SkFloat.h revision 1915fd09f3b60eb907f5ab155e8379b589e2bae1 
1
2/*
3 * Copyright 2008 The Android Open Source Project
4 *
5 * Use of this source code is governed by a BSD-style license that can be
6 * found in the LICENSE file.
7 */
8
9
10#ifndef SkFloat_DEFINED
11#define SkFloat_DEFINED
12
13#include "SkFixed.h"
14
15class SkFloat {
16public:
17    SkFloat() {}
18
19    void    setZero() { fPacked = 0; }
20//  void    setShift(int value, int shift) { fPacked = SetShift(value, shift); }
21    void    setInt(int value) { fPacked = SetShift(value, 0); }
22    void    setFixed(SkFixed value) { fPacked = SetShift(value, -16); }
23
24//  int     getShift(int shift) const { return GetShift(fPacked, shift); }
25    int     getInt() const { return GetShift(fPacked, 0); }
26    SkFixed getFixed() const { return GetShift(fPacked, -16); }
27
28    void    abs() { fPacked = Abs(fPacked); }
29    void    negate() { fPacked = Neg(fPacked); }
30
31    void    shiftLeft(int bits) { fPacked = Shift(fPacked, bits); }
32    void    setShiftLeft(const SkFloat& a, int bits) { fPacked = Shift(a.fPacked, bits); }
33
34    void    shiftRight(int bits) { fPacked = Shift(fPacked, -bits); }
35    void    setShiftRight(const SkFloat& a, int bits) { fPacked = Shift(a.fPacked, -bits); }
36
37    void    add(const SkFloat& a) { fPacked = Add(fPacked, a.fPacked); }
38    void    setAdd(const SkFloat& a, const SkFloat& b) { fPacked = Add(a.fPacked, b.fPacked); }
39
40    void    sub(const SkFloat& a) { fPacked = Add(fPacked, Neg(a.fPacked)); }
41    void    setSub(const SkFloat& a, const SkFloat& b) { fPacked = Add(a.fPacked, Neg(b.fPacked)); }
42
43    void    mul(const SkFloat& a) { fPacked = Mul(fPacked, a.fPacked); }
44    void    setMul(const SkFloat& a, const SkFloat& b) { fPacked = Mul(a.fPacked, b.fPacked); }
45
46    void    div(const SkFloat& a) { fPacked = Div(fPacked, a.fPacked); }
47    void    setDiv(const SkFloat& a, const SkFloat& b) { fPacked = Div(a.fPacked, b.fPacked); }
48
49    void    sqrt() { fPacked = Sqrt(fPacked); }
50    void    setSqrt(const SkFloat& a) { fPacked = Sqrt(a.fPacked); }
51    void    cubeRoot() { fPacked = CubeRoot(fPacked); }
52    void    setCubeRoot(const SkFloat& a) { fPacked = CubeRoot(a.fPacked); }
53
54    friend bool operator==(const SkFloat& a, const SkFloat& b) { return a.fPacked == b.fPacked; }
55    friend bool operator!=(const SkFloat& a, const SkFloat& b) { return a.fPacked != b.fPacked; }
56    friend bool operator<(const SkFloat& a, const SkFloat& b) { return Cmp(a.fPacked, b.fPacked) < 0; }
57    friend bool operator<=(const SkFloat& a, const SkFloat& b) { return Cmp(a.fPacked, b.fPacked) <= 0; }
58    friend bool operator>(const SkFloat& a, const SkFloat& b) { return Cmp(a.fPacked, b.fPacked) > 0; }
59    friend bool operator>=(const SkFloat& a, const SkFloat& b) { return Cmp(a.fPacked, b.fPacked) >= 0; }
60
61#ifdef SK_DEBUG
62    static void UnitTest();
63
64    void assertEquals(float f, int tolerance = 0)
65    {
66        union {
67            float   fFloat;
68            int32_t fPacked;
69        } tmp;
70
71        tmp.fFloat = f;
72        int d = tmp.fPacked - fPacked;
73        SkASSERT(SkAbs32(d) <= tolerance);
74    }
75    float getFloat() const
76    {
77        union {
78            float   fFloat;
79            int32_t fPacked;
80        } tmp;
81
82        tmp.fPacked = fPacked;
83        return tmp.fFloat;
84    }
85#endif
86
87private:
88    int32_t fPacked;
89
90public:
91    static int GetShift(int32_t packed, int shift);
92    static int32_t SetShift(int value, int shift);
93    static int32_t Neg(int32_t);
94    static int32_t Abs(int32_t packed) { return (uint32_t)(packed << 1) >> 1; }
95    static int32_t Shift(int32_t, int bits);
96    static int32_t Add(int32_t, int32_t);
97    static int32_t Mul(int32_t, int32_t);
98    static int32_t MulInt(int32_t, int);
99    static int32_t Div(int32_t, int32_t);
100    static int32_t DivInt(int32_t, int);
101    static int32_t Invert(int32_t);
102    static int32_t Sqrt(int32_t);
103    static int32_t CubeRoot(int32_t);
104    static int Cmp(int32_t, int32_t);
105};
106
107#endif
108