sh_math.c File Reference

#include "sh_math.h"
#include <math.h>
#include <string.h>

Include dependency graph for sh_math.c:

Macros
#define	M_PI   3.14159265358979323846
#define	Y00   0.28209479177387814347f /* 0.5 * sqrt(1/pi) */
#define	Y1n1   0.48860251190291992159f /* -sqrt(3/4pi) * y */
#define	Y10   0.48860251190291992159f /* sqrt(3/4pi) * z */
#define	Y11   0.48860251190291992159f /* -sqrt(3/4pi) * x */
#define	Y2n2   1.09254843059207907054f /* 0.5 * sqrt(15/pi) * xy */
#define	Y2n1   1.09254843059207907054f /* -0.5 * sqrt(15/pi) * yz */
#define	Y20   0.31539156525251999825f /* 0.25 * sqrt(5/pi) * (3z^2 - 1) */
#define	Y21   1.09254843059207907054f /* -0.5 * sqrt(15/pi) * xz */
#define	Y22   0.54627421529603953527f /* 0.25 * sqrt(15/pi) * (x^2 - y^2) */
#define	A0   3.14159265359f /* PI */
#define	A1   2.09439510239f /* 2PI/3 */
#define	A2   0.78539816339f /* PI/4 */

Functions
void	sh_zero (SH9 *sh_ptr)
	Initialize SH coefficients to zero. More...
void	sh_project_directional (const vec3 dir, const vec3 color, SH9 *out_sh)
	Projects a directional light into SH coefficients. More...
void	sh_eval_irradiance (const vec3 normal, const SH9 *sh_ptr, vec3 out_color)
	Evaluates the irradiance from SH coefficients in a given direction. More...

Macro Definition Documentation

A0

#define A0   3.14159265359f /* PI */

A1

#define A1   2.09439510239f /* 2PI/3 */

A2

#define A2   0.78539816339f /* PI/4 */

M_PI

#define M_PI   3.14159265358979323846

Y00

#define Y00   0.28209479177387814347f /* 0.5 * sqrt(1/pi) */

Y10

#define Y10   0.48860251190291992159f /* sqrt(3/4pi) * z */

Y11

#define Y11   0.48860251190291992159f /* -sqrt(3/4pi) * x */

Y1n1

#define Y1n1   0.48860251190291992159f /* -sqrt(3/4pi) * y */

Y20

#define Y20   0.31539156525251999825f /* 0.25 * sqrt(5/pi) * (3z^2 - 1) */

Y21

#define Y21   1.09254843059207907054f /* -0.5 * sqrt(15/pi) * xz */

Y22

#define Y22   0.54627421529603953527f /* 0.25 * sqrt(15/pi) * (x^2 - y^2) */

Y2n1

#define Y2n1   1.09254843059207907054f /* -0.5 * sqrt(15/pi) * yz */

Y2n2

#define Y2n2   1.09254843059207907054f /* 0.5 * sqrt(15/pi) * xy */

Function Documentation

sh_eval_irradiance()

void sh_eval_irradiance	(	const vec3	normal,
		const SH9 *	sh_ptr,
		vec3	out_color
	)

Evaluates the irradiance from SH coefficients in a given direction.

Parameters

normal	Normalized surface normal.
sh_ptr	Pointer to the SH structure.
out_color	Output color (vec3).

sh_project_directional()

void sh_project_directional	(	const vec3	dir,
		const vec3	color,
		SH9 *	out_sh
	)

Projects a directional light into SH coefficients.

Parameters

dir	Normalized direction vector pointing TOWARDS the light source.
color	Linear RGB color/intensity of the light.
out_sh	Pointer to the SH structure to accumulate into.

sh_zero()

void sh_zero

(

SH9 *

sh_ptr

)

Initialize SH coefficients to zero.