SkMath.h File Reference

#include "include/private/base/SkAssert.h"
#include "include/private/base/SkCPUTypes.h"
#include <cstdint>
#include <climits>

Go to the source code of this file.

Functions
static int64_t	sk_64_mul (int64_t a, int64_t b)
static constexpr int32_t	SkLeftShift (int32_t value, int32_t shift)
static constexpr int64_t	SkLeftShift (int64_t value, int32_t shift)
template<typename T >
constexpr bool	SkIsPow2 (T value)
static unsigned	SkMul16ShiftRound (U16CPU a, U16CPU b, int shift)
static U8CPU	SkMulDiv255Round (U16CPU a, U16CPU b)

Variables
static constexpr int16_t	SK_MaxS16 = INT16_MAX
static constexpr int16_t	SK_MinS16 = -SK_MaxS16
static constexpr int32_t	SK_MaxS32 = INT32_MAX
static constexpr int32_t	SK_MinS32 = -SK_MaxS32
static constexpr int32_t	SK_NaN32 = INT32_MIN
static constexpr int64_t	SK_MaxS64 = INT64_MAX
static constexpr int64_t	SK_MinS64 = -SK_MaxS64

Function Documentation

sk_64_mul()

static int64_t sk_64_mul ( int64_t  a, int64_t  b  )

inlinestatic

Definition at line 33 of file SkMath.h.

                                                      {
    return a * b;
}

SkIsPow2()

template<typename T >

constexpr bool SkIsPow2 ( T  value )

inlineconstexpr

Returns true if value is a power of 2. Does not explicitly check for value <= 0.

Definition at line 51 of file SkMath.h.

                                                              {
    return (value & (value - 1)) == 0;
}

SkLeftShift() [1/2]

static constexpr int32_t SkLeftShift ( int32_t  value, int32_t  shift  )

inlinestaticconstexpr

Definition at line 37 of file SkMath.h.

                                                                          {
    return (int32_t) ((uint32_t) value << shift);
}

SkLeftShift() [2/2]

static constexpr int64_t SkLeftShift ( int64_t  value, int32_t  shift  )

inlinestaticconstexpr

Definition at line 41 of file SkMath.h.

                                                                          {
    return (int64_t) ((uint64_t) value << shift);
}

SkMul16ShiftRound()

static unsigned SkMul16ShiftRound ( U16CPU  a, U16CPU  b, int  shift  )

inlinestatic

Return a*b/((1 << shift) - 1), rounding any fractional bits. Only valid if a and b are unsigned and <= 32767 and shift is > 0 and <= 8

Definition at line 61 of file SkMath.h.

                                                                        {
    SkASSERT(a <= 32767);
    SkASSERT(b <= 32767);
    SkASSERT(shift > 0 && shift <= 8);
    unsigned prod = a*b + (1 << (shift - 1));
    return (prod + (prod >> shift)) >> shift;
}

SkMulDiv255Round()

static U8CPU SkMulDiv255Round ( U16CPU  a, U16CPU  b  )

inlinestatic

Return a*b/255, rounding any fractional bits. Only valid if a and b are unsigned and <= 32767.

Definition at line 73 of file SkMath.h.

                                                         {
    return SkMul16ShiftRound(a, b, 8);
}

Variable Documentation

SK_MaxS16

constexpr int16_t SK_MaxS16 = INT16_MAX

staticconstexpr

Definition at line 18 of file SkMath.h.

SK_MaxS32

constexpr int32_t SK_MaxS32 = INT32_MAX

staticconstexpr

Definition at line 21 of file SkMath.h.

SK_MaxS64

constexpr int64_t SK_MaxS64 = INT64_MAX

staticconstexpr

Definition at line 25 of file SkMath.h.

SK_MinS16

constexpr int16_t SK_MinS16 = -SK_MaxS16

staticconstexpr

Definition at line 19 of file SkMath.h.

SK_MinS32

constexpr int32_t SK_MinS32 = -SK_MaxS32

staticconstexpr

Definition at line 22 of file SkMath.h.

SK_MinS64

constexpr int64_t SK_MinS64 = -SK_MaxS64

staticconstexpr

Definition at line 26 of file SkMath.h.

SK_NaN32

constexpr int32_t SK_NaN32 = INT32_MIN

staticconstexpr

Definition at line 23 of file SkMath.h.