SkFloatBits.h File Reference

#include "include/private/base/SkMath.h"
#include <cstdint>
#include <cstring>

Go to the source code of this file.

Macros
#define	SkScalarAs2sCompliment(x)   SkFloatAs2sCompliment(x)

Functions
static int32_t	SkSignBitTo2sCompliment (int32_t x)
static int32_t	Sk2sComplimentToSignBit (int32_t x)
static uint32_t	SkFloat2Bits (float value)
static float	SkBits2Float (uint32_t bits)
static int32_t	SkFloatAs2sCompliment (float x)
static float	Sk2sComplimentAsFloat (int32_t x)

Macro Definition Documentation

SkScalarAs2sCompliment

#define SkScalarAs2sCompliment

(

x

)

SkFloatAs2sCompliment(x)

Definition at line 72 of file SkFloatBits.h.

Function Documentation

Sk2sComplimentAsFloat()

static float Sk2sComplimentAsFloat ( int32_t  x )

inlinestatic

Return the 2s compliment int as a float. This undos the result of SkFloatAs2sCompliment

Definition at line 66 of file SkFloatBits.h.

                                                     {
    return SkBits2Float((uint32_t)Sk2sComplimentToSignBit(x));
}

Sk2sComplimentToSignBit()

static int32_t Sk2sComplimentToSignBit ( int32_t  x )

inlinestatic

Convert a 2s compliment int to a sign-bit (i.e. int interpreted as float). This undoes the result of SkSignBitTo2sCompliment().

Definition at line 31 of file SkFloatBits.h.

                                                         {
    int sign = x >> 31;
    // make x positive
    x = (x ^ sign) - sign;
    // set the sign bit as needed
    x |= SkLeftShift(sign, 31);
    return x;
}

SkBits2Float()

static float SkBits2Float ( uint32_t  bits )

inlinestatic

Definition at line 48 of file SkFloatBits.h.

                                                {
    float value;
    memcpy(&value, &bits, sizeof(float));
    return value;
}

SkFloat2Bits()

static uint32_t SkFloat2Bits ( float  value )

inlinestatic

Definition at line 41 of file SkFloatBits.h.

                                                 {
    uint32_t bits;
    memcpy(&bits, &value, sizeof(uint32_t));
    return bits;
}

SkFloatAs2sCompliment()

static int32_t SkFloatAs2sCompliment ( float  x )

inlinestatic

Return the float as a 2s compliment int. Just to be used to compare floats to each other or against positive float-bit-constants (like 0). This does not return the int equivalent of the float, just something cheaper for compares-only.

Definition at line 59 of file SkFloatBits.h.

                                                     {
    return SkSignBitTo2sCompliment((int32_t)SkFloat2Bits(x));
}

SkSignBitTo2sCompliment()

static int32_t SkSignBitTo2sCompliment ( int32_t  x )

inlinestatic

Convert a sign-bit int (i.e. float interpreted as int) into a 2s compliement int. This also converts -0 (0x80000000) to 0. Doing this to a float allows it to be compared using normal C operators (<, <=, etc.)

Definition at line 20 of file SkFloatBits.h.

                                                         {
    if (x < 0) {
        x &= 0x7FFFFFFF;
        x = -x;
    }
    return x;
}