamma Error propagation. gamma_correct Is used to write sRGB-compatible 8-bit image files. is_power_of_2 Determine if a given integer is an exact power of 2. lerp Interpolate linearly between two provided values. log_2 log_2_int_i32 Compute an integer base-2 logarithm function. log_2_int_i64 Compute an integer base-2 logarithm function. log_2_int_u32 Compute an integer base-2 logarithm function. log_2_int_u64 Compute an integer base-2 logarithm function. mod_t Computes the remainder of a/b. Provides the behavior that the modulus of a negative number is always positive. next_float_down Bump a floating-point value down to the next smaller representable floating-point value. next_float_up Bump a floating-point value up to the next greater representable floating-point value. quadratic Find solution(s) of the quadratic equation at2 + bt + c = 0. radians Convert from angles expressed in degrees to radians. round_up_pow2_32 Round an integer up to the next higher (or equal) power of 2. round_up_pow2_64 Round an integer up to the next higher (or equal) power of 2.

## Type Definitions

 Float Spectrum