Intrinsics

Hardware Intrinsics for the SH4 fast-math instructions More...

Files
file	fmath.h
	Inline functions for the DC's special math instructions.
file	fmath_base.h
	Base definitions for the DC's special math instructions.

Macros
#define	F_PI   3.1415926f
	PI constant (if you don't want full math.h)

Functions
static float __pure	fipr (float x, float y, float z, float w, float a, float b, float c, float d)
	Floating point inner product.
static float __pure	fipr_magnitude_sqr (float x, float y, float z, float w)
	Floating point inner product w/self (square of vector magnitude)
static float __pure	fsin (float r)
	Floating point sine.
static __pure float	fcos (float r)
	Floating point cosine.
static __pure float	ftan (float r)
	Floating point tangent.
static __pure float	fisin (int d)
	Integer sine.
static __pure float	ficos (int d)
	Integer cosine.
static float __pure	fitan (int d)
	Integer tangent.
static float __pure	fsqrt (float f)
	Floating point square root.
static float __pure	frsqrt (float f)
static void	fsincos (float f, float *s, float *c)
	Calculate the sine and cosine of a value in degrees.
static void	fsincosr (float f, float *s, float *c)
	Calculate the sine and cosine of a value in radians.
static uint32_t __pure	pvr_pack_bump (float h, float t, float q)
	Calculate the offset color value for a set of bumpmap parameters.

Detailed Description

Hardware Intrinsics for the SH4 fast-math instructions

Macro Definition Documentation

F_PI

#define F_PI   3.1415926f

PI constant (if you don't want full math.h)

Referenced by pvr_pack_bump().

Function Documentation

fcos()

static __pure float fcos ( float r )

inlinestatic

Floating point cosine.

Parameters

r	a floating point number between 0 and 2*PI

Returns

cos(r), where r is [0..2*PI]

ficos()

static __pure float ficos ( int d )

inlinestatic

Integer cosine.

Parameters

d	an integer between 0 and 65535

Returns

cos(d), where d is [0..65535]

fipr()

static float __pure fipr ( float x, float y, float z, float w, float a, float b, float c, float d )

inlinestatic

Floating point inner product.

Returns

v1 dot v2 (inner product)

Referenced by vec_dot().

fipr_magnitude_sqr()

static float __pure fipr_magnitude_sqr ( float x, float y, float z, float w )

inlinestatic

Floating point inner product w/self (square of vector magnitude)

Returns

v1 dot v1 (square of magnitude)

Referenced by vec_fipr().

fisin()

static __pure float fisin ( int d )

inlinestatic

Integer sine.

Parameters

d	an integer between 0 and 65535

Returns

sin(d), where d is [0..65535]

fitan()

static float __pure fitan ( int d )

inlinestatic

Integer tangent.

Parameters

d	an integer between 0 and 65535

Returns

tan(d), where d is [0..65535]

frsqrt()

static float __pure frsqrt ( float f )

inlinestatic

Returns

1.0f / sqrt(f)

fsin()

static float __pure fsin ( float r )

inlinestatic

Floating point sine.

Parameters

r	a floating point number between 0 and 2*PI

Returns

sin(r), where r is [0..2*PI]

fsincos()

static void fsincos ( float f, float * s, float * c )

inlinestatic

Calculate the sine and cosine of a value in degrees.

This function uses the fsca instruction to calculate an approximation of the sine and cosine of the input value.

Parameters

f	The value to calculate the sine and cosine of.
s	Storage for the returned sine value.
c	Storage for the returned cosine value.

fsincosr()

static void fsincosr ( float f, float * s, float * c )

inlinestatic

Calculate the sine and cosine of a value in radians.

This function uses the fsca instruction to calculate an approximation of the sine and cosine of the input value.

Parameters

f	The value to calculate the sine and cosine of.
s	Storage for the returned sine value.
c	Storage for the returned cosine value.

fsqrt()

static float __pure fsqrt ( float f )

inlinestatic

Floating point square root.

Returns

sqrt(f)

ftan()

static __pure float ftan ( float r )

inlinestatic

Floating point tangent.

Parameters

r	a floating point number between 0 and 2*PI

Returns

tan(r), where r is [0..2*PI]

pvr_pack_bump()

static uint32_t __pure pvr_pack_bump ( float h, float t, float q )

inlinestatic

Calculate the offset color value for a set of bumpmap parameters.

This function calculates the value to be placed into the oargb value for the use of bumpmapping on a polygon. The angles specified should be expressed in radians and within the limits specified for the individual parameter.

Parameters

h	Weighting value in the range [0, 1] for how defined the bumpiness of the surface should be.
t	Spherical elevation angle in the range [0, pi/2] between the surface and the lighting source. A value of pi/2 implies that the light is directly overhead.
q	Spherical rotation angle in the range [0, 2*pi] between the surface and the lighting source.

Returns

32-bit packed value to be used as an offset color on the surface to be bump mapped.

Note

For more information about how bumpmapping on the PVR works, refer to US Patent 6,819,319, which describes the algorithm implemented in the hardware (specifically look at Figures 2 and 3, along with the description in the Detailed Description section).

Thanks to Fredrik Ehnbom for figuring this stuff out and posting it to the mailing list back in 2005!

References F_PI.