u_distortion_mesh_rift.c File Reference

Rift-style lens distortion, as used by the Oculus Rift DK2 and CV1. More...

#include "math/m_api.h"
#include "math/m_vec2.h"
#include "u_distortion_mesh.h"

Include dependency graph for u_distortion_mesh_rift.c:

Data Structures
struct	u_rift_distortion_render_info
struct	u_rift_distortion_tan_fov
struct	u_rift_distortion_scale_offset

Functions
static struct xrt_vec2	to_tan_angle (const struct u_rift_distortion_render_info *info, struct xrt_vec2 ndc)
	Computes the tan angle of a NDC point, as seen from the eye.
static float	value_at (const float *k, int j)
	Value of the curve at knot j.
static float	slope_after (const float *k, int n, int j)
	Slope the curve leaves knot j with.
static float	slope_before (const float *k, int n, int j)
	Slope the curve arrives at knot j with.
static float	hermite (float p0, float m0, float p1, float m1, float t)
	Standard cubic Hermite: value p0 with slope m0 at t=0, value p1 with slope m1 at t=1.
static float	curve (const float *k, int n, float s)
	Magnification at curve position s.
static float	magnification (const struct u_rift_eye_profile *profile, float rho)
	The magnification for a squared tan-angle radius.
static struct u_rift_distortion_render_info	compute_render_info (const struct u_rift_panel *panel, const struct u_rift_eye_profile *profile, uint32_t view)
static struct u_rift_distortion_tan_fov	fov_from_eye (float lens_diameter, float eye_relief, float rot_rad)
	Computes the tangent FOV for an eye from the given parameters.
static float	physical_fov_sweep (const struct u_rift_distortion_render_info *info, const struct u_rift_eye_profile *profile, const struct xrt_vec2 edge, int axis, float sign)
	Walk from the lens centre to edge, and return how far the view reaches in one direction.
static struct u_rift_distortion_tan_fov	physical_fov (const struct u_rift_distortion_render_info *info, const struct u_rift_eye_profile *profile)
static struct u_rift_distortion_tan_fov	fov (const struct u_rift_panel *panel, const struct u_rift_eye_profile *profile, const struct u_rift_distortion_render_info *info)
static struct u_rift_distortion_scale_offset	ndc_mapping (const struct u_rift_distortion_tan_fov *fov)
static struct u_rift_distortion_scale_offset	uv_mapping (const struct u_rift_distortion_scale_offset ndc)
static void	colour_fringing_scales (const struct u_rift_eye_profile *profile, float rho, float *scales)
void	u_compute_distortion_rift (const struct u_rift_panel *panel, const struct u_rift_eye_profile *profile, uint32_t view, float u, float v, struct xrt_uv_triplet *result)
	Oculus Rift distortion implementation.

Detailed Description

Rift-style lens distortion, as used by the Oculus Rift DK2 and CV1.

Author

Beyley Cardellio ep1cm.nosp@m.1n10.nosp@m.n123@.nosp@m.gmai.nosp@m.l.com

Function Documentation

curve()

static float curve ( const float *  k, int  n, float  s  )

static

Magnification at curve position s.

References CLAMP, hermite(), slope_after(), slope_before(), and value_at().

fov_from_eye()

static struct u_rift_distortion_tan_fov fov_from_eye ( float  lens_diameter, float  eye_relief, float  rot_rad  )

static

Computes the tangent FOV for an eye from the given parameters.

Parameters

lens_diameter	The diameter of the lens.
eye_relief	The eye relief of the lens.
rot_rad	The rotation of the eye, in radians. Max 30 degrees.

References CLAMP, DEG_TO_RAD, and MAX.

hermite()

static float hermite ( float  p0, float  m0, float  p1, float  m1, float  t  )

static

Standard cubic Hermite: value p0 with slope m0 at t=0, value p1 with slope m1 at t=1.

Any equivalent arrangement of these terms will do.

Referenced by curve().

magnification()

static float magnification ( const struct u_rift_eye_profile *  profile, float  rho  )

static

The magnification for a squared tan-angle radius.

References u_rift_eye_profile::k, u_rift_eye_profile::k_count, and u_rift_eye_profile::max_r.

Referenced by physical_fov_sweep().

physical_fov_sweep()

static float physical_fov_sweep ( const struct u_rift_distortion_render_info *  info, const struct u_rift_eye_profile *  profile, const struct xrt_vec2  edge, int  axis, float  sign  )

static

Walk from the lens centre to edge, and return how far the view reaches in one direction.

axis picks x or y; sign is -1 for the left and up directions, which run towards negative tan-angle.

References magnification(), MAX, and to_tan_angle().

slope_after()

static float slope_after ( const float *  k, int  n, int  j  )

static

Slope the curve leaves knot j with.

Referenced by curve(), and slope_before().

slope_before()

static float slope_before ( const float *  k, int  n, int  j  )

static

Slope the curve arrives at knot j with.

Same as slopeAfter everywhere except knot n-2; see section 5.3.

References slope_after().

Referenced by curve().

to_tan_angle()

static struct xrt_vec2 to_tan_angle ( const struct u_rift_distortion_render_info *  info, struct xrt_vec2  ndc  )

inlinestatic

Computes the tan angle of a NDC point, as seen from the eye.

Referenced by physical_fov_sweep(), and u_compute_distortion_rift().

u_compute_distortion_rift()

void u_compute_distortion_rift	(	const struct u_rift_panel *	panel,
		const struct u_rift_eye_profile *	profile,
		uint32_t	view,
		float	u,
		float	v,
		struct xrt_uv_triplet *	result
	)

Oculus Rift distortion implementation.

References u_rift_eye_profile::k_count, and to_tan_angle().

value_at()

static float value_at ( const float *  k, int  j  )

static

Value of the curve at knot j.

Referenced by curve().